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Project Specific Discussions => Dynamic Processors => Topic started by: abechap024 on February 28, 2011, 06:06:50 PM

Title: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on February 28, 2011, 06:06:50 PM
Rev 3 Boards :)

Thanks guys.

http://www.acsoundstudio.com/diy/Pye/rev314/REV314_BOM1.pdf
http://www.acsoundstudio.com/diy/Pye/rev314/rev314_pcbPNG.png

So boards are almost done and on their way to me, then I can ship them out! Thanks for everyone who participated, wouldn't of happened with you! Got a few extra so they are still available through the white market thread or store. Bring on the compression!!

Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Biasrocks on February 28, 2011, 06:17:24 PM
Great project Abe. I must question the removing of the gain stage.  I would seriously consider leaving it in, even if it seems excessive. I'm sure in many studio situations the output gets padded down, just like older tube limiters like the BA6, etc do. I'd rather pad it, than not have enough drive for the next thing down the line.

The noise gate, otoh I could definitely do without.

Mark
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on February 28, 2011, 06:22:35 PM
Hi Mark,
The Gain stage in question is before the compressor. It was originally operated by a switch and I assume it was to make the unit able to interface with mic level.
-Abe
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Rob Flinn on February 28, 2011, 06:25:03 PM
The whole circuit is fairly simple and I have no doubt it should work without too much trouble. The only thing that might be a little iffy is the Hartley type oscillator, as it centers around a transformer that I haven't been able to get specs on. But only one way to find the right one, in my mind and that's to dive in and test out a couple.

I take it you're experienced at designing pcb's which have RF on them ?

I made an experimental PWM gain cell using a PWM control chip a few years back, which worked, but was quite sensitive.  It's not so easy getting stuff stable at RF.  

The transformer that you haven't got the specs for is a critical part of the circuit & probably not an off the shelf part.  It may have to be made to order.  

You could perhaps consider using a PWM chip, it contains the oscillator & you just feed it a control signal to change the pulse width.  You can program the oscillator frequency with a cap or 2.  The only issue may be that the response isn't the same as the Pye.

That said i would love to find a use for the 2 original Pye GR meters that I have sitting on the shelf  ;)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Kingston on February 28, 2011, 06:26:34 PM
how is that dbx 160vu clone project working right now? should you perhaps concentrate on getting one project working at a time? or are you just looking for help troubleshooting prototypes?

I'm just saying drawing PCB's with "iffy Hartley type oscillator that centers around a transformer that you haven't been able to get specs on" is shooting from the hip in complete darkness.

[edit]

years in retrospect it seems I was really mean, don't know why. I'm sorry about that. The work you do is of great quality with all the prototype iterations visible here.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on February 28, 2011, 06:38:18 PM


how is that dbx 160vu clone project working right now? should you perhaps concentrate on getting one project working at a time? or are you just looking for help troubleshooting prototypes?

I'm just saying drawing PCB's with "iffy Hartley type oscillator that centers around a transformer that you haven't been able to get specs on" is shooting from the hip in complete darkness.


Yes, I've been waiting for a while while the dBX 160 gets rolling. But In my spare time I've been working on this. I am now fairly confident that the DBX is going and just waiting on the boards to get here. So I'm starting on this project now. I originally was going to breadboard the whole thing, but then realized it would be easier to order a few prototype PCBs and experiment with those and other people raised interest in also wanting a couple, so this is merely a thread to see if other people would like some. I'm definitely not trying to say this is a completed Idea, but it needs to start somewhere, and personally would rather have something hands on to design around than an abstract Idea, or design.
     
     Also I could wait around forever trying to convince someone to open up their PYE comp and get some more information on the oscillator transformer, or I could just try it out myself. I realize many people on the forum would much rather not take such a leap, and I understand that. Many others on the other hand might get some enjoyment out of finding one that works and sharing with the rest. I somehow don't think it will be as hard as some might imagine it to be.  If no one else wants to also order a PCB I will be perfectly fine with that.

The whole circuit is fairly simple and I have no doubt it should work without too much trouble. The only thing that might be a little iffy is the Hartley type oscillator, as it centers around a transformer that I haven't been able to get specs on. But only one way to find the right one, in my mind and that's to dive in and test out a couple.

I take it you're experienced at designing pcb's which have RF on them ?

I made an experimental PWM gain cell using a PWM control chip a few years back, which worked, but was quite sensitive.  It's not so easy getting stuff stable at RF. 

The transformer that you haven't got the specs for is a critical part of the circuit & probably not an off the shelf part.  It may have to be made to order. 

You could perhaps consider using a PWM chip, it contains the oscillator & you just feed it a control signal to change the pulse width.  You can program the oscillator frequency with a cap or 2.  The only issue may be that the response isn't the same as the Pye.

That said i would love to find a use for the 2 original Pye GR meters that I have sitting on the shelf  ;)


Ah Yes Rob,
I remember our conversation. I've thought about using a PWM chip and realize that I want an original to compare it to. That way I'm not shooting totally in the dark when designing a new oscillator.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Rob Flinn on February 28, 2011, 06:46:55 PM
Someone with RF experience will be needed to design the transformer. I'm not sure measuring a transformer from a real Pye will be much help.  I suspect you would need to do a CJ hack job on it to know how to recreate it.   I was talking with some very experienced old boy television engineers about the transformer, & they advised me to find an old school radio design engineer. 
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: kepeb on February 28, 2011, 08:10:09 PM
denied.

dont try, then you cant design/make it wrong.
two projects at one time is not allowed or you may be banned.

just kidding,
I don't see what the problem is here. if I decided a year from now to design the same thing from ground up, I'm sure I would be very grateful for your efforts and documentation here.
even if it just meant me avoiding any hurdles you came up against and posted about in the thread.

good luck :)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on February 28, 2011, 08:47:53 PM
Haha! Thanks, Yes at least we can start posting together ideas and anything we find. I'm going to post up what information I have. And maybe a whole redesign of the oscillator is in order. I secretly would love to redesign the whole side-chain.....stand by..
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: mylesgm on March 01, 2011, 02:50:53 AM
doubt I'll be much help but I say go for it, what to lose except time?
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: haima on March 01, 2011, 04:22:27 AM
I know someone with an original pair - I may be able to open them up to get some basic info, voltages etc. I doubt the owner would be ok with taking a hacksaw to that transformer though!  ;D
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Kingston on March 01, 2011, 04:23:34 AM
INA134 type input and DRV134 type output...

a whole redesign of the oscillator is in order...

redesign the whole side-chain...

design the transformer...

CJ hack job on it to know how to recreate the transformer...

And most importantly:

"I've never had the opportunity to listen to one but am excited to try something totally unique in the gain reduction element department."


You have here a perfect opportunity to learn and design something completely new, and what do you choose? to clone something you haven't ever even heard?

What the heck is wrong with you people!

[edit]

years in retrospect it seems I was really mean, don't know why. I'm sorry about that. The work you do is of great quality with all the prototype iterations visible here.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: dmp on March 01, 2011, 10:57:18 AM
Quote
You have here a perfect opportunity to learn and design something completely new, and what do you choose? to clone something you haven't ever even heard?
What the heck is wrong with you people!
I've never had the opportunity to hear a Neve preamp, a tube preamp, a 1176 compressor, etc. etc. but I started building these projects a year ago and not only have I learned an incredible amount about electronics and recording equipment, but I've started to learn what 'great' means for recording equipment - not just with my ears but interacting with other musicians. I believe one of the best ways to learn is to study what's been done before. Due to the high cost of recording equipment most people can't study an original example. But with the schematics & this forum, a person can learn a lot by jumping in with both feet.
Saying someone shouldn't try something, for this reason or that reason, isn't constructive.
Trying to design a great piece of recording equipment without a substantial background in using, designing, and building IS
Quote
shooting from the hip in complete darkness
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: damnyankee on March 01, 2011, 10:58:26 AM
It's the challenge of doing it, Kingston - it's in our American DNA.  We try to create and re-create the impossible.  ;D
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 01, 2011, 12:38:42 PM


You have here a perfect opportunity to learn and design something completely new, and what do you choose? to clone something you haven't ever even heard?

What the heck is wrong with you people!

HAHA! Of course I have complete faith that this sounds fantastic. Seems Like "you people" have lost faith in a lot more than just cloning audio equipment. In my mind the stuff I SHOULD be cloning is the stuff I've never heard before. Maybe I'm just crazy. I don't have an extra 10,000$ sitting around to buy one.  ;D ;D ;D

And now that I think about it, every project I have built I've never heard the originals. NEVER. 1176, SSL comps, API pre, MElcor pres , 990 opamps, Eq's, UPGrading equipment. If "you people" ;) think you have to hear a piece of equipment before you can work on it, then nothing would ever get done, and no new designs would ever get made!

Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: strangeandbouncy on March 01, 2011, 12:59:23 PM
Kingston,



   actually, this really might be worth doing blind . . . . There is nothing like a Pye, if they get it right . . .



        MIne rule . . .


          ;)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 01, 2011, 08:24:58 PM
     Here is my take on the schematic. Note there is a separate PCB for all the switches, for the sake of a easier build. There will be 3 Lorin switches, one for ratio, one for decay and one for limit (on/off). I moved the limit option from the ratio selector so simple Lorin switches could be used. Otherwise we would have to used a 3 pole 5 position external switch along with all the wires.

    Also shown are the most adequate transistor replacements I could find. If someone knows of a sub that would work better please let me know. Especially with TR11 , the CHOPPER transistor. :D

    PCB Layout soon to follow...

-Abe

NEW Circuit Layout Rev 1 (http://www.acsoundstudio.com/DIY/Pye/Information/circuit1.jpg)
Pye Front Panel (http://www.acsoundstudio.com/DIY/Pye/PYE-front.jpg)
Original schematic: page 1 (http://www.acsoundstudio.com/DIY/Pye/PYE1.jpg)
Original schematic: page 2 (http://www.acsoundstudio.com/DIY/Pye/PYE2.jpg)
Pye User Manual (http://www.acsoundstudio.com/DIY/Pye/pyebook.pdf)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: haima on March 01, 2011, 08:31:47 PM
Abe - Can I suggest giving your schematics a revision name, ideally in both the image and the file name. That way as things are improved or changed we all know we're on the same page?

Thanks for doing this - I hope it works out!
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 01, 2011, 09:01:08 PM
Good Point!
Done and done.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: haima on March 01, 2011, 09:05:21 PM
I meant actually changing the image file - so that when you are looking at it you can see that it's rev1 or rev2 or whatever...   ;D - All good.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 02, 2011, 01:12:43 AM
yea...that is what I did...you might need to refresh your browsers cache....or download the file

EDIT: OK NOW its fixed! haha
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 02, 2011, 01:58:37 AM
Ok...so more reading I find that this oscillator is known as a "blocking oscillator" as referred to in the manual. It outputs a square wave.

Food for thought :

http://mysite.du.edu/~etuttle/electron/elect37.htm


there are many ways to make an oscillator...many easier ways since when the PYE was originally designed. If it was designed today I imagine it might use a 555 chip as the oscillator or they even have ICs that's main purpose is to oscillate. I imagine we can't just pull the old oscillator out and put a new one in...or could we?
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: shabtek on March 02, 2011, 03:12:23 AM
I think Kingston is just trying to reality check you. Enthusiasm makes it is easy to put too much on ones plate.
Good choice of project though. Don't think there are many diypwm comps. Keep it up.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 02, 2011, 03:16:57 AM
Sorry for my frequent responses....want to update with what I've found...to get some ideas.

www.acsoundstudio.com/DIY/Pye/Information/schematic_NEW_OSC2.jpg
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: damnyankee on March 02, 2011, 10:13:43 AM
...there are many ways to make an oscillator...many easier ways since when the PYE was originally designed. If it was designed today I imagine it might use a 555 chip as the oscillator or they even have ICs that's main purpose is to oscillate. I imagine we can't just pull the old oscillator out and put a new one in...or could we?
You could always breadboard one up and test the differences between the two...  ;D

By the way, AC: which Pye compressor are you cloning?  I may be in for a pcb from ya!

Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Rob Flinn on March 02, 2011, 12:09:15 PM
One needs to be a little bit careful doing 250KHz circuits on a breadboard.  You may get stray capacitance that makes an otherwise great circuit not work.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: leadbreath on March 02, 2011, 12:46:30 PM
hey abechap nice going, u can definitely count me in for some of these pcb's.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: jandoste on March 02, 2011, 04:53:09 PM
hey abechap nice going, u can definitely count me in for some of these pcb's.

me too !
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Rob Flinn on March 02, 2011, 05:16:44 PM
With regards to the oscillator.  As far as I'm aware a 555 puts out a square wave or a triangle wave with a cap added. I'm no expert on discreet oscillators, but I think they normally put out a sine wave, which might rule out using a 555.

I think that many of these old style PWM compressors vary the mark/space ratio by changing the break point on a comparator, so that it triggers at different heights on a sine wave fed to the other input.  Thus varying the mark space ratio.

It would be useful to get a scope on a real Pye to see what the signals doing in different places.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 02, 2011, 05:31:12 PM
With regards to the oscillator.  As far as I'm aware a 555 puts out a square wave or a triangle wave with a cap added. I'm no expert on discreet oscillators, but I think they normally put out a sine wave, which might rule out using a 555.

I think that many of these old style PWM compressors vary the mark/space ratio by changing the break point on a comparator, so that it triggers at different heights on a sine wave fed to the other input.  Thus varying the mark space ratio.

It would be useful to get a scope on a real Pye to see what the signals doing in different places.

Yes I also first assumed that the discrete oscillator would probably output a sine wave, but doing some reading in the manual, the oscillator type used in the pye was of the blocking oscillator variety. Blocking oscillators output a square wave/triangle depending on the transformer used. At least they should, but because of the use of the transformer are very prone to ringing and over shoot, I do think this would be our main huge stumbling block, requiring a oscilloscope to tune the oscillator for variations in the transformers. Really a huge time sink. Lets throw that old design out, as I'm sure the man who first designed the compressor would do if he had a stash of 555's available.

Granted if anyone happens to have a PYE laying around PLEASE open it and take note of the waveform type and amplitude!

Which is my next question....the whole side-chain looks to be run off one -12v rail, so at what amplitude should the oscillator output?

Also, Rob what your saying about the circuit changing the mark/space ratio....that makes sense that the oscillator would output a sine - -  -cause I cant seem to understand how it would do that with the oscillator outputting a square wave. I still have more reading and digging to do...good stuff though.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Rob Flinn on March 02, 2011, 05:46:26 PM
It maybe that the oscillator is set to output a triangular wave, because that will work in the same way with a comparator as the sine wave, all be it with a slightly different response.

I know someone with a PYE that might let me get a scope on it. I'll make some enquiries.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 02, 2011, 05:47:40 PM
It maybe that the oscillator is set to output a triangular wave, because that will work in the same way with a comparator as the sine wave, all be it with a slightly different response.

I know someone with a PYE that might let me get a scope on it. I'll make some enquiries.

That would be great.  ;D
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Rob Flinn on March 02, 2011, 05:51:04 PM
Emailed owner.

If you put a cap on the ouput of a 555 it makes a saw tooth wave.  Well it actually looks a bit more like a sharks fin.   But it would probably be ok to use.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 02, 2011, 08:27:28 PM
Hi Rob,
Actually I mis-spoke earlier. I can't seem to find where I read that a Blocking type oscillator can produce a triangle wave output. Seems that they only produce Square waves. Though there must be something we are missing here, It seems very important we get someone in this world to sit down in the same room as an oscilloscope and a pye unit. Lets hope you email works some magic :D
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: grantlack on March 02, 2011, 08:57:42 PM
even if this doesn't end up 'pye' per se, i like the thought of venturing into a less ubiquitous form of compression.  i was actually just looking into shelling out for a 4060 manual when this thread got going, must be subliminal messages flying around...  haven't found a legible shot of the 4060 schematics (any revision), but i'm curious to compare them to these.

@ mr. bouncy- while we're on a pye kick, how did mr. purpose's eq end up comparing to yours?
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: mad.ax on March 03, 2011, 05:06:01 AM
Disclaimer : I'm far from a PWM expert, so I may be totally off base here !

The operation is explained in the Pyebook.pdf previously posted. The problem is that this book obviously refers to a different set of schematics than the ones posted along. (components numbers are different).

The oscillator (VT12 in the pdf, TR14 on the schemo) outputs a pulse signal rather than a square one. Actually it is a square but the cyclic ratio is not 50/50. Otherwise you would get a minimum attenuation of 50% of the signal at any settings.
Then TR13(VT11 in the pdf), switches out that pulse according to the sidechain and decay time setting.

Unfortunately no information is given about the width of the pulse. This would need to be measured on a real Pye. The Pyebook also cite 200 and 250KHz as the frequency of the oscillator. Given that this frequency must be filtered out by the LPF (L1, L2 on the schemo), I guess it's important to get it right, so this should be measured too.

Short of those measurements, you could experiment with a variable square wave generator with adjustable mark:space ratio once you got the rest of the circuit prototyped. Find the frequency that is filtered off nicely, and the ratio that gives the correct decay time.

Hope this helps.

Axel
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: michal_k on March 03, 2011, 09:22:05 AM
I know it may be a long shot but just an idea: how about using uC and it's DAC output as an oscilator: you can generate any waveshape without changing a circuit itself so it would be easy to adjust even after pcb's are manufactured. I know that frequency like 250k may be difficoult to achieve, but those new chips can do a lot of fancy stuff.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 03, 2011, 03:39:22 PM
Yes, that's definitely not a bad thought. But a simple 555 correctly configured can give a wide range of waveforms. IF we had a scope of the actual waveform we were trying to replicate would be great.

http://focus.ti.com/docs/toolsw/folders/print/tlc555calc.html  <--handy tool... the search continues
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: sahib on March 03, 2011, 06:26:55 PM

I have only had the opportunity to look at the schematics and the service manual. As Axel pointed out indeed the manual refers to different circuit but the principle is explained.

Michal_k, your idea is not a long shot, in fact it would be greatly more stable and smart. I'll have a stab at this and see what we can come up with but in any case it should not be a problem.

Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 03, 2011, 11:02:35 PM
Sahib,
I have a really blurry schematic that the manual is referring to. The only thing that is different (as far as I can make out) is the output stage is a bit different, but everything else (including the side chain) is very much similar.
I made out enough to make these references:

TR16 = VT14
TR15 = VT13
TR14 = VT12
TR13 = VT11
TR12 = VT10

eidt:A little update on my end...I have the whole circuit in a simulator, I'm trying various voodoo and hudoo to coax it to preform and allow me to get some usable info. Slowly learning things though


Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: michal_k on March 05, 2011, 06:17:13 AM
Michal_k, your idea is not a long shot, in fact it would be greatly more stable and smart. I'll have a stab at this and see what we can come up with but in any case it should not be a problem.

cool, let me know what you figure out. I'll be more than happy to help with coding.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 16, 2011, 03:08:14 AM
Ok well, Making good progress, a lot of people seem to have really good ideas. I have gotten some interesting and useful results by modeling the circuits in "TINA" but it takes SOOO long to analyze the 250khz pulse wave that I really want to just dive in and do this puppy. Me and a few other brave souls who want circuit boards post on this thread once we have 10 people we can make it happen at 50$ a board shipped. I want to emphasize think of this as a personal board to run experiments on, while I have no doubt with the proper amount of know how and fiddling we will get them to work, at this point think of it as a glorified bread board, which brings me to my next point:

The PCB has the original circuit with updated transistors (you can buy everything at mouser) the main hang up (which is only a hang up till we figure it out ;D) is the oscillator circuit so I've made room for a tiny digital type (s/pdif type) transformer. I'm not saying that kind will work I'm just saying that size wise it should get us in the ballpark so that's the footprint I made for our "mystery" transformer.

But many of you out there (and I agree) feel like since the pye was first made back in the 70's technology has improved quite a bit and there are much much easier was to obtain an emulation of whatever that original oscillator was making  using a 555 chip or whatever. So I've left a good portion of free space for fiddlers to fiddle.

Obviously not a project for everyone but I know a few of you out there really showed some interest so heres a chance to get in on it.
Abe

(http://www.acsoundstudio.com/DIY/Pye/Information/pcb_1.jpg)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: michal_k on March 16, 2011, 04:59:45 AM
What are the board dimmensions? I may now the place where they will do it for faaaar less, even if you oder just one.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: ChrisPbass on March 16, 2011, 07:37:43 AM
Abe, just want to say good luck with this & thanks for all the effort. I'm not really in a position to be a beta tester for this as I don't have enough knowledge to tinker with the oscillator circuit, but I do know these are cool compressors. I knew someone with some of these who had to sell them on, great pity...but when I get some projects finished, this will be on the new list.
Cheers
Chris
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Niketouille on March 16, 2011, 09:30:37 AM
I'm in for a pcb too... and ready to beta test !!
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: leadbreath on March 16, 2011, 11:44:15 AM
im in for 1 set, ill get my mad scientist cap on!!!
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: michal_k on March 17, 2011, 08:41:37 AM
I've just started reading the schematic and I've got one question: How is compression rate controlled? I understand that by changing resistors with compression rate switch we make the dc offset bigger, but what's the offset effect on oscilator? does it change PWM duty cycle? So that the higher ratio the smaller duty cycle - less energy left?

Michal
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 17, 2011, 11:22:32 AM
Well according to the manual when the signal goes over the threshold energy from the signal gets chopped. The more compression taking place the more energy is chopped from the signal. but its fairly simple:

The DC control voltage is applied to the base of TR13
This then gets mixes with the Pulses created by the Oscillator circuit.
This then is fed to TR11 which cuts the necessary energy from the signal

But I don't think thats exactly what you asked....I too am wonder exactly how it shapes the PWM signal and I'm beginning to suspect that maybe it works slightly different then the manual says....but then again that could just be my limited understanding of the circuit. The pulses switch on and off the transistors in sucha say that it ends up doing what the designer wanted. On the simulator It looked as though the chopping signal would have more positive pulses when there was more compression, but not really a change in PWM. That was just for one of the random fiddlings I was working on though. Just throwing it out there. I for one will much rather work on a real circuit then a S L O W W W simulation...(at least in a case like this)


Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 17, 2011, 11:36:26 AM
What are the board dimmensions? I may now the place where they will do it for faaaar less, even if you oder just one.

I checked into this and It looks like that the prices is going to be about the same, and when you consider shipping to me and then shipping out, the price is pretty reasonable. (Just letting everyone know!)

-Abe
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: leadbreath on March 23, 2011, 07:10:54 PM
so when will these pcb's be available??
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 23, 2011, 08:13:42 PM
so when will these pcb's be available??

Well so far we have 2 boards (or when you said "set" are you in for 2?)  if we can get 3 (or 2) more people to get boards we can make it happen.

If no one else wants boards at this point then I'll just wait till I have enough moolla to cover the rest, but as it stands right now we don't have enough to cover even the set up charge!

I don't want to make any false claims and say anything but this project is not for beginners but at the same time it should not be that hard....
All it takes is for one person to figure out what is going on and then we'll all know what to do.

Heck, I'm confident that by sure brute force of time and stubbornness the answer to a replacement oscillator is right here.

Come on people!
 :)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: leadbreath on March 23, 2011, 08:46:38 PM
hey abechap

sorry, i must have gotten over excited but i actually meant 1 board. its sad there's not enough interest, this could be a very interesting project.

Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 23, 2011, 08:50:13 PM
Thats ok! :D Well It shouldn't be long now. I have a couple REC gigs that should get us over the top and I'll send an order for the boards.

It not for everyone but I think its kinda cool going into the unknown and figuring it out.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 30, 2011, 04:10:20 AM
Hi All,
in my spare time I got some boards ordered and put together this BOM

www.acsoundstudio.com/DIY/Pye/Information/BOM/Pye_Proto_1_BOM.pdf (http://www.acsoundstudio.com/DIY/Pye/Information/BOM/Pye_Proto_1_BOM.pdf)

Boards should be here in a couple weeks...

-Abe
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: sahib on March 30, 2011, 04:25:24 AM
Abe, I am not sure if you sorted out the oscillator but I have not had the opportunity to look at it. However, I am going to Istanbul this weekend for the entire month of April and I will have plenty of time to look at it.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 30, 2011, 04:47:36 AM
I haven't really had time to do a whole lot with it. I've come to a stopping point till the boards get here. I've found quite a few possible RF/Pulse type transformers that might work. And also the IC based oscillator ideas...
Glad to hear you will have time.

-Abe
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: ptron on March 30, 2011, 06:00:16 AM
Id love to try looks like a true nice iron for the rack but id be total lost fiddling with this before u guys get it shmokin :)
Totaly interested tho for when osc is figured :)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: reanimatorstudio on March 30, 2011, 02:38:22 PM
I have a pile of DIY waiting to be finished. On the other hand I think this thread is a brave one (like the good old days) and one that should be supported. Have you got an idea of the total cost for this project (without case, meter and knobs)?
Another inconvenient thing is shipping from America. Belgium customs charges a lot on parcels shipped buy USPS. Do you have a solution for that?
Do you know if the cadac G255 uses the same technique? If so I have one, unfortunately no schematics. We could use it as a source of information.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: strangeandbouncy on March 30, 2011, 02:40:34 PM
Hi,


  the only vintage cadac comps I ever saw were optical . . .


   ANdyP
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: MicDaddy on March 30, 2011, 03:07:50 PM
Interested in pcb

Looking forward to seeing a new generation of PYE compressors   :o
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: reanimatorstudio on March 30, 2011, 03:09:13 PM
Thanx ANdyP, that's what I thought, but the guy I got it from, told me it was the same principle as a PYE compressor the bastard!
That makes this project even more interesting to me
Of the topic but have you got any schematics or info on the cadac G255?
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on March 30, 2011, 03:51:36 PM
Hi,
Yea...this project is a tad adventurous I guess, but if a pye is going to be (re)born anywhere in cyber space I do believe this forum is the place for it :)

Point and case: one great forum member sent me a run down of pics of the oscillator circuit and an oscilloscope readings.

Thats a huge boost to this project I'll post the pictures asap. It looks like the transformer is a small toroid core with a few wire wraps around it. Really not as hard as I imagined making a transformer for this might be. Not saying it will be really easy, just that at least now we know what we are trying to recreate looks like.


Still a little fuzzy on exactly how it works, but we'll figure it out.

Pictures soon to come.... :)

(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010617.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010598.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010600.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010606.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010608.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010611.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010613.jpg)
(http://www.acsoundstudio.com/DIY/Pye/Pictures/P1010615.jpg)






Much Thanks Rob!!
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: strangeandbouncy on March 30, 2011, 04:37:45 PM
Hi Reanimator,


  you might try FunkyJunk, cos thats where I heard em . . .
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Niketouille on March 31, 2011, 09:24:39 AM
About the cathode of D1 :
- What is the DC voltage ? I suppose it is +Vcc but it would be better to mesure it.
- What is the exact duty cycle ? Frequency seems to be around 310 kHz but I can't read the "time off" duration.

Any ideas about the variable cap ?
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: tmuikku on April 01, 2011, 03:13:44 PM
I wonder how this would sound if one brought the switching frequency into low mid frequencies?  :-X How about a FPGA to give some nice harmonics with DSP power?:) Its friday and listening to some The Flamin Lips ;)
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: mata_haze on April 01, 2011, 03:51:31 PM
Hi Reanimator,


  you might try FunkyJunk, cos thats where I heard em . . .


please guys let us know if you need schematics and stuff. we don't have much about htese comps here at FUNKY but I will do my best to help.

Mattia.
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on April 01, 2011, 04:45:09 PM
Yes lots of questions too on my mind. I just ordered a bunch of toroidal cores approximating the size of the one pictured and also some magnet wire. I figure If I make a hundred of them I'm bound to get some results that can lead  us in the right direction. I:'m sure there is a much more scientific way to approach this but until I know how its the brute force method! I'm hoping maybe these prototype boards will lead to something worthwhile after all...
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: Niketouille on April 03, 2011, 04:29:41 AM
Why are you trying to clone the oscillator ????????
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: abechap024 on April 03, 2011, 08:35:12 AM
Why are you trying to clone the oscillator ????????

Why not?
Its a very fundamental part of the compressor. It will be interesting....
Title: Re: PYE Compressor/Limiter PCB: FEELER
Post by: haima on April 03, 2011, 08:54:33 AM
Why are you trying to clone the oscillator ????????

Because we don't know to what degree the oscillator contributes to the sound of the compressor? - perhaps it's inconsequential, or it might be completely intrinsic.

The waveshape, duty cycle etc could make quite a difference...?

I'm no expert though... hopefully in the long run it can be replaced with something simpler.

Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 05, 2011, 03:21:49 PM
yes exactly.
Also if anyone is interested I put a link up on my site to pre order

Cheers!
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on April 06, 2011, 11:26:45 AM
"The waveshape, duty cycle etc could make quite a difference...?"

As you said we don't know but I guess it could. Depending on the chopper frequency (and spectrum) the audio spectrum before filtering will change. Perhaps the filtering cancel all those effects but I'm really not sure about that.
As I understand in a blocking oscillator all these parameters are dependant of the ...é"'(§è!ç.. transformers. That's why I think it is far easier and faster to reproduce the waveshape with another oscillator. Anyway if the cloned oscillator works it is... groovy.

Title: Re: PYE Compressor/Limiter Thread
Post by: grantlack on April 06, 2011, 02:26:59 PM
duty cycle looks to be 20-30% but fewer sec/div on the ol' scope would be beneficial. that's quite a fall time!  not quite a classic square wave, is it  :-\

too bad we don't have an FFT plot, that would make life much easier.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 06, 2011, 09:53:19 PM
...é"'(§è!ç.. transformers.

Haha that about sums up my feelings on the transformer too!

 ;D
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 11, 2011, 05:10:49 PM
(http://www.acsoundstudio.com/DIY/Pye/Pictures/PI_3141/downsize04.jpg)

They are here!
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on April 11, 2011, 05:58:58 PM
hey abe

nice looking pcb's man!!!
i dont know if this will help but i was trawling through the internet the other day and i found a posting (cant remember what forum) about a pye comp that had a faulty inductor?? the person didnt know what it was for but he did posta picture and it looked like one of the carnhill inductors.
now i dont know if its the oscillator or something else but unfortuneatley i didnt download the photo of it and now i cant find the bloody site no more >:(
would an inductor be used anywhere else except the oscillator?
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on April 11, 2011, 06:14:09 PM
This might be the one :
http://www.gearslutz.com/board/geekslutz-forum/380364-variable-inductor-pye-comp.html
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on April 11, 2011, 07:01:25 PM
btw, money sent for 1 x pcb

cheers bru...
Title: Re: PYE Compressor/Limiter Thread
Post by: spreemusik on April 11, 2011, 07:48:31 PM
This might be the one :
http://www.gearslutz.com/board/geekslutz-forum/380364-variable-inductor-pye-comp.html
52.5mH, 80 series resistance, and a standard core with a tuning slug. That should be pretty easy to wind. Then it only needs to be tuned to the resonant frequency. I'm guessing it's a steep filter for the PWM signal.
Title: Re: PYE Compressor/Limiter Thread
Post by: Rob Flinn on April 11, 2011, 08:29:36 PM
That's not really the difficult part to source, it is used in the low pass filter that removes the chopper HF signal.

The difficult part is the RF transformer, which I think Abe is working on at the moment.

By the way good looking work Abe !
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on April 23, 2011, 10:02:00 AM
Got my pcb this morning with...the annual tax !!!
Does someone know something about the others transformers (input/output/sc ) ? Some mesures would be great...
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 23, 2011, 12:01:17 PM
Glad you got it!

Some measurements of an actual unit would be great. But because of its low -16V supply rail, someone was saying that we will need at least 1:3 3:1
(more like 1:4 4:1) on input and the opposite on the output.
I believe for the side-chain is just a 1:1, but would be nice to have some conformation on this. I bought some from edcor for the project, a 10k:600 on the input, 600:10k output and 1:1 sidechain. I'll let you know how it goes...
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 23, 2011, 12:34:38 PM
(http://www.acsoundstudio.com/DIY/Pye/Pictures/pye_torroid.JPG)

Also found some torroids that look like the original....found them on the bay..just by chance!
Title: Re: PYE Compressor/Limiter Thread
Post by: Hank Dussen on April 23, 2011, 12:51:00 PM
Some members here own or have access to these compressors.
Surely it can't be that hard to measure the ratios...
Title: Re: PYE Compressor/Limiter Thread
Post by: Rob Flinn on April 23, 2011, 02:03:51 PM
Some members here own or have access to these compressors.
Surely it can't be that hard to measure the ratios...

It's not that difficult to work out how many turns the primary & secondary are.  If you look at the 2nd circuit board pic I posted you can see the transformer about 1" in from the left where there is an E printed on the board.   It's something like 3 turns &  the other winding 5 turns.
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on April 23, 2011, 04:43:39 PM
R33 should be 8,2 ohms right ??? not 8,2k ?
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 24, 2011, 03:24:44 PM
Ops! Yes your right. Good catch. Looks like I have some un-soldering to do...


Oh wait, on the original schem it says 8.2 ohms but on the original parts list it says 8.2k - and my gut goes with the parts list cause 8.2k is quite more common then 8.2 ohms...
But I had someone tell me it probably is 8.2 ohms...so I would go with that.

But who knows....Just try and see I guess. I 'll try 8.2k first since thats whats in there already
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on April 25, 2011, 12:39:41 PM
hey abe

got my pcb's, nice work! im loving the "playground"!!

thanks
mick
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on April 25, 2011, 05:50:10 PM
8,2 ohms is much more logical than 8,2k.
8,2k induce a lots of nfb and therefore a very low output level. I mean that's what my over-excited brain first thought....
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on April 25, 2011, 10:07:59 PM
Okay, well that is what someone was telling me too. Which makes a lot of sense now :) I need to learn more about all this :D!
So first errata!!

r33 is not equal to 8.2k
r33 is equal to 8.2R

First of many I suspect!

Cheers,
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: reanimatorstudio on April 26, 2011, 05:43:45 AM
For many reasons (feedback, output impedance, output level, power of the resistor, relation to other components,...) I believe R33 is 8,2 ohm
Title: Re: PYE Compressor/Limiter Thread
Post by: Rob Flinn on April 26, 2011, 06:53:06 AM
If you look at the 2nd circuit board picture I posted.  On the bottom edge below one of the inductors is a large 8R2 resisitor.  Whether this is R33 I have yet to find out but ...............
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 05, 2011, 03:49:30 AM
2N4124 quantity is 2 in the bom instead of 1.
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 05, 2011, 04:40:53 AM
and R52 is a trimmer not a fixed resistor...
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 05, 2011, 05:28:28 AM
Add a 1k resistor in series with the meter ??? I'm refering to the pye manual.
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 05, 2011, 06:01:06 AM
About the dual 330 ohm pot I will use a dual 2,2k lin pot with a 390 ohms resistor in between the wiper and the bottom legs.
... too much post today !!!
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 05, 2011, 10:21:57 AM
Add a 1k resistor in series with the meter ??? I'm refering to the pye manual.
You need a 1k in R1 if not using an external meter.

Good stuff! Updating BOM

THNX!

Hows your build going? I have mine about 3/4 stuffed with just random parts around....also 550/560 *should* work in lue of 549/559 I had some laying around we'll see!

I hopin they at least do somthin!

EDIT: found another error, BOM should have TR18 as BC559A
Title: Re: PYE Compressor/Limiter Thread
Post by: Rob Flinn on May 05, 2011, 03:49:06 PM
Quote
About the dual 330 ohm pot I will use a dual 2,2k lin pot with a 390 ohms resistor in between the wiper and the bottom legs.
... too much post today !!!

It's not a dual 330R pot !  It's a dual rotary switch.  I'm hoping to visit my friend soon & measure what the steps are.   I suspect that you may manage to get something happening using your 2K2 pot and 390R, but the rotary switch automatically gives you the correct make up gain like on an API 525, so it may not work correctly.   I will post some more on this as soon as I have the information.

Quote
If you look at the 2nd circuit board picture I posted.  On the bottom edge below one of the inductors is a large 8R2 resisitor.  Whether this is R33 I have yet to find out but ...............

Can confirm that this is correct & that R33 is 8R2, & it looks to be at least 1/2Watt
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 05, 2011, 05:57:12 PM
Great thanks for confirming. I updated the BOM.

Also some of the resistors look like they are 1/2 watt...I think that is a bit of overkill though....if a 56ohm resistor was connected to the -16 rail straight to ground it would only dissipate a little over 1/4watt. And the output section will probably be using the most current and its all connected with 56ohm...


....Long story short, My bets, we will be fine without cumbersome 1/2 watt. If not I'll buy everyone a Sparkling water!

Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 05, 2011, 06:00:08 PM
Didn't know it is a stepped pot, so I will wait until you could mesure it. Schematic is a bit unclear about that.
I'm still waiting parts for this project so nothing is soldered yet...
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 05, 2011, 06:08:14 PM
16V into 56 ohms is actually about 4.5W...
Title: Re: PYE Compressor/Limiter Thread
Post by: ruckus328 on May 05, 2011, 06:09:44 PM
16V into 56 ohms is actually about 4.5W...

Beat me to it.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 05, 2011, 06:14:53 PM
Yes, even in the manual it has a mysterious "attenuation box" thingy...
Hopefully we can use a ganged bot to linearly control gr/gain. but until someone can check it for sure (Rob!) its only a guessing game
Title: Re: PYE Compressor/Limiter Thread
Post by: reanimatorstudio on May 05, 2011, 06:56:24 PM
I know from an insider that Radial is trying to do build this one for the lunchbox. I wouldn't be surprised if they are following this thread.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 05, 2011, 07:11:02 PM
16V into 56 ohms is actually about 4.5W...

Woops yea my mistake, I was looking at 1/4 amp in current.  ::)
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 05, 2011, 07:11:49 PM
I know from an insider that Radial is trying to do build this one for the lunchbox. I wouldn't be surprised if they are following this thread.
interesting...too bad we can't go underground. If they are reading this thread:

Get some different knobs for your stuff! ;D

If they are reading why don't they chime in? They must have a budget, or at least a working unit in front of them. Don't they know its not nice to let all the little people do all the work! ;)
Title: Re: PYE Compressor/Limiter Thread
Post by: Songguy on May 06, 2011, 11:52:31 AM
There's always a way to go underground ;)

Abe, if you put together a kit for this you can count me in.

Chris
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 06, 2011, 03:03:44 PM
Well we'll see, this whole thing could turn in to a big resistor fry, possibly not work at all (thats for radial;)
no seriously though...it might not work...
haha!

Least it beats playing the lottery...we can just burn our money at home!


eventually I would love to stock parts for this board.

Cheers,
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 08, 2011, 01:45:26 PM
R2/R1/R1/R2/R1/R2..... confusion in my brain...
So there is no R1 and R2 is 240ohm as on the board.
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 08, 2011, 01:53:44 PM
R40 is R68 in the bom and the schematic.
By the way this resistor seems to be bypassed on the schematic, probably during the test procedure.
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 08, 2011, 02:05:59 PM
So :
R2/R1
R40/R68
R11/R67
R8/R58
R10/R66
R69/R74
R7/R57
R76/R71
R6/R56
R70/R75
R72/R77
R5/R55
R3/R53
R33 is missing in the bom
What are you using to design pcb ?
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 09, 2011, 06:25:21 AM
Okay my mistake,
There where two R1s on the BOM. Now its fixed. On the board it seems labeled fine. I've gone through and all the other numbers seem to correspond. I don't know if I follow you...

The whole input gate  section we threw in the trash so in order to keep the original schem and my schem somewhat refrenceable to each other, I kept the numbers the same. That is why there might be R numbers missing. But don't worry resistors don't care what number you call them anyway. Updated BOM


Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 09, 2011, 06:27:31 AM

R33 is missing in the bom


No its there - just right at the top of the list, I try to organize everything not by reference number, but resistor value.

AC


Also I want to instill confidence in this build...I'm expecting it to work, though its more fun ot joke that it won't. IF it doesn't work for whatever reason, then I'm going to be out a lot cause I ordered about 30 extra circuitboards!

Heres to hoping.

Also thanks to you Niketouille  for helping me refine the BOM.
Cheers!
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 09, 2011, 11:21:15 AM
Those resistors have bom and schematic number that are the same but on the board it's different... Nevertheless the values are correct.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 09, 2011, 11:29:38 AM
Those resistors have bom and schematic number that are the same but on the board it's different... Nevertheless the values are correct.


Oh I do see what you mean....That sucks! How in the #$%^ did that happen. Sorry about that :o

I'll update schem and BOM

Seems to just be the switch PCB, probably while I was importing/exporting the different PCBS the nums got messed up. But BOM/Schem fixed now! :-)
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 10, 2011, 09:37:24 AM
Ordered all the rest of the parts needed for this build...should have some news by the end of this week...
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 13, 2011, 02:49:13 PM
Ok update....

last night put it all together, and these are my findings so far. Bear in mind I haven't gotten nearly as much time to tweak on it as I have planed to do (i'm going to go mess with it some more just after this post)

EDIT: passes signal as it should. I have edcor 4:1 and edcor 1:4 input/output respectively. Sounds good! I had to insert a trimmer resistor to bias some of the transistors correctly, it was a slight variation from the schematic.

The occilator is not working...I tried a few different hand wound toroids and nothing...but I am doing something wrong obviously...going to research the toroids a bit more, and then if I can't get those to work its off to the playground with my friends the NE555 chips...

Ok really strange part....it compresses.......

with no oscillator?

Anyway does require more finessing...will keep posted.

Cheers,
Abe

Update: on the Switch PCB resistor R75 says "11k" and it needs to be paralleled also with a 20k to get the correct ratio.


Thanks
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 14, 2011, 03:41:38 PM
HAha! So Sick! its working

Details to come...
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Songguy on May 14, 2011, 06:09:35 PM
Awesome Abe!

Title: Re: PYE Compressor/Limiter Thread
Post by: gemini86 on May 14, 2011, 06:10:28 PM
Impressive, sir! (as chester would say)
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 16, 2011, 08:31:42 AM
Well let me give some more updates on exactly what happened:

I got everything together, first power up there was only a faint weak trebly distorted sound coming out...after many hours of angry words I finally realized, stupidly I didn't have it grounded correctly. So grounded it and it started producing some real sounds.

At first I had the two stages connected to a 10k dual ganged pot. But for testing purposes I un hooked them and used different pots for input/makeup gain. that stages seem pretty immune to using different values, I think right now I have a 10k pot with a 3k resistor on the leads and the a 50k pot on the makup stage, I'm sure it could probably use some tweaking later.

So next power up the side-chain was acting funky....with no signal the meter would sit around "0" (i just had a vu hooked up to it but I think it requires a 1ma DC meter) but its seemed to respond correctly...the meter was bouncing to the music, just was off...

So come to find out, I had the decay switch rotated one notch to far to the left when I soldered it in, and also a 2n4124 transistor was burnt out probably from me messing with some of the trim pots and maybe turning them too far to one side (just a guess).

Mind you during all this the oscillator was not working and the 100 ohm resistor by the oscillator was getting hot to the touch.
Well I switched out different hand wound transformers....getting very discouraged, thinking well this is crazy....Its not going to work...so I just took the little transformer out (i tested about 5 different ones up to that point).

And well then I made those changes as stated before, and other fiddlings and well installed one final little hand wound transformer....(mainly to get the meter to sit at "0" because I found it doesn't with no transformer installed)

But low and behold!! WE get signal!
There is a waveform that very closely matches the pictures I was sent of a working pye. You can imagine my excitement... So next thing is to probe the base of the chopping transistor.....and by turning the ratio switches I can artificially trigger the side-chain...and what do a see on the oscilloscope? These amazing waveforms! They get wider during peak reduction and smaller during less reduction, just like the manual states! I was blown away, I have no Idea how it does it but it does, it was very beautiful to see (I had been staring at a blank oscilloscope for many hours....that could be why :))


Well anyway, very excited its working, I do a few more tests, also the side-chain isn't detecting audio correctly (like it was) and I have to move wires and what not to get it to work intermittently. But I'm very confident I will get the problem sorted, as it was responding correctly before, and the only big issue in my mind was getting the oscillator to work, and I think its easier to get to work than any of us could of imagined.

My oscillator is running at 500khz so I need to tweak the transformer etc....

anyway very excited how this is turning out, my oscilloscope broke (how ironic!) so I've stopped working on it for the time being, otherwise I (hopefully) would of brought news of a completely working unit.

Going to continue progress today. Either by fixing mine, or borrowing a friends down the street.

Thanks for bearing with my long post, hopefully someone finds this helpful (and not radial! ;) )
Cheers,
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Rob Flinn on May 16, 2011, 09:07:18 AM
This sounds very encouraging Abe.    Hard work pays off !!
Title: Re: PYE Compressor/Limiter Thread
Post by: Davo on May 16, 2011, 09:38:48 AM
Nice job Abe, very exciting!
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 16, 2011, 10:47:36 PM
Switch D6 and D7 sidechains doides opposite than footprint! Spent all day banging my head against the wall!!

It works!

Cheers!

Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on May 17, 2011, 08:18:19 PM
Switch D6 and D7 sidechains doides opposite than footprint! Spent all day banging my head against the wall!!

It works!

Cheers!

Abe

What do you mean exactly ?
Title: Re: PYE Compressor/Limiter Thread
Post by: Rob Flinn on May 17, 2011, 08:45:38 PM
Switch D6 and D7 sidechains doides opposite than footprint! Spent all day banging my head against the wall!!

It works!

Cheers!

Abe

What do you mean exactly ?

He means install them the wrong way round compared to  the screen print on the top of the pcb.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 17, 2011, 11:07:17 PM

He means install them the wrong way round compared to  the screen print on the top of the pcb.

Yep.

thx,
Abe


Oh PS, found that when the oscillator isn't oscillating the meter doesn't sit at zero and the 100 ohm resistor heats up. Also I pulled the one toroid that worked out and tried some different versions to try and get the frequency more ~250khz...turns out it was very lucky that I took notes on the one that worked, because it seems very particular on what transformer it will and will not oscillate with.I tried about 5 other designs before rebuilding the one that works. I think we need to source some t-50-2 (i believe thats what was pictured on the original) I am having a time sourcing them....but Ive only tried fleabay and mouser... Found some T-25-2 on fleabay - from the UK. Also learned that the T-"xx"-2 numbers stand for size of the toroid and the T-50-"x" number stands for type (they are color coded, 2 is red).

Also I don't think a ne555 chip implementation will work...Seems that the sidechain voltage directly changes the oscillator frequency...at least thats what I can tell from the tests I've done with the cheap digital oscilloscope I've borrowed while I wait for parts on my analog one.

I think pn3640 isn't a good replacement...Its hard to find a good data sheet on the original v405 chopping transistor, but I think the circuit can't saturate the pn3640 completely so it just amplifies the chopping wave, instead of switching it on and off...I am looking at some promising substitutes.
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on May 18, 2011, 01:06:14 AM
hay abe, well done man!!!

this is turning intoa very interesting thread!!
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 28, 2011, 11:41:47 AM
Also R75 marked on the meter board is actually 11k parralled with a 20k to get the  correct ratio ~ 7096.7 ohms

Got my red torroids today.... getting ready to test them
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on May 31, 2011, 08:38:07 PM
Yes, I couldn't get Red Toroid to work...? But using a Iron powder and ferrite core toroid I'm able to get it to run at roughly 220khz.

But now I'm realizing the sidechain isn't responding correctly....very jumpy and not very pleasant. So Instead of throwing the whole mess through my window and hacking it up in the garden, I decided to take a break from it for a bit.



Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on June 02, 2011, 01:20:23 AM
I hate to post again....but I feel like I should give an update. Also considering its good news :-) 

I've been trying out various toroids,  I found one that is getting closer. Now the sidechain preforms as it should, no more "dirty" compression. And the  sound of this unit is actually very nice. Getting to the point of being usable ;D

The last torrid was oscillating at around 200khz but it was a kind of dirty oscillation. But it wasn't sufficient to work the chopper transistor correctly.

So the one I'm currently experimenting with oscillates at about 80khz, much cleaner oscillation, and sidechain is responding as it should. There is some slight high frequency feed-through, I'm assuming from the chopping frequency being lower than designed for.

Can't wait to post some sound examples when its 100% working.

Thanks,
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: mylesgm on June 02, 2011, 03:56:46 AM
I dont know about others but I'm happy for you to keep posting little updates as I'm definitely interested...
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on June 04, 2011, 12:48:52 AM
I uploaded a clip of the pye compressor compressing on the diy soundcloud account. You can hear a tiny bit of the HF feedthrough, but I seem to have sussed that out by changing the torroid


Here is a video of the chopping waveform:

http://www.youtube.com/watch?v=UgwpulCjuaA (http://www.youtube.com/watch?v=UgwpulCjuaA)

Cheers,
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: Davo on June 04, 2011, 02:30:58 AM
Nice progress Abe!!
Title: Re: PYE Compressor/Limiter Thread
Post by: Govinda Doyle on June 04, 2011, 09:54:05 PM
Keep going Abe,
they are fat sounding compressors!
G
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on June 11, 2011, 05:22:39 PM
Found the solution to the problem I've been having with these units.


Works Great, and Sounds great! Really totally natural sound to it. Surprising for something that totally makes mince meat of the signal. Now I need to rack up my pair for my Stereo Buss!

People want audio clips? Also want me to offer pre-wound toroids in my shop?

Also I'm getting an ERRATTA sheet together with information on the toroid. I'll send that along with anyone who orders a PCB
Cheers,

Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: tomcat on June 11, 2011, 07:07:48 PM
Cool! Yes pre-wound torroids would be nice!
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on June 12, 2011, 02:24:36 AM
yeah man ill second the torriod option abe.

looking foward to getting this thinng hooked up.
Title: Re: PYE Compressor/Limiter Thread
Post by: zayance on June 12, 2011, 05:31:54 AM
Well never used or heard a Pye, could be a nice try, so pre-wound torroids for me too...

PS: If this one was in 51X format, it would have been cool too....
Title: Re: PYE Compressor/Limiter Thread
Post by: Songguy on June 12, 2011, 01:52:08 PM
+1 for pre-wound torroid. Thanks Abe!
Title: Re: PYE Compressor/Limiter Thread
Post by: gemini86 on June 12, 2011, 02:24:09 PM
Might I be so bold as to say maybe nix the prewound toroid. This is DIY, and you're doing most of the 'doing' already... no neet to let you build our projects for us. It would be nice, however to have access to the materials you used EG, be able to buy the toroidal core and appropriate amount of magnet wire from you, then we can wind away, saving you your hard-earned free time. :)

Good work on this Abe.

BTW, used to live in Provo as a kid, have family in SLC. Utah is a beautiful place, if you don't mind the weather extremes... :)
Title: Re: PYE Compressor/Limiter Thread
Post by: Biasrocks on June 12, 2011, 03:50:06 PM
+1 on the pre-wound,

There's enough to worry about in a first time build, I'd rather have something that I know will work.

Mark
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on June 13, 2011, 08:25:37 AM
Might I be so bold as to say maybe nix the prewound toroid. This is DIY, and you're doing most of the 'doing' already... no neet to let you build our projects for us. It would be nice, however to have access to the materials you used EG, be able to buy the toroidal core and appropriate amount of magnet wire from you, then we can wind away, saving you your hard-earned free time. :)

Good work on this Abe.

BTW, used to live in Provo as a kid, have family in SLC. Utah is a beautiful place, if you don't mind the weather extremes... :)

Touche. The toroid are surprisingly simple to make. It would be just as easy for me to wind them as sell the individual parts. I can totally respect doing it yourself. The knowledge must be spread! :)

Yes you need a scope.
Yes this project is still in its infancy.
and yes its totally worth building it.

One grounding trace might have to be cut. This board is the last one I let the computer decide how to run the grounds...
I'lll put that in the erratta today if needs be. not hard to do, a little pain in the butt but hey that DIY.


And UT is great...I never thought I would end up living here, but the longer I stay the more I like it.

Cheers!
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on June 13, 2011, 08:33:39 AM
and why doesn't it automatically oscillate using the toroid and winding ratio of the original?

The original *looks* like its using a t-25-2 core and 5 and 3 windings.

I've tried that combination many many times, and never could get it to work. My only assumption could be that the red core toroid we see in the pictures is actually a toroid with a much higher inductance rating than the t-25-2.

I can only get it to oscillate by sandwiching toroids together. The inductance goes up....the frequency goes down. The capacitance goes up the frequency goes down.  In my limited testing as long as the circuit is oscillating at the correct frequency the sound doesn't change.

It will probably be worth looking into some high inductance small toroids, if someone wants to roll their own but only use one toroid. but for right now I can supply toroids that work for people that are more into recording than fiddling with equipment (Stuck in rural utah you all can guess what side of that fence I've found myself on)

Okay Thanks as always, :)
Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on June 13, 2011, 08:47:45 AM
Quote
I can supply toroids that work for people that are more into recording than fiddling with equipment

u said it abe, i havent even had time to look at the pcb/schematic never mind comtemplating winding my own coil.

u build it, we'll buy it. simple as...
Title: Re: PYE Compressor/Limiter Thread
Post by: 0dbfs on June 13, 2011, 09:03:36 AM
I've had some practice rolling stuff before...

10 turns? 6 turns? That sounds real easy.

Cheers,
j
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on June 13, 2011, 09:06:57 AM
Quote
winding my own coil.

is it just me or does that sound dirty...??? :o ;D
Title: Re: PYE Compressor/Limiter Thread
Post by: Songguy on June 13, 2011, 11:40:58 AM
+1 you build it, I'll buy it. Thanks Abe.
Title: Re: PYE Compressor/Limiter Thread
Post by: ptron on July 05, 2011, 03:50:47 PM
Quote
winding my own coil.

is it just me or does that sound dirty...??? :o ;D

ehehehehehe im glad im not the only one
Title: Re: PYE Compressor/Limiter Thread
Post by: Mlewis on July 07, 2011, 06:00:43 AM
wow.. love to try this project! I've used a bunch of Pye compressors over the years and they really do rule
Title: Re: PYE Compressor/Limiter Thread
Post by: dandeurloo on July 08, 2011, 10:12:28 AM
wow.. love to try this project! I've used a bunch of Pye compressors over the years and they really do rule

Just wondering what you have used them on?  Curious
Title: Re: PYE Compressor/Limiter Thread
Post by: Mlewis on July 09, 2011, 06:10:42 AM
well, last time i used them i wanted to use them on the drum rooms but the producer got me to squish all sorts with them, AC guitar, kick, snare etc. i still think they would probably be best for drum rooms, parallel drum subs, parallel vocal compression. the kinda squishing where you look at the crazy gain reduction going on and raise an eyebrow at the producer to see if he's happy about the situation!!
Title: Re: PYE Compressor/Limiter Thread
Post by: dandeurloo on July 09, 2011, 11:42:03 PM
sounds fun!
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on July 14, 2011, 03:01:05 AM
hey abe

just curious what input/output/sidechain transformers u used??

mick
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on July 14, 2011, 10:11:06 AM
 I found 2:1 stepdown input  and 1:2 step up output work fine and 1:2 step up for the sidechain.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on July 19, 2011, 11:59:21 AM
check 1st post for consolidated errata


also for the inductors use these:

http://www.mouser.com/Search/ProductDetail.aspx?R=6310-RCvirtualkey54200000virtualkey542-6310-RC
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on October 03, 2011, 07:59:09 PM
hey abe

howzit going?  im busy getting parts together for this build, are u still gonna offer the oscillator torroids??

cheers
mick
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on October 04, 2011, 02:10:19 AM
hey abe

howzit going?  im busy getting parts together for this build, are u still gonna offer the oscillator torroids??

cheers
mick

Ya do you need one?

-Abe
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on October 04, 2011, 09:40:55 AM
ja, maybe 2 :D
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on November 01, 2011, 06:23:35 PM
This thread is getting kind of old but I do plan on offering the boards along with complete build manual. I just bought a impedance measuring device as to find an easy replacement for the toroid in the oscillator that i custom wind using 2 separate transformers (one is a mysterious black one that I bought a bunch of off flea bay a while back so I have no idea how to determine its impedance beyond measuring it.)

But to keep the flame alive here is a beatiful case that Dan of custom cases is going to be offering!!

(http://www.acsoundstudio.com/pi_3141/Pye1_smaller.jpg)


 8)
 
Title: Re: PYE Compressor/Limiter Thread
Post by: spase on November 01, 2011, 06:25:54 PM
YEAH i like this pannel.Looks Great
Title: Re: PYE Compressor/Limiter Thread
Post by: Niketouille on November 01, 2011, 07:01:54 PM
Any info regarding the thresold steps ?
FP looks great, what meters are you using ?
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on November 01, 2011, 07:09:53 PM
Any info regarding the thresold steps ?
FP looks great, what meters are you using ?

Hi, were using Hairballs 1ma meters. The threshold steps are basically 10 to 10 they really don't transfer to any concrete dB steps or anything, the input fader can be wired how ever one chooses, we didn't want to lock people in.

Title: Re: PYE Compressor/Limiter Thread
Post by: providedrailroad on November 02, 2011, 05:11:28 PM
Are you going to be offering DIY PCB's for this unit?
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on November 02, 2011, 05:20:01 PM
hey abe

nice to see this post, im just busy sourcing parts for this project, looking foward to seeing those elusive oscillator inductors!

thanks
mick
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on November 02, 2011, 09:39:57 PM
Are you going to be offering DIY PCB's for this unit?

Yep thats the plan.

@leadbreath yep ma man! will get everyone updated
Title: Re: PYE Compressor/Limiter Thread
Post by: valvusmusicus on November 14, 2011, 02:57:28 PM
Hi
Sorry, Am I being a bit dense, but I cant finr the original schematic in this thread
Could someone less dense direct me to it please

Cheers All :'(
Title: Re: PYE Compressor/Limiter Thread
Post by: Biasrocks on March 08, 2012, 01:50:05 AM
Are you going to be offering DIY PCB's for this unit?

Yep thats the plan.

@leadbreath yep ma man! will get everyone updated

Hi Abe

Is this going to happen?

I see pre-built ones on your site, but no boards available.

Regards,
Mark
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on March 08, 2012, 12:14:21 PM
Hi Mark,
Getting ready for DIY version "Rev 2" making it more simple to build. The original circuit (and boards) are fairly tricky to implement things such as a custom wound oscillator transformer and a very sensitive grounding scheme. Plus a few silkscreen mistakes on the boards.
Rev 2 should be much better, easier to build, going to have options for lots of good stuff that the DIY crowd usually likes to see. (optional electrically balanced input, And using the NE555 chip for oscillator, etc). Simple things that I'm sure the original designers might use if they existed back then. Shouldn't effect sound too much at all, still keeping the Class A discrete make up gain etc etc.

Coming in a month or two I imagine.
Title: Re: PYE Compressor/Limiter Thread
Post by: 0dbfs on March 08, 2012, 12:24:52 PM
Dang. That sounds sweet!
I'm in for at least two units.
Any chance these will be stereo/dual-mono?

Cheers,
JoBu
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on March 08, 2012, 12:28:08 PM
Dang. That sounds sweet!
I'm in for at least two units.
Any chance these will be stereo/dual-mono?

Cheers,
JoBu

Good! And yes they will be able to be stereo linked. The Pye's have an exceptional stereo linking as well: They sum the audio before the side-chain and then sum the DC after the side-chain. Pretty nice.
Title: Re: PYE Compressor/Limiter Thread
Post by: 0dbfs on March 08, 2012, 12:38:29 PM
So is that switchable like on the various gssl turbo variants?

ie; CV from summed audio, or CV from summed SC's.

One more question, are the PCB's sized such that you can make a stereo unit? either 1RU or 2RU? I'm thinking yes from following this thread but was just wondering...

If so, i'll plan for 2x stereo units. Awesome projects Abe!

Cheers,
jb
Title: Re: PYE Compressor/Limiter Thread
Post by: Biasrocks on March 08, 2012, 12:45:22 PM
Very cool Abe, it'll be nice to add this to the arsenal.

I picked up an old MXR Dual Limiter recently that uses a chopper as well. A very interesting sound.

Regards,
Mark
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on March 08, 2012, 12:53:28 PM
So is that switchable like on the various gssl turbo variants?

ie; CV from summed audio, or CV from summed SC's.

No, well actually, I guess you could, but thats not how it was originally designed. I don't know what the benifits of just doing one or the other would be, but could be cool! But the original is just Linked or Mono.

Quote
One more question, are the PCB's sized such that you can make a stereo unit? either 1RU or 2RU? I'm thinking yes from following this thread but was just wondering...

The PCBs will be small enough to fit 2 channels (for stereo) in one standard 9" deep rack. Dan from collective cases already has a faceplate if you want to go that route, and its 2 RU. I think you could fit one channel in 1 RU, but not 2 (unless you got pretty creative with the front panel space...

Best,
Abe


@Mark, sounds interesting. Got Schems for the MXR :)?
Title: Re: PYE Compressor/Limiter Thread
Post by: Biasrocks on March 08, 2012, 01:32:03 PM
@Mark, sounds interesting. Got Schems for the MXR :)?

Yep, I'll send them over.

Regards,
Mark
Title: Re: PYE Compressor/Limiter Thread
Post by: Script on March 08, 2012, 10:14:30 PM
So is that switchable like on the various gssl turbo variants?

ie; CV from summed audio, or CV from summed SC's.

...I don't know what the benifits of just doing one or the other would be...


CV from summed audio (or summing to mono before SC) makes the comp "deaf to stereo".

Either way I might be interested in a stereo set, depending on price.
Title: Re: PYE Compressor/Limiter Thread
Post by: PRR on March 11, 2012, 12:33:20 AM
> my take on the schematic

D4 D5 D6 D7 drawn wrong. Should be full wave bridge, not ring-modulator.

There's no Zener in the original power supply.

> the oscillator transformer

Not a "radio" part. It is the singer from a camera flash unit. You could almost use a camera flash oscillator, except the frequency is low.

It's not critical. I'd be inclined to a 555. Just need to get the duty-cycle way low.
Title: Re: PYE Compressor/Limiter Thread
Post by: Grummy77 on March 11, 2012, 03:01:06 AM
Always strive to make improvements and fix things. But I'd like to say to also remember if something ain't broke don't fix it. Make updated versions but I'm glad you're keeping your original Pye available. I hope the newest updates sound even better but I must say I think about your Pye a lot since I heard the clips you posted in this thread on GS: http://www.gearslutz.com/board/high-end/561673-high-end-drum-bus-compressor-suggestions-5.html#post7090697"]http://www.gearslutz.com/board/high-end/561673-high-end-drum-bus-compressor-suggestions-5.html#post7090697

There were many comps compared in this thread and your Pye was hands down my fave. Close second for me was the FCS stuff. But seriously your Pye sounded so unique amongst the great many comps compared in there. Somehint about the way it handled the top end for me was a fantastic breath of squished air. 

Personally I don't really care if it sounds anything like the original PIE comps. I checked out the Waves plugin and was not impressed. If it's a reflexion of what a real Pie sounds like then your version may actually sound better (for me and my music anyways).

Can't wait to afford to pick one up. I might have to go the kit road first as picking up components a little at a time fits my current budget a little better. I do think that your current pricing is a great deal though. If I could gt away skipping the mortgage one month I'd have one already.  ;D

All the best.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on March 12, 2012, 12:22:20 PM
> my take on the schematic

D4 D5 D6 D7 drawn wrong. Should be full wave bridge, not ring-modulator.


Yes, that original mistake took me hours and hours to figure out why the side-chain wasn't working correctly. But finally did figure it out and i sure did feel stupid.

Quote
> the oscillator transformer

Not a "radio" part. It is the singer from a camera flash unit. You could almost use a camera flash oscillator, except the frequency is low.

It's not critical. I'd be inclined to a 555. Just need to get the duty-cycle way low.

Interesting it being part of a camera flash, that does make sense. That was the hardest thing to get working, was finding the right torriod/windings for that and to get it working at the correct frequency. Your right about the 555. I've been recently testing a 555 circuit that is:
Much easier to implement
Much easier to fine tune the frequency
And a cleaner oscillation.

And as far as what the Switching transistor sees, its the exact same as the blocking oscillator. So I anticipate no change in sound.


@Gummy77 thanks for the advice! Its true, I don't want to change anything that is going to matter sound-wise. BUT for everyone going to be building this (myself included) this rev 2 should be much much easier. Plus DIYing it It shouldn't be too expensive. So keep on making those mortgage payments, soon these boards will be out!
Title: Re: PYE Compressor/Limiter Thread
Post by: Grummy77 on March 12, 2012, 03:32:01 PM
Yeah! That's what I wanna hear!  ;D
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on March 12, 2012, 05:07:13 PM
hey abe

glad to see this thread is still alive.

i finally got my pcb all hooked up and i subbed in the 120r resistor in place of the
oscillator inductor but unfortuneatley its not working. :-\ all im getting a very low oscillating sound coming through?
ive double checked everything and im pretty confident its not a mistake on my side, am i still missing something??
i see ur talking about using a 555 chip should i be looking at this instead???

cheers
mick
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on March 12, 2012, 05:33:35 PM
hey abe

glad to see this thread is still alive.

i finally got my pcb all hooked up and i subbed in the 120r resistor in place of the
oscillator inductor but unfortuneatley its not working. :-\ all im getting a very low oscillating sound coming through?
ive double checked everything and im pretty confident its not a mistake on my side, am i still missing something??
i see ur talking about using a 555 chip should i be looking at this instead???

cheers
mick

Hey Mick,

is your oscillator running?

Wait, just reread your post, sorry I think there was some confusion, you can sub the 120R resistors for the L1 and L2 inductors of the filter circuit, not the oscillator torriod. But you can sub a 555 chip set to ping at 250Khz and feed that into D1
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on March 13, 2012, 01:11:39 PM
hey abe

right, with u now. do u have any of the oscillator torroids available? im not exactly sure how to work on the 555 chip??

mick
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on March 13, 2012, 04:24:32 PM
Hi Mick,
What I did is on the "playground" part of the PCB solder in a dip 8 socket and then you wire up the power for the NE555 chip. (remembering that the "+" rail is actually ground, so you hook the "gnd" of the 555 chip to the negative rail and the VCC to "gnd" etc etc) Hope i didn't make things more confusing, but important to remember since the Pye runs off a negative rail.

Anyway, then I am using a 100p capacitor as the timing cap, and then used a 20k resistor from the power to discharge pin and a 2k trimmer (to fine tune the frequency) to the Trig pin. Using the totally standard setup you always see the ne555 circuit setup as (2 resistors and a cap) Then you feed that directly into D1.

You might want to use the TLC555 as some cheaper NE555's don't even get up to a faster oscillation than about 150khz and you want to set yours to 250khz.

Also be sure to use a 1nf cap across the power rails close to the chip. Helps stabilize it. Good luck!
Title: Re: PYE Compressor/Limiter Thread
Post by: touane on March 15, 2012, 02:11:06 AM
Hi Abe (and everybody else), glad to see this is still alive, sounds like a most interesting project! Also glad it seems NE555 will substitute easily a custom wound oscillator I had no idea how to put this together.

My question would be, if I go the NE555 route, can I eliminate R47, TR14, R49 and C25? Otherwise it is not clear to me where the emitter of TR14 would be connected to. Maybe u can sketch us a small circuit example for the use of this IC?

Best Regards,
M.
Title: Re: PYE Compressor/Limiter Thread
Post by: usekgb on March 16, 2012, 10:57:54 PM
This thing sounds awesome!  I think I need a couple channels.

Cheers,
Zach
Title: Re: PYE Compressor/Limiter Thread
Post by: RATMNL on March 21, 2012, 10:08:40 PM
yeah, so do I!

Title: Re: PYE Compressor/Limiter Thread
Post by: desol on April 20, 2012, 12:58:28 PM
Any word on the new run of boards Abe?
Title: Re: PYE Compressor/Limiter Thread
Post by: Majestic12 on June 09, 2012, 03:40:24 AM
Anything new on this?
Title: Re: PYE Compressor/Limiter Thread
Post by: Govinda Doyle on September 24, 2012, 05:40:02 AM
go abe go!
I know this is a project worth waiting for!
G
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on September 24, 2012, 07:02:28 AM
Hello :)
Yes I have the rev 2 boards (had them for a while now) just checking and making sure the NE555 chip replacement for the oscillator sounds like the original toroidal oscillator and various other things. I admit I need to get cracking on it. Thanks for the reminder guys!! Should have boards and kits available soon.
Title: Re: PYE Compressor/Limiter Thread
Post by: haima on September 24, 2012, 07:25:26 AM
Cool!

Not that I need to start another project.... but...... I've always wanted one of these ::)
Title: Re: PYE Compressor/Limiter Thread
Post by: Govinda Doyle on September 25, 2012, 01:48:02 AM
Awesome Abe!!!
yes yes yes!
Title: Re: PYE Compressor/Limiter Thread
Post by: kpearsall on September 25, 2012, 02:02:39 AM
DIY is gonna kill me......

I'm in :)
Title: Re: PYE Compressor/Limiter Thread
Post by: Dr_J on September 25, 2012, 02:32:48 AM
... it's killing me too...  ;D
sooooo much DIY to do...

Great project!! Respect Abe!
I'm in for one!

ROCK-ON!
Title: Re: PYE Compressor/Limiter Thread
Post by: desol on September 25, 2012, 11:47:05 AM
Sounds good Abe. Sure hope the replacement components work out ok!
Title: Re: PYE Compressor/Limiter Thread
Post by: desol on November 09, 2012, 04:34:33 PM
Bump. Bump. Bump. Bumpity bump...   ;D
Title: Re: PYE Compressor/Limiter Thread
Post by: sm58 on November 12, 2012, 05:20:56 AM
Hello :)
Yes I have the rev 2 boards (had them for a while now) just checking and making sure the NE555 chip replacement for the oscillator sounds like the original toroidal oscillator and various other things. I admit I need to get cracking on it. Thanks for the reminder guys!! Should have boards and kits available soon.

very cool, love it, i'am in for two
Title: Re: PYE Compressor/Limiter Thread
Post by: monocle on November 12, 2012, 04:28:41 PM
Wait so much!
Fantastic project
Title: Re: PYE Compressor/Limiter Thread
Post by: websoul on November 15, 2012, 06:05:23 AM
I would love to build a dual mono/stereo of this!  The Pye is one of my fav comps on drums :)
Title: Re: PYE Compressor/Limiter Thread
Post by: Gearsef on November 17, 2012, 05:41:39 AM
I would LOVE to build one of these. I use the PIE-Compressor Plug-in in almost every mix.
Title: Re: PYE Compressor/Limiter Thread
Post by: reanimatorstudio on November 17, 2012, 03:35:21 PM
Quote
I would LOVE to build one of these.

Me too
Title: Re: PYE Compressor/Limiter Thread
Post by: bieckmusic on November 17, 2012, 05:41:26 PM
I Definately want one :-)

Greg
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on November 17, 2012, 06:12:04 PM
They do sound pretty amazing. They are a PAIN to get working in the current Revision 1.  but totally worth it, sounds like nothing else on acoustic guitars, drum bus, bass, electric guitars....

But Rev 2 is almost done.... :)

Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on November 17, 2012, 06:13:33 PM
PS did a shoot out with a buddy of mine against the plug-in version and the DIY version totally blew it out of the water in every regard. The plugin sounded "grey" and the diy sounded rich full and alive. Something very cool going on with PWM compressors.
Title: Re: PYE Compressor/Limiter Thread
Post by: Gearsef on November 17, 2012, 06:37:36 PM
Come on abe, stop teasing  :P If I can source the money I will buy one of your built and tested Rev.1 units beginning of next year! Good way to start the new year, don't you think?!
Title: Re: PYE Compressor/Limiter Thread
Post by: Majestic12 on February 02, 2013, 06:51:43 PM
Anything new on this ?
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on February 02, 2013, 10:19:45 PM
Ordering the new prototype 8) PCB. Should be soon. Very excited about this!
Title: Re: PYE Compressor/Limiter Thread
Post by: Kid Squid on February 03, 2013, 01:49:18 AM
Nice work Abe !
Title: Re: PYE Compressor/Limiter Thread
Post by: irfrench on February 03, 2013, 06:51:14 PM
I'm totally in for some PYE action!

Sub'd.
Title: Re: PYE Compressor/Limiter Thread
Post by: pyjaman on February 03, 2013, 09:11:52 PM
That's very good news!
Title: Re: PYE Compressor/Limiter Thread
Post by: desol on March 30, 2013, 05:31:46 PM
Just checking in Abe. How's this coming?
Title: Re: PYE Compressor/Limiter Thread
Post by: rascalseven on April 19, 2013, 11:53:00 PM
BUMP!!! 

 :) :) :) :)
Title: Re: PYE Compressor/Limiter Thread
Post by: pyjaman on May 23, 2013, 08:02:22 AM
Last BUMP is more than one month old... ;)
Any news on this,Abe ?
(gentle harassment)
Title: Re: PYE Compressor/Limiter Thread
Post by: leadbreath on May 23, 2013, 08:43:16 AM
ive got one of the original pcb's offered by abe and had to put it aside as i was in the process of moving house. i will be having another go at this legendary compressor in the next couple of weeks.
 the main issue with this build is the oscillator inductor, the rest of the circuit is pretty straight forward.
i'll try to get this inductor substituted by an ic that oscillates at set frequency and post updates here if any success.

mick
Title: Re: PYE Compressor/Limiter Thread
Post by: desol on August 01, 2013, 10:26:52 PM
Well, 6-7 months have passed...any news, or is this project not going to materialize?

Just wondering.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on August 01, 2013, 11:03:17 PM
Well, 6-7 months have passed...any news, or is this project not going to materialize?

Just wondering.

Its still in the works...just finalizing things. New PCB design etc....hopefully sooner than later.
:)
Title: Re: PYE Compressor/Limiter Thread
Post by: moltenwok on January 03, 2014, 02:16:52 PM
Any news on this team??
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on January 17, 2014, 01:50:10 AM
 ;D ;D

Optional toriodal oscillator or chip oscillator.

They will be available soon...getting the build manual and things organized.
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on January 17, 2014, 01:52:55 AM
Little bit of testing that went on a month or so ago...good to go :)

Title: Re: PYE Compressor/Limiter Thread
Post by: desol on January 17, 2014, 06:03:56 PM
I feel myself getting mildly excited about DIY again?? Strange...

First thing I need to say, is that I have a slight idea of how much time you've put into this Abe, and
for that I want to say 'thank you'.

Build Manual? You're being too nice. :)

This is a cool unit. Any chance we could get a 'quick debriefing on how the circuit operates?
Is Dan doing a new front panel design for the unit? (I noticed the meter...)
And lastly, pro's/con's involved in using the different oscillators?

Cheers!
Title: Re: PYE Compressor/Limiter Thread
Post by: abechap024 on January 17, 2014, 07:35:30 PM
Thanks!

Any chance we could get a 'quick debriefing on how the circuit operates?

Well, I've opted for the cinemag input transformer and glad I did. Sounds nice. The circuity is all very simple class A transistors...very nice tone to the unit. Transistors are so inexpensive and simple. Makes me want to build more stuff without opamps...

So the gain is controlled by a fader pot on the input and a fader pot on the output. Its a feedback compressor so the signal splits off before the make-up gain stage and is sent through a step-up transformer to some germanium diodes and the sidechain. I think this is what makes this compressor very unique... It has a very musical release circuit. I'm not quite sure HOW it does it exactly, only that it is very cool! Along with the PWM gain control it hands the peaks of the signals very well.

So moving on, the rectification ends of with a DC signal that tracks the audio and added with the release time that is chosen. It is then used to control the PWM signal. And the PWM signal is in turn used to control the gain of the audio. Its the same idea behind light dimmers and switching power supplies...turn a signal on and off extremely fast and how long you leave it off or how long you leave it on can control how much RMS energy gets through.

So Enter:
 The oscillator. It oscillates at 250khz. To get a good stereo matched pair, you must make sure that they are as close to the same oscillating frequency as possible. Easy in theory, not as easy in practice with toroids with wires and capacitors as the timing reference, as these all drift with temp and humidity...but can be used and obviously worked excellent. The oscillator sends out a "ping" every 250khz. This ping is then turned into a version of a triangle wave. This is then combined with the DC control signal the sidechain spits out and walla! A pulse width modulation. This gets sent to the base of a switching transistor and it chops up the audio.

The 555 timer chip can be set up in a pinging oscillator type configuration, and you can adjust the frequency with a screwdriver! (yay!) also stable and uses less current than the toroid and less chance of noise getting into things it shouldn't. The ping from the 555 timer gets sent to the circuitry that creates the triangle wave.

Quote
Is Dan doing a new front panel design for the unit? (I noticed the meter...)


yes Dan has some cases

Quote
And lastly, pro's/con's involved in using the different oscillators?

Well the impedance changes when you use the different circuitry, so a cap has to be changed to get the correct value of triangle wave. In practice I can not tell the difference and in theory it shouldn't affect the audio in anyway.
Title: Re: PYE Compressor/Limiter Thread
Post by: shot on January 17, 2014, 08:54:11 PM
Uhhh...damn Abe you're killing me!
I haven't calibrated my clx-vu to pronounce it finished, I've already got my 176 board and I'm ready to start it... and then you anounce plans for this beauty! Oooohhh....
Title: Re: PYE Compressor/Limiter Thread
Post by: desol on January 17, 2014, 10:06:09 PM
@ Abe

Great! Thanks for the explanation!

Excited to start putting together a BOM for the unit. Haven't built a DIY kit for a while...so this will be interesting!  :)
Title: Re: PYE Compressor/Limiter Thread
Post by: thomasdf on January 18, 2014, 04:33:41 AM
Sounds like a kickass projects... Can't wait to read more about it! Thanks so much Abe
I'd love a pair of these... !!

Best,

Thomas
Title: Re: PYE Compressor/Limiter Thread
Post by: Dr_J on January 18, 2014, 03:13:37 PM
Hi Abe,

Good to see the progress!

I'm ready to go for it  ;D

ROCK-ON!
Title: Re: PYE Compressor/Limiter Thread
Post by: kpearsall on January 23, 2014, 12:50:14 AM
Super excited to build a pair!
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: abechap024 on February 11, 2014, 01:34:27 AM
Okay guys. Pre-order is open. 8)

It will stop, exactly on March 10th so I can get the boards back asap :)

It should be a fun build!

Thanks!
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: kramerb1 on February 11, 2014, 02:00:37 AM
Just ordered 2 pairs! Cheers Abe! I know it's been a labor of love.
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: usekgb on February 11, 2014, 09:57:18 AM
Sweeeeeeet!  Will order a pair shortly.
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: 0dbfs on February 11, 2014, 11:54:21 AM
Ordered four PCB's. Was hoping to do a rack of eight but I'll wait for the next run.

Really looking forward to building and using these.

Thanks for this Abe!

Cheers,
jonathan
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: desol on February 11, 2014, 12:21:33 PM
Stereo set ordered! Thx
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: desol on February 12, 2014, 12:00:44 PM
Abe, what are the proper meters for this unit? Is there a file available in order to get the scales printed off?

Thx
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: abechap024 on February 12, 2014, 04:23:19 PM
Abe, what are the proper meters for this unit? Is there a file available in order to get the scales printed off?

Thx

Yes I'm getting all the documents organized. You will want to get some of the 1ma meters from hairball. The sidechain is touchy and I have it working with these meters, if you want to use other meters I cant garuntee it will work perfectly, and you would probably have to change some parts. I just leave the stock GR insert it because it is pretty close to the correct scale. I do have some inserts I will make available though.
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: desol on February 12, 2014, 05:50:33 PM
This is the one here I'm assuming... (based on the frontpanel cutouts)

http://www.hairballaudio.com/shop/product_info.php?cPath=25&products_id=64
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: nickvivid on February 15, 2014, 12:14:58 PM
Hey guys, is there a BOM / Estimated cost for parts for these units? I'm trying to budget whether i can afford to build 2 or 4 of them right now, thanks.
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: Gearsef on February 16, 2014, 05:40:55 AM
Just a quick question:
If I order a quantity of 1, will this be a stereo unit build?
Thanks  ;)
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: Majestic12 on February 16, 2014, 05:54:57 AM
Just a quick question:
If I order a quantity of 1, will this be a stereo unit build?
Thanks  ;)

No, you will need two of them for a stereo pair.
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: Gearsef on February 16, 2014, 07:25:09 AM
Thanks!
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: nickvivid on February 21, 2014, 12:00:07 PM
Is the BOM the same / similar to the rev 1? I was going to order everything needed to populate the boards this week if possible
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: Dr_J on February 21, 2014, 01:15:17 PM
Hey Abe,

great news!!
I'm in for 2!

ROCK-ON!
Title: Re: PYE Compressor/Limiter Thread *Pre Order in White Market*
Post by: abechap024 on February 26, 2014, 02:03:38 AM
Is the BOM the same / similar to the rev 1? I was going to order everything needed to populate the boards this week if possible
Its close, but a few slight updates. New one in the works....
Thanks!
abe
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: abechap024 on March 21, 2014, 02:04:10 PM
BOM on first post of this thread  :D
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: Grummy77 on March 21, 2014, 07:25:30 PM
 ???

Forgive my ignoramusness but what the deal with "CAP100, CAP200, CAP300, CAP350, CAP200RP, CAP250RP" in the BOM?

 Sizing of the pins?
What do I look for on Mouser or DigiKey to make sure I'm picking the right size or parts for these?

Trim pots - What's the deal with "22R, RELEASE TRIM, 5K1 METER TRIM, 220K, 1M8(USE RESISTOR)?

Since all the resistors are "RES400", I'm assuming they are just standard resistors.

I think most of the rest actually make sense to me.  :o
 :P
Thanks.


Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: usekgb on March 21, 2014, 09:49:31 PM
Adding lead spacing to the BOM would be very helpful when putting an order together.  Do you have that information available?
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: desol on March 22, 2014, 01:03:55 AM
I way prefer to get the board first, and then order my BOM. Half the time I end up ordering personal choice parts anyway...(aside from key components).

Do we really need to ask Abe to hold our hand through everything?  ;) I think he's done a little more than enough guys.

I measure all my own lead spacings anyway, just to be sure.
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: Grummy77 on March 22, 2014, 01:44:58 AM
Fair enough.
I've just been so stoked and excited I just wanted to get it all in.

Also I'm not especially experienced. Just teaching myself as I go.

I think a ad said there will eventually be some instructions. If I was smart I'd have patience and wait for that.
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: desol on March 22, 2014, 08:33:34 PM
I wasn't entirely describing your post Grummy.

FWIW, I'm assuming that 1/4 watt, 6.5mm resistors are used for this build. I too am unfamiliar with those notations cap100, res400, etc.

 
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: desol on March 24, 2014, 05:25:37 PM
@Grummy  :) ...patience is so important in DIY. If you like what the unit does when it's finished, you're going to have it a long time...so it's best to take the build nice and slow and do your best
getting everything right. Being in a rush is an invitation for small mistakes, which are easily done in this craft...and sometimes quite difficult to resolve later, which results in even more frustration.


Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: nickvivid on March 25, 2014, 06:52:26 PM
Abe, can't wait for the boards, and thanks for the new BOM. Will start ordering parts asap.

As for the power xformer, how many amps are these units expecting to draw? I was thinking of getting one xformer to power the 4 I'm building, but perhaps that isn't a good idea. Your input is appreciated.
Title: Re: PYE Compressor/Limiter Thread *boards ordered* BOM up!
Post by: abechap024 on April 02, 2014, 09:16:11 PM
Abe, can't wait for the boards, and thanks for the new BOM. Will start ordering parts asap.

As for the power xformer, how many amps are these units expecting to draw? I was thinking of getting one xformer to power the 4 I'm building, but perhaps that isn't a good idea. Your input is appreciated.

I don't know the exact numbers but it is very low power... (150ma each maybe??) I'm sure your one power tx will be plenty for 4 units.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Studio Mollan on April 06, 2014, 09:24:00 PM
Hi!
I got a few of these around from an old project of mine.
http://www.lundahl.se/pdf/1517.pdf
Could these be used as output and interstage transformers?
/
Emil
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on April 09, 2014, 12:49:02 AM
Hi!
I got a few of these around from an old project of mine.
http://www.lundahl.se/pdf/1517.pdf
Could these be used as output and interstage transformers?
/
Emil

I don't see why not. They will *work* fine for the output, but its going to limit your maximum output level. I would wire them up for 1:2 operation.
I wouldn't waste them on interstage, but you sure could try it!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: usekgb on April 28, 2014, 07:18:36 PM
Hey Abe.  Is there any way to make sure you received payment from me?  I was just looking at my PayPal account, and don't see anything.  I'm pretty sure I sent you payment for boards though.  Thanks!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: kramerb1 on April 28, 2014, 07:30:29 PM
Hey Abe, I received my boards! They look great! Also noticed a couple extra little DOA boards included. Where can I find info on those? Can't wait to start rocking these out.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: pyjaman on April 29, 2014, 03:52:32 AM
are you sure they're not the monolytic and discrete oscilator boards ?


One question, by the way :
what specs should the interstage transformer exhibit ( input impédance, expected max input level ) ?
Would, for example a mic input transformer work ?
Thanks !

Laurent.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tazwolf on April 29, 2014, 03:49:20 PM
the extra small pcbs are for choice of oscillator, 555 or transformer.
Just received my pcbs here in Sweden thanks!

/TAz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: [email protected] on April 30, 2014, 08:32:29 AM
Got mine today too..  8) Thx Abe
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on May 01, 2014, 01:19:05 PM
Received mine yesterday.

Quick question,

T3 the inductor for the daughter board.

Any info on that Abe?

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on May 01, 2014, 04:52:19 PM
Since the boards arrived, I started to collect items in my BOM and I have few questions.

1. to repeat what Biasrocks previously asked... any info on T3 for discrete board?

2. I'm confused with R38... in the original schematic this is a 100R resistor. Abe listed it as an inductor with value 12 uH in the BOM1, and on some previous pages here Abe mentioned to use 120R as a sub for L1 and L2. This is what confuses me - what is L2? It's not on the board (maybe I'm not looking for it carefully enough), it's not in the BOM1. Is this R38 with original value 12 uH? Can I sub it for 10uH inductor (12uH is not available in local shops)?

3. Is there any special reason that in BOM1 capacitor C38 has value 0.1uF and it's not listed along C11 and C13 that have value 100nF. This is the same value and same footprint cap! 100nF=0.1uF. Is it maybe some different voltage rating or something else different in between those caps?

4. Tantalum C27... is voltage rating of 16V enough or it should be 25V...or more?

5. Transistors TR18 & TR16... any preference between BC560A and 2N3906 or I just grab what I have first around?

6. Can I use any other input transformer other than Cinemag? Cinemags are expensive in europe (especially here in Croatia!) cause shipping from US can kill!

7. Output transformer is wired from output XLR (U4) label on board, right? This U4 is unbalanced out?

:)

thnx!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 02, 2014, 12:50:48 PM
Is it possible to feed (somehow) a stereo pair from only 1 oscillator?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Dr_J on May 10, 2014, 02:25:06 PM
Hi Abe,

boards arrived well, thanks!!

Now i'll have finish my mouser card  :D

Any additional infos on the inductors? Impedance, max DC?

Let's get build these beauty...  ;D

ROCK-ON!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 12, 2014, 08:19:24 PM
Abe, you mentioned previously in the thread when you were describing the manner in which this compresses things that there is a germanium diode in the signal path.  I didn't see that in the Mouser Cart.  The 1N5817 diode replaces the germanium OA47.  But is there a noticeable difference between these two?  I was curious about it because you implied that it might be a factor for why the behavior of this compressor is so unique/nice.  Just curious about that.

Also, Somewhere you noted that the compressor doesn't use much power.  I was looking around Mouser to see if there was anything that would do.  Any hints?  Do I want a center tap on the secondary?  I don't have the boards yet, so some of this might be obvious upon examining them.

Finally, I went looking for some Cinemag transformers, and the part number on the BOM wasn't listed on their site under line input transformers.  I am guessing that it is just the tail end of the part number that specifies the little things that is not there.  Anyhow, if anyone has some guidance on what all that means, and how to go about obtaining them, I wouldn't mind some direction.  The other two transformers for the side chain and the output as well.  I can decipher power transformers on guitar tube amps, but these are new to me, and I'd like to get it right the first time.

Sorry for all of the questions, newbie or not, but I hope that this can be an answer one time correctly and move on type thing.  Thanks again for all of the time putting this monster together.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Jeremy.Starseed on May 13, 2014, 03:08:13 PM
Turns out I have a thing for Toroids. Something about their infinite nature, their likeness to vortices and so on.

Wondering about the "Alternative to the TLC555 route" if that makes any sense. A little spiel about how to wind & properly tune the coil would be great!

Found a nice pair of meters for this one, kinda square and boxy looking, like most things British from that era.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 14, 2014, 08:24:40 PM
More questions.  I looked at the circuit layout that is in the first page (Reply #16), and the power in is, 16V.  There is a bridge rectifier so I guess that it is just a 115/230V to 16 transformer.  The image of the circuit board layout says 24V.  So that has me a bit confused.  Either way a small power transformer for this looks like it is $10-12 at Mouser. 

The oscillator boards have four holes that seem to be to connect them to the main board.  Are there supposed to be pins, similar to the pins Jeff sells for the 2520 DOA, and sockets for these?  It'd be kind of cool, probably overkill, but cool anyways.  Okay, if anyone has tips, thanks in advance.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 15, 2014, 12:24:09 AM
Abe, you mentioned previously in the thread when you were describing the manner in which this compresses things that there is a germanium diode in the signal path.  I didn't see that in the Mouser Cart.  The 1N5817 diode replaces the germanium OA47.  But is there a noticeable difference between these two?  I was curious about it because you implied that it might be a factor for why the behavior of this compressor is so unique/nice.  Just curious about that.


The diodes are just for the side chain, to rectify the audio into a dc control voltage. Your probably thinking of a 2254 compressor or diode bridge :) Sorry if I misled you, but the gain reduction is PWM and is very unique indeed!

Quote

Also, Somewhere you noted that the compressor doesn't use much power.  I was looking around Mouser to see if there was anything that would do.  Any hints?  Do I want a center tap on the secondary?  I don't have the boards yet, so some of this might be obvious upon examining them.


Yes you could use a 24V ac (or DC) wall wart 1 amp and it would run fine. These things don't use that much power...

Quote
Finally, I went looking for some Cinemag transformers, and the part number on the BOM wasn't listed on their site under line input transformers.  I am guessing that it is just the tail end of the part number that specifies the little things that is not there.  Anyhow, if anyone has some guidance on what all that means, and how to go about obtaining them, I wouldn't mind some direction.  The other two transformers for the side chain and the output as well.  I can decipher power transformers on guitar tube amps, but these are new to me, and I'd like to get it right the first time.


Send them an email, the stock the part, its just the "PC" version of it and the others don't fit the footprint! You have to email them to order anyway so it isn't really an extra step

Quote
Sorry for all of the questions, newbie or not, but I hope that this can be an answer one time correctly and move on type thing.  Thanks again for all of the time putting this monster together.
Patrick

No problem! Glad to do it and diy is a fun road and even more to use :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 15, 2014, 12:25:18 AM
Is it possible to feed (somehow) a stereo pair from only 1 oscillator?

Thats a very interesting idea.... :D Probably! But then again the channels might feed into each other strangely...haven't tried it.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 15, 2014, 12:32:49 AM
are you sure they're not the monolytic and discrete oscilator boards ?


One question, by the way :
what specs should the interstage transformer exhibit ( input impédance, expected max input level ) ?
Would, for example a mic input transformer work ?
Thanks !

Laurent.

So the interstage I've found to work best is 1:4. Edcor for example is what I use wsm600/10k I have used the 1:5 wsm600/15k its a balancing act...the higher ratio transformer actually changes the ratio of the compressor somewhat, but can lower the distortion somewhat...but then again isn't always idea either. I like the sound of the 1:4, thats what I usually use! Though experiment. share what you find if you so desire.
A mic transformer might work just fine. It doesn't have to necessarily "sound good" or have low THD as its just for the sidechain. And crappy transformers roll off the low and high end that can actually make the compressed audio sound even bigger in a cool way.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 15, 2014, 12:38:27 AM
More questions.  I looked at the circuit layout that is in the first page (Reply #16), and the power in is, 16V.  There is a bridge rectifier so I guess that it is just a 115/230V to 16 transformer.  The image of the circuit board layout says 24V.  So that has me a bit confused.  Either way a small power transformer for this looks like it is $10-12 at Mouser. 

The oscillator boards have four holes that seem to be to connect them to the main board.  Are there supposed to be pins, similar to the pins Jeff sells for the 2520 DOA, and sockets for these?  It'd be kind of cool, probably overkill, but cool anyways.  Okay, if anyone has tips, thanks in advance.
Patrick

I use dupont connector pins and headers to connect the oscillator boards, works quiet nicely while being very cost efficient. Or just use header pins and solder the daughter board on, doesn't necessarily have to be removable.

ALSO THIS IS A GOOD TIME TO NOTE:

the original ran off of 16v. You also ask or use an original pye and they have very low headroom, and you have to have some sort of make up gain...kinda a pain.

Well in my ignorance I just boosted the voltage to like 22V that and the step up output transformer can blow your head off now. Everything still runs cool, and sounds great (or better, less distortion) so thats what I do now. Suite yourself. Default I would say 22V

Which 20v to 24v transformer will work. Ideally dual secondaries if you are wiring up 2 in the same box.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 15, 2014, 12:41:58 AM
Also I think I should consolidate all this info somewhere into a pdf of the like, and calibration/wiring info...that way it will be easier to put together.

Also  would people be interested in parts kits??

Is it too late? I know buying transformers from cinemag can kinda be a pain, only because they seem to like to sell in quantity....Ideally I would just order a whole bunch and then ship them out, I wonder if people would be interested in this? Granted knowing me it would take forever to actually get them shipped out.  :o :o but they do seem to have less parts then the clx.....hmmm
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 15, 2014, 12:44:21 AM
A note about the transistors on the BOM....

Just get the ones in parentheses. the low gain "A" version of the BC's for some reason is now hard to find. Note you will want to turn the transistors around 180 degrees when subbing them.

Also thanks all! Couldn't be possible without everyone getting involved with the project. I just put one together a couple days ago and it is a nice build. Well worth it too! Great on drums...unique and fun and all that jazz..so hopefully people enjoy it on the bench and off! ;D
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 15, 2014, 12:48:03 AM
For me the transformers are always a troubling part.  I am able to get my head turned around about if I want a wsm600/10k or a wsm10k/600 very easily.  I'd assume it was the latter for output, but then I can't remember which I'd like for the sidechain.  I have already paid for the boards, is a kit still an option?  We'd have to add the xlr's and the IEC for Dans cases on the order as well.
Patrick

EDIT: Thinking a bit more, just adding the transformers for a kit would be fine.  The Mouser cart makes it pretty easy for the hard to package parts making it easier on you.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 15, 2014, 06:50:11 AM
I've found a site, they use something else for the oscillator:

http://circuitsalad.com/2013/09/09/updated-squezal-pwm-compressor-schematic-layout-and-demo/

Maybe this can be an option...

BTW, is there an estimated date for the second run to be shipped?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 15, 2014, 05:43:11 PM
I got an email back from CineMag, and it looks to be about $115 for two input transformers plus shipping.  If there is a way to lower this price with a group buy, then by all means I would be interested.  Otherwise, I have a price.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 16, 2014, 12:34:08 AM
I've found a site, they use something else for the oscillator:

http://circuitsalad.com/2013/09/09/updated-squezal-pwm-compressor-schematic-layout-and-demo/

Maybe this can be an option...

BTW, is there an estimated date for the second run to be shipped?

Why not just use the TLC555 timer board included in the PCB? That is a neat looking comp though.

End of this month is the eta
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 16, 2014, 12:36:02 AM
If I did put together a parts package, It would probably be less total than an order from mouser...So it could be a win win...IDK might be too late in the game for this round as most people probably sourced their parts.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 16, 2014, 11:27:29 AM
I'm all for a parts kit.  It makes things much less stressful for me.  I have that amazing ability when given the opportunity to make a choice between two similar parts, I instinctively pick the wrong one.  So Parts kits are welcome.  I have already bought boards in the latest go around along with a case from Dan.  So if there is a way to make the parts kit a standalone purchase, excellent.  The other thought I had was making the oscillator parts an add on for the inductor parts.  It seems to me that there is a good amount of interest, but that the chip version is more of a plug and chug set up.  So make the sure thing the default, and the inductor parts something that if you want to try it, a choice you make for some extra fun.  Yes fun.  Anyhow, I am for this, and if you are going to, I suppose you'd need to poll the crowd.  Oh yeah, if I can get a spare IEC for the other case I got from Dan, that'd be great, :)
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 16, 2014, 07:45:44 PM
OK good to know. I'll run some numbers and stuff, maybe send out some emails too.

Also I wanted to mention that I used PM1000 input transformers wired backwards (they are like 1:3, so it made a 3:1 stepdown) for a lot of the first pyes and they sounded great! So that is an option (cheaper, a little more colored, but cool!)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on May 17, 2014, 09:18:58 AM
Hi Abe,

Just populating my boards and have some questions.

1. What is the orientation of C10 ?  There seems to be 2 "+" signs next to it.
2. Is there a viewable circuit diagram on line for this board ?   I think I am noticing some différences between this rev and the original board you sent me.
3. When you say the substitute transistors need to be reversed I am not sure what the orientation should be.  should the body of the transistor follow the silk screen legend ?
4. T4 the interstage transformer.  which pins are primary & which are secondary ?

That is it for the time being.   I could probably have answered these myself if I had a diagram.   Would be vey useful....

Thanks in advance.

Rob
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 17, 2014, 03:24:50 PM
Most everything you need should be in this post

http://groupdiy.com/index.php?topic=43351.msg540369#msg540369 (http://groupdiy.com/index.php?topic=43351.msg540369#msg540369)

Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on May 17, 2014, 08:26:59 PM
Thanks Patrick,

I am not sure if that is the latest diagram.  there is only one 52mH inductor on the pcb & current BOM where as this this circuit diagram has two.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on May 18, 2014, 11:28:27 AM
from the AC Sound Pi-3141 Pre-Order (PYE Comp) 2nd Round!! PREORDER OPEN! thread...

Anthony has created a Mouser Project "cart" for a stereo pair based on Abe's BOM
http://www.acsoundstudio.com/diy/Pye/rev314/REV314_BOM1.pdf

ABE provided us with a link for the small knobs
Allied Electornics doesn't have an order history (drives me nuts) Here are the small ones:
https://www.alliedelec.com/search/productdetail.aspx?SKU=70097809

Aaron found these on Mouser
Smaller Knobs - http://ca.mouser.com/ProductDetail/Davies-Molding/1510AH/?qs=/ha2pyFadujrUgPg1/sA6O7cgb4nyXIT0wlO%2bgfqsYQ=
Larger Knobs - http://ca.mouser.com/Search/ProductDetail.aspx?Davies-Molding%2f1500AU-BLACK-LINED%2f&qs=sGAEpiMZZMuiwDVLTMm01ajIGS4kAMb6V0%2bTv0RgI2A%3d

I copied Anthony's cart & updated it to include enough knobs for a stereo unit
the cart is here - https://ca.mouser.com/ProjectManager/ProjectDetail.aspx?State=EDIT&ProjectGUID=21765FC6-F15D-4DA2-B601-0CF69821FEC6


Not added to the cart are these suggestions by Patrick
553-F117X Power Transformer - http://ca.mouser.com/ProductDetail/Triad-Magnetics/F117X/?qs=A0MODW4pnbT5S1q6Eo9XRQ==
693-6200.2100 IEC + Fuse drawer - http://ca.mouser.com/ProductDetail/Schurter/62002100/?qs=/0Eb3QIYuIav9VnbOIB16w==
568-NC3FD-L-1-B Female XLR Connector (2X) - http://ca.mouser.com/Search/Refine.aspx?Keyword=568-NC3FD-L-1-B
568-NC3MD-L-1-B Male XLR Connector (2X) - http://ca.mouser.com/ProductDetail/Neutrik/NC3MD-L-B-1/?qs=jCymNF74TgVYElHTaGE12w==

These are the meters we need... 8027-WF VU Meter
http://www.hairballaudio.com/shop/product_info.php?cPath=25&products_id=64

Transformers (Thanks Aaron -  Grummy77)
Iput - you need two for a stereo unit
Cinemag CMLI-15/15B http://cinemag.biz/line_input/line_input.php
Output - One of these
TTPC600/10K https://www.edcorusa.com/ttpc600-10k
or Two of these
TPC600/10K https://www.edcorusa.com/tpc600-10k



I was thinking that the inputs and outputs could be combo jacks...
http://www.neutrik.com/en/audio/plugs-and-jacks/jacks/combo-i-series/

...not sure if the effort is worth it... but sometimes it might be nice to just stick a TB-303 into it :)






Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on May 18, 2014, 12:59:11 PM
Yeah Steve!

Thanks for compiling all that.
(This is Aaron by the way)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 25, 2014, 11:47:27 AM
I'd like to use lundahl on the input and on the output.

Can someone help me please which trafos would fit in this circuit?

Thanks!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on May 25, 2014, 02:06:34 PM
Curious what the original ratios were for input/output transformers.

Step down on input, step up on output or 1:1, 1:1?

Anyone know??

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on May 26, 2014, 06:21:29 AM
Curious what the original ratios were for input/output transformers.

Step down on input, step up on output or 1:1, 1:1?

Anyone know??

Mark

You need step up on output 1:2 or 1:4. Otherwise the signal is very quiet (like the originals) I've used stepdown on the input and they have worked fine. But 1:1 input is probably the best. Its in the BOM
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on May 29, 2014, 10:19:44 AM

for one stereo PYE compressor


Mouser Project Cart is updated to include Fuse drawer and XLR's

AC Sound PI-3141 Dual Channel Compressor MAY2014

http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=331ad05ac3
Price is $212 Canadian with shipping

Add to supplies from Mouser:

TWO 8027-WF VU Meter's
http://www.hairballaudio.com/shop/product_info.php?cPath=25&products_id=64

TWO Input Transformers - Cinemag CMLI-15/15B http://cinemag.biz/line_input/line_input.php
FOUR Output Transformers - TPC600/10K https://www.edcorusa.com/tpc600-10k

ONE :) uber hot case - http://collectivecases.com/pie.html


There I hope that's all the bits on one place
Cheers
Steve
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 29, 2014, 11:03:11 AM
I think you need one more set of Edcor transformers for the sidechain.  So two Cinemag input transformers and four Edcor transformers for a stereo compressor. Fixed
Patrick

Addition: Hey Abe, if we just get the Edcors, you can wire them forward or backwards to get 1:4 or 4:1 right?  I only ask because if everything works fine that way, then we'd only need one part number and could buy in bulk.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on May 29, 2014, 02:34:47 PM
I think you need one more set of Edcor transformers for the sidechain.  So two Cinemag input transformers and four Edcor transformers for a stereo compressor.
Patrick

Addition: Hey Abe, if we just get the Edcors, you can wire them forward or backwards to get 1:4 or 4:1 right?  I only ask because if everything works fine that way, then we'd only need one part number and could buy in bulk.

You're absolutely right... and I ordered 4 last night :)
The above post has been modified to reflect this
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Matt D on May 31, 2014, 05:39:52 PM
How about this power transformer?

http://www.mouser.com/Search/Refine.aspx?Keyword=vpt-24 (http://www.mouser.com/Search/Refine.aspx?Keyword=vpt-24)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 31, 2014, 06:10:40 PM
That looks to be 12 parallel/24 volts in series on the secondary winding.  For a single channel unit, that would be fine in series.  For a stereo unit, I think you would want one that does 24/48 on the secondaries, so that there are two separate windings, one winding for each of the compressors.  Just to keep things separated.  That is what I thought Abe said a number of posts back.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Matt D on May 31, 2014, 06:17:21 PM
How about this

http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT48-520/?qs=sGAEpiMZZMvwUzoUXIIvyTw34uqMHR%252but33G0eT%252b6y4%3d

or this

http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT48-1040/?qs=sGAEpiMZZMvwUzoUXIIvyTw34uqMHR%252budyV6EVq1EYo%3d (http://www.mouser.com/ProductDetail/Triad-Magnetics/VPT48-1040/?qs=sGAEpiMZZMvwUzoUXIIvyTw34uqMHR%252budyV6EVq1EYo%3d)

How much current does each unit draw?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 31, 2014, 09:16:13 PM
I believe he said it was very small, around 150 mA/compressor.  The first one (553-VPT48-520) would be more than enough at 1.0A in parallel wiring.  That would be a nice transformer because you could wire it for 115V or 230V on the primary side.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Matt D on May 31, 2014, 10:18:58 PM
Oh well, I ended up ordering the second one.  Should do the job just as well I hope.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on May 31, 2014, 10:58:06 PM
http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=35cd91b9d8  (http://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=35cd91b9d8)

I had done a Cart for this as well... the pots are split shaft, depends on what knobs youre using and a couple of the trimmers are a little small, but will fit... hope i did mine right, the cart is for a 2 channel build and only came to $137usd +shipping (i dont remember if i added i/o conectors on this either)  And i didn't include power transformer, so i guess that could make up the difference.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 01, 2014, 01:13:50 AM
I added it to my cart without logging in and it is ~$160 US.  There were knobs on the list, and I'm not sure if the transformer was added.  Anyways, it is not that much difference in price once it is in USD.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: dogma on June 01, 2014, 07:42:52 PM
I do mostly electronic music so mixing eurorack, elektron ect. Now how would the pie compressor work in an electronic mixing situation. I may be tracking and mixing some drums and gtrs but I'd be building it for mixing, 2 buss, drum buss. How would it be in that context?
I'd love to read a thorough user review
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on June 01, 2014, 07:49:30 PM
Gotta find the Gearslutz page with the samples on it.  This this sounds insane on a 2bus from what I've heard (others that have either built em or heard em first hand).  Can't wait for the new boards to go out. ;D ;D ;D ;D ;D
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: dogma on June 01, 2014, 08:06:56 PM
Also is this a feed forward or feedback deal? I ask becUse the great river does both and then a blend of - the other pwm schematic does both. It's a very cool feature on the tonelux comp and I would love to have something like that as a possibility
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 01, 2014, 08:50:43 PM
In this link, on page 10 (http://groupdiy.com/index.php?topic=43351.msg701217#msg701217) or so, Abe explains it as a feedback compressor. 

Here is a link to the GS thread (http://www.gearslutz.com/board/high-end/642076-pye-compressor-example.html) that has an example of it.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on June 02, 2014, 02:15:19 AM
Also post #s 112 & 98 in this thread: http://www.gearslutz.com/board/high-end/561673-high-end-drum-bus-compressor-suggestions-4.html?highlight=little+devil (http://www.gearslutz.com/board/high-end/561673-high-end-drum-bus-compressor-suggestions-4.html?highlight=little+devil)

Some good examples on drum bus. These are the samples that really got me fired up about this comp. Something about the way the top end sparkle remains intact compared to pretty much every other example in that thread. Can't wait to have mine built!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on June 02, 2014, 11:28:22 AM
That looks to be 12 parallel/24 volts in series on the secondary winding.  For a single channel unit, that would be fine in series.  For a stereo unit, I think you would want one that does 24/48 on the secondaries, so that there are two separate windings, one winding for each of the compressors.  Just to keep things separated.  That is what I thought Abe said a number of posts back.
Patrick



For real?
In post #265 Abe said this with regards to power transformer: "Yes you could use a 24V ac (or DC) wall wart 1 amp and it would run fine. These things don't use that much power..."

I assumed he was referring to a stereo unit because he specifies 1 amp. Damnit. I already ordered the mouser cart too. Balls.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: abechap024 on June 03, 2014, 07:20:56 AM
Also is this a feed forward or feedback deal? I ask becUse the great river does both and then a blend of - the other pwm schematic does both. It's a very cool feature on the tonelux comp and I would love to have something like that as a possibility
Its feedback. you could pretty easily tweak it to be feedforward but might get kinda squirly. Or might sound awesome. I dont know, dont really have a desire to try as I like it as is, but all you would do is feed the sidechain transformer with a signal pre pwm transistor.

Also this compressor will work great for electronic music, it handles transients very well so it is your friend.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 03, 2014, 11:14:20 AM
As far as total power is concerned, I do not see a problem.  Having the two separate secondaries will probably keep the crosstalk in the transformer down for a lower noise floor.  It might not matter, but I understand the idea.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on June 04, 2014, 10:44:46 AM
Any word on the next set of boards?  And I might be interested in popping a switch to go from FB/FF.  It would be a pretty cool feature.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on June 12, 2014, 10:29:14 AM
Any word on the next set of boards?

+1
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 12, 2014, 02:58:03 PM
This would be my first attempt at a project off of this forum. So forgive the basic question(s).

Are the boards (and possibly toroid) currently available?

How does the process work for ordering these items?

Thanks you.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 12, 2014, 03:09:57 PM
The boards are in the pre sale state, at some point enough will be ordered so that it is economical for Abe to have a bunch manufactured.  There is a Mouser cart for all of the bits and pieces, and Collective Cases has the box for it.  As far as the toroid for the PWM, the build (this) thread has a lot of discussion on it and possibles to use from Mouser.  The toroid can also be replaced with the 555 circuit, making matching freq's much easier, with no change in sound.  There are options, and depending on how you wish to approach this you can act accordingly.  Personally, I am making the 555 circuit because if the sound and performance are not effected, it should be easier to get it done that way.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 12, 2014, 03:27:36 PM
Thank you Patrick.

So is the mechanism for getting on the pre-sale list simply saying I want a pair in this thread? Or somewhere else?

Thanks again, and bear with, I'll get the hang of this....

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 12, 2014, 03:47:22 PM
I went to acsound.com and ordered one there.  It is Abe's site.  There is also a thread in the White Market where you can get all of the store/ordering/news info.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 12, 2014, 04:54:31 PM
Thanks again. i went to Abes site and ordered two. I ordered the meters from HB, and I ordered the case.

Im having trouble getting the mouser cart to load from a couple pages pack.

Then its just the transformers, and I want to be dead sure on those before I order them.  :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 12, 2014, 05:20:28 PM
There were a couple of Mouser carts, one Canadian, one US. I just went to the page, and added it to my cart and then checked out the price.  Abe has mentioned the transformers in this thread a couple of times.  I asked Cinemag about the input transformers and they said ~$115 with shipping, if I remember correctly.  The Edcors have also been listed, and from what I understand, they are about $12 a piece.  I am not worried about the info in the thread, but there was mumblings from Abe about kits.  If it was at a reduced price, I'm all for it.  Considering I am waiting for the boards, waiting for the kit is nothing different.  But, I do like saving/getting a deal.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Sylvain D. on June 13, 2014, 10:48:06 AM
" I asked Cinemag about the input transformers and they said ~$115 with shipping,"

Hey Patrick,
Is that for both channels?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 13, 2014, 10:52:35 AM
Yes, Here is what the message read, "Thank you for the inquiry about the CMLI-15/15BPC.  They are $52.37 each
+ sales tax.  UPS Ground will be $10.50."  About $115, I guess sales tax gets added in there as well, so probably a bit more.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Sylvain D. on June 13, 2014, 11:17:27 AM
Thanks Patrick,
Sounds pretty reasonable for a pair of Cinemags...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 13, 2014, 12:48:44 PM
I should note I gave Cinemag my address, so the shipping could change depending on where you live.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Sylvain D. on June 13, 2014, 01:07:46 PM
...understoood.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Travis1000 on June 18, 2014, 01:34:34 PM
Hey Abe (and anyone else who might be able to answer my questions),

I'm getting the boards I order stuffed and for the most part, everything is going great. Here are a few questions I've had:

-How do I know I have the orientation of the rotary switches correct? Where is pin 1 on the PCB? Also, should the switches be attached to the backside of the board so that the the resistors and text of the board is facing away from the front panel? Does this even matter?

-How does one implement the stereo link switch and the off, in, bypass switch? I'm guessing some sort of Lorlin rotary but I'm far too green to discern a way to wire these switches!

-Lastly, is there a calibration procedure?

Once I overcome these obstacles I should have a working compressor in no time!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 18, 2014, 01:57:59 PM
The enclosure arrived from Dan this morning. Looks even better in person than the photos. Great bit 'o kit!

Havent seen the meters, Mouser cart or boards yet.....

Travis: What version boards are you building?

Have not done anything with transformers yet. I have some vintage UTCs of various design. Once I dig them out I may ask questions about suitability.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Travis1000 on June 18, 2014, 02:02:20 PM
Mdainsd I am building the boards marked rev 3.14 these were from the first pre-order back in feb/march.

Aside from not flipping the transistors that I'm using substitutes on, its gone together fairly smooth.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 18, 2014, 02:34:28 PM
Travis. As I have no experience in this thing other than opening a couple of boxes and reading everything I can about it, I will only venture the following:

Your question about the switches and which side of the board they mount to. Comparing the silkscreen on the Collective Cases enclosure with the image of the 3.14 PWB...the switches would need to be mounted on the backside of the PWB with the silkscreen, header and other components facing away from the front panel for everything to line up (control name wise).

But...everything should be verified with the schematic and an ohm meter.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on June 18, 2014, 08:57:48 PM
Got some lovely Jensen 1:4 transformers for output and interstage-Abe could you please indicate the input and output side of the interstage and the phasing. Cheers can't wait to hear it!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 19, 2014, 07:36:57 PM
Mouser cart arrived today, YES!

So lets see, enclosure, check. Mouser Cart, check. Meters, in transit (I think). Boards....boards, where are the boards?

Im looking forward to this build. Hoping I made a good first choice...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: AntoineQ on June 23, 2014, 05:04:29 AM
I'm thinking about Carnhill VTB1148 (1:3.4 ratio, 50:600ohms, if I'm right) for interstage and output, will it be fine?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on June 23, 2014, 02:52:17 PM
Hmmm, my jensens are 10k:600 which was similar to the edcors Abe suggested. Re the switches I don't think it matters on there orientation as long as they match the front panel labeling. I tried to line up the knob flat but it didn't so just went with it! Cheers team
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on June 24, 2014, 03:09:59 AM
Ah ha-just doing the second pcb-thanks for sorting that Abe!  The Decay switch apears from the visible pcb track to need the sw center pins horizontal. Oh yeah-obviously I was gonna use the jensens 600:10k. Cheers...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: taliska on June 29, 2014, 02:23:03 PM
Hey All!

Any news on how the second pre-order is progressing?

Cheers,

Kaz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 29, 2014, 04:19:42 PM
I emailed Abe on about the 19th. he indicated them shipping in two weeks would or sometime this coming week (June 30~July 7)

Fingers are crossed. I have everything else on hand am looking forward to starting on this!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on July 01, 2014, 01:46:40 PM
Since the boards appear to be close, I thought it would be a good time to ask about the parts kits that Abe suggested earlier.  I was wondering if Abe was still interested and how much support from the community there was.  I am in for a stereo parts kit should that be an option.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on July 02, 2014, 04:42:37 PM
I emailed Abe on about the 19th. he indicated them shipping in two weeks would or sometime this coming week (June 30~July 7)

Fingers are crossed. I have everything else on hand am looking forward to starting on this!

Awesome... got all the bits but the second board that I goofed up on when I ordered the first :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Travis1000 on July 07, 2014, 10:01:23 PM
I've done a lot of thinking and staring at data sheets, but I still haven't found a very elegant solution to the in/bypass/off switch. My best idea right now is to hook one leg of the mains up and the xlr inputs as wells as the comp inputs but then I would 9 poles. Anyone got a much better idea?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on July 07, 2014, 10:38:32 PM
Sorted the transformers now, for the off/on/bypass I'm thinking hard wire the mains on and relay switch supply to pcb and relay switch bypass, definitely don't want mains and audio anywhere near each other!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on July 09, 2014, 05:40:24 AM
Thing I'm puzzled about now is the stereo link hookup-any thoughts team?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on July 09, 2014, 06:17:59 AM
Would this setup work fine?

ll1540 on the input
ll5402 on the output?

And Abe, you wrote about the pn3640 wouldn't be the best part. Can you suggest a sub for that?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 11, 2014, 11:04:45 AM
I received an email from Abe with a tracking number for the boards! I havent really found a build thread on this project and havent seen pictures or progress reports from others on how they did with this or the earlier revision boards??? Whats up?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 11, 2014, 07:12:48 PM
Im probably going to do a step by step pic build when my boards get here on monday :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Travis1000 on July 11, 2014, 07:58:41 PM
mine are mostly built. I had to learn a little bit about molex connectors and will probably crimp connectors and assemble my case this weekend. All I have left is to figure out how to wire the off/bypass/in and the stereo link switches and I will be in business! I was hoping Abe (or someone as equally talented) could chime in on how they accomplished wiring those switches.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 11, 2014, 09:07:16 PM
What is your plan for the bypass? Im thinking relays right at the XLRs. one pole of a three position rotary for the relay control and one pole for line power control.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: jplebre on July 12, 2014, 09:14:11 AM
Ok, I think I'm confusing myself since this thread actually refers to the design stage, prototype stage and early revisions of the board.
In fact, I think the schematic I've been looking at is for an older board.

I have a number of questions that I've seen asked before but I think I didn't see a clear answer for them, or didn't fully understand the answer.
I'm hoping since this is a relatively young project this can help people out in the future:

1 - what type of standoff where this holes designed for? (daughter cards)
I would like to use something like these: http://uk.mouser.com/ProductDetail/Harwin/H3161-01/?qs=%2fha2pyFadug3VX%2fUDMyIBS4JZa3XRA0iPtgDHljT%2f5fvV1Sd5e0%2fQg%3d%3d and actually use this as a slot. I've been using the above sockets in a bunch of DOA like the API and the neve cards and they've been working flawlessly.
Maybe someone sees an issue with the frequency the clock will be working at?


2 - orientation of lorlins? I've seen this asked before but I may have skipped the answer.
The lorlins are marked on the PCB but with no orientation. Perhaps it doesn't matter for the first 2, but the last one is capped, so the orientation probably matters?

3 - Capped lorlin: I'm not sure what you mean by "Change to 4P1T".

4 - what is the meaning of your notation for transistors on your bom? | TR# | Substitutes ID (Sub alternatives ID) | Original ID |

5 - Any transistors that should be on standoffs? eg. maybe be changed to try and match units etc?

6 - C11 and C13 marked as 100nF and C38 is marked as 0.1uF. Same value/typo?

7 - Orientation of C10 and C35? These are marked with 2 + + on both holes.
I'm sure someone asked this but I guess I missed the answer.



8 - Any point in putting 100r trimpot on R23, 10k on R42 or 5M on R48? or just put the 22r/5k1/1M8 respectively??


Could we please see a picture of one of your finished PYE units or a wiring diagram? Still not sure about the on/off/bypass and stereo link. I've seen some ideas above by making some little input boards with relays etc is this what you intended?

As anyone went forward and got these https://www.edcorusa.com/ttpc600-10k for sidechain and output?
how did the 1:4 work on the output?


Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Travis1000 on July 12, 2014, 11:54:37 AM
jplebre,

I can tell you that any schematic you've been looking at is not the same as any board marked rev 3.14, I believe Abe is working on getting a build document together that will contain an updated schematic.

Here are my best answers to your questions:

Quote
1 - what type of standoff where this holes designed for? (daughter cards)

in post 268 of this thread, Abe says he uses a pin from Dupont. He goes into further detail in that post.

Quote
3 - Capped lorlin: I'm not sure what you mean by "Change to 4P1T".

You can convert Lorlins by unscrewing the nut on the shaft and moving the metal ring with the tab on it to the appropriate hole.
This random post I found on the web explains a little better http://forum.simflight.com/topic/76599-ne1-familiar-with-these-convertible-rotary-switch/ (http://forum.simflight.com/topic/76599-ne1-familiar-with-these-convertible-rotary-switch/)

Quote
4 - what is the meaning of your notation for transistors on your bom? | TR# | Substitutes ID (Sub alternatives ID) | Original ID |

it's my understanding that you will need to use the substitutes in most of those positions, but in order to do so they need to be rotated 90 degrees. See post #270 from Abe for a better explanation.

Quote
6 - C11 and C13 marked as 100nF and C38 is marked as 0.1uF. Same value/typo?

I didn't worry too much about this, it seems to be something that didn't get updated from revision to revision.

Quote
7 - Orientation of C10 and C35? These are marked with 2 + + on both holes.
I'm sure someone asked this but I guess I missed the answer.

C35's + should be to the right (closest to the edge of the board). C10, I also believe should be to the right. All the other caps that have the line below the two holes, the + leg goes to the right.

That's the best I can do for now, your other questions I don't really know the answers to.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on July 12, 2014, 04:33:09 PM
Well, Look what showed up in the mail?

(http://patrickfromdavis.com/Pictures/PIE_Comp/Small_Images/Package-Small.jpg)

Now I know I'm a jerk for doing this, but it would look nice as a 51X/500 Module...

(http://patrickfromdavis.com/Pictures/PIE_Comp/Small_Images/Boards-Small.jpg)

Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 12, 2014, 11:19:25 PM
The boards look good in the photos! Any documentation come with the boards?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on July 13, 2014, 01:02:36 PM
Nope, the package only has the boards in it.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 14, 2014, 06:34:28 PM
The boards arrived this morning. They look very nice.

I thought Id start on the simpler bits. I picked the switch board. Oopps. Im not going to solder anything here until Im sue, and Im not right now. I think I have the SWB (ratio) switch figured out. Even got the flat on the shaft in the right position so the knob set screw bares on the flat. But then....

Question one: SWC(limit) is called out on the schematic as 4 pol/3 pos, but the silkscreen on the face plate is two position???

Answer one: Disregard "Circuit1" schematic AND switch PWA labeling. Set switch for 2 position (remove tab, rotate switch fully CCW , insert tab into most CCW hole)

Question two: Where can I find a schematic for tracing boards? The only one I have found is "Circuit1" dated 4/5/11

Answer two: Referring to the original Pye AND the "Circuit1", I can get close enough

R70 on the switch board is labeled 6K8, but both the original Pye schematic and "Circuit1" (although it is referenced as R75) show 11K???

In the mean time I will stuff the P/S section and test that first.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: taliska on July 18, 2014, 06:25:08 AM
My boards arrived this morning, thanks Abe! ;)

I imagine a lot of people are going to use the collectivecases case, but for those that aren't...

Anyone tried to fit this in 1U yet? Seems like it should be doable...

Cheers,

Kaz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 18, 2014, 12:39:00 PM
The transformers seem like they will be an issue in 1U if Edcors are to be used.

The other thing is 12 rotary controls and two meters in 1U is pretty busy?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: taliska on July 18, 2014, 01:36:12 PM
The transformers seem like they will be an issue in 1U if Edcors are to be used.

The other thing is 12 rotary controls and two meters in 1U is pretty busy?

Yeah, I'm not too familiar with the edcors, but assuming they're the pcw600/10ks, then the height including the pins is around 34mm. The cinemags are about 29mm including the pins. 1U is 44.5 mm in height according to Wikipedia.

Oh, and I count 6 rotary switches and four (10k log) pots according to the BOM (for a stereo pair)...am I missing something?

<edit>
Yes I am...mono/stereo and in/out/bypass switches. Had assumed that those could just be put on toggles, but just realised that I hadn't mentioned it...
</edit>

By a happy coincidence I happen to have a couple of 10k log pots lying around that are the tiny prv6s type...so I think it might be possible...of course, might not be very usable! ;)

I haven't really thought super hard about it yet, but w492 eq has 16 pots in 1U, though obviously no meters. For that project I've decided to do 2U because of usability. Undecided on prr176, but might go 2U so that I can get the sturdier modushop case and have more cooling options. This one seems simple enough to consider for 1U, but I haven't tried laying anything out in fpd yet, so I could be way off...

I've got a huge modushop order to place at some point...  ;)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: taliska on July 18, 2014, 03:06:12 PM
For anyone interested in doing 1U, I think it's going to be possible...but will require a few things (well at least for my quickly mocked up vision of it!):

- The PRV6 style pots I mentioned previously plus a little bending of their pins.
- Resistors in-between the rotary switches on the pcb mounted on the back instead of the front.
- Maybe an extra spacer for the switches, but just measured things up and it's looking like it won't be required.

The rotary switches are 51mm apart from each other centre to centre (more likely 2 inches...2.54 x 2 = 5.08 cm). The pcb is 30mm high. The PRV6s are under 14mm diameter. If everything was arranged so it didn't overlap, then the tightest you could get it would be 30mm + 14mm which is cutting it a bit too fine and would look weird. Allowing some overlap means that a pin or two on the pots would need to be bent, but it makes it work.

FYI...I've attached a non-final mock up for inspiration...don't judge too harshly as it only took me five minutes...(it's a bastardised version of a PRR176 layout that I'm now not going to use, so the meter cutouts are good and everything else is spaced roughly correctly, but it still needs some fine tuning and hpgl...

Kaz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: taliska on July 18, 2014, 03:08:44 PM
Oh, and here's a pot/lorlin comparison photo for those that are interested...

P.S. The other good thing about those pots is that they're 10% tolerance and rated for 1.5W...though they are a little bit pricey...around £8 each...
Title: Re: PYE Compressor/Limiter Thread
Post by: jplebre on July 20, 2014, 02:41:31 PM
check 1st post for consolidated errata


also for the inductors use these:

http://www.mouser.com/Search/ProductDetail.aspx?R=6310-RCvirtualkey54200000virtualkey542-6310-RC

Hi I purchased these and ended up with some monsters about 3mm wider than the through holes
(https://www.dropbox.com/s/zfeb2od95m92j5j/pie%20inductors%20maybe.JPG)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 23, 2014, 10:07:46 PM
just a note - the cart i put together needs to have 150uf electrolytic caps changed to 50v, they are 16v in the cart.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 23, 2014, 11:23:55 PM
I must have used your cart, LOL. But... all those caps dont need to be swapped out, some are even identified on the board as 16V. Really wish there was a schematic that matches the boards...

if it is your cart, whats ups with the trimmer for R44 (500K) its not like the others, more like a shaftless pot on its side. The leads wont fit through the hole. Im getting ther ruglar square blue ones for there.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 24, 2014, 09:41:31 AM
It was the only one that mouser had in stock at the time.  I got it to fit and work, just not as elegant as the bournes trimmers.  +1 on the schematic thing.  I haven't been able to get mine going yet.  Once I do I'm going to write up a little build guide for it though as this project kind of needs one.  There are a bunch of questionable things with the project that need clarification.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 24, 2014, 10:32:45 AM
Im getting closer to trying things out but Ive still got a way to go. The boards have the P/S sections fully populated. The rest of the board(s) have all their Rs, Cs and Ds installed, but no transistors. I want to verify the P/S first. It was good timing of your post about the value for the 150uF caps. There are a couple that look to be across the rail so while they may not have blown immediately @ 16Volts on the supply, I want to up the rail to 22 volts.

Dont know if you have discovered it yet or not, but the pads for the trimmers have a problem. As long as you use a trimmer that has all three leads in a row it will be fine. But if you install trimmers with the center lead in one of the alternate pads, there is no connection. What I did is install the trimmers and fold the center lead (before soldering) back over the active center pad and solder.

I sure hope we arent orphaned on this build. This is my first diy from this forum and Ive invested a good chunk of change in it so far. I did email Abe asking how the build documents were progressing, but got no reply  :(
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 30, 2014, 02:52:04 PM
Has anyone on the forum gotten Rev 3 boards up and running?
Title: Re: PYE Compressor/Limiter Thread
Post by: jplebre on July 30, 2014, 03:29:05 PM
check 1st post for consolidated errata


also for the inductors use these:

http://www.mouser.com/Search/ProductDetail.aspx?R=6310-RCvirtualkey54200000virtualkey542-6310-RC

Hi I purchased these and ended up with some monsters about 3mm wider than the through holes
(https://www.dropbox.com/s/zfeb2od95m92j5j/pie%20inductors%20maybe.JPG)

argh forgot to actually finish the message. Can anyone suggest replacement inductors for the 50mH one?

Cheers
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 30, 2014, 03:38:27 PM
I used that one in my boards. bent the leads at a proper distance from the inductor body. Then bent them towards each other, and finally another right angle bend to head down to the through holes. A short piece of insulating tube on each leg where they go through the board (dont want it shorting to R2s lead) and it seems fine to me. Its still way lower than the filter cap right next to it.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 30, 2014, 03:51:50 PM
OK, after annoying the ever living hell out of Abe (sorry man).  I finally got my V. 3.14 boards working, and i gotta say, IT WAS WELL WORTH IT!!!!!!  This is now the squish master supreme on my drum bus, its got a TON of character to it!  As a sort of penance for annoying him, I've put together a little manual of sorts that I will update as needed.  It has an updated (less confusing BOM) as well as a collection of errata and explanations of confusing things on the board/BOM.  I did not go into the T3 build (just the monolithic build).  Hopefully this will clarify a few things and get a bunch of these bad boys up and running!  PS feel free to msg me about it, I feel like i should deflect some fecal matter away from abe for a while lol.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 30, 2014, 04:27:45 PM
Thank you for your efforts to put that together! Looks like I was getting close on my own (I had found the trim pot pad issue and figured out C10), but its nice to read confirmation.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: jplebre on July 31, 2014, 10:18:52 AM
Thank you so much SR! I already see some things I was unaware about this version of the board.
This will surely make it much easier to troubleshoot and assemble. And it will make it easier for Abe :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on July 31, 2014, 02:50:15 PM
Cool nice work-looks like I'm on the right track-only query is the stereo link hookup!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 31, 2014, 02:57:50 PM
BAH thanks for reminding me.  I will add that to the document - but essentially you're going to marry pin 1 on each board to each other with the switch and the same with the second pin.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 31, 2014, 03:19:40 PM
Manual updated (see post with it on pg. 18)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: moltenwok on August 01, 2014, 05:53:51 AM
Cheers-top work-I guess the phasing is important with T4 pri/sec. I figured the bottom of each pair pin 2&4 counting downwards is hot. Using Jensen 10K61-1M as side chain and output-nearly there...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 01, 2014, 09:37:54 AM
@moltenwok I think it matters more if you're not using 1:1.  This is the side chain trasnformer and I believe effects the ratio amount more than the audio itself, phase here I don't think would even matter since the side chain is only feeding the chopping circuit and doesn't "interact" with the audio passing through.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on August 01, 2014, 02:06:49 PM
@moltenwok I think it matters more if you're not using 1:1.  This is the side chain trasnformer and I believe effects the ratio amount more than the audio itself, phase here I don't think would even matter since the side chain is only feeding the chopping circuit and doesn't "interact" with the audio passing through.

Thank you for your build document, very helpful!

Curious what your choice of transformers were in which positions.

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 01, 2014, 02:20:53 PM
XSM600/10K for the side chain and WSM600/15K output.  This compressor has some serious character.  Simply amazing on the drum bus.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 01, 2014, 08:36:51 PM
A little more information on these Pre-trimmed pots please.

Are they ones with dual values indicated on the PWA? or something else?

Is there going to be an alignment procedure?

Thank you.
 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 03, 2014, 08:13:17 PM
The pre trim value is to the right of the POT value in the BOM (if there is no value, you set it later on... ie: power supply, you need to trim to get your 18-24v)  The release trim is a personal preference, you need to play with it to see what you like. (i left mine in the middle, its plenty aggressive for me).  Im still trying to figure out the meter trim adjustment, since mine doesn't seem to do much of anything, may be a board mistake, or i made a mistake on the build.  (if i did err its certainly not effecting the sound).  If thats what you're talking about regarding the alignment procedure, we're in the same boat of the unknown.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on August 05, 2014, 06:15:15 AM
Hi

I'm interested to know what people have been using for the T3 option.  Or if the majority have been using the IC option?

Anyone done an A/B between the two? 

I used these compressors years ago, I had forgotten about how cool they can sound, looking forward to getting a pair in rack. 

Thanks Abe.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on August 05, 2014, 01:20:05 PM
Quote

I copied Anthony's cart & updated it to include enough knobs for a stereo unit
the cart is here - https://ca.mouser.com/ProjectManager/ProjectDetail.aspx?State=EDIT&ProjectGUID=21765FC6-F15D-4DA2-B601-0CF69821FEC6




This mouser link doesn't work for me? Is this finger trouble or broken links? 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 06, 2014, 01:23:50 AM
Please be sure to double check the 150 electrolytic caps so that you get the 50v's (and keep 4 16vs for a stereo build) if youre going to use my cart.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 06, 2014, 11:14:12 AM
I got my 50V replacement caps, but they are just too big a footprint for the board IMHO. Im ordering some 35V versions. I dont see any reason for them not to be sufficient for this application even with the rail set to 22V.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 06, 2014, 03:45:46 PM
float em if you have to i believe theres over 35v going through the side chain section.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 06, 2014, 06:22:10 PM
Good point. Ive got them anyway, just do as you said and float them.

Do you think we will ever see a schematic that matches the board?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 06, 2014, 10:42:31 PM
I would love to see that too, might shed some light on my meter adjust issue.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on August 07, 2014, 05:35:38 AM
Please be sure to double check the 150 electrolytic caps so that you get the 50v's (and keep 4 16vs for a stereo build) if youre going to use my cart.

Thanks used your cart. 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: ravachol on August 14, 2014, 05:40:39 AM
Why float in this case? (If somebody following this could add commentary, that'd be great.)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 14, 2014, 09:50:50 AM
The board layout doesn't allow for a cap that size on the TOP since other components are too close.  If you're able to source a cap with that rating that will fit in the given size, then there should be no problem.  I put the cap on the bottom since i was going to be using larger standoffs in the 2u case.  (thought this was explained earlier in the thread)  But just in case... there ya go.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 14, 2014, 10:41:29 AM
Did you get the metering debugged?

Im still chugging along on my slow build. Boards are done less the Cinemags. Working on the physical layout of PS, boards, transformers bypass boards etc. Going to use stepped attenuators (pots) for input and output controls.

Today I hope to finish the anti-rotation plates that go under all the rotary controls. I know most people just lop off that stud and solider on, but im a little OCD about that stuff, LOL. Same with mounting the controls to the face plate and shortening all the shafts so the knobs fit just so....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 14, 2014, 02:25:28 PM
Still Nothing on the meter calibration.  Without an accurate schematic, its hard to tell WHAT is exactly wrong.  Though Abe insists that he's gotten those boards to work properly, there might be some fine print there, I was going to put a larger value pot in there to see if that helped anything at some point in the near future.  Right now, it looks like that pot is in parallel with some other resistors that are feeding the meter which doesn't match what i have seen in any iteration of the schematic.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on August 19, 2014, 03:50:57 PM
Still Nothing on the meter calibration.  Without an accurate schematic, its hard to tell WHAT is exactly wrong. 

Right now, it looks like that pot is in parallel with some other resistors that are feeding the meter which doesn't match what i have seen in any iteration of the schematic.


Bottom line, we need a current schematic.

It's also slightly disconcerting that Abe is largely MIA.

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 19, 2014, 05:00:08 PM
A member is working on an updated schematic.  no word on when that'll be done since he's reverse engineering it from the board.  With the exception of the meter calibration, there doesn't seem to be anything else "wrong" with the circuit that I've found.  Has anyone else completed one of the newer version boards?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 19, 2014, 08:25:49 PM
The schematic is close. Its all cadded out. Now I have to bounce it back against the board to see if I got it right.

Ive found a couple of discrepancies. The one thats got me interested right now. Is the diode array at the end of the SC. Abe has it as a full wave bridge driving the output transformer. But the original schematics have the diodes arranged differently. But if SR1200 has his boards running with the diodes per the silkscreen, I guess possibly the original Pye schematic had an error.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 20, 2014, 12:45:56 AM
Dont forget that Abe took things out and moved things around... its not EXACTLY the PYE comp.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on August 20, 2014, 09:57:34 AM
The schematic is close. Its all cadded out. Now I have to bounce it back against the board to see if I got it right.

Ive found a couple of discrepancies. The one thats got me interested right now. Is the diode array at the end of the SC. Abe has it as a full wave bridge driving the output transformer. But the original schematics have the diodes arranged differently. But if SR1200 has his boards running with the diodes per the silkscreen, I guess possibly the original Pye schematic had an error.

I, too, am working on a schematic, and will have it done in a couple of days.
Looks to me like the original PYE has the full wave bridge (I have several original schematic scans, and they are all the same), but the schematic I have from Abe (circuit1.jpg) is not a bridge.
This build is certainly a "modified" rendition of the circuit, but it should sound pretty close.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 20, 2014, 11:36:55 AM
Yes. You are right. I was getting brain fade. Im working on a 670 simultaneously with this Pye build. The Pye schematics do show a bridge. "Circuit1" is definitely wrong, but I have no idea what that schematic references to? The original AC boards? There is a post early on in this thread where Abe made mention of having mixed up this diode arrangement, and found it after some troubleshooting. I think all is well on the 3.14 rev boards SC bridge wise.

Here are the board issues that I know of or have found (again for rev 3.14 boards)

1) C10 having two "+" signs on the silk screen. Plus goes to the right when viewing the board with the AC logo upright.

2) Alternate wiper pads for trimmers not connected. If you use a trimmer with the alternate pinouts, you need to jumper on the back of the board.

3) C7 "+" sign on silk screen reversed.

4) Two additional resistors in the meter circuit. The first one R67 (1K) takes the place of an outboard resistor in the original that needs to be installed if NOT using an additional remote meter. The second one R65 (1K5) unknown reason, I havent quite finished with that one, looks to be in parallel with the meter (Needs to be verified).

5) Neither the core connection or the metal shield connection on the Cinemag transformer are connected to anything. I plan to experiment with that once all is up and running.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on August 20, 2014, 03:52:55 PM
Yes. You are right. I was getting brain fade. Im working on a 670 simultaneously with this Pye build. The Pye schematics do show a bridge. "Circuit1" is definitely wrong, but I have no idea what that schematic references to? The original AC boards? There is a post early on in this thread where Abe made mention of having mixed up this diode arrangement, and found it after some troubleshooting. I think all is well on the 3.14 rev boards SC bridge wise.

Here are the board issues that I know of or have found (again for rev 3.14 boards)

1) C10 having two "+" signs on the silk screen. Plus goes to the right when viewing the board with the AC logo upright.

2) Alternate wiper pads for trimmers not connected. If you use a trimmer with the alternate pinouts, you need to jumper on the back of the board.

3) C7 "+" sign on silk screen reversed.

4) Two additional resistors in the meter circuit. The first one R67 (1K) takes the place of an outboard resistor in the original that needs to be installed if NOT using an additional remote meter. The second one R65 (1K5) unknown reason, I havent quite finished with that one, looks to be in parallel with the meter (Needs to be verified).

5) Neither the core connection or the metal shield connection on the Cinemag transformer are connected to anything. I plan to experiment with that once all is up and running.

I just finished my schematic, and agree with all of these.
#1, the big + is correct.
#2, right, again
#3, yep
#4, looks to be a scaling resistor for the meter.  Yes, it is in parallel.
#5,  this may be so that you could use other transformers.  I sure would ground the core and the case.
As soon as I check my schematic one more time, I'll post it.  There may still be errors, and corrections are welcome.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 22, 2014, 06:27:31 PM
Potential additional problems.  :(

The switch board has to be installed upside down tho get the right switch through the right hole in the front panel if using The cool case by Dan. The silkscreening for the switches on the front panel is laid out as one would expect, lower values or off = CCW, higher values or on = CW

Switch board, SWA (DECAY) OK, but SWC (LIMIT) and SWB (RATIO), rotate opposite of silk screening on front panel. So the unit will be in Limit when the switch says off and vice versa. And if the switch for ratio is set per the face plate to 1:1 the unit will be in 5:1 and vice versa throughout the range of the ration switch.

Also, If you spec'd rotary switches with the flat on the shaft, they cannot be installed in that board in a way that would put the flats where they are supposed to be. I worked around by finding a place to instal the switch where the flats are at the top (roughly) of the shafts so that the set screws on the knobs tighten against the rounded part of the shaft...kludge.

I've checked this several times but would like another to verify?

Bruno?

If verified the fix isnt too bad. All the traces on the switch board are available on the backside, so a few clad cuts and re-stuffing the resistors would fix it. However, if I have to correct mine I think I will pitch the switchboards altogether and buy new rotary switches with regular terminals and build them up individually. This will also allow me to put the flats where they belong so the knobs can be secured properly to the shafts.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 22, 2014, 09:33:29 PM
Dunno about this.  My ratio switch (and all my other knobs/switches) are working exactly as marked on the front panel.  Being upside down doesn't change the direction of the min/max of the pot/switch, switching it front/back would do that.  But you are right about the flats on the switches not lining up.  I wound up grinding down another flat area for the knob to grab.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 22, 2014, 09:42:57 PM
Yeah I know that turning them upside down doest change the direction of rotation on a switch or a pot. I did the ring out on the component side of the switch board, where the switches should be mounted.

have you had a scope on it?

Im still rechecking and rechecking...

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on August 23, 2014, 03:55:16 PM
I'm about to order transformers for my build. I want to go all Edcor since Cinemag is way to expensive. Maybe some day I'll swap, but for now I have to think about costs.

1. What would be a substitute for the Cinemag on the input? Should I go with Edcor 10K:10K or 10K:600 ? WSM or XSM?

2. Would there be a difference if I put 600:600 transformer on the output instead of 600:10K or 600:15K?

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 23, 2014, 04:16:48 PM
Im not good with the transformers. But, to replace the cinemag input transformer, the closest Edcor I think is the WSM15K/15K.

The 1:1 ratio for the output transformers doesnt seem too good. Early on in this thread those ratios were talked about by Abe. It seemed settle at 1:2 up to 1:4 . Im building mine with Edcor XSM10K:600 in those locations.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on August 23, 2014, 10:07:34 PM
Im not good with the transformers. But, to replace the cinemag input transformer, the closest Edcor I think is the WSM15K/15K.

Great! Thanks!

But in one early thread Abe mentioned that he used 10K:600 for the input. I don't know if that performed well since it was an early prototype. Now my gut feeling says this one would be the best solution. I don't know...

Quote
The 1:1 ratio for the output transformers doesnt seem too good. Early on in this thread those ratios were talked about by Abe. It seemed settle at 1:2 up to 1:4 . Im building mine with Edcor XSM10K:600 in those locations.

Ok, now there's two different approaches!
You are using 10K:600 for the output... and SR1200 recommends 600:10K (or 600:15K)
And I'm more confused than I was before!
 :o
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 24, 2014, 12:10:22 AM
"You are using 10K:600 for the output... and SR1200 recommends 600:10K"

Same transformer, just turned around. That should help, no?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on August 24, 2014, 10:43:21 AM
Same transformer, just turned around. That should help, no?

True that!
But somewhere round here there was a discussion with measurements provided that reversing transformers is not the same as using dedicated ones. So I was... oh... OK... I'm too picky I know... sorry  :)  8) :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 24, 2014, 11:33:35 PM
The side chain can use these transformers any which way, just trade some noise for some gain in various configs according to Abe.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on August 25, 2014, 02:46:18 AM
Yes, I know that.

But I'm still in doubt what to order for the input transformer.
Should I go with 15k:15k or 10K:600?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 25, 2014, 04:39:33 PM
OK, lets see how this goes.....

Attached is a schematic I did for the AC boards. It includes the main board and the switch board.

Page 2 is not attached as that is specific build information for my unit, harnessing etc.

There may be some small errors, but I think I got it. However if you find any, let me know and I will update the drawing AND roll the revision.

Updated to rev b on 8/27/14
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on August 25, 2014, 06:05:58 PM
Thanks for doing this.  I made a schematic myself, but was waiting for Abe's blessing before publishing.
You have 2 R80s.  I believe that the one connected to the input pot wiper should be R81 with a value of 20k.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 25, 2014, 06:27:30 PM
Corrected, updated and re-posted! Im sure there will be more...

Did you get a chance to verify my findings on the switch board?



Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 25, 2014, 10:05:46 PM
The meter feeds back into itself like that?  Hmmmm
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 25, 2014, 10:27:24 PM
That seems to be the way it is wired, Get your ohm meter out, it should take thirty seconds to bounce off the schematic. Let me know if you find anything.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on August 26, 2014, 03:15:31 AM
You have INPUT POT labeled twice!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on August 26, 2014, 10:06:12 AM
haha. Good ol copy and paste.....

I'll fix it, but the schematic is laid out pretty much like the board. All the headers are in the approximate location and orientation as on the board.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on August 26, 2014, 02:53:00 PM
Hey guys. Haven't been here in a while, had some things come up which took me away from this awesome compressor.
Kind of strange to see all these issues etc going on? ...and abe's no longer around?

I don't believe it. Seems like too nice of a guy.  ;D

Def still full tilt on this project...in a bit, when things get smoothed out. Nice to see you guys are ironing out some of these details, for us slower types.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on August 26, 2014, 03:46:38 PM
I see it more that the community is coming together to get something working.  Abe has been quite busy lately and doesn't have much time to hit the boards lately.  And yes, Abe is an awesome guy, but sometimes the more important things take up our time.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tazwolf on September 02, 2014, 04:17:26 AM
Hi
Does anybody have any suggestions as to where is the best place to take the audio signal from  if I want to display audio input level on a LED VU meter?

/Taz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on September 02, 2014, 11:06:12 AM
Hi
Does anybody have any suggestions as to where is the best place to take the audio signal from  if I want to display audio input level on a LED VU meter?

/Taz

I guess it would be on the input transformer's output (or at the input leg of C3; or at the input leg of the IN potentiometer). But you'd need to add a driver of some sort depending on what kind of meter you're using.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on September 02, 2014, 11:23:39 AM
Now I have a question!

PN3640 is obsolete almost everywhere I searched!
I can get MMBT3640 (http://www.alldatasheet.com/datasheet-pdf/pdf/54301/FAIRCHILD/PN3640.html) which is from the same product line but it's SOT-23 package. I could solder wires on it's legs and connect it on the board but it would look ugly and may be prone to break after some time.
On some place I found info that MPS3640 (http://pdf.datasheetcatalog.com/datasheet/motorola/MPS3640.pdf) is supposed to be replacement but it's values on datasheet differ a bit. Can this be used? (this one is available in a local shop and it's cheapest!)

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 02, 2014, 11:54:39 AM
Hmmm. I got my 3640s from mouser.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on September 02, 2014, 02:46:43 PM
Abe has been quite busy lately and doesn't have much time to hit the boards lately.  And yes, Abe is an awesome guy, but sometimes the more important things take up our time.

Fair enough, but I would expect for at least the first round of building the guy that developed the project be present to iron out things.

That includes providing an up to date schematic which takes about 5 minutes time. Instead we had to put one together by reverse engineering!

I would suggest that this build thread be one of Abe's priorities until things are sorted. Lot's of questions remain.

Mark

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on September 02, 2014, 05:58:19 PM
Hmmm. I got my 3640s from mouser.

Yeah well, seem like only Mouser carries them!
Someplace I read that it was discontinued in 2012.

My problem is that in my country Mouser charges too much for shipping. It's not affordable to pay 10 times the price for it!

Could someone check the links to datasheets I put in my previous post and cross check if MPS3640 would work.  ;D
I did cross check and noticed MPS3640 has positive current values, while PN3640 has negative. (in fact it's just the same numbers but without minus sign so I'm hesitant to think it's maybe ok). It could be it's a different switching transistor, but why would it be listed as replacement... uhh... im confused...  :o
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 03, 2014, 11:58:41 AM
Shot,

The MPS3640 data sheet I looked at has "negative values" listed. Its a PNP switching transistor, which is what is called for. What I do see for both types is that the pinout  (when looking at it with the flat facing you is) from left to right e,b,c.. Be sure to double check before installing. The pinouts on the board are c,b,e for that transistor. Abe used the square pad at each transistor site for the collector (or maybe more correctly "pin 1" as the majority of the transistors used have the collector on pin 1), and I added those to my schematic..
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 03, 2014, 02:28:17 PM
Besides the meter issue, what other questions remain?  I'll see if i can get them answered.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on September 03, 2014, 03:56:59 PM
Shot,

The MPS3640 data sheet I looked at has "negative values" listed. Its a PNP switching transistor, which is what is called for. What I do see for both types is that the pinout  (when looking at it with the flat facing you is) from left to right e,b,c.. Be sure to double check before installing. The pinouts on the board are c,b,e for that transistor. Abe used the square pad at each transistor site for the collector (or maybe more correctly "pin 1" as the majority of the transistors used have the collector on pin 1), and I added those to my schematic..

Yeah, I also cross checked those two datasheets and MPS3640 seems to be biased for positive current while PN3640 is for negative. Beside that, all the values are exactly the same. All but one - they differ in Rise Time. Maybe there's some other transistor similar to MPS3640 but in the negative current range that will do.

Bruno2000 was kind enough to promise to send me couple of PN3640's.  :) :) Thumbs up for him!! So I'll go with suggested part.
But there may be other builders with no access to Mouser, or Mouser stops carrying them since they are already discontinued, so it would be cool to have an alternative for this switching transistor.
I'm still tempted to put sockets in the TR11 position and try different transistors beside the suggested one. That may happen when I finish my unit. But now it's far from being finished since I'm waiting for transformers and some other parts. I ordered them just recently.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on September 03, 2014, 04:10:29 PM
Besides the meter issue, what other questions remain?  I'll see if i can get them answered.

In context with meter issue, try to ask what would it take to be able to use regular vu meter!
I have a lot of regular (mostly cheap chinese) vu meters that look cool and I'd like to use a couple. I guess that would require adjusting value of R65 and R67. But if there's anything specific on that...

And also, what would be the difference if R38 is fitted with 12mH inductor compared to 100R resistor.
Should I just forget the inductor and go with the resistor? I get the impression most of you guys did that without problems...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tazwolf on September 03, 2014, 05:11:28 PM
Hii
Do any of the transistors need to be matched?

/Taz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 04, 2014, 11:02:48 AM
@ Taz, not to my knowledge.  My unit works fine, i didn't match anything.

@shot, we're barely getting questions regarding the circuit as is, don't think we're going to get an answer about a possible mod, but I'll ask.  As far as the difference goes, just socket the part and try both and see what sounds better.  I did the 2 inductors on mine.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 04, 2014, 02:00:00 PM
Shot.

"And also, what would be the difference if R38 is fitted with 12mH inductor compared to 100R resistor.
Should I just forget the inductor and go with the resistor? I get the impression most of you guys did that without problems..."

It is a L/C network vrs a R/C network for the -12V regulator used to power the SC. It wont affect anything, use the resistor.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tazwolf on September 04, 2014, 02:04:49 PM
Hi Sr1200
Thanks for the response to the matching transistors question.
btw : just to let you know, whenever I look at a thread you are on I get an infection blocked from meirrecords.com.
This is with avast, thought you should know.

Regards
Taz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 06, 2014, 08:52:58 PM
Yeah avast is one of the worst virus protection programs you can install, they refuse to update their definitions or site lists.  (ive actually spoken to them on the phone.. their ACTUAL response:  "we can't rescan every time there's a problem" my response:  "the problem was over 4 years ago, the site was cleaned in less than 24 hours after infection, you're telling me you haven't scanned in over 4 years"......   "SILENCE". ) Just be aware that your AV doesn't keep lists up to date.  There have been a lot of new things that have come out in the last 4 years lol.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 16, 2014, 11:08:43 PM
Has anybody finished one yet?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 17, 2014, 11:04:36 AM
Not yet, but very very close! All the harnessing is done. Step attenuators built. Bypass boards done as well as power supplies.

Only thing missing is the input transformers which are being wound now.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 19, 2014, 12:28:26 PM
Awesome....I hope it works perfectly on first power up. :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 19, 2014, 01:38:21 PM
Me too! :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on September 19, 2014, 01:56:57 PM

Only thing missing is the input transformers which are being wound now.

I'm waiting on the Cinemag transformer too, which they tell me will be in the next 2 weeks.  So if anyone is going to do this project now is a good time to order that part.

I accidentally ordered the leaded type if anyone interested in buying a couple of leaded  Input transformers?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 19, 2014, 02:16:01 PM
I ordered the pcb mount but I opted for the "B2" variant rather than the standard "B"
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on September 19, 2014, 04:23:58 PM
Interesting,  is the choice of the  CMLI-15/15B2 just for belt and braces?   

I was quoted $52.75 for the CMLI-15/15B.  What is the cost of the CMLI-15/15B2?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 19, 2014, 04:33:45 PM
yeah, B2 has dual faraday shields, extra 5 bucks. i think of it as insurance in case of noise issues with the proximity of the power transformer, LOL

Dont know how close you have been following this thread, but there are no shield connections for the input xfmr on the board. If you want to use it or them, it will need to be addressed on the back of the board.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 19, 2014, 04:48:22 PM
I didnt have any issue with the power transformer on this circuit, but DO NOT have a cell phone anywhere NEAR this thing... it picks up a LOT!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on September 19, 2014, 06:22:44 PM
there are no shield connections for the input xfmr on the board. If you want to use it or them, it will need to be addressed on the back of the board.

Are you able to expand on what you mean by addressed at the back of the board?  I hadn't noted anything on this when reading the thread and can not find anything when searching.

Thanks
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 19, 2014, 06:39:41 PM
There is no support for this build other that what we builders are coming up with.

In my post #398 I posted a schematic that I did for the board. If you refer to it you see that the shield connections for the input transformer arent connected. On the bottom of the board you can experiment with adding a jumper from theses shield pins to analog ground or chassis ground or one each if you used the B2 version of the transformer. If you used the B version only one of them is a shield. Go to cinemag for datasheet as to which one is the single shield.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 19, 2014, 11:33:46 PM
There is no support for this build other that what we builders are coming up with.

I'm sure  Abe understands that he's needed, and will chime in at some point...who knows what he's got on his plate.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on September 20, 2014, 09:05:54 AM

 If you used the B version only one of them is a shield. Go to cinemag for datasheet as to which one is the single shield.


Thanks for the info mdainsd.  That Schematic is really going to help me out with a few things I was unsure with earlier in the build. 

I'd be interested to know if people of been using the B or B2 version!  I would be inclined to put the input transformer shields to the star ground.



Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 25, 2014, 10:07:25 AM
after looking at 2 schematics, I still can't figure out what the meter circuit is supposed to be (correctly) there's an error in there somewhere, unless I really messed up something.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 25, 2014, 11:09:38 AM
SR, how about a picture of yours?

Ive checked my schematic so many times around that meter area I can do it in the dark, LOL

The only differences from the original is the addition of two resistors: The 1K in series with the meter. this was off board on the original PYE design and Abe simply moved it onto the circuit board. The second is the  1K5 that is in parallel with the meter terminals, as a scaling resistor for the selected meter. 

Ive recently sourced an original manual for these PYE compressors, there are several versions, all very similar but yet different.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 25, 2014, 12:14:37 PM
Pic of the compressor?  Ill have to see if i have any from the completion.  But I think what is off is the 1.5k.  The trimmer does next to NOTHING on mine.  (turning the trimmer full either way moves the needle maybe 1-1.5 db on the meter which is not enough to get the meter to sit in the center).
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on September 25, 2014, 02:18:49 PM
TIP :   Make sure that you have the wiper connected on trimmer R44.  Depending on the particular type of trimmer you use it may not be connected, due to a fault on the pcb layout. You may need to add a bridge between pad & wiper. This has been discussed before.   If you do not have this connection you will get through quite a lot of 1n400x diodes in the psu part of the circuit because they burn up ....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on September 25, 2014, 03:11:14 PM
TIP :   Make sure that you have the wiper connected on trimmer R44.  Depending on the particular type of trimmer you use it may not be, due to a fault on the pcb layout. You may need to add a bridge between pad & wiper. This has been discussed before.   If you do not have this connection you will get through quite a lot of 1n400x diodes in the psu part of the circuit because they burn up ....

IIRC this is true for ALL of the trimmers except the Voltage adjust.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on September 25, 2014, 03:58:55 PM
Yes that is correct if youre not using in line trimmers (which im not) i have little bridges on the wipers of all of them except the voltage adjust.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on September 30, 2014, 01:10:48 PM
OK, this is where I'm at.  I have one channel passing a signal.  If you see attached pic.  The yellow trace is the input signal & the Blue trace is the very noisy output signal.   It seems to have some oscillator artifacts.

I could post some transistor voltages, but I'm not convinced they're all correct as the compressor doesn't seem to be doing much apart from passing a noisy signal.
Would be very useful at this time if someone who has a working unit could post the transistor V's & give us a hint as to how to calibrate the presets.   Anybody know of someone who could do this ?

Off to France on a job tomorrow so, won't get to work on my unit for a few days but should be able to get on line.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 30, 2014, 02:00:58 PM
Cant help you (yet), still waiting on input transformers. The only poster that has indicated he has a working unit is SR1200.

Does that HF stuff go away as you lower the input? Not familiar with computer scopes, but is the output set on 5V per division? 10:1 probe or something?

I have left the chopping transistor(s) off of my boards until I get clean audio in and out...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on September 30, 2014, 06:33:29 PM
The HF stuff is there regardless of input level.   

You can test the amps without an input transformer, just hookyour testsignal  to the input pot.   The first transistor is decoupled with a cap.

The scope might have been set to 1:10.  I'm not sure I only just got it, because my ancient analog scope died the first day I was trying to test this unit.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 06, 2014, 02:57:42 PM
I now have meter action, but no actual compression ......  However I'm using some old GR meters that look they they have come from original Pye's, so they may not be the same F.S.D as the ones you guys are using.

Still could do with some info on how to set these presets.   SR1200 do you have any info since you seem to be the only person with a working unit ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 06, 2014, 04:22:11 PM
Any resolution to that HF hash you had all over the place?

My transformers arrived this morning, so hopefully this weekend I can wade into mine......

Seems if you are getting meter deflection that the side chain is working to a point. Did you triple check the pin-out on the chopping transistor? Thats about all thats left between the meter drive and the audio path.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 06, 2014, 05:12:31 PM
No, I still have HF all over the place after the chopping circuit.

I have checked the chopping transistor pinout.  I wish I had more info about the presets.   I read the original PYE manual, but most of the presets are factory set fixed resistors so there's really no info on how they should be set.   
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 06, 2014, 05:49:45 PM
LOL. Yeah Ive got several original PYE manuals now, not much use really. I thought I had it made with the transformer specs in one of them. Only value listed: "DC resistance very low" wow, that sure helped. Can you disable your oscillator easily? I think I would approach trying to get clean audio through it at roughly unity gain, then start in on the SC et al.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 06, 2014, 06:02:39 PM
Yes, it's easy to disable the oscillator, I just unplug it ...... However there is some real weirdness going on & I still can't seem to get a clean signal.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 06, 2014, 06:12:29 PM
Sounds like you are dealing with some sort of oscillation. Its funny I recall one of the first replies in this thread and it was yours asking about the trickyness of designing RF circuits.

I havent powered mine. But when I was talking to Cinemag about transformers the very helpful gentleman asked if I had a schematic, which I provided to him. He suggesting removing C3, 4 and 5. Possible issue here?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 06, 2014, 07:08:32 PM
Don't think the caps are the issue I get a clean signal until the junction of R16 R17.  the other side of R17 is where it becomes full of RF.   I tried installing 49mH inductors that I had instead of R1 & R68, but it makes little or no difference.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 06, 2014, 08:57:22 PM
If you dont calibrate the "chopper" you're going to have a bad time.  Are you sure you have the clock set to the correct (or thereabouts) rate?  When i first powered mine up all i got was noise and a headache, after i calibrated that chip, all was well.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 07, 2014, 06:12:46 AM
That was the first thing I did ....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 07, 2014, 06:53:56 PM
I found a mistake I made.....   

I incorrectly hooked up the s/c transformer, so the primary was open circuit.  Sorted that out & had one channel sort of working, but I think the calibration was all over the place.   

I also had the meter working, but not properly.  I couldn't get it to sit at zero with no GR happening, & when it did operate it was a bit "on/off".  However that could be down to the calibration.

Anyway something happened & it's not good anymore.  Will have to investigate further tomorrow.





Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 08, 2014, 08:18:54 AM
Some observations about the trimmers

R42

If you hook a scope up to junction R17/R18 & play with trimmer R42 it enables you to make an injected sine wave symetrical.  Note that at this point you will see the side chain signal superimposed onto the audio signal, so it will appear a bit ....fuzzy ...  See the yellow trace in the attached pic

R23

If you scope the output R23 makes an injected sine wave appear on the output socket more symetrical.  Although on my unit it won't make it completely symetrical (more investigation required).  See blue trace in attached pic.

R44

This appears to change how much the sidechain affects the audio signal.

I know the 2 oscilloscope traces are out of phase. That's to do with where I connected the scope probes. The overall signal is in phase.

I'm still getting a superimposed sawtooth wave on my output signal.  I'm not entirely sure where this is coming from at the moment.  I don't think it's anything to do with the sidechain because the frequency is much lower, unless it's a sum & difference type artifact.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2014, 12:52:46 PM
I now have one channel working quite well now.   Still a little bit of RF, but it's compressing properly.

The meter circuit also is working, although I can't get it to zero when there is no GR happening.   This could well be because I am not using the specified meters.     So, I will probably need to play with some resistors to get it working.

One thing worth noting is that if turning the output pot up a lot, the a sine wave seems to distort quite badly, which made me think that the unit had an issue.  So it seems quite level dependent.   This may not be an issue with an original unit where these controls are ganged together.  However it could be a transistor biasing issue, where some of the resistors have been changed from the original values.

SR1200 do you have a way to check these observations ?  I would be interested to know whether it's just me getting these issues, so I know whether I need to carry on tweaking the circuit.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 10, 2014, 01:37:08 PM
thats good news Rob! Was it a matter of fooling with the trimmers? Or fooling with the input output level controls? Or a combination of the two?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2014, 01:42:37 PM
A bit of both.   I was prodding the pcb a bit, & found some areas that affected the response, so I reflowed the solder..

I'm using a garderners 10k:10k on the input, an OEP on the sidechain, & a Jensen JE123p in a 1:3 configuration on the output.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 10, 2014, 01:55:07 PM
How did you organize the output transformer? As a 3:1 step down (seems like this cant produce diddly for output) or the other way 1:3 step up?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2014, 02:59:38 PM
1:3 step up.  They are quadrifiler wound so they have 4 identical windings.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 11, 2014, 09:48:48 AM
This thing has gain for DAYS, and yes, turning up the gain is going to  distort quite a bit, at modest levels, I usually dont get above 2 on the font panel markings.   The threshold im still not sure IS a threshold, it almost seems to act like  half of an 1176 input knob (increasing this without touching the output results in a hotter level out).  As for the meters, mine sit at around the 4 (4.2) mark on the meters when idle (which was my only "problem" that remains with the cirucuit).  RF is a byotch with this unit.  Don't have ANYTHING that might even think of generating any kind of radio freq. cause this thing will pick it up and use it (iPhones are the worst, i literally have to put my phone on the other side of the room or this thing will start talking)  From what I've read though, this behavior was observed on an original PYE comp as well, so im not that worried about it, when i use it i just airplane mode or turn the phone off, the time im disconnected from the world is well worth the tonal golden squish that this thing delivers.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 11, 2014, 11:33:37 AM
Did you hook up the missing shield on the input transformer?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 11, 2014, 01:22:24 PM
The threshold im still not sure IS a threshold, it almost seems to act like  half of an 1176 input knob (increasing this without touching the output results in a hotter level out). 

As I said previously R44 seems to have something to do with threshold or at least how much the signal is chopped at R17.

Sr1200 how did you set your trimmers ?  Did Abe give you any info on this ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 12, 2014, 09:48:55 PM
Not sure what you mean by set my trimmers.  Most of the trimmers were supposed to be "pre trimmed" the only ones that would have needed adjustment after the fact were the voltage regulator trimmer, the chopper (which i used a DMM to calibrate) and the meter adjust which did nothing for me.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 13, 2014, 12:08:45 PM
A lot of work, but no cigar. I really buckled down on this project over the weekend. The devil is in the details...

Finished the harnessing, wired the xlrs, fine detailed the mechanical things like mountings, handles etc.

Got the hotel power supply up, bypass boards working, meter illumination dialed in.

Then got the boards installed and hooked up. On board power supplies checked, adjusted and investigated for noise (none).

Its been doing a P/S burn in. I'll give it 72 hours then start through the signal amp....so far not a thing gets warm so am optimistic about reliable operation.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 13, 2014, 02:03:09 PM
Not sure what you mean by set my trimmers.  Most of the trimmers were supposed to be "pre trimmed" the only ones that would have needed adjustment after the fact were the voltage regulator trimmer, the chopper (which i used a DMM to calibrate) and the meter adjust which did nothing for me.

So apart from the Vreg trimmer & the chopper frequency, you just left all the other trimmers as they came from the supplier ?    If so, how do you know they are set correctly ?

Did you install a trimmer in position R48 or just put the 1M8 fixed resistor as Abe suggested ?    As far as I can see R48 is the resistor that scales the meter.   I'm not sure that R42 & R44 are to do with calibrating the meter.    Maybe someone a bit cleverer than me could elaborate ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 13, 2014, 11:02:45 PM
The BOM states what the trimmers were supposed to be set at before installation.
I did use the fixed resistor, and those two resistors i believe are at least partially to blame for the meter calibration not working.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 14, 2014, 06:00:35 AM
The BOM states what the trimmers were supposed to be set at before installation.
I did use the fixed resistor, and those two resistors i believe are at least partially to blame for the meter calibration not working.


It actually says "Value selected on test " on the original diagram for the presets.  Which normally means that they test the unit and then select a value for the resistor.   This suggests that the resistance value on the diagram is just a nominal value, & that it would change depending on the operation of a particular unit.  It probably means that the nominal value works perfectly for most units, but on the other hand it may not.      I think, however I will try your method  of presetting them to the nominal value & see what happens.  It's probably likely to get me more in the ball park.

With your meters do they just sit away from zero ?     My meters do move depending on how much I turn up the i/p level, but they never completely go to zero, even with no input signal.  This suggests either that there is a residual signal hitting the meter or that somehow there is compression happening even with no input.  Possibly a trimmer thing .........     

I'm also wondering whether I need the extra resistor R65 because I'm not using a Hairball meter as i have some original PYE meters.   So the F.S.D may be different to the Hairball ones.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 15, 2014, 09:50:24 AM
I have a feeling you're on to something with the meters, and no mine dont sit at 0 either, from what i understood, the original meter on the pye sat in the middle not at 0, either way, my adjustment pot does almost nothing (full up or down the swing on the meter is like around 1db of movement according to the stock hairball meter)  Im wondering if i should adjust the set screw on the front of the meter to compensate, though i was told thats not generally a good idea to play with that...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 15, 2014, 11:40:45 AM
The adjuster on the front of the meter is used to mechanically zero the meter when the unit is not turned on.
 
I tried shorting the added resistor (R65 I think from memory).   But it seems to reduce the meter action that I have to maybe 1dB, as opposed to quite a large amount of swing with it in place.  It's possible that one of that one of the transistors is out of bias & is putting a small residual voltage across the meter with no signal present. 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 15, 2014, 12:06:17 PM
Rob, if you are using original PYE meters (and are certain they are the correct value) then you should remove R65, not short it. The other  resistors  (R46 & R45) are the same values that show on original PYE schematics. The added 1K series resistor (R67) is in the original design but it was not on the circuit board. It is now for convenience.

Disconnect the S/C transformer so that there is no signal for it to act upon.

1) Is the circuit generating pulses at the base of TR11? It should not be. If it is I think it is time to look at the bias on the transistors in the output of the S/C as you mentioned.

2) More to follow...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 15, 2014, 04:19:39 PM
Rob, if you are using original PYE meters (and are certain they are the correct value) then you should remove R65, not short it. The other  resistors  (R46 & R45) are the same values that show on original PYE schematics. The added 1K series resistor (R67) is in the original design but it was not on the circuit board. It is now for convenience.

Right, hadn't noticed that.  I just disconnected R65 & it actually made the meter sit higher (further away from zero) than with it connected.  I then put a lower value resistor in place & this makes it sit closer to zero than the specced value of R65

Disconnect the S/C transformer so that there is no signal for it to act upon.

1) Is the circuit generating pulses at the base of TR11? It should not be. If it is I think it is time to look at the bias on the transistors in the output of the S/C as you mentioned. This leads me to believe that something is out of bias, & is creating a sidechain signal when there is no signal present.

Please see attached scope trace for the base of TR11 with the s/c transformer pulled. 

If you look at the post after this I will attach a scope trace that shows what happens when I turn up the input signal (a sine wave at 1KHz) with no s/c trafo attached at the base of TR11.   The more I turn it up the bigger the second trace gets.   
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 15, 2014, 04:20:51 PM
Attached pic relates to my previous post.  Only 1 attachment per post ...

The trace shows an AF signal with the pulse from the attached pic in the previous post superimposed on top of it.  I'm not quite sure why I should be seeing any sign of the audio signal here with the s/c transformer detached.  You will also notice that with the i/p turned up this much the sine wave is no longer symetrical, perhaps suggesting a bias issue, although the input signal was quite big.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 15, 2014, 04:56:38 PM
Removing R65 SHOULD increase any deflection the meter had before removing the resistor. That resistor is a parallel shunt across the meter to scale for the 1mA Hairball meter. So I see no problem there.

So we have the meter indicating a small amount of G/R, AND we have pulses at the chopper with no S/C hooked up. I suspect the meter circuit is actually representing what it "thinks" is going on, so Im not sure the problem is there. I dont have my PYE manuals here. I will retrieve them tonite, but I remember in the foldout that explains the chopping actions that with a signal UNDER the threshold no chopping occurs.

If mine were running I think I would start by looking at that 1.8m resistor installed instead of a trimmer at R48. Possible lift one end of it and also one end of R50. If this is done TR13 shouldnt be conducting (no base current). Then check for pulses at the base of the chopper, if they are still there we have a problem in that network around TR12.

Have you messed with R44?

Edit: Your second trace is at the base of the chopper? If you have audio there and the S/C is disconnected I tend to wonder about the actual chopper transistor?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 15, 2014, 07:01:12 PM
mdainsd your analysis makes sense

 I agree that the meter is displaying what it thinks is there.  It appears that if the s/c transformer is disconnected that there are only 2 ways for the audio signal to get into the s/c.  Via the chopper transistor or through the power rails.   Out of the 2 through the chopper seems most likely.    That would also account for a signal on the meter perhaps.

With regards to R44 can I refer you to my post no. 454.

Unfortunately I start a contract for a few weeks tomorrow, so I may not get much time on this for a while. 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 15, 2014, 07:32:47 PM
How big is the test signal you are using as an input? I would think starting around .77Vrms?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 15, 2014, 08:14:17 PM
I could be way off base here, but with the IC version, shouldnt the "chopper" be constantly running?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 15, 2014, 11:06:11 PM
It's 4am here and I just woke up and had a light bulb moment.  I think I have the 1M8 installed incorrectly.  This would definitely account for some of the issues that I'm personally encountering.    Unfortunately I can't do anything about unless I can snatch half an hour this evening, if I don't get back from London too late.    Looks like it's going to be a long day. ...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 15, 2014, 11:59:23 PM
I could be way off base here, but with the IC version, shouldnt the "chopper" be constantly running?

No. The oscillator located on the daughter board should always be running (250kHz). But the base of the chopping transistor gets no pulse if the signal is lower than the threshold. From the manual: "switch inoperative (100% open)"

This where we should be with Rob's. He has disconnected the side chain its the same as no signal in or less than threshold so we need to get to no pulses on the switching transistor.

Hopefully he just installed that 1.8m resistor wrong and the circuit was off, so it was passing pulses. Fingers crossed!

Sr, have you ever scoped the base of the switcher in yours? I wonder because you have said that yours shows a little gain reduction even with no signal. Sound familiar?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 16, 2014, 12:54:28 AM
Thats quite possibly the issue with the meter, ill have to take it out over the weekendand look at it.  Both of my channels are functioning as expected compression wise and if i set my threshold above the level thats coming in i dont get compression, just the sound of the compressor not doing anything. 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 16, 2014, 04:44:07 PM
OK, so I installed the 1M8 correctly, and there are things that are better about the way I have one of the channels working, but it's still not great.   The channel is definitely showing compression, but not a great deal.  The meter trimmer will however now scale the meter.   


The residual signal on the base of the chopper transistor is still present.  See attached pic.     This is with no input signal.     Tweaking the 500K trimmer will raise and lower the level of this residual signal.   Thus the meter won't zero. .......
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 16, 2014, 04:50:27 PM
this next pic shows that the signal is much cleaner than previously.

Yellow trace 1 is taken from TR4.  Blue from  C10.    You can see there is still RF on the blue trace.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 16, 2014, 06:37:46 PM
I was just looking at some of the other PYE diagrams I have & noticed one with a slightly different arrangement for the meter feed compared to the pdf diagram that someone  reverse drew from the board   You will notice that there is an extra 4k7 resistor in series with C21, & both are in parallel with R41 the 15k.I don't think this is an error on the part of  you guys who reverse engineered the diagram from the board, because I have another original version that has the 4k7 missing.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 16, 2014, 06:39:48 PM
I'm also questioning that we should see nothing on the base of TR11 with no compression happening.  I have some pics of scope traces here that I took from a real PYE that a friend owns, & it seems that you do have very narrow  downward spikes, See attached pic for little or possibly no compression.  I'm not exactly sure whether this is compressing, because I made these pics several years ago for Abe, when he was experimenting .  It's possible that I might be able to  scope it again if I can find some time, so that I'm absolutely sure what is going on with TR11 base with no signal present.

See next post for quite heavy compression
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 16, 2014, 06:40:53 PM
See previous post for details.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 16, 2014, 07:31:28 PM
I got my information from several pye manuals, I have not had the luxury to probe around a real one. Also, the one you  got to mess with, how long since it had been calibrated? Maybe it turns out that there is always some compression going on, sure doesnt seem ideal to me, but it may be what it is.

Good luck on your trip!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 17, 2014, 08:52:58 AM
Also, the one you  got to mess with, how long since it had been calibrated? Maybe it turns out that there is always some compression going on, sure doesnt seem ideal to me, but it may be what it is.
I've no idea when the original unit was last calibrated, probably not for ages.  However the units sound great, so I don't think that there was an issue with them.  The thing is if you did want to calibrate it, you would need some original documentation to tell you how to do it ........

Also have a constant  side chain signal pulse which might last microseconds, is not really a problem because it's hardly chopping anything out of the signal.   Therefore very little gain reduction is happening.  So with that in mind I suspect that the fact there is a constant very short pulse on TR11 base may be a red herring when considering meter issues.  It may be that there is just a d.c offset in the meter circuit.

One thing I will try when I get a chance is to add the 100k that is missing from ground to bases of TR15 & TR18.  That looks to me like it needs to be there.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 21, 2014, 12:01:17 AM
Got things further along over the week end. Ive fully loaded the boards with the exception of the oscillator and the switching transistor. I want to get the signal amp sorted out by itself then work on the side chain, then add the osc and transistor.

No smoke, and signal from input to output with disclaimers (more on those later). Very very clean.
I started my evaluation using a 100Hrz signal. Have a power meter across the input and a second for probing. Plus the scope.
The side chain actually responds as far as developing a negative dc signal. The decay is close in time but I didnt even bother trying to zero that in. The ratio dc offsets work, although I have four different original PYE schematics and they all have different R values for these resistors. I'll dial those in after everything else is right.  Setting to 1:1 removes the compression DC signal as it should. Limit I didnt spend much time with so not sure about it.

I lowered the input to 10 Hrz and with the decay in minimum you can see the dc control voltage responding to the sine wave.

Back to the signal amp. As soon as I started going up in frequency the signal started to drop. By 500Hrz it was down 3 dB...rubbish. I took C5 out and the frequency response between the input and the first transistor was within the manual spec, actually a bit better. Ive got stepped pots (linear)  in the threshold and gain positions, but I dont like the way they work. Ive found enough original information that those should be 40dB/2dB per step, step attenuators. I will correct that in time.

Now im up to the LP filter that removes the artifacts of the 250Khz switching. More problems. It too is rolling the signal off rapidly as frequency rises (we are talking about 1Khz). I gave it a rest there. My thought is since the three capacitors in the LP filter and C5 were all the same value, that perhaps I got a bad or mislabeled batch of 1nF caps.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 21, 2014, 04:48:13 PM
I managed to nip out to the garage briefly.

I just checked the F resp of one of my channels with the s/c transformer pulled & the oscillator board pulled.   I get a slight lift in level around 20KHz but no noticeable drop until around 27KHz.  It's flat to lower than my speakers would reproduce sound too.

The minute I plug the s/c transformer & oscillator back in the RF kicks in.

That's all that I had time for.  Hope it helps.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 23, 2014, 05:20:59 PM
More progress!

Replaced the defective caps in the LP filter, Now that passes signal front to rear. Down about 1dB at 20Khz, fine for now and probably for good.

Installed the oscillator board, and? Nothing! OK another board problem, this time on the oscillator (IC) board. Its the trimmer center pin issue again but in reverse. Now if you use a pot there with the leads inline you need to jumper the middle pad to the center auxiliary pad. I cannot get my oscillator up to 250Khz, End of pot only gives about 200Khz. But again, it is good enough for now.

Installed the switching transistor.

Checked signals. Weird. Where I expect to see these PWM pulses, I get a DC level with the pulses. The more input level the more - the control signal to the switching transistor. I dont get the waveforms shown for the original  >:( BUT, It compresses beautifully.  Im wondering if the switching transistor is operating more like a regular transistor and as the base voltage changes it is syphoning more signal to ground rather than chopping it, Limiting works too, but the limit level (output) is quite a bit higher than compressed output.

1:1 works, no compression as it should be.  2:1.,3:1 and 5:1 "look" reasonable on the scope, but I'll have to graph each of their response curves to be sure.

Biggest problem right now is absolutely no meter movement under any condition, Zero all the time  :(

Rob, as far as oscillator noise on the output signal, mine has a tiny amount at low levels. I also see it is very sensitive to the scope and sig gen leads.

SR1200, my unit does not display any issue with cell phones. I actually laid the phone on the circuit board and carried on a conversation on speaker while monitoring output, both below compression threshold and under heavy compression. I see nothing on the scope.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 23, 2014, 06:56:56 PM
A picture of the patient...

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 23, 2014, 08:22:47 PM
Got the no meter movement sorted out, I missed one solder joint, damn.

I have an idea on zeroing the meter, but Im waiting on that until I verify if this thing is really working the way it is supposed to.

The lowest compression threshold mine will start compression at (currently) is -10dBm. manual says lowest should be -24dBm. Not sure why yet.

EDIT: Its going to take a while to get this thing just right. Yes, it compresses right now. Im sure it sounds sweet, but I dont even want to hear it until I get it looking good on the test equipment.

Im starting to get a feel for the controls and trimmers. Here is my initial ideas of what they do.

R23 - I believe this trimmer is to adjust the unity gain that this thing would normally have. I say normally because the original has the threshold control reverse gained to the output make up. Ours dont, we have separated controls. My plan is to use my power meters on the threshold and make up attenuators and set them at mid range (20dB), then adjust R23 for unity gain. If I cant get it there then I will revisit the output transformer and select a ratio that gets the unity gain within adjustment range.

R52 - When I first studied the schematic I  thought this might be to calibrate the decay times. I dont think so any more. I set my input level at -24dBm with the input attenuator wide open. Then while monitoring the control voltage I adjusted R52 until the volatage was just coming off of the no compression level. Now it handles threshold as low as -24dBm, just like te manual. Set like this the G/R meter now sits at about 1dBm with no compression. When all else is done I will zero the meter with a slight adjustment to the R45 R46 divider. I cant check the upper threshold (+14dBm) because my precision signal generator doesnt have the legs for it, LOL

R42 - Meter full scale adjustment. I so far just upped the input level to where the control signal travelled as far as it would and then adjusted the meter for 20dBm.

The above three trimmers all interact with one another.....it will take a little doing to figure out the procedure for a full calibration.

R44 - Still a mystery. Havent play with it enough yet
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on October 24, 2014, 12:27:50 AM
phone calls dont seem to set it off too much, but when texts come in, its like joe zawinul is in the house lol.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 24, 2014, 04:43:44 AM
Glad you seem to have made some progress. I have managed the odd half hour on this in the last couple of days, but have made no real progress.   I had one channel working, but still the RF on output, and not really in calibration at all.  The meter is working but won't sit at zero.  Main concern at the moment is ridding myself of the dreaded RF. 

Mdainsd.
Did you use the inductors for R68 and R1 ?   

Are you susing an off board PSU ?

I would be interested to see your layout of boards & transformers.  All mine are off board.

When I adjust R23 it looks like it has something to do with the asymnetry of the output, since it affects the signal in that way. Also it is affecting the biasing of TR5 which would have that effect.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 24, 2014, 01:57:03 PM
Rob,

I used the resistors in those two locations (R68 & R1).

I have an off board power supply in there. But its for hotel functions i.e. Relay board, meter illumination and anything else I may want to hang on there.

How much shielded twisted pair did you use in your build? All the AC wiring in mine (mains and low voltage) is wired with shielded twisted pair, with the shield tied to chassis ground at one place. All the audio that runs anywhere is also shielded twisted pair (only exception the s/c xfmr wiring which is just twisted pairs) shield tied to analog ground. Be careful with test leads, They add a lot of noise to the output if you dont watch lengths and grounds.

I'll post a picture of the layout hopefully this weekend. Ive got the second board out of it right now so it doesnt look finished.

I do see how R23 affects the symmetry of the first stage output. I wonder if I can just put the distortion analyzer across the first stage  and just adjust for lowest distortion?

Keep at it we are getting close!

Like I said Im going to build new attenuators for my two controls, but that can come whenever. Need to find that cool calculator that was posted around here for determining R values.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 24, 2014, 02:39:44 PM
I took some resistance readings from the stepped switches of the real Pye compressors I got to play with.  I have them in spreadsheet format. If you send me your email I can mail you the spreadsheet.  I'm not entirely sure whether it will make much sense, & it was 2 or 3 years ago so I'm not sure I can explain them very well.    Might be possible to do them again.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on November 08, 2014, 07:58:57 PM
Up and RUNNING! 2 channels doing their thing. It has spent a lot of time on the test bench. I have yet to hear audio through it but thats next.

Going to go instal it into the drum buss, I really like what I have heard these do for drums.

I still want to rework the step attenuators for this thing. The switches arrived and are in the machine shop to modify....always something

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bieckmusic on November 08, 2014, 08:54:43 PM
great job mdainsd!!

mind me asking, about how much the build cost, and how difficult??

looks gr8 :) :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on November 08, 2014, 09:08:18 PM
Mine hasn't come off my Drum Bus since it came off the bench.  It works really nice if used lightly on acoustic guitars as well.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on November 08, 2014, 09:26:10 PM
great job mdainsd!!

mind me asking, about how much the build cost, and how difficult??

looks gr8 :) :)

Thank you!

Im into it just about 800 Dollars. It could be done a little cheaper but Im anal about things like NOS 60's knobs (even though there are reproductions) and the pull handles. And I added relay bypass and a hotel P/S. Adding all Mil-Spec silver wire teflon coated added to it too.

Its not that the build is hard, it is labor intensive, there is a ton of harnessing to be done. The boards themselves are high quality. The errors on them are minimal, the worst being having to jumper some adjacent pads around the trimmers, hardly a problem.

You will need a scope and a signal generator at a minimum.

A friend of mine has been watching the progress and he is dying to buy it from me, but I dont want to build it again, so he wont be obtaining it, LOL, I want to get on to the next big project!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bieckmusic on November 08, 2014, 09:30:23 PM
Thanks so much for the info, I do need to get a scope and signal generator.  Plus I don't have an rms voltmeter, which really messes me up sometimes... 

great job!!

Greg

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on November 24, 2014, 11:58:43 AM
Got just one channel up and running, and have a couple of observations.
1.  My osc signal is pretty nasty looking, not like the traces you published.  I need to have a look at it out of circuit.  No problem adjusting to 250kHz,
2.  No matter what I adjust, I cannot get a signal with less than 3% distortion through the system, even with the osc pulled.
More testing next weekend.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on November 28, 2014, 12:20:30 PM
Wondering if we have a definitive version of this build at this time.

It seems like it's still up in the air and I would like to start this project with
at least a reasonable expectation of success.

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on November 28, 2014, 04:47:59 PM
Mark, I think you will be OK. There has been a little fooling around with it since the support never materialized from the maker of the boards.

But, it works. There are a couple of working ones, and a couple coming to life but going through some teething problems. The more that come on line the easier it will be to identify pitfalls and avoid them.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on November 30, 2014, 03:29:23 PM
Progress!
Both boards pass audio, and I get about 30dB of gain with both pots full up and the sc xf disconnected.  Side chains are not matched at all, so something is wrong.  No time this weekend to check components, but back at in a couple of weeks.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on November 30, 2014, 04:46:25 PM
Also, beware Edcor transformers!  I ordered 4 of their 600:10k for the sidechain.  One was terminated incorrectly (CT and End reversed).  Now they track together in "compress / off", but there is still something wrong in "limit / on"
I am constantly amazed by you folks with limited test gear that get these projects done........
Best,
Bruno2000

edit, spelling error.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on November 30, 2014, 06:39:47 PM
Check the seven conductors that hook the main board to the switch board carefully. It would be easy to make  mistake there.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on November 30, 2014, 07:01:20 PM
Thanks for the thought, but I'm using ribbon cable.  Less chance for error.
Probably bad solder/
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 15, 2014, 11:11:37 AM
I have 2 channels up and running, tracking really well, but have a couple of questions to those of you that have built. 

What Voltage are you running on the rail?  The manual calls for 16V, but I have seen 20-21V mentioned. 

What output transformer are you using?  Mine are really sensitive to loading on the output.  Seems to me that there would be a beefier output section to drive a transformer.

More thoughts:

I have a drawing #84575/00 that shows a completely different output section with an output transformer that has a feedback winding.  The scan is not so good.  Anyone have a better one?

I question the 175 ohm choke in the power supply section.  Makes the output rail pretty soft.  Thinking about winding my own choke with a MUCH lower DCR.

I made some in/out graphs, and will post later today.

Thanks for the help!

Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 15, 2014, 06:38:41 PM
Hi Bruno

I run my rails at -22V

I use the edcor 600:10K XSM (I think) for the output as well as the side chain. Ive fooled with them both, running them forwards and backwards, also all the way across the windings or just center tap to one side, trying to find just the right balance.

I have that schematic you are talking about with the output transformer with feedback and a full PP output. Ill see if I can get it scanned, no promises though.

As far as that 30dB gain...These things are originally designed for unity gain. The two attenuators are physically linked in the originals. This is where I am with that. They should be in lockstep with each other, if you increase the threshold one step, a corresponding decrease of one step on the gain attenuator should still be giving unity gain throughout (in 1:1 ratio). Mine does not yet do this and I believe that the problem is the willy-nilly choice of the output transformer.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 16, 2014, 04:19:05 PM
Thanks for the info!  When I ran the output up, and connected a 600r load to the output, some strange things began to happen.  The circuit is just not stable.  All it has are those 560s running on 16V (22V).  That's not much swing.  Now I know in the "Pye book" the circuit shows an output transformer, but I wonder if this wasn't meant to be an interstage transformer rather than an output(?).  That's why this "new" (to me) circuit is of interest.

Here is my input vs. output graph showing the curves.  Looks like the 1:2 setting might be really nice!

Best,
Bruno2000

Edit:  The curves are 1:2, 1:3, 1:5, and Limit
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 17, 2014, 12:18:38 AM
Wow! Those curves look about right on. Was the red top line the limit trace? If it is ist should be 8 dB above the knee of the red trace below it. You're close!

I was trying to do the same by photographing the Oscope with a modulated burst, what a pain in the ass, LOL.

Does that graph represent the full range of threshold?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 17, 2014, 09:38:47 AM
I should have mentioned that these are stereo sweeps, but the two cards are not "linked".

The input and output controls did not change for any of these sweeps, just the "ratio" and "limit" switches.  I did run the same sort of tests at different input/output settings, and as expected, the knees just moved up and down.

More output tests this weekend.

Best,
Bruno2000

oo812green
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 17, 2014, 04:37:11 PM
Hmmm. Puzzling. You say no adjustment were made to the threshold or gain controls, but the different sweeps are displaying different threshold levels. The knees should all be at the same place, except for limit which should be 8dB above the threshold obtained from the compression ratios.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 17, 2014, 04:46:53 PM
Hmmm. Puzzling. You say no adjustment were made to the threshold or gain controls, but the different sweeps are displaying different threshold levels. The knees should all be at the same place, except for limit which should be 8dB above the threshold obtained from the compression ratios.

Could that be because I have made no effort to adjust R52?  All of the other "trimmers" on my boards except the Voltage adjust are the suggested resistor values.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 17, 2014, 05:06:26 PM
So I'm going to ASSume that I need to make a 2 section pot or switch that is 10k log for the input section coupled with a 10k r/log for the output section.  Might take some tweaking to get it right.........
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 17, 2014, 05:36:58 PM
No, you dont have to do that. As long as you remember that the two controls work in tandem (if you turn one up, turn the other one down), all is good.

If you turn them both up, you will run into distortion pretty quick.

I am working at replacing mine with stepped attenuators, the originals state in the manual "40dB attenuators 2/dB/step reverse coupled"
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 17, 2014, 05:51:40 PM
No, you dont have to do that. As long as you remember that the two controls work in tandem (if you turn one up, turn the other one down), all is good.

If you turn them both up, you will run into distortion pretty quick.

I am working at replacing mine with stepped attenuators, the originals state in the manual "40dB attenuators 2/dB/step reverse coupled"

That sounds like a great idea!  I should do that too.
This weekend I'll try adjusting R52 to see if I can line up all of the knees.  Any other tests you'd like?
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 17, 2014, 05:59:58 PM
Question: So when the attenuator is in the "middle", the input pot is 20dB down, and the output pot is 20dB down as well?
Thanks!
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 17, 2014, 06:24:42 PM
Basically, yes. that is the cross over point were both attenuators are at the same value.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 18, 2014, 12:18:48 PM
I calculated the r values for a 2 dB/step stepped attenuator with a total value of 10k and a max attn of 40dB, and am going to try and put them together this weekend.  Now if the middle of the attn is 20 dB down for each section, and the overall gain of the comp with both pots up full is about 30dB, where does the extra 10dB come from to make it unity  gain?
Thanks!
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 21, 2014, 03:11:42 PM
I've made performance improvement by replacing the 50 mH choke in the BOM with one I wound myself.  MUCH lower DCR, less PS sag on the outputs.  Feeds 600 ohm load OK now.  Running the rail at 16V like the original, but looking to add a 10dB boost circuit on the output with more swing available.
No change in the knee positions  That's still a mystery.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 21, 2014, 03:30:23 PM
Forgot to say that I also made the dual 2 dB / step 40 dB attn, and reverse on one shaft.  It works GREAT.  PM is you want the values. 
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 23, 2014, 10:31:31 AM
For those of you building this piece, I have found that the output circuit is MUCH more stable if you use a choke (L1) with a low DCR.  I bought the one on the BOM, and it measured about 170r.  I wound a couple myself on Ferrite cores that have a DCR of about 5r.  Just my $0.02 YMMV.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on December 25, 2014, 11:07:22 AM
Good stuff Bruno and thanks...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Travis1000 on January 03, 2015, 11:13:27 AM
Hey all, I've finally gotten to put the time in and get this thing all wired up. One question I can't seem to find the answer to: there appear to be trace jumpers on the board near TR16, R59, and R61.  As well as one near the edge of the board and R42. There are also some on the switch board. Should I be jumping these to something?

So far, I have gotten audio to pass in one of my board and the other passes audio but with a lot of hash, it's quite noisy still.

I am still figuring out how to tune the chopper, I'm new to the world of oscilloscopes so any info on what I am looking for on the scope for a properly tuned chopper would be much appreciated. Thanks!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on January 03, 2015, 01:01:40 PM
The only trace jumpers that may be needed are at the VRs. The footprint allows several different VRs to be used. The center connection in each case has three different holes for different VRs. I f you use VRs that dont have all three pins inline you need to jump the center holes together. What I did is just fold the center lead of the VR over on the backside of the board and solder it to all three pads.

Scopes: see if you can find tutorials on youtube. The ground connection on the probe is important, it needs to be short and connected to B+ (common) close to where you are probing.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on January 28, 2015, 02:31:14 PM
The BOM says you can use a 5k1 resistor for R42.  Put in trimmers both set to 5k1 if you want good tracking at the knee when linked.......  Adjust the side that "droops".
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on February 08, 2015, 01:01:26 PM
I have both sides of the compressor up and running, passing audio and compressing.  They sound great, just waiting for my scope to arrive before I properly calibrate the chopper.   but so far really pleased.

I have the same meter problem that has been discussed in earlier posts.  I meter 4db of gain reduction when no audio is being passed.  Meter adjust makes small changes, but not enough to zero.   Interestingly when I take the IC out of the circuit I meter 8db of gain reduction.  Has anyone got any further thoughts on this issue? 

I know some of you have been tweaking various trimmers and experimenting.  Is anyone getting close to a definitive setup.  I have everything set up and built to the sr1200 build guide. 

I have grounded in the following way to the star ground.

Pin one from input and output XLR's
Ground from output on PCB
Pins 2 , 6 and 7 from CMLI-15/15B2
IEC earth


Your question about the switches and which side of the board they mount to. Comparing the silkscreen on the Collective Cases enclosure with the image of the 3.14 PWB...the switches would need to be mounted on the backside of the PWB with the silkscreen, header and other components facing away from the front panel for everything to line up (control name wise).

But...everything should be verified with the schematic and an ohm meter.

This is wrong, to be fair It does say to check with an ohm meter and schematic.  However I spent ages triple checking.  To clarify for anyone about to build this, the components face the front panel and the Lorlin switches should be soldered on the same side as components and silk screen.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 11, 2015, 10:47:15 AM


I have the same meter problem that has been discussed in earlier posts.  I meter 4db of gain reduction when no audio is being passed.  Meter adjust makes small changes, but not enough to zero.   Interestingly when I take the IC out of the circuit I meter 8db of gain reduction.  Has anyone got any further thoughts on this issue? 

I know some of you have been tweaking various trimmers and experimenting.  Is anyone getting close to a definitive setup.  I have everything set up and built to the sr1200 build guide. 




Your question about the switches and which side of the board they mount to. Comparing the silkscreen on the Collective Cases enclosure with the image of the 3.14 PWB...the switches would need to be mounted on the backside of the PWB with the silkscreen, header and other components facing away from the front panel for everything to line up (control name wise).

But...everything should be verified with the schematic and an ohm meter.

This is wrong, to be fair It does say to check with an ohm meter and schematic.  However I spent ages triple checking.  To clarify for anyone about to build this, the components face the front panel and the Lorlin switches should be soldered on the same side as components and silk screen.

When you say 4dB and 8dB of meter reduction, what meter are you using?  I'm using a standard 1 mA meter and am going to have to make a custom scale since the gain reduction that I measure with my audio test set does not correspond to ANY commercial scale I have seen so far. 

+1 for the Lorlin switches, although I decided to go with the original switch configuration, and did not use the switch board.

Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on February 11, 2015, 06:50:00 PM

When you say 4dB and 8dB of meter reduction, what meter are you using?  I'm using a standard 1 mA meter and am going to have to make a custom scale since the gain reduction that I measure with my audio test set does not correspond to ANY commercial scale I have seen so far. 


I'm using the hairball 1mA meter.  I mean to say that powered up but with no signal the meter sits at 4db on the scale.  I noticed in the youtube prototype video it is sitting not on, but pretty close to zero.   

Where does your meter sit on power up with no signal?   
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 12, 2015, 12:57:36 PM

When you say 4dB and 8dB of meter reduction, what meter are you using?  I'm using a standard 1 mA meter and am going to have to make a custom scale since the gain reduction that I measure with my audio test set does not correspond to ANY commercial scale I have seen so far. 


I'm using the hairball 1mA meter.  I mean to say that powered up but with no signal the meter sits at 4db on the scale.  I noticed in the youtube prototype video it is sitting not on, but pretty close to zero.   

Where does your meter sit on power up with no signal?

Even though my meters are 1 mA full scale, the existing linear scale on the meters  goes from "0" to "4".   With no signal, my meters read 0.1, just barely above "0".   I made a spreadsheet with overall gain reduction, with compensation for loss through the circuit.  I'll post my scale when I get it finished.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on February 14, 2015, 08:54:44 AM
Thanks Bruno, so it looks like I need to work out an issue somewhere in my meter circuit. 

For anyone looking for a budget scope I have Just got the DPScope 2.  It is 2 channel USB and also can be used to show readings as as DMM.   

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on February 14, 2015, 04:18:04 PM
This thing pushed me into buying (my first) scope also!
I've ordered Hantek 6022BE (yeah - the cheap one!)

I have the boards all stuffed, meters and transformers ready but I'm still waiting on the scope and enclosure.

Keeping my fingers crossed and trying not to be impatient...
:)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tommia on February 15, 2015, 10:33:00 AM
is an 100k resistor between ground and the bases of TR15 & TR 18 needed? It is in the original schematic but not on the pcb?


For those to trace problems:
First see if it passes audio if so the circuit from tr1 trough TR10 is OK.
second if the meter moves when you connect audio than the circuit  from TR12 trough TR18 on the main board is working.
If you can't find TR11 in Europe order MMBT3640 at farnell.


Calibration of the meter will follow
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on February 19, 2015, 10:59:59 PM
Somewhere I posted that after I looked at the switch board for the 50th time and played with it that they are OK as is.

I messed with R52 until the meter was indicating the lowest with no audio input. Mine sits with the needle just off of zero with no signal. R42 is what I used for meter calibration, not zero. As Ive said mine always has chopping pulses present, even with no signal. they are just tips of very narrow pulses but they are there.

Mines been running just fine in the studio for several months now.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on February 21, 2015, 11:41:35 PM
Ok, Abe is mia.

No mention of the Pye kit or tech support on his website,  there is a fully built version you can buy for $1,700.

It seems Abe managed to get his product up and running with help from the fine folks on this forum and then chose to abandon the everyone who bought into his apparently flawed product.   

Sad.    :(

I want to thank the people in the GDIY community who are willing and able to get help the pye builders up and running.

You guys rock!

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on February 22, 2015, 08:22:34 AM

It seems Abe managed to get his product up and running with help from the fine folks on this forum and then chose to abandon the everyone who bought into his apparently flawed product.   

I want to thank the people in the GDIY community who are willing and able to get help the pye builders up and running.

You guys rock!

Mark

I've heard Abe is MIA but I don't think this build is flawed.  There aren't any mistakes on the board that will stop proper operation and the information required to get an operational unit is all within this thread. 






Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on February 22, 2015, 07:22:11 PM
I think I'd agree with that. The last version of the boards go together just fine, with only the slightest modification.

There are some other builds on this forum that seem like real horror shows in comparison.

If you have decent skills you should be able to get these up and running.

If you love DIYing then you will continue to refine the tuning of these mainly through time with a scope and meter and a handful of transformers.

Who knows what happened to Abe, probably circumstances beyond his control.

I consider myself lucky to have purchased a pair of these boards (wish Id bought four).

Ive turned down $4K for my unit. What would I replace it with?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 22, 2015, 08:30:02 PM
Ok, Abe is mia.

No mention of the Pye kit or tech support on his website,  there is a fully built version you can buy for $1,700.

It seems Abe managed to get his product up and running with help from the fine folks on this forum and then chose to abandon the everyone who bought into his apparently flawed product.   

Sad.    :(

I want to thank the people in the GDIY community who are willing and able to get help the pye builders up and running.

You guys rock!

Mark

There are no flaws in the board, but some in the BOM.  YMMV.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Biasrocks on February 23, 2015, 12:13:09 PM
If you have decent skills you should be able to get these up and running.

If you love DIYing then you will continue to refine the tuning of these mainly through time with a scope and meter and a handful of transformers.

I'd prefer to have a base build with a  bom that works, I'm not sure that's currently the case.

After that's accomplished, then certainly there's plenty of room for experimentation and improvement.

That has been the way I've done the majority of my DIY projects for the past number of years, from LA2A's to 33609's.

There are no flaws in the board, but some in the BOM.  YMMV.
Best,
Bruno2000

Perhaps we could compile a list of changes / mods that are required in one place so that they are easily accessible.

I'll start.

TIP :   Make sure that you have the wiper connected on trimmer R44.  Depending on the particular type of trimmer you use it may not be, due to a fault on the pcb layout. You may need to add a bridge between pad & wiper. This has been discussed before.   If you do not have this connection you will get through quite a lot of 1n400x diodes in the psu part of the circuit because they burn up ....

IIRC this is true for ALL of the trimmers except the Voltage adjust.
Best,
Bruno2000

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 23, 2015, 01:34:04 PM
If you have decent skills you should be able to get these up and running.

If you love DIYing then you will continue to refine the tuning of these mainly through time with a scope and meter and a handful of transformers.

I'd prefer to have a base build with a  bom that works, I'm not sure that's currently the case.

After that's accomplished, then certainly there's plenty of room for experimentation and improvement.

That has been the way I've done the majority of my DIY projects for the past number of years, from LA2A's to 33609's.

There are no flaws in the board, but some in the BOM.  YMMV.
Best,
Bruno2000

Perhaps we could compile a list of changes / mods that are required in one place so that they are easily accessible.

I'll start.

TIP :   Make sure that you have the wiper connected on trimmer R44.  Depending on the particular type of trimmer you use it may not be, due to a fault on the pcb layout. You may need to add a bridge between pad & wiper. This has been discussed before.   If you do not have this connection you will get through quite a lot of 1n400x diodes in the psu part of the circuit because they burn up ....

IIRC this is true for ALL of the trimmers except the Voltage adjust.
Best,
Bruno2000

Mark

Actually, that's exactly what I'm doing at the moment Mark; re-compiling a new BOM, double checking all parts for lead spacing, values, etc. I learned the hard way not to entirely trust someone else's BOM(I'm sure we all have). No offense to anyone, but I definitely prefer customizing my own parts as per the board and appreciate anything that's been provided thus far.

Trimmers need (i believe) to be installed along the 'base -T' of the footprint that's provided on the board I think, with the leads being 3 inline.  For the transistors, I'm assuming that with the originals, they install as per the footprint on the board and replacements need to be backwards...

For the input transformers, I have two Trident A range line inputs(10k-10k - 1:1) that I'm planning on using for the PYE.
I'm pretty excited about it.  It's been a while, but I'm gonna get on this now.  Be nice to see Abe around these parts again. From what I've heard and seen, it's a nice sounding unit.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 24, 2015, 11:41:46 PM
Cheers to mdainsd and others who have contributed information to the thread. You guys are a huge help, after reading through the whole thing. I hope I can get mine up and running as well...  ;D

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on February 25, 2015, 12:05:51 PM
You can! Just ask away here if you have questions. I always check this thread to see how others are coming along.

Be sure to find the schematic I posted in this thread, I think its around page 19

These compressors are well worth the effort.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 27, 2015, 01:36:27 PM
Quick question Mdainsd.  Where did you source the boards for your relay bypass? It looks like a good idea that I'd like to implement as well.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Electrobumps on February 27, 2015, 02:15:06 PM
Quick question Mdainsd.  Where did you source the boards for your relay bypass? It looks like a good idea that I'd like to implement as well.

Dave, who designs the Don Classic (http://www.thedonclassics.com/) gear kindly drew a relay circuit for me to put on perfboard.  Have uploaded with this post.

I've still being trying to work out what is going on with my meter. 

Is it correct that adjusting R52 (release) should change the meter reading when no signal is present?  adjusting this and the meter trim I can zero the meter.   This also gives me the shortest possible release which I do like the sound of.

Can any one shed any light on what is going within the circuit? 



Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on February 27, 2015, 04:19:12 PM
Quick question Mdainsd.  Where did you source the boards for your relay bypass? It looks like a good idea that I'd like to implement as well.

ebay. heres one like mine. I think I paid 2.99 each for mine.

http://www.ebay.com/itm/Two-DPDT-Signal-Relay-Module-Board-DC12V-Version-for-PIC-Arduino-8051-AVR-/130690277968?pt=LH_DefaultDomain_0&hash=item1e6dbf6250

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on February 27, 2015, 04:53:57 PM
Quick question Mdainsd.  Where did you source the boards for your relay bypass? It looks like a good idea that I'd like to implement as well.

Dave, who designs the Don Classic (http://www.thedonclassics.com/) gear kindly drew a relay circuit for me to put on perfboard.  Have uploaded with this post.

I've still being trying to work out what is going on with my meter. 

Is it correct that adjusting R52 (release) should change the meter reading when no signal is present?  adjusting this and the meter trim I can zero the meter.   This also gives me the shortest possible release which I do like the sound of.

Can any one shed any light on what is going within the circuit?

My relay board is wired differently, but either way will work.

Im at work so Im going by memory...I started by injecting a 1Khz sine wave at -24dB into the input, with the input attenuator  wide open (short circuit position). I had the scope on the end of R50 designated with the square pad. Then watching the steady state DC, I adjusted R52 until that level just barely started to move from the no signal level. If Im recalling correctly, I then increased the input by 20dB and adjust R42 for a meter reading of 20dB gain reduction. As you can see in the picture of mine the meters sit so damned close to zero with no signal, that Im not going to bother messing further with it. And if I did, I would use the mechanical zero on the meters as we are talking less than the width of the zero marker on the meter.

Note: only the -24db input will be in calibration with the front panel markings depending if you used a pot or a switch. To get it to track the front panel markings for threshold you have to build true 40dB stepped attenuators @ 2dB/step. The output control markings are all hosed up so, there is no making it match those markings at least on the case I have.

The hot ticket is to put it back as original with the two stepped attenuators ganged together, with one in reverse of the other. Plug the output hole on the front panel. Or add a make up gain section and put the control for it in there and disregard the markings...

I hope this helps, a little?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 28, 2015, 03:58:48 PM
Thanks for the links! 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 06, 2015, 06:09:30 PM
Few days ago I've finished stuffing two boards of Pye...

Today I had a little spare time and I was rushing to do the wiring on one of the channels and to power it up.
When I switched it on, I don't know should I be happy or not!

It is passing audio but it's a bit noisy. White-ish noise, no hum or buzz. But a bit too high it seems.

It is working only in limit mode. Limiting is very nice, but with a bit of thump on the attack.

Vu meter seems to work! I was expecting to have meter all over the place without any logical sense to gain reduction, but it sits on a steady position and it is reacting to peaks that it is limiting. I'm using meter from ebay and scale is generic 0-1ma. It is sitting steady on 0.2ma and goes higher when gain reduction is applied. I'll probably do a custom scale for those meters after measuring it's deviations.

I haven't calibrated the chopper yet! Had no time to do it! I had less than half an hour to do the rest of the wiring and turn it on.
And the bad thing is that I have to travel tomorrow and I'll be gone for a week, so my impatience will turn to agony!

My units are built following the SR1200's BOM but with one exception - I've used 1:2 edcors on both interstage and output. That's what I had around!

Now I'm wondering if I wired output transformer wrong way.
Does it have to be 600ohm on the primary or 10k on the primary?
Now I have 600ohm going to 10k and my commons sense is telling me it is wrong, and I should reverse it.
Should I?

I've used inductor on L1 positon. Should I ditch those and go with resistor as Bruno2000 suggested?

Huh... it's going to be a long week contemplating on it before I have a chance to try to get back to it and start debugging it...

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on March 11, 2015, 04:57:11 PM






My units are built following the SR1200's BOM but with one exception - I've used 1:2 edcors on both interstage and output. That's what I had around!

Now I'm wondering if I wired output transformer wrong way.
Does it have to be 600ohm on the primary or 10k on the primary?
Now I have 600ohm going to 10k and my commons sense is telling me it is wrong, and I should reverse it.
Should I?

I've used inductor on L1 positon. Should I ditch those and go with resistor as Bruno2000 suggested?

Huh... it's going to be a long week contemplating on it before I have a chance to try to get back to it and start debugging it...

:)

Luka

Limited participation still for a bit, but I'll start here.
My objection to L1 as it's stated in the BOM is that the resistance is too high.  If you are going to feed a relatively low load, the voltage drop across L1 is too much, and the Voltage fed to the output section fluctuates a good bit.  If you use a resistor,  the filtering of the inductor is lost.  I wound my own inductors with #30 wire, and got the best of both worlds.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 11, 2015, 06:13:08 PM
Limited participation still for a bit, but I'll start here.
My objection to L1 as it's stated in the BOM is that the resistance is too high.  If you are going to feed a relatively low load, the voltage drop across L1 is too much, and the Voltage fed to the output section fluctuates a good bit.  If you use a resistor,  the filtering of the inductor is lost.  I wound my own inductors with #30 wire, and got the best of both worlds.
Best,
Bruno2000

Bruno! I'm so glad you're back!

I have never wound an inductor. I feel I should understand them enough before rolling my own. Is it complicated?

I'm still out of town, like 500km far from my bedroom lab with pye still left on the table. I'll get back to it during the weekend and try to calibrate the chopper and see how it goes from there...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 13, 2015, 07:53:23 AM
Ok, I'm back to it!

I'm working on one channel. Though I have two, I still haven't got the enclosure to put them into, so this is still pcb with a bunch of wires sitting on my bedroom table. I haven't tested the second channel since I don't have space on the table. I would have to finish the first one.

I have adjusted the chopper to 250khz. All okay!

It seems that it is working almost correctly. I don't know!
The meter is working nice. Responds very nice. I don't have a scale in decibels for it, but it sits idle on 0.2mA when no GR is applied.
Switches seem to work okay. When switching ratios and limiter the needle on the meter bounces hard, but that I would say is normal since I saw on Abe's video it is doing the same.
Ratio, Limit and Decay seem to behave as they sould.

But first what I notice is that the noise is very high. I haven't measured it, but it is very noticable. Could that be due to the fact that this isn't mounted in a metal enclosure? If I put my finger around the edge of ratio resistors (small pcb with lorlins) I make the buzzy part of the noise dissapear. It still has white noise component unchanged and it works normal.  I'm guessing this will dissapear once it is in metal box, right? But what about the rest of the noise?

When it starts compressing the signal, on the first few milliseconds of the attack, it has a noticeable THUMP added in the low end. I noticed that this happens when a large transient in the input signal comes in. This is especially noticeable when compressing vocal since the vocal sample I've used has no low end below 200hz.  It's not like like on dbx160VU when you have click on every transient due to the slow attack behavior. This is something added to the signal, and it doesn't sound right!

I haven't readjusted no trimmers yet. They are set in a position suggested in BOM before soldering.

What should I do next? How to get rid of the noise and this annoying thump on attacks?

I'll try to capture a video of it's behavior so you can see and hear for your self.
In the meantime, here's the photo just for fun! :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on March 13, 2015, 11:57:36 AM
Good to see progress!

Not sure about your noise issues, but.....

Your input transformer is not shielded and has longish unshielded wire runs.

The input pot (I see you are not using step attenuators?) also has long unshielded wire runs.

I wired mine using shielded twisted pairs about everywhere, power, attenuators basically everything except the wiring to the switch board.

Keep at it!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on March 13, 2015, 02:21:20 PM
I'll second the input transformer suggestion. I had the cheapish/unshielded edcor's on my D-la2a for the first bit and was noticing quite a lot of 60hz hum when I put it through a freq analyzer on the pc., from the onboard toroid.....so I decided to get into some original inputs and it made a huge difference. I'd definItely roll with the cinemag's on input as suggested, even if they are a few bucks.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on March 14, 2015, 12:05:35 AM
Ok, I'm back to it!

I'm working on one channel. Though I have two, I still haven't got the enclosure to put them into, so this is still pcb with a bunch of wires sitting on my bedroom table. I haven't tested the second channel since I don't have space on the table. I would have to finish the first one.

I have adjusted the chopper to 250khz. All okay!

It seems that it is working almost correctly. I don't know!
The meter is working nice. Responds very nice. I don't have a scale in decibels for it, but it sits idle on 0.2mA when no GR is applied.
Switches seem to work okay. When switching ratios and limiter the needle on the meter bounces hard, but that I would say is normal since I saw on Abe's video it is doing the same.
Ratio, Limit and Decay seem to behave as they sould.

But first what I notice is that the noise is very high. I haven't measured it, but it is very noticable. Could that be due to the fact that this isn't mounted in a metal enclosure? If I put my finger around the edge of ratio resistors (small pcb with lorlins) I make the buzzy part of the noise dissapear. It still has white noise component unchanged and it works normal.  I'm guessing this will dissapear once it is in metal box, right? But what about the rest of the noise?

When it starts compressing the signal, on the first few milliseconds of the attack, it has a noticeable THUMP added in the low end. I noticed that this happens when a large transient in the input signal comes in. This is especially noticeable when compressing vocal since the vocal sample I've used has no low end below 200hz.  It's not like like on dbx160VU when you have click on every transient due to the slow attack behavior. This is something added to the signal, and it doesn't sound right!

I haven't readjusted no trimmers yet. They are set in a position suggested in BOM before soldering.

What should I do next? How to get rid of the noise and this annoying thump on attacks?

I'll try to capture a video of it's behavior so you can see and hear for your self.
In the meantime, here's the photo just for fun! :)

Shield everything.  I have to turn off my cell phone to test on bench.
Edcor open frame inputs won't do.  Get the Cinemags or equal.  Maybe some old British inputs.
My $0.02, but maybe that's too much to pay.........
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 14, 2015, 06:20:53 AM
Hey guys! Thanks for the help!

I'll change all those wires to shielded ones as soon as I move those boards into an enclosure!
And when I do that, should I tie the ground (screen) of the cable to the earth or to B+ ??

I'm on the cheap side with transformers unfortunately. It would be too expensive for me to get cinemags all around, but what I'll do is to wrap all the transformers in copper foil and bend a piece of sheet metal around them. That way they will be double shielded - metal enclosure will shield everything plus sheet metal will shield transformers. That should help I guess...

But that still leaves me with a bigger problem and that is those ugly thumps on the attack.
I've wired the second board (still using the same wires from the first one - so noise is present in the same amount) and went to see what's happening on that board. Just the same! Attack thumps and behaves just as the first board! Must be some wrong component they both have in common. Those two channels were built with every component exactly the same. I was stuffing them simultaneously and checking with DMM everything twice, so no wonder they act the same...

Here's the video I've uploaded to show you how it sounds and what those thumps are.
The noise in the background is all from the unit. It's not camera noise!
But I'll fix that noise with your advices!

https://www.youtube.com/watch?v=j6FHFdfSGxA

You may notice that thumps are in relation with the ratio. On 2:1 (not in the video) they are almost non-existant. On 5:1 they are severe and on 3:1 there are some.

It's saturday. I'll have to rush to buy me an enclosure asap today, not too loose the weekend work! I know where to get a nice one!

:)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tommia on March 15, 2015, 11:35:21 AM
another mistake is R70. It is not 11K but 11k parallel to  a 20k resistor resulting in 7k1.  This will improve the feel of the ratio.
You could use 1k5 in series with 5k6.

Attack problems: turn R52 clockwise
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 15, 2015, 07:12:51 PM
Thanks! I'll try the R52 trimmer to see if it helps!

If you follow the pcb silkscreen or Abe's build buttler, you'll notice that R70 is 6K8.
I don't know why is it labeled 6k8 (11K) on the schematic...
I've installed 6k8...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 15, 2015, 08:51:38 PM
I've tried changing the value of R52. It indeed has something to do with the speed of the attack. It almost removed the thump from the attacks, but I'm not sure how it affected the release times. I don't mind if release also drifts a bit, but I'll have to measure it if it went off too much.
Also, when changing R52, zero GR spot on the meter moves towards 0.4mA. If I get attacks to behave acceptable, I'll deal with this later...
But I'm moving in a good direction.

I have wrapped edcor transformers with self-adhesive copper foil I had bought long ago on ebay. Wasn't expecting any change, but it actually dropped the noise a bit! I believe when I put all of it in the metal enclosure it will drop to an acceptable level.

I've bought the enclosure yesterday but I'm not sure if my two units will fit onto the 2H front panel since I have huge meters.
I haven't put the boards inside the case yet. Had no time (weekends are not what they used to be...).

:)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tommia on March 16, 2015, 08:12:54 PM
a lot of noise can come from the filtering inductors (50mH) try 120 ohm resistors like indicated.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on March 16, 2015, 10:30:48 PM
Thanks Tommia! I'll try that!

In the meanwhile, I've spent most of the day working on the front panel. I've bought chassis with blank front panel and I'm doing my own front panel design. Drilling, painting, sanding and stuff... I like to do my custom panels.

Tomorrow I'll try to replace inductor with resistor, do the new wiring and mount the boards and transformers into the chassis.
I'm feeling optimistic and close to finishing this baby...

:)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on April 01, 2015, 03:17:43 PM
Is it possible to change the attack, or is it a kind of compresson structure where it is impossible?

If it is possible, what is the component I have to tweek ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: snaper on April 09, 2015, 09:39:34 AM
Hi,

Moved this question from another thread :

Anyway. I've bought a couple of DOA boards from ACSounds, payment was done, weeks ago, but no information from their side.
Nothing regarding shipping, etc.

Tried to mail them, no answer.
Tried to PM to Abe here, box is full.

Today checked their site, almost everything is out of the stock.

Know somebody what happends to them?

Just for clear, the base of my problem is not that 20 dollars, but I really really need those boards :D
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on April 09, 2015, 01:04:54 PM
There was a Facebook post in January that he was dealing with some personal issues.  That has been the only contact for 6-8 months.  I imagine that he wants to get things out to everybody that has bought stuff, he seems like that type of person, but if something has happened in his personal life, then I suppose that that takes priority.  I'm hoping everything gets smoothed out and he returns, he has some nice projects and has been very helpful in the past.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on April 12, 2015, 12:35:16 PM
So I've made some progress!

I've built my own front panel as an additional sheet metal on the pre-made enclosure. A little paint, some waterslide decals and that's it! I'm not going cheap other enclosures - it's just that I like doing this part for myself.  Did five other units this way and I like looking at it in my studio rack, knowing it's 100% DIY me! :)

I realize it was a mistake to try to calibrate this compressor in a shoebox. A big mistake! Most of the problems I had back then are gone now. When mounted into an enclosure, I did completely new wiring. I don't have problems with noise anymore. I can hear noise only when both in and out potentiometers are max cw. The noise is "healthy" meaning it doesn't contain 50hz or 100hz hum. I'm hoping to lower it even more with diy inductors on L1 position (thanks to Bruno2000).

Most of the time in past two weeks I've spent debugging my relay board that is supposed to switch stereo link signals between boards. I had to move the relay board with it's small psu to the other side of the enclosure to avoid HF buzz it injected into the output transformer. Thankfully I had enough free space inside to do it.

I'm not experiencing severe "thumps" on the attack anymore. Right channel has none at all, while left channel can sometimes thump when the signal is near the treshold. If input is high enough so it grabs a lot of audio, then this thump doesn't happen. It probably has to do with the fact that I was messing a lot with trimmers on the left channel before I put the board into the enclosure. I left all the trimmers (except voltage regulator) untouched on the right channel. I've tried to put left's trimmers to an original position, but I'm not sure if I did. I'll probably unsolder most of them, readjust them and return them back to the board.

Metering doesn't make sense, but it behaves exactly the same on both channels (that's after I put left channel trimmers to the original value). I like it how it moves. But makes no sense! hehe! I would need to measure the treshold and ratio curves before I can start tackling with meters. I plan to print my custom scale on those ebay meters I'm using, but to be able to do that I would need to know what's going on those signals. And funny fact is I totally dig the mA scale and I'm tempted to leave it as it is. But on the other hand it feels kinda ridiculous not to finish the damn meter!

Can anyone explain to me how to measure and plot the ratio of the unit?

I have an oscilloscope (usb cheap one, with two inputs) and PC audio card. I also have an access to a laptop with Smaart 7 software for measuring audio signals.
Still don't have any dedicated signal generator except PC's audio interface, so I'm limited to 20-20khz and not more than 2 Vac generated signal! But I guess signal generator from my PC won't be a problem.
So how do I do it?
:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: snaper on April 13, 2015, 04:42:25 AM
So I've made some progress!

I've built my own front panel as an additional sheet metal on the pre-made enclosure. A little paint, some waterslide decals and that's it! I'm not going cheap other enclosures - it's just that I like doing this part for myself.  Did five other units this way and I like looking at it in my studio rack, knowing it's 100% DIY me! :)

I realize it was a mistake to try to calibrate this compressor in a shoebox. A big mistake! Most of the problems I had back then are gone now. When mounted into an enclosure, I did completely new wiring. I don't have problems with noise anymore. I can hear noise only when both in and out potentiometers are max cw. The noise is "healthy" meaning it doesn't contain 50hz or 100hz hum. I'm hoping to lower it even more with diy inductors on L1 position (thanks to Bruno2000).

Most of the time in past two weeks I've spent debugging my relay board that is supposed to switch stereo link signals between boards. I had to move the relay board with it's small psu to the other side of the enclosure to avoid HF buzz it injected into the output transformer. Thankfully I had enough free space inside to do it.

I'm not experiencing severe "thumps" on the attack anymore. Right channel has none at all, while left channel can sometimes thump when the signal is near the treshold. If input is high enough so it grabs a lot of audio, then this thump doesn't happen. It probably has to do with the fact that I was messing a lot with trimmers on the left channel before I put the board into the enclosure. I left all the trimmers (except voltage regulator) untouched on the right channel. I've tried to put left's trimmers to an original position, but I'm not sure if I did. I'll probably unsolder most of them, readjust them and return them back to the board.

Metering doesn't make sense, but it behaves exactly the same on both channels (that's after I put left channel trimmers to the original value). I like it how it moves. But makes no sense! hehe! I would need to measure the treshold and ratio curves before I can start tackling with meters. I plan to print my custom scale on those ebay meters I'm using, but to be able to do that I would need to know what's going on those signals. And funny fact is I totally dig the mA scale and I'm tempted to leave it as it is. But on the other hand it feels kinda ridiculous not to finish the damn meter!

Can anyone explain to me how to measure and plot the ratio of the unit?

I have an oscilloscope (usb cheap one, with two inputs) and PC audio card. I also have an access to a laptop with Smaart 7 software for measuring audio signals.
Still don't have any dedicated signal generator except PC's audio interface, so I'm limited to 20-20khz and not more than 2 Vac generated signal! But I guess signal generator from my PC won't be a problem.
So how do I do it?
:)

Luka
Nice front!
You should create a tutorial :D
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on April 21, 2015, 02:58:58 PM
Hello guys!

It's good to see there is progress in this project.
I fired up 1 channel just to see how it works.
It passes audio, and after connecting the trimmer center legs to the pads I have sidechain signal and I can get gain reduction.
The overall sound is good, it is compressing.

I've read the whole thread, and I have some problems.
The information is here in the topic, but in tiny little pieces...

Can someone please write a summed (would be better point to point) calibration procedure?
Ok, for this project, and without the help of the designer its clear that we need some serious equipment, but after buying all the 6 transformers and other (sometimes hard to get) pieces, we need to set it up correctly, because it wasnt so cheap.
So in my example I have a friend who has signal generator, oscilloscope, distortion meter and so on, but I'd like to have the knowledge what set where, what measure.....etc

I know everybody is on their own way calibrating this unit, but a summed procedure would be very good at this point.
Im sure a lot of PCBs are stuffed and waiting for this information:)

The main question for me is: How to set the trimmers, and what should I measure with what (scope, what input signal...)
I also have the meter zeroing issue....

I built this for mastering, to get 2-3 db gain reduction, and what I hear from one channel is good. But for mastering (as you all know) I need every parameter to work properly.

Thank you, and looking forward to your answers, because for me it's a very difficult project with the calibration.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on May 09, 2015, 12:28:52 AM
Hey, not sure I'd want to use this comp for mastering, but to each their own.  Its not a quiet compressor by any means and it definitely isn't transparent (color city).  No attack time either...
As far as the trimmers go, I'm pretty sure that all those numbers were either on the schematic or earlier in this thread.  Most of them with the exception i think of the power trimmer needed to be set prior to installation.   The only other trimmer would be on the "chopper" board which no one can tell you "how" to set, you need to use an oscilloscope (or a DMM that reads hZ) and get it in the ball park according to the spec.  The value on this is going to change depending on the chip.  The 2 units I did had very different resistant values so, theres no "set it to 3.4k" kind of answer for that.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: iprovlek on May 09, 2015, 02:03:18 AM
Luka! Pye looks amazing...

great job Luka!

 ;D
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 09, 2015, 01:34:18 PM
Hello!

Thanks for the help!
About the mastering and the color:
I used the cinemag on the input and without putting it to its box I have -110db noise level, on unity gain.
With edcors connected to the input, yes it is noisy. The cinemag has its metal can to eliminate noise.
Try this comp without the output transformer! OK, it will loose volume but it is very transparent. That's why I decided to choose another output trafo. Just listen it once without any edcor in the signal (that's where the color is coming from)
I personally like a lot that the attack is so fast, that is exactly what I wanted from this comp.

So just adjust the trimmers to the pretrimmed values and set the chopper frequency?
OK, I give it a try!
Thanks!

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tazwolf on May 12, 2015, 05:46:09 AM
Hi
Precsott: could you tell me where you bought the cinemag input transformers? Was it directly from
Cinemag? If so how much was it with shipping?

Regards
Tazwolf
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 12, 2015, 06:57:00 AM
here is my reply from cinemag:

The CMLI-15/15BPC is $52.75. Priority Mail Flat Rate, for which insurance is not available and tracking dubious or non-existent, will be $24.75.  DHL will be $34.
Yes, directly from cinemag, they will reply fast and kind.

I live in Budapest, its far but you will get similar shipping I think.
I suggest to choose DHL, because my first package lost somewhere in the post system.
In my opinion it is very important to have a metal can for the input, and short shielded cable everywhere in this comp. This way it's not noisy.

I also plan to try a THAT outsmart IC on the output, I will post my experiences after trying it. That's because I really liked the transparent sound of the comp without output transformer, and I may build it switchable . On the other hand the edcor color is nice, but I have it in my chain already in my PM670.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tazwolf on May 13, 2015, 04:30:09 AM
Hi Prescott!
Great Thanks for the info I will go for a switchable output as well I think.
/Taz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 13, 2015, 05:24:20 AM
Is there a little PCB available for the THAT chip?
Anyone?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on May 13, 2015, 10:55:45 AM
Is there a little PCB available for the THAT chip?
Anyone?

There were dual output balancing boards for theThat chip that would work that were used with Keiths SSL 9K boards.  You could see if Gustav has any.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 14, 2015, 08:09:49 AM
Yes, I remembered the same way.
But now it's not in his store.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 14, 2015, 02:20:58 PM
Is there a source in Europe for the case?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: taliska on May 14, 2015, 09:13:21 PM
Is there a source in Europe for the case?

Don't think so...well, not if you're looking for something pre-made.

A lot of the EU guys get their generic cases from modushop:

http://modushop.biz

I'm in the UK and just recently checked out the price difference between getting modushop cases and doing my own rear panels using fpd vs importing the basic cases from collective cases  and I think importing is the better solution in the end (a modushop case plus fabricated rear is more hassle and costly than importing). If you punch out the rear panel yourself that is cheaper, but time consuming.

The other option is Frank at NRG. He seems to have impressive new generic cases available with pre made rear panels, but they're newer so I haven't seen them around much yet:

http://www.frontpanels.de/nrg-case-19-enclosures/

Also, Dan at collective cases has a specific pye case in addition to his generic cases:

http://www.collectivecases.com
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: prescott on May 19, 2015, 06:58:49 PM
Thank you!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Dreams on July 13, 2015, 04:31:23 AM
Anyone still working on these? I've got one going (slowly) at the moment, just checking in.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on July 13, 2015, 10:08:33 AM
I've got one going, but it's spread out all over my bench right now.  Gonna be putting it in a box soon :)
Jensen input transformers, and an extra Class A gain stage on the output feeding a Carnhill OPT
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 13, 2015, 01:18:00 PM
I got one working. Maybe a bit too noisy and with a mismatch of output gains (dual unit).
But I took it to studio to play with it and later I'll see to fix those issues.
Compression in this unit is incredible sounding!
:)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 13, 2015, 03:32:23 PM
My stereo unit is in the rack in the studio where it lives on the drum buss.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 13, 2015, 03:35:35 PM
If anyone has given up on their project I'd be interested in two more boards (the later version).  8)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on July 13, 2015, 11:09:01 PM
My stereo unit is in the rack in the studio where it lives on the drum buss.

Thats where mines been parked as well... it does something really nice to the high end.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on July 23, 2015, 09:29:20 AM
I was making some power inductors for someone here on the forum, but can't remember who it was :(
Please PM me.
Thanks!
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on July 27, 2015, 07:58:11 PM
Finally...parts list is ordered. It's about time...

:)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: lotus on August 04, 2015, 05:01:47 PM
HI y'all just wondering if anyone has any spare boards left that they would be willing
to part with?
Eric
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on August 07, 2015, 07:28:21 PM
I'm still yet to begin mine but have the case, meters, and will buy transformers and parts to stuff boards soon...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 16, 2015, 08:42:54 PM
Couple questions for anyone...

Does it matter which side of the switchboard I mount the switches on? I was assuming that they should be mounted on the backside of the pcb, with the silk screen facing away from the front panel.

Does anyone know of a good receptacle and pin combo that works well for the oscillator plugin?  I would like to be able to unplug it if needed. I've searched for a Millmax solution but it's tough to nail down. I think the pcb and plugin mounting hole sizes are ~1.25mm. I've already incorrectly ordered some stuff from Mouser regarding this, so this is a second time around.  ;D

Regarding c7. I think a few people had mentioned that the polarity was silk screened backwards. There's no mention of this in the build guide. Was this a false alarm or is this cap indeed marked backwards?

Thanks :)


Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 18, 2015, 07:59:32 PM
I was able to remove the switches quickly and cleanly thanks to my desoldering gun. Happy days...

It's odd because, based on Abe's picture somewhere in this thread, the switches are mounted on the silkscreened side, however, both the molex footprint and the silkscreened switch functions indicate that the switches are mounted on the backside of the switchboard in order to make sense when mounted on the frontpanel. This means that the switchboard has to be mounted in the frontpanel upside down to make sense with the functions on dan's frontpanel. No biggy...but dan should've made the ratio, limit and release the other way around to match the switchboard. That's why it made sense to me, that they were to be mounted on the backside of the switchboard.... but I guess not!

As far as the millmax pins...I guess no one has an answer so I'll just keep digging in and researching cause it would be nice to be able to unplug the oscillator need be...

There's no indication anywhere recently in the thread or the build guide that the polarity of c7 is indeed backwards, so those folks that mentioned it earlier in this thread(cause ya know, I did read the whole thread) must be wrong. Those posts should be removed if so, as they create confusion.

Back at it... :)



Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 19, 2015, 12:17:31 PM
The switches and the connector go on the silkscreened side of the switch board. I had trouble with that too at first.
If you have one of Dan's cases the board does install upside down, (connector towards the bottom.)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 19, 2015, 12:25:46 PM
C7 is marked backwards.
Refer to post 386 for known issues.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 19, 2015, 08:11:40 PM
Ah...ok. Thanks Mdainsd. I'll reverse those then...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on September 23, 2015, 03:43:21 PM
As far as the millmax pins, perhaps Jeff at CAPI can give you some advice.  All of the DOA's seem to use them.  I had this same idea and asked about it earlier, but the common thought was to just get it working and leave it be.  Still wondering about it, but life got in the way of my projects, so I am waaaaaaay far behind.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on September 24, 2015, 10:28:20 AM
I used MilMax pins, but the holes on the board were the wrong size.  Too small.  So, I used a piece of wire through the hole and into the pin.  I'll look up the part number of the pins I used and post it.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 24, 2015, 10:57:03 AM
I just used leads cut off of some of the diodes and used them. I never had a reason to remove that board anyway.

The only thing I left removable at first was the chopper transistor. Just pushed it into its pad holes while getting things up and going then soldered it.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 24, 2015, 08:33:11 PM
As far as the millmax pins, perhaps Jeff at CAPI can give you some advice.  All of the DOA's seem to use them.  I had this same idea and asked about it earlier, but the common thought was to just get it working and leave it be.  Still wondering about it, but life got in the way of my projects, so I am waaaaaaay far behind.

Hey Patrick

I spent a good while trying to find the right mounting holes sizes on various Millmax data sheets, but it always seemed that the receptacles and pins that were meant to go together had different mounting hole sizes, whereas the Pye has the same mounting hole size for both the pin and receptacle(board/daughter board). I probably spent 2-3 hours going over data sheets and attempting to measure sizes and they were still incorrect when they arrived.  ;D I believe the mounting holes @ the oscillator board are ~1.25mm. I may just leave it and solder them as I have a good desoldering gun and it wouldn't be that hard to remove if need be. I'm not sure if another round with Millmax is worth it. :) Seems to be somewhat tricky to get it right.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 26, 2015, 04:18:15 PM
Progress thus far...

(http://i700.photobucket.com/albums/ww10/desol777/P9260686.jpg) (http://s700.photobucket.com/user/desol777/media/P9260686.jpg.html)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 29, 2015, 07:51:41 PM
Has anyone who's bought the Pye case, had an issue with the meter bezel(47mm) cutout, being too big? The cutouts on my case are 50mm...which leaves a 3mm gap.

I have the hairball 8027-wf 1ma meters.

Cheers and thanks.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 08, 2015, 08:40:42 PM
...waiting on transformers(David at cinemag is good to deal with, and prices were reasonable), new front panel coming(thanks Dan  :) ), after which I'll place my final order from Mouser. Mouser's shipping is great...takes like 2 days to get here.(canada)

waiting waiting waiting...   >:(  ;D



---oh yeah!...and inductor's are coming(thanks Bruno :) )
Title: STOCKING PCB'S FOR PYE COMPRESSOR
Post by: dandeurloo on October 10, 2015, 11:48:07 AM
I will be stocking the PCB's along with my cases for this project.  Hopefully I will have the PCB in stock in a few weeks.  Cases are in stock now.  It will be nice to see these and the CLX's back to life!



Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: dandeurloo on October 29, 2015, 01:04:30 PM
PCB's are in stock now for these as well.

http://collectivecases.com/?product=ac-sound-pi-3141-vintage-pwm-compressor-circuit-board
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tskguy on December 17, 2015, 09:34:26 AM
Dan,

Just ordered a pair of PCB's.. Case will be getting ordered after the new year.. I love the sound of a PYE comp.. Cant wait to build it.

Eric
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: dandeurloo on December 28, 2015, 11:59:57 AM
I think I will start building one of these soon as well.  I have heard form a number of guys that have finished thier Pye's that it is a pretty easy build and sounds great.  I am gathering all the info from the thread and putting together my info like I normally do for a new project.

Thanks to mdainsd, bruno2000, sr1200, Rob Flinn and a few other guys this should be a nice project to start off the new year.  I may even go for 4 channels of it!

Thanks guys!

 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on December 28, 2015, 12:36:39 PM
I really love my PYEs.  Pretty easy build.  I combined the "input" and "output" controls into one stepped switch, and added a 20dB Neve Class A gain stage with its own output control.  More details to come.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: kosi on December 28, 2015, 01:34:48 PM
the project sounds really interesting.
question for Bruno 2000: Do you sell your custom inductors ?

thanks,
Andreas
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on December 29, 2015, 04:44:42 PM
Hey guys.

I'm wondering how to wire up the power switch when using bypass(relays). I'm thinking of using a separate power supply for the bypass boards.  When putting the unit in bypass(powering the relays), is it supposed to effectively cut power to the compressor itself? I'm trying to understand how the bypass is supposed to work. If the inputs/outputs are on single pole double throw relays, isn't simply turning the unit off the same as bypass? I always thought bypass just removed the compression....but left the rest of  the circuit in.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on December 29, 2015, 06:13:08 PM
It can be either, or both can be available.  The both idea seems to be a more recent idea, but either is not uncommon.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 29, 2015, 07:29:19 PM
Hey guys.

I'm wondering how to wire up the power switch when using bypass(relays). I'm thinking of using a separate power supply for the bypass boards.  When putting the unit in bypass(powering the relays), is it supposed to effectively cut power to the compressor itself? I'm trying to understand how the bypass is supposed to work. If the inputs/outputs are on single pole double throw relays, isn't simply turning the unit off the same as bypass? I always thought bypass just removed the compression....but left the rest of  the circuit in.

In mine I used a separate "hotel" power supply to operate the  bypass boards and the lamps.

I used double poll double throw relays, two per channel  The XLR (+ & -) inputs go to the "commons" connections on one relay. The other relays "commons" go to the XLR out (+ & -). The N.C. contacts are wired from one relay to the other, so no power to the relay board connects input to output (bypass). Then or course the N.O. contact are wired to the input and output of the compressor boards.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on December 30, 2015, 09:49:49 AM
Hey Mdainsd(..and thx Patrick)

So when you turn the power switch to bypass, it cuts power to the relay boards but the compressor itself remains powered, is that right?(it would seem right, because you would want the needles and lights to remain active in bypass)

Where did u take your shield connection from, for pin 2/6 of the cinemag?

I'd like to get signal working first through the unit before plugging in the oscillator, etc. I do have a scope and sig gen. Do I simply leave out the oscillator plugin to focus on getting the amps working? I'll have a closer look over schematic when I have more time tonight (I'm not great with electronics theory). :-[  :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on December 30, 2015, 10:26:46 AM
Yep, you got it. The bypass switch cuts the power only to the relay boards, the compressor remains on.

I left the chopper transistor out for initial signal runs. But leaving out the oscillator board will accomplish the same thing.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on January 19, 2016, 07:05:43 PM
Coming along guys, coming along....

Building my workbench and getting final parts soon. Hope to get some good progress done in the next week or two.
It's been busy last few weeks at work. Yikes...but time permits.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Bowie on January 19, 2016, 08:56:19 PM
Coming along guys, coming along....

Building my workbench and getting final parts soon. Hope to get some good progress done in the next week or two.
It's been busy last few weeks at work. Yikes...but time permits.
Good to hear.  I'd like to build a pair of these but am waiting to hear from a few more people who have navigated this build as I don't  currently have enough spare time to experiment and troubleshoot something that's not well documented. 
Best of luck with yours and thx for updating your progress.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on January 22, 2016, 09:31:49 PM
Thanks Bowie.

I'll give the real credit here to Mdainsd and Bruno for really sussing out some of the 'stuff' with this build. These guys are awesome.
I like the way Mdainsd 'measured' his way through the build rather than hoping for the best, per say. That's the best way to do it, imo, if one's capable.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sage on February 03, 2016, 02:23:04 AM
Hello there

I am building the PYE with the AC Sound Pi-3141.
I have a bag of PNP Transistors - 2N1132 and I was wondering if that would be a valuable substitute to the BC560C.
I looked up the specs and they seem very close - the  only big difference in numbers  I see is :

Forward current transfer ratio (hFE), min: 30 for the 2N1132 while the BC560C has Forward current transfer ratio (hFE), min: 420

I apologize for my ignorance but is that a big factor?

In the BOM  each BC560C has a different suggested replacement  depending if they are TR1 or TR10.... and some just don't have any suggestion for substitutes....

Here is the complete datas for the 2N1132:

    
2N1132 Transistor Datasheet. Parameters and Characteristics.

Type Designator: 2N1132

Material of transistor: Si

Polarity: PNP

Maximum collector power dissipation (Pc), W: 0.6

Maximum collector-base voltage |Ucb|, V: 60

Maximum collector-emitter voltage |Uce|, V: 40

Maximum emitter-base voltage |Ueb|, V: 5

Maximum collector current |Ic max|, A: 0.6

Maksimalna temperatura (Tj), °C: 175

Transition frequency (ft), MHz: 60

Collector capacitance (Cc), pF: 45

Forward current transfer ratio (hFE), min: 30

Noise Figure, dB: -

Package of 2N1132 transistor: TO5



Sage
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 18, 2016, 10:45:57 PM
Alright. Parts in...populating continues...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 25, 2016, 02:52:53 PM
Layout basically done, switches wired up, waiting on 12v power supply for bypass and meters, sidechain tx's on their way...I'm having fun with this! :) Can't wait to power it up and start feeding a signal through it.

(http://i700.photobucket.com/albums/ww10/desol777/P2250730.jpg) (http://s700.photobucket.com/user/desol777/media/P2250730.jpg.html)

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 25, 2016, 04:41:44 PM
the project sounds really interesting.
question for Bruno 2000: Do you sell your custom inductors ?

thanks,
Andreas

Yes.  PM me.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sage on March 18, 2016, 10:10:34 AM
Hello there

back on the thread - I never received any comments on my PNP replacement comments... I went ahead and mounted those cans I had and we'll see how they do....

In the meantime I had a nice talk with David at Cinemag, ordered some trafos from him - of course the Input CMLI 15/15BPC but also a 600:15k 1:2 high quality OUTPUT and a less expensive option for the SIDE CHAIN OUPUT which I am not sure I will be using as much.

Once I receive them I will post so if anyone else wants an alternative to Edcor will have the exact model number to order from Cinemag - given we picked the right ones...

More soon...

Sage
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: trashcanman on March 20, 2016, 03:11:51 AM
Are there any self-etch files for these boards floating around? I noticed abechap024 said they'd offer them eventually.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on March 20, 2016, 08:19:25 AM
Are there any self-etch files for these boards floating around? I noticed abechap024 said they'd offer them eventually.

Did you look here http://collectivecases.com/?product_cat=pcb
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: jonathanmorbin on April 26, 2016, 05:32:51 AM
Hi, So i finally got myself a pair of boards and got one stuffed but it doesn't quite seem to be working correctly. Is there anyone who has a completed one able to post some typical voltages on the most recent schematic to help trouble shoot?

 Im keen to contribute to this thread as much as possible, my unit seems to drop quite a lot of level by the time it reaches TR5 and i find myself having to trim R23 a lot to stop it from clipping. I also seem to have a problem in the Control circuit because when i have the base of TR11 in circuit the level is reduced to almost inaudible. I can only get my TL555 to 268Khz, I'm not quite sure what its supposed to be but i don't think this is causing my problems so far. I trimmed all the trimmers to their suggested value and have opted for the higher voltage rail of -22v. To test the input and output amplifiers i have to take TR5 out of circuit.

Im currently using a That 1240 as my input buffer and no output transformer as my budget is a bit tight at the moment. However I'm pretty sure i should be able to at least get the circuit functioning correctly like this don't you think? I shall post updates if i get any further but if anyones got any ideas that could help me along that would be most appreciated.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on May 02, 2016, 09:29:00 AM
It's coming along... 24v/12v power all hooked, bypass boards working....wiring coming along. 12v power supply took FOREVER to come in. :)

Coming along, coming along...

(http://i700.photobucket.com/albums/ww10/desol777/P5020730.jpg) (http://s700.photobucket.com/user/desol777/media/P5020730.jpg.html)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on May 07, 2016, 08:57:32 PM
Hey guys. For anyone that's done the relay bypass, should my bypass routing go straight from in to out? Or do I want to keep any of the transformers in bypass?

The way I have it hooked at the moment, it's bypassing from in straight to out.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: thomasdf on May 08, 2016, 11:40:55 AM
That 's the interest of a "true" bypass :)
Straight wire! I'd keep it this way ;)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on May 08, 2016, 03:49:05 PM
If you can have it so that the comp side chain is "off" then that is generally the other type of bypass that uses the circuit and not "true" bypass.  The more modern things seem to follow the way you have it wired.  Seems to me you can have the best of both worlds if you can set it not to compress much of anything.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on May 08, 2016, 06:04:28 PM
Hey guys..

Thanks for your reply. That what I originally thought would make more sense, to bypass the sidechain leaving the transformers in. I think the way I have it now, in-out will be fine....and a bit less stuff to figure out to. :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: jonathanmorbin on May 09, 2016, 03:24:58 PM
Im pretty sure that is what the 1:1 compression setting is for, on that ratio there will be no compression so effectively you are using it as a line amp and not a compressor. Alternatively you could put a switch in at the base of TR11 which will stop the Control voltage but i have not got mine fully up and running so i can not be sure this doesn't effect the circuit. This is what i did so that i could test the line amp side of the circuit.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on May 09, 2016, 04:09:01 PM
That makes sense on the 1:1 compression setting...i didn't think of it that way before. ? Hmph. I'll have to look more into that later.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: jonathanmorbin on May 16, 2016, 08:32:07 AM
Hi, So update on where I'm at. I didn't read the Build Manual so i had TR16, TR18 and TR12 the wrong way round. After switching this around i was still not getting compression however i found out that i needed the side chain transformer the other way around.(Im just using a cheap microphone 1:4 transformer) As I've read this really does make a big effect on the threshold. At some point I'm hoping to do some more in depth testing so i can understand it better.

My distortion level is pretty high and i can't seem to get it lower. With a 1Khz Sine wave i have -10db on the output at the fundamental and -35db as the first harmonic, i haven't done the sums but that seems far too high. I have played around with R23 but it doesn't seem to have too much effect on the THD when its roughly in the right place, i have used this trimmer to adjust for the highest level going out at C19 to lower the threshold as much as possible so that i don't have to drive the input as hard.

My meter is going the wrong way but this may be because I'm using a hairball meter that is meant for an 1176, i have tried switching the polarity but that doesn't effect it. More investigation needed.

Question regarding using a stepped dual attenuator or a dual potentiometer, Did you leave a resistance at the minimum for the output/input? Because obviously when you have the output at 0 you have no output so I'm wandering if its worth leaving a bit of signal going through and then adding a gain stage so that you can really get this compressor slamming. Or is this threshold potentiometer supposed to work so that with no compression (1:1) it should be hold its gain level regardless of where you have the knob set?

Just to Reiterate i currently am running this transformer less with Line drivers and receivers and it's currently laid out on my bench and not in a chassis yet. That will be my next step. I hoping once i get it fully functional i will borrow a real one and run some tests together…..i will of course post any findings i have.

EDIT: I had my output from sound card turned down which is why i was having to push it hard to get 15db+ compression, now i can seriously slam it before the output reaches 0. 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on May 16, 2016, 03:09:26 PM

Question regarding using a stepped dual attenuator or a dual potentiometer, Did you leave a resistance at the minimum for the output/input? Because obviously when you have the output at 0 you have no output so I'm wandering if its worth leaving a bit of signal going through and then adding a gain stage so that you can really get this compressor slamming. Or is this threshold potentiometer supposed to work so that with no compression (1:1) it should be hold its gain level regardless of where you have the knob set?



IIRC I used 40dB stepped switches, 21 position, 2dB/ step, one forward, one backward.  I have a spreadsheet somewhere. .......
Best,
Bruno2000

 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tskguy on May 21, 2016, 01:04:13 PM
Hey everyone,

Does anyone have a good Mouser project for this? I swear I saw one but dug through the thread with no luck...

Thanks!!

E
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on May 26, 2016, 09:15:09 AM
I have one, but it needs a few changes...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on May 26, 2016, 10:04:39 AM

Question regarding using a stepped dual attenuator or a dual potentiometer, Did you leave a resistance at the minimum for the output/input? Because obviously when you have the output at 0 you have no output so I'm wandering if its worth leaving a bit of signal going through and then adding a gain stage so that you can really get this compressor slamming. Or is this threshold potentiometer supposed to work so that with no compression (1:1) it should be hold its gain level regardless of where you have the knob set?



IIRC I used 40dB stepped switches, 21 position, 2dB/ step, one forward, one backward.  I have a spreadsheet somewhere. .......
Best,
Bruno2000

Found the spreadsheet.  PM me with your email if you want it.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on June 10, 2016, 05:31:39 PM
Can I also get a spreadsheet for switches?

Or better yet, is there a calculator to determine what resistor values to use when using 23 step switch?

I already have 23 pos. switches so I'd like to use them. I'll ditch the potentiometers since this compressor really is a beast and I want to use it not only when mixing but also in mastering. And for that, since recallability is a must, I should have ins and outs on switches...

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on June 21, 2016, 07:43:29 PM
Hey guys. For anyone that's done the relay bypass, should my bypass routing go straight from in to out? Or do I want to keep any of the transformers in bypass?

The way I have it hooked at the moment, it's bypassing from in straight to out.

Looking good! You laid yours out just about the same as mine.

Mine bypasses in to out direct.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on July 12, 2016, 02:29:51 PM
Hey guys.

Can anyone offer any advice on how to go about calibrating the oscillator? I have a scope and sig gen, but not a lot of exp using them. A little more detail on the process would be awesome.

Thanks and cheers!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: salomonander on July 17, 2016, 06:06:36 PM
hey
im about to give this build a shot. im a bit confused about transformers though. can i use any of the old british iron i have lying around? :

- marinair 10k:10k
-gardners that can be wired either 600:600, 600:1200 or 600:300

id really appreciate if someone smarter than me can tell if i could use those for in- and output....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Majestic12 on August 05, 2016, 03:13:33 AM
Hey guys.

Can anyone offer any advice on how to go about calibrating the oscillator? I have a scope and sig gen, but not a lot of exp using them. A little more detail on the process would be awesome.

Thanks and cheers!

Hi Desol,

from your pictures it looks like you have not mounted the trimmers on the oscillator boards correctly. They seem to be aligned verticaly on the pcb holes which basically shorts out all pins.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on August 06, 2016, 09:08:51 AM
Majestic. Thanks so much for pointing that out!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: salomonander on August 16, 2016, 03:18:45 PM
sorry i have to bump this one more time regarding transformers
i assume im fine with a 10k:10k input transformer
can i use a 150:600 on the output - or will impedance be messed up

sorry for the nnob questions i just cant answer it myseld. thanks
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on August 29, 2016, 08:36:47 PM
Any chance someone has resistor values for 23 step switch?
Or just to point me to some calculator?

I'd really like to swap potentiometers to switches and I already have some spare 23 step ones!

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: kosi on August 30, 2016, 02:08:41 AM
Send Bruno2000 a pm, he has a spreadsheet for a 21step switch,
see  Reply #635

Any chance someone has resistor values for 23 step switch?
Or just to point me to some calculator?

I'd really like to swap potentiometers to switches and I already have some spare 23 step ones!

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 10, 2016, 02:38:48 PM
Hey guys! Progress....I've managed to get both channels up and running and have been burning them in for the last day. The output sections seem to have gotten better/quieter from just burning in?, adjusting the levels, etc over the last 6 hrs. Fixed a few small problems. Basically both channels seem to be acting identically. Audio sounds good on both channels but the output signals are odd looking vs coming in(attached photo). I'm thinking this might be from the channels not being calibrated properly. Switchboards are functioning identically as well. Both my meters are showing half way on the scale. I think the original Pye's were like this. I'll need to figure out how to get them to zero.  Can someone help with the calibration procedure? I'm kinda new to this, but i'm having fun at it! :)

(http://i700.photobucket.com/albums/ww10/desol777/P9100748.jpg) (http://s700.photobucket.com/user/desol777/media/P9100748.jpg.html)

(http://i700.photobucket.com/albums/ww10/desol777/P9100743.jpg) (http://s700.photobucket.com/user/desol777/media/P9100743.jpg.html)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on September 10, 2016, 02:56:50 PM
That looks like the 250kHz leaking through.  I see (?) that you have your scope connected to the board side of the output.  Try looking at the output side of the output transformer.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 10, 2016, 04:57:45 PM
Hi Bruno! Yes, the sines look normal post output transformer. 

Now(i suppose) it's just a matter of getting the meters to sit right, doing the calibration and testing. Any advice with how to set the oscillator with the scope? Best place for the scope leads?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on September 10, 2016, 05:57:25 PM
Both my meters are showing half way on the scale. I think the original Pye's were like this.

The original Pyes I deal with aren't like this.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 11, 2016, 10:44:54 AM
Hmph. Well, thanks for letting me know Rob.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on September 15, 2016, 01:04:54 PM
Out of curiosity, if you were to get different output transformers, what would you try?  It might be nice to get a list and some general details for future builders.  Not sure that there is a huge amount of interest, but still.
Patrick

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 15, 2016, 02:34:06 PM
Don't know yet. I'd have to find out the impedances, etc...then choose a high quality, good sized unit based on that I think. I need to learn a few things first about measuring, etc. I think Joe put a whole separate output section and quality transformer on his...

Anyway, there has to be at least better than these edcors. :) (i'm assuming)

Here's something else had to do(for anyone building). Hole for meter adjust through frontpanel:

(http://i700.photobucket.com/albums/ww10/desol777/P9150796.jpg) (http://s700.photobucket.com/user/desol777/media/P9150796.jpg.html)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 27, 2016, 11:40:35 AM
(accidental erase of previous posts. Sorry to anyone who was looking!)

Well, DMM came in and I was pretty close. Channel 1 measured at 255khz. Channel 2 - 254.8khz. :)

Anyway, dialed them both down to 250. Still need to suss out an intermittent noise issue (I think at tr8) on right channel. Comes and goes, comes and goes. Got the vintage LED's in the meters and spec'ing out some white smaller knobs for it. This unit sounds exactly as I imagined it should sound. lol I'm still kinda blown away by it's character even a few weeks after having it here...with my other units. It's very powerful, the way it grabs and manipulates and in combination with the portico 5043(which i normally use to trail things) it's insane. Instant incredible sound.

Anybody have any tips for swapping out transistors, while doing minimal damage to the tiny pads/holes?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on September 27, 2016, 03:40:53 PM
I sacrifice the transistor coming out. I snip its leads as close to the transistor as possible. Using tweezers i grab the lead and add heat to get it out of the hole, Then follow up with a solder sucker or wick to clear the hole.

Glad you are getting good results now. I haven't had much time to post of even play with stuff as the band I'm in is gaining traction and its consuming some serious time.

I will go back and find my notes on how I calibrated mine, but what i remember is I set the input to maximum sensitivity (10dB on the NEG side), then put the scope on the side chain where you see the DC control signal. I used a precision meter to verify the tone going in was at -10dB and adjusted R52 (I think) until the DC on the scope just barely started to drop (remember these things are ass-backwards with  their negative supply rail, so that DC level "dropping" is actually an increase in control. Once that was done I set the  input attenuator to 0dB and raised the input to 0dB and checked that the the control level was just starting downwards.

Mine sits with the meters at zero with no compression and I did nothing with the values of those restores around the meter.

The weak area of this build is specing the output transformer and also the input transformer for the side chain...but...I found these damned things worked so well for what I needed, I quit fiddling with it and just use it.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 30, 2016, 02:55:36 PM
Hi Mdainsd! :) Thanks so much for the reply. Best of luck on your guys band endeavors!

I'm a little confused about the input control; how it's supposed to work. The front panel silkscreen(as on the originals) connote that the input(threshold) should be at zero all the time...and then you turn it into the negative(like other compressors) to get gain reduction. Easy. However on mine, depending on mic pre gain...it starts to compress as I turn UP the input from let's say zero at the bottom (if the pot were turned fully counter clockwise). Maybe I have the pot wired backwards?

I did realize that something wasn't making sense with the operation of input control on my unit, but the unit seemed to be working fine so I hadn't looked into it too much at that point.

In the manual on the basic control circuit operation, I'm assuming that we want to probe the 'end' of the control signal which is at the base of tr11.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 02, 2016, 04:12:06 PM
Made some more progress on this after it being on the shelf for the last 2 years (yikes).

Turns out my noise on the output was the jensen transformer I was using, or how I'd hooked it up possibly.  I need to get the data sheets again.   I subbes in a 600:10k Gardeners octal & all is well.   Although like Bruno says it looks like it could do with another roughly 6dB of gain. I notice that on the attached pic of an alternative version of the PYE it seems to have a rather more beefy output stage.

I'm using a pair of OEP transformers for the sidechain & Gardeners octals for the inputs.

I still wish we knew more about these trimmers.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 02, 2016, 05:21:43 PM
Hi Mdainsd! :) Thanks so much for the reply. Best of luck on your guys band endeavors!

I'm a little confused about the input control; how it's supposed to work. The front panel silkscreen(as on the originals) connote that the input(threshold) should be at zero all the time...and then you turn it into the negative(like other compressors) to get gain reduction. Easy. However on mine, depending on mic pre gain...it starts to compress as I turn UP the input from let's say zero at the bottom (if the pot were turned fully counter clockwise). Maybe I have the pot wired backwards?

I did realize that something wasn't making sense with the operation of input control on my unit, but the unit seemed to be working fine so I hadn't looked into it too much at that point.

In the manual on the basic control circuit operation, I'm assuming that we want to probe the 'end' of the control signal which is at the base of tr11.

you may want to revisit your input "threshold wiring".
 The lower you turn it (counter-clockwise), the lower the knee of compression. So if it is set to say -10dB. As soon as your input goes above that number it start to compress anything above that at the ratio you have selected.

Note: If you have the threshold on -10dB and the ratio selected for "limit", then anything above -2dB is limited. There is an offset on limit of 8dB.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 02, 2016, 06:22:58 PM
you may want to revisit your input "threshold wiring".
 The lower you turn it (counter-clockwise), the lower the knee of compression. So if it is set to say -10dB. As soon as your input goes above that number it start to compress anything above that at the ratio you have selected.

Note: If you have the threshold on -10dB and the ratio selected for "limit", then anything above -2dB is limited. There is an offset on limit of 8dB.

Not really getting your explanation here. Is the threshold level not fixed & you just wind more or less signal into it to get it compressing at different levels of signal.  The input pot is just a level control surely ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 03, 2016, 01:52:25 PM
Not really getting your explanation here. Is the threshold level not fixed & you just wind more or less signal into it to get it compressing at different levels of signal.  The input pot is just a level control surely ?

The input or threshold is an attenuator. When it is turned fully ccw (-10dB), there is no attenuation to the input signal at all, straight through into the compressor. The base compressor circuitry uses this -10dB as the knee if adjusted correctly. The output gain is also set at minimum (in fact some original PYEs have these two controls on the same shaft).

As you turn the threshold CW you are attenuating the signal going into the compressor portion. The output or makeup gain would be increased the same amount.

So, to reiterate: threshold set to -10dB, no attenuation, compression starts at -10dB input level. No output make up gain, so signal leaves compressor at same levels it came in albeit with compression at levels above -10dB.

Threshold set to 0dB: Input (lets say 0dB) is attenuated down to -10dB where the compressor does its work. Then the output or makeup gain is set for 10dB, boosting the output back up to the same as the input, again albeit the compression above 0dB.

This works so much easier when the threshold and makeup gain are on the same control.

I hope this helps.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 03, 2016, 02:23:31 PM
So what you are saying is that the input control should be reverse log (if it were an individual pot) so that as you turn it clockwise you turn the signal entering the compressor down & therefore you get less compression because your peaks over -10dB won't be as much.   The threshold (electronically speaking) is fixed & remains at -10dB regardless ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 03, 2016, 05:05:52 PM
Yes Rob. I think we are talking the same language about it now,  :D

My input and output are stepped attenuators as opposed to pots.

Does it help you?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 03, 2016, 05:48:28 PM
Yes, thanks that clarifies things.

I now have the oscillation problem return after it was behaving so well for a day ....  WHat a PITA.   about 44KHz saw tooth
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 04, 2016, 03:00:50 AM
Ok. After removing and replacing tr8, my suspicions were correct! Indeed it was the component causing the noise issue on the right channel. I found it by chance when I touched a leg on the transistor with a little screwdriver and it went pop!...and the noise disappeared. :) ...In addition, with just the XLR output cables plugged in and both channel amps cranked...i noticed i still had a  teeny tiny little buzz in each channel. After some poking around, I sourced it to the bypass relay boards and hence the 12vdc power supply which needed to be grounded. After replacing the transistor and grounding the 12v supply, both of my channels are now dead quiet....no cell phone interference(i never experienced any of that), no buzz or hum.

Indeed I did have the thresholds wired backwards... Now they function as they should, increasing compression as they're dialed further into the counter-clockwise position.

I tried to follow Mdainsd instructions on setting r52(release). I set the threshold for -10db, maximum reduction...and input a -10 db signal(.24vdc sine) into both channels. I already had the release trims previously turned all the way down(meters at zero). The base of tr11 showed the normal pulses(spikes) on both channels which increased when I applied the -10db signal. I increased the release trimmers until the pulses just barely started to move upwards and then set them both identically and left them there. Hopefully I did this correctly!

Interestingly, I remembered that I had the Eddie Kramer Pye plugin on my computer, which is supposed to be a digital true replica of a Pye unit. So, I booted the workstation up and ran a drum loop through it to check the controls. Unsurprisingly, it was operationally identical to the DIY unit...including the volume bump/offset that happens when one switches to limit. Only real difference is, this hardware unit sounds incredible....and the plugin, well....sounds like a plugin.

So...both these channels now are working properly(as far as I can tell!). Other than waiting on the knobs, running a few more tests, etc. I'm feeling like they're close to being buttoned up!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 04, 2016, 01:07:43 PM
Great to hear! Another one is alive.

Yep you aligned yours the way I did mine. If you compared it to the plug and got the same results, then I'd say that way of aligning these is a good one.

Mark
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 09, 2016, 05:05:15 AM
Wish I'd known about this when I was populating the boards

http://buildbutler.org/build/pi-3141-rev3-chip-version#_22K

On another note I'm still getting quite a lot of 44KHz on the outputeven after the tranasofrmer.  I tamed it a bit by soldering a 10k acorss pin 2 & 3 on the XLR.    Still not really sire where it's coming from.  Other than that both channels seem to be working.   I wish we knew for sure what all these trimmers do.   
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 09, 2016, 05:16:32 PM
I don't understand! You left the 22k's out? I just checked my unit and the sine's do look normal at the xlr's with compressor switched in and different ratio's. 1k sine at .77v.

Edit: Actually, I just tested them again and I think I just had the output knobs off a bit. Checked with outputs aligned, and they seem to switch the same on the scope. :) However, I may change makeup pot to stepped switch in the future.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 09, 2016, 06:50:26 PM
I don't understand! You left the 22k's out? I just checked my unit and the sine's do look normal at the xlr's with compressor switched in and different ratio's. 1k sine at .77v.

I did notice something about my unit tho, and something I kind of suspected. My ratios are different on the scope between the channels. They both work good...but the right channel produces more compression per click. I'm thinking something isn't matched in the sidechain or isn't working quite up to snuff on the left channel. I'll have to study the schematic more to hone in on a likely component.

No I didn't leave the 22k's out.   It's just an app to help you find the components on the board easily.  You click on a compinent in the list on the left & it shows you where it is on the board.

I made a double attenuator, which isn't working quite right, probably because I rather rushed it to check it out.   Both my channels work after a fashion, but I don't think they're quite right.    I'm going to rebuild the attenuator in the next couple of days & see what I get.   

I believe R52 is actually a decay adjust.  I have a copy of a pye manual with a circuit diagram where R52 (which is R48 on this diagram is lablelled decay.  See attachment.

So if that is the case, which seems likely, what do the other presets actually do ?

R23 on Abe's board is not an adjust on test on the real diagram I have posted.  So who knows what that does.
R42 on Abe's board looks like it does meter scaling perhaps.  But that part of the circuit is different to the original, probably to cope with the meters you guys are using.  I need to probably restore to original because I am using some Pye type meters.  But this coukd be causing the meters to sit away from zero.
R44 & R48 I'm not sure about, I gues the thing to do is scope the area & see what effect they have on the sidechain signal.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 09, 2016, 07:56:56 PM
I noticed that neat piece of software that everything was dialed into. :)

Yes, I'm pretty sure it's in the build guide as well. R52 is release(decay). The way I have mine set is that it's basically turned all the way down(counter-clockwise till it clicks)...which lowers the meters to zero. Then calibrated up from there, using the scope. It still leaves the meters at zero. I didn't change any other trimmers from the screen print on the boards. I tried to dial R42 but it did nothing for me...so I left it at 5k1.

Would be nice to have an actual calibration procedure. Not exactly sure which Pye unit Abe's is based off of.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 09, 2016, 08:13:00 PM
One other thing is that some of these PYE's have a threshold range from -24dB to +16dB.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 10, 2016, 12:55:35 AM
Yep, they are all over the place. There are variants, One with a more substaintial output amplifier. Another with a gate and/or gain section in the front end.

The step attenuators are 40 dB 2 dB per step. That matches the -24 to 16dB version (or face  plate) The case I have is marked -10dB to +10dB, so i guess next time I have it open do a full measurement and see which is closer. I did use -24dB as my base input signal level. It probably can't output +16 on the more modest output section.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2016, 02:27:44 AM
Mdainsd

Can you clarify which preset you used to set the threshold since R52 is definitely a release trim?  You said in a previous post that you made some notes when you calibrated,  this would be very useful to the rest of us if you would care to share.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 10, 2016, 11:14:31 AM
The threshold is fixed isn't it? At -10db? If the input exceeds the -10db, it gets compressed.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2016, 02:28:20 PM
The threshold is fixed isn't it? At -10db? If the input exceeds the -10db, it gets compressed.

OK, I didn't twig that was what the case was.  I'd still like to know what the other AOT (trimmers) do.  One looks to adjust the meter, but does it set for zero or scale the meter so it reads the correct GR.  If it scales it & the meter is sitting about zero with no signal there is an issue somewhere else. For example another AOT resistor is causing gain reduction with no signal.     
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on October 10, 2016, 07:47:34 PM
Rob, I am not understanding  "If it scales it & the meter is sitting about zero with no signal there is an issue somewhere else. For example another AOT resistor is causing gain reduction with no signal. 

When there is no signal the meter should be at zero as there is no compression going on. These are not like Fairchilds and others that the meter sits way up at 0dB on a VU meter when there is no compression.  Edit: At least that is how mine is working, go to "AC Sound PI-3141 Stereo Compressor Pie Pye" on youtube, it shows the prototype with the meter in operation

Maybe Im misunderstanding what you are saying?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2016, 08:50:51 PM
I fully understand the meter doesn't sit up like on a UREI .  I have 2 origianl PYE meters here for my build so I need to dump  R65 & R67.  I'm just trying to get my head round the operation of the meter circuit

The preset R42 is either for scaling the meter, i.e making it so that if you have 10dB gain reduction happening it shows 10 dB on the meter, or to zero the meter so there is no voltage across it with no GR.

Looking at the diagram I posted a couple of posts above
The meter moves when there is pwm action, but is the meter movement derived from the current change through VT11 & R44/R74 or from the other branch through R41, or both.   It looks to me like R41 is trimmed so that the node R44/R74 is at the same voltage as bottom of R41 for no signal to zero the meter.     I am still getting my meter off zero with no signal. Since I can't zero it with R41, something must be out of trim so that some PWM action is happening with no signal, which is what is getting the meter to sit up,
This is why I would like to know what the other trimmers do.

Sorry if I'm harping on about this, but I'm close to getting this sucker working, & understanding this seems to be key.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 10, 2016, 09:27:17 PM
Rob is yours sitting just off zero like in Abe's video? If you dialed the release all the way down and left R42 at 5.1k it should be like Abe's. All your other trimmers are at suggested values right? I used a little of the meter adjust screw to fine adjust even closer to zero after the calibration.

Glad you're close to getting it running. The more signal you feed into it, the better it sounds.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 10, 2016, 09:56:35 PM
Rob is yours sitting just off zero like in Abe's video? If you dialed the release all the way down and left R42 at 5.1k it should be like Abe's. All your other trimmers are at suggested values right? I used a little of the meter adjust screw to fine adjust even closer to zero after the calibration.

I don't have the same meters Abe is using.   The thing I'm not getting is why one uses the release trimmer to zero the meter ???
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 10, 2016, 10:07:58 PM
R52 states 1k....so that's where I had the trimmer at first. That put my meters close to center on first power up. I turned R52 down cause I read Mark's post relating to how he had calibrated the unit + I tried r42 to move the meters...which didn't seem to do much. The position of the release trimmer didn't seem to affect the sound of the unit. The only thing that seemed to change was the overall volume and meter position. Pretty sure I listened to it with the trimmer at 1k and turned down and there wasn't a major difference. So I just left R52 adjusted to minimum position(ccw) and carried on with the rest of the calibration suggestion from there, which when done still left them close to zero.

Not sure why he didn't print the trimmer functions on the board. But you can more or less kinda figure out by where they're located(I think). If we had an actual procedure that would be cool. :) The units probably should be -24, +16 on the meter scale like you mentioned before. It doesn't bother me much if the scale is a little off, cause I love the sound of the unit. :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 11, 2016, 04:56:18 PM
R52 states it's a 1K trimmer on the original diagram I posted.  That doesn't mean it's necessarily set to 1K, although it could be.  When I scope the base of the chopper transistor adjusting R52 changes the level of the Pulse, with it set at zero I'm getting about 300mV pulses.   I find it difficult to believe that they would bother putting an AOT resistor in there if in actual fact it needed to be shorted for the unit to operate correctly.

R44 & also R42 change the width of the pulses.     R52 has more influence on the meter level than R42

Can you point me to "rest of the calibration procedure ? "
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 11, 2016, 09:35:16 PM
I wish I could. I've been looking for a calibration procedure myself. Strange it wasn't in the Pye manual, etc.
My r52 trimmer isn't shorted. After calibrating it back up on the scope with the threshold cranked, it was probably about 2 or 3 turns in from the bottom click where the control spikes began to move upwards.

The other trimmers were left on suggested settings.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 12, 2016, 07:09:15 AM
I wish I could. I've been looking for a calibration procedure myself. Strange it wasn't in the Pye manual, etc.
My r52 trimmer isn't shorted. After calibrating it back up on the scope with the threshold cranked, it was probably about 2 or 3 turns in from the bottom click where the control spikes began to move upwards.

The other trimmers were left on suggested settings.

When you says suggested settings, you mean the fixed values that ABe seems to suggest next to the trimmer values on the boards ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 12, 2016, 08:57:28 AM
Yep. The pre-trimmed values.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 12, 2016, 02:35:51 PM
I have put jumpers in for R65 & R67, which makes the particular meters I'm using work much more responsively.  This effectively puts the circuit back to original specs.

I managed to get one channel working quite so it looks quite good on test gear. on the meter I'm struggling to get much more than 12dB of reduction to show. 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on October 14, 2016, 07:54:30 PM
I got both channels working what looked like fairly well tonight.    I got the bit through for the stepped attenuators.  That seems to make things a bit more predictable.  WHat I was finding using 2 pots is that when you try to trim the things you have more variables which means there is a layer of randomness.     Unfortunately in my new workshop I don't have a monitor system just yet so this is all based on looking at it on a scope and milivlot meter & putting an audio signal in.   Really want a listen to this thing
Soon....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on November 28, 2016, 09:21:46 AM
Rob

What ever happened with the Pye? Did you get things sussed out with it....get a chance to try it on anything?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on November 28, 2016, 06:14:25 PM
Rob

What ever happened with the Pye? Did you get things sussed out with it....get a chance to try it on anything?

Yes I did get it working & it did sound good on a couple of things I tried on on my work bench.    I am trying to get a proper front panel sorted. I'm using 6 pole 5 way switches so that the lim is on the same switch as the ratio.   I drew a diagram for it but have yet to see if it worksbecause I can't find my molex pins since moving my workshop.  I did thins to save space so I can use bigger meters than danderloo uses for his case.   If it does I'll post it here.  I have a bunch of the switches if anyone want some.

In the mean time one of my dogs has smashed up one of the original Pye meters I was using.  So I need to try and glue all the bakelight back together & get a piece of glass cut.     He's a very clumsy dog but has a lovely temperament.  It's my fault for leaving it underneath where his food is kept.   See pic of him sleeping on my tool bag .....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Dreams on November 28, 2016, 06:22:46 PM
I've actually picked this back up a couple days ago. The calibration is still somewhat mystery, but I'm plugging away. Any tips or procedures anyone feels like sharing would be v much appreciated. Getting the "threshold" correct seems to be my problem, but all the trim pots interact, so.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on November 28, 2016, 06:33:20 PM
I've actually picked this back up a couple days ago. The calibration is still somewhat mystery, but I'm plugging away. Any tips or procedures anyone feels like sharing would be v much appreciated. Getting the "threshold" correct seems to be my problem, but all the trim pots interact, so.

The reality is that it is a lot easier to get going if you make the stepped in/out attenuator switch on a 2 pole 24way switch.  This automatically turns up the make up as it compresses more like on the API525.  It all looked very random before I fitted them.     I'm still not wildly sure exactly how all the presets should be set but it works & sounds fine.   I think most people are setting some of the presets to the nominal values on the diagram, which is what I did.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Dreams on November 28, 2016, 07:21:55 PM
Thanks Rob. I've got a 12 position switch rigged up for 2db steps, with build out resistors to make it go to 10k, if that makes sense? I'm building a single channel into 1 rack space, so that might be the best I'm gonna be able to do.

At the moment i have separate I/O controls because I'm trying to figure out how the gain works through it... if i was sure the transformers were correct, it would certainly narrow things down for me.

Anyway, I can get the thing to "work," but the measurements don't really make sense yet... I wish i could get my hands on an original for an hour!

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on November 28, 2016, 08:02:58 PM
You will find it very difficult to  figure the gain out unless you have both the in & out on one switch.   I spent months on & off trying to make sense of it.  It only came together when I had both on one switch.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Dreams on November 28, 2016, 08:11:08 PM
Haha fair enough, I'll throw it back in there now that I know the circuit is working as it should. I meant to say that in my last post...

Did you just leave the trimmers where they were? I was getting no change in pulse width at the chopper transistor with them set at the nominal values, but that also may have something to do with the sidechain transformer I'm using...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on November 28, 2016, 10:54:49 PM
He's a very clumsy dog but has a lovely temperament.  It's my fault for leaving it underneath where his food is kept.  See pic of him sleeping on my tool bag .....

He looks like a good boy! It looks like he knows he's in trouble..  :) ...and/or he's about to fall asleep!

@Dreams: I know for mine I just went with the pre-trimmed values printed on the board and everything seemed to look ok on the scope.

 
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on November 29, 2016, 04:37:47 AM
Haha fair enough, I'll throw it back in there now that I know the circuit is working as it should. I meant to say that in my last post...

Did you just leave the trimmers where they were? I was getting no change in pulse width at the chopper transistor with them set at the nominal values, but that also may have something to do with the sidechain transformer I'm using...

I just used a pair of cheap OEP transformers in the sidechain.  They are the 1+1:2+2 version, but are wired 1:2+2 to give me 1:4.  They seem to work fine.   For input I have a pair of Gardners 10k:10k, which are british vintage.  In trying to keep it an all British affair I was using some gardners 1:4 mic transformers on the output but whilst they seems t work well I wasn't sure they could handle the level so I subbed in some Edcor XSM 600:10k that were lying around doing nothig.  I might get some Carnhills to replace them.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on December 02, 2016, 09:00:08 PM
I wish i could get my hands on an original for an hour!

You mean like one of these bad boys
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on December 02, 2016, 09:09:40 PM
Another shot
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on December 02, 2016, 09:24:01 PM
The other side.  After playing around for a while this afternoon, I would say the clones sounds remarkably similar.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Dreams on December 02, 2016, 09:36:39 PM
Awesome.

You gonna have it for a few days? I could use a few measurements....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on December 02, 2016, 09:53:29 PM
I'm on site & don't have the time or test gear for measurements unfortunately.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on December 20, 2016, 12:45:30 AM
Has anyone who's bought the Pye case, had an issue with the meter bezel(47mm) cutout, being too big? The cutouts on my case are 50mm...which leaves a 3mm gap.

I have the hairball 8027-wf 1ma meters.

Cheers and thanks.

Yeah mine don't fit. Also the faceplate on the case doesn't fit the rest of the case either. When I screwed it together it bowed the faceplate.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on December 24, 2016, 01:22:12 PM
I just bought the case and pcb from dan...nothing else yet. So the hairball meters do not fit, and the meter adjust hole has to be drilled?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on December 26, 2016, 01:24:48 PM
I just bought the case and pcb from dan...nothing else yet. So the hairball meters do not fit, and the meter adjust hole has to be drilled?


Both a friend of mine & myself bought cases from Dan. The Hairball meters seem to fit perfectly on his case but on my case the holes are a bit wide. So however i put in the meters there is some extra space. We also find that the adjustment on the front of the meters gets in the way & they don't sit flush. I ended up drilling holes to make space for the adjustment screw to get them to sit flat. We also noticed that the colour on the faceplate is different between the two of our cases, & that the screws on my faceplate don't line up perfectly. So when I put mine together the faceplate bows a little. lso my friend noticed some bubbles under the paint of the bottom of his case. He figures there must have been rust painted over. Pretty disappointing considering how much we paid for the cases. Yours might be ok though. Just seems like it's a bit of a gamble ordering from that place.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on December 26, 2016, 01:28:21 PM

So after a few years of sitting on the parts & stuffing the board a little at a time. My friend (also in this thread) & I are coming close to completion. We're very exited to finish. We are just unclear on a few things & hoping some of the more experienced builders on here will be able to shed some light for us.

1 - Where do we solder in the side chain transformer?

2 - Is it possible to have a seperate sidechain in with this transformer?

3 - What are you guys using for the dual/Stereo link switch?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on December 26, 2016, 05:02:36 PM
1. you solder it where the header called t4 is
2. I don't understand your question
3. A standard miniture toggle switch dpdt
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on December 26, 2016, 06:37:31 PM
1. you solder it where the header called t4 is
2. I don't understand your question
3. A standard miniture toggle switch dpdt


Thanks for the quick response I kind of figured 1 & 3 out looking through everything on here. I don't know how I missed that.

2- I'm asking if there's a way to implement an external side chain input on here easily. Has anyone on here done that? Is it even possible? Would it be as simple as having a switch connecting another input to the sidechain transformer & switching between the existing path & the external in? Or am I totally out to lunch?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on December 27, 2016, 07:18:04 PM
Received the boards and case from Dan today. I did a quick test fit and the front faceplate bows. This may be something I can remedy, but for now I'll start compiling the various carts for all the components. Should I make my own build thread or clutter this one up even more?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on December 27, 2016, 07:47:05 PM

Thanks for the quick response I kind of figured 1 & 3 out looking through everything on here. I don't know how I missed that.

2- I'm asking if there's a way to implement an external side chain input on here easily. Has anyone on here done that? Is it even possible? Would it be as simple as having a switch connecting another input to the sidechain transformer & switching between the existing path & the external in? Or am I totally out to lunch?

Personally it's not something I would implement, so I don't really have an interest in spending any time on it.   
Why don't you try it and report back.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on December 27, 2016, 07:53:42 PM
Received the boards and case from Dan today. I did a quick test fit and the front faceplate bows. This may be something I can remedy, but for now I'll start compiling the various carts for all the components. Should I make my own build thread or clutter this one up even more?

Go throught this thread and read it. Entirely!
Stuff that is now boring to read will at some point if you go troubleshooting ring in the back of your mind and you'll know to return and re-read again parts that are relevant. At that point you'll be much more familiar with the schematic and parts and it won't be boring to read. :)

Stick to the BOM posted by SR1200
Use the PYE3 14SCHB.pdf schematic as a reference
Triple check everything
And you'll probably be without problems!

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: frederickalonso on December 28, 2016, 08:31:25 AM
I have the pcb's but need to order the parts when i have time.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 10, 2017, 07:35:58 PM
I should be able to get the wiring finished this weekend! But I'm sure I'll have some troubleshooting to do...
Also, I'll be sending 24VDC to the boards...should I be sending 24VAC instead since there appears to be on board rectification? I guess I'll lose a some voltage to the diodes but I should be able to meet the 18-22 VDC range.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 10, 2017, 07:38:50 PM
additional pic
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 12, 2017, 12:11:00 PM
So far so good. The choppers were calibrated to 250kHz spot on. I do have one question though, for the 18-22VDC measurement....is this measured between B+/B- or is it measured between B+/ chassis ground? I have 18.38 between B+/B- and 23.28 between B+/chassis ground. I should be good then right?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 13, 2017, 02:17:35 PM
Measurement is between  B-neg(+) and B-pos(-). I set mine to 22v.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 13, 2017, 02:24:09 PM
B+ and chassis GND should be tied together at a single point. So they should measure the same.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 13, 2017, 08:21:57 PM
Ok made a couple changes. My B+ is tied to chassis ground on pin 1 input xlr. I get -22 at B-(positive probe) to B+ (Negative DMM probe).
I guess I am confused about the whole analog ground thing. isn't there technically DC on B+ after retification?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 14, 2017, 11:28:46 AM
Has anybody measured the actual ratios of this comp? I'm having very funky readings with mine...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 14, 2017, 01:56:30 PM
Has anybody measured the actual ratios of this comp? I'm having very funky readings with mine...

Yes.  I'll see if I can find my AP graphs and post.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 14, 2017, 02:08:31 PM
Yes.  I'll see if I can find my AP graphs and post.
Best,
Bruno2000

I saw your graphs in this thread somewhere. And they look quite good.

My graphs look like approx. 3.5:1 at all ratio settings. And ratios are very level dependent.

Could you please elaborate on which preset trimmers values you used? Also, did you put in 82p cap or 1n cap after the osc? I've scoped the base of the chopper with both values and couldn't get the graphs that look like in the original unit. And I get a ton of static GR if I don't tweak the R42 drastically lower (<1K).

Another question if you don't mind. Were you able to get unity gain through the compressor without additional output stage?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 14, 2017, 03:38:33 PM
I saw your graphs in this thread somewhere. And they look quite good.

My graphs look like approx. 3.5:1 at all ratio settings. And ratios are very level dependent.

Could you please elaborate on which preset trimmers values you used? Also, did you put in 82p cap or 1n cap after the osc? I've scoped the base of the chopper with both values and couldn't get the graphs that look like in the original unit. And I get a ton of static GR if I don't tweak the R42 drastically lower (<1K).

Another question if you don't mind. Were you able to get unity gain through the compressor without additional output stage?

I don't remember about the osc cap.  Used whatever the original BOM said.  No weirdness on the trimmers IIRC.
I could never get unity gain, thus the added Neve output section.  Still working on the 4060 output section that added the needed gain.
https://groupdiy.com/index.php?topic=65187.0
Best,
Bruno2000

Edit:  Added pdf of comp curves (?)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 15, 2017, 07:53:24 AM
Actually, I would argue that the circuit has all the gain as it is.  It's possible to verify this by removing the chopper transistor completely (removing the 555 chip won't work since the chopper is still biased half open and shunts the signal to GND).
This means that we have static gr going on which is wrong. From the original scopes it shows just short downward spikes that shouldn't drop the level noticeably.

I suppose that the interaction of the circuit and the blocking osc is not as simple. And 555 osc behaves differently.

It would really help if somebody could scope the base of the chopper without input signal and post the graph here.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 15, 2017, 04:12:50 PM
Actually, I would argue that the circuit has all the gain as it is.  It's possible to verify this by removing the chopper transistor completely (removing the 555 chip won't work since the chopper is still biased half open and shunts the signal to GND).
This means that we have static gr going on which is wrong. From the original scopes it shows just short downward spikes that shouldn't drop the level noticeably.

I suppose that the interaction of the circuit and the blocking osc is not as simple. And 555 osc behaves differently.

It would really help if somebody could scope the base of the chopper without input signal and post the graph here.

I respectfully disagree.  I tried everything I could to get unity gain from the comp.  The best I could do was a 6dB loss with some pretty wild value changes.  Add to that that the output section in the 4060 schematic adds about 28dB of gain.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 15, 2017, 04:36:47 PM
I respectfully disagree.  I tried everything I could to get unity gain from the comp.  The best I could do was a 6dB loss with some pretty wild value changes.  Add to that that the output section in the 4060 schematic adds about 28dB of gain.
Best,
Bruno2000

I could get unity gain with 1:3 step-up on the output. If you're using 1:2 step-up, you'll get 6dB loss, I agree.

I played with the circuit a lot in the sim, and it's unity gain if SC operates correctly (and with 1:3 output tx). 4060 output uses another output transformer, so its apples to oranges comparison.

However, this is not my main point. I'm saying that in it's current state the osc and the following circuit is not forming the correct waveform at the base of the chopper. I think we need to concentrate on this first. And deal with the unity gain issues later.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 15, 2017, 04:51:48 PM
I could get unity gain with 1:3 step-up on the output. If you're using 1:2 step-up, you'll get 6dB loss, I agree.

I played with the circuit a lot in the sim, and it's unity gain if SC operates correctly (and with 1:3 output tx). 4060 output uses another output transformer, so its apples to oranges comparison.

However, this is not my main point. I'm saying that in it's current state the osc and the following circuit is not forming the correct waveform at the base of the chopper. I think we need to concentrate on this first. And deal with the unity gain issues later.

Ah, a step up XF on the output............
My reply was based on no transformers at all........
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 15, 2017, 10:53:58 PM
Up and running! https://youtu.be/Pa7UC_Gr3_o

Trim pots are very crucial to proper setup. Here is how I think of it (even though it may not be technically right, this is what I heard/saw)

1) Compression amount is determined by a very specific range on R23. Set it just before the audio craps out or the compression sounds unpleasing

2) R52 is maxed to one side. Deals with meter zero'ing. But not as much as R48

3) R48 has a very particular sweet spot for meter zero'ing. Get it in the 0-4dB range and then crank R52 which ever way to get the meter right on zero

4) R42 wasn't doing too much for me, but I think it influenced the meter speed and how fast the meter was swinging. Nominal value is fine.

Getting both meters similar is tricky, count the turns on the pots. Also, make sure the 100ms and 3.2 s decay times are actually what the meter does, R48 will change this.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 16, 2017, 11:45:29 AM
I got a mail from Abe not too long ago indicating that he was getting back to it. Be really nice to see him here soon....

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 16, 2017, 02:39:12 PM
Very good.

I'm still curious to see the ratios that other builders get. It's very easy to measure. Feed the signal to the compressor and set it so it just starts compressing. Increase the signal 10 dB. You should get 5 dB/3 dB/2 dB increase for each respective ratio (2:1/3:1/5:1).

Anybody? It takes just a couple of minutes.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 19, 2017, 12:51:23 PM
I used a 440Hz sine tone. I guess I would need 23db return to get a proper 5:1 for this example. I'm sure Trim Pot adjustment will remedy this ratio issue. Send and return vol are in dB.
Here are my calculated ratios:

Send Vol   Ratio   Return Vol   Actual Ratio   Channel
-24              2:1           -25                 N/A                         L
-24              2:1           -25                 N/A                         R
-14              2:1           -19.4            1.8:1                       L
-14              2:1           -19.4            1.8:1                       R
-14              3:1           -20.6            2.3:1                       L
-14              3:1           -21.0            2.5:1                       R
-14              5:1           -21.0            2.5:1                       L
-14              5:1           -21.8            3.1:1                       R
-14              Limit      -16.4            1.2:1                       L
-14              Limit      -17.6            1.4:1                       R
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 19, 2017, 03:23:47 PM
 eddie_ruff_

Thanks for your effort!
1 dB increase is too small to give any meaningfull information about ratios. You need to increase the signal by a 10 dB to calculate ratios correctly.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on February 19, 2017, 08:58:15 PM
I did! I started at -24dB and then went up by 10dB to get -14dB
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 20, 2017, 03:44:29 AM
I did! I started at -24dB and then went up by 10dB to get -14dB

Ah, I see. For some reason I had very strange formatting on my phone and misread your table.

So the compression starts at -23 dB?
What values of trimmers did you set? (EDIT: disregard, I've found the info in your previous post)

EDIT2: Do you have a scope? Could you scope the output of the oscillator and the base of chopper without signal?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 03:38:54 PM
Ah, I see. For some reason I had very strange formatting on my phone and misread your table.

So the compression starts at -23 dB?
What values of trimmers did you set? (EDIT: disregard, I've found the info in your previous post)

EDIT2: Do you have a scope? Could you scope the output of the oscillator and the base of chopper without signal?

Here ya' go.
T/D 1uS
1V/D
Anything else while I've got it on the bench?
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 20, 2017, 03:47:10 PM
Here ya' go.
T/D 1uS
1V/D
Anything else while I've got it on the bench?
Best,
Bruno2000

Wow, cool! Thanks a ton!
A base of chopper would be helpful. Without signal or at the onset of compression.

What sidechain trafo are you using? 1:4 or something else?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 03:50:23 PM
Wow, cool! Thanks a ton!
A base of chopper would be helpful. Without signal or at the onset of compression.

What sidechain trafo are you using? 1:4 or something else?

Sidechain 1:4
Using the 555 so base?
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 20, 2017, 04:02:22 PM
Sidechain 1:4
Using the 555 so base?
Best,
Bruno2000

I mean the base of TR11 (the PN3640).

I suspect that my ratios are screwed because of the sc trafo. I'm currently using 1:2 as was suggested in another thread by someone who claimed to have measured the originals. Gonna get a higher ratio tafo and see if it changes anything. I've been messing with this for almost a week and the circuit behaves as it should. But the ratios are way off.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 04:13:51 PM
I mean the base of TR11 (the PN3640).

I suspect that my ratios are screwed because of the sc trafo. I'm currently using 1:2 as was suggested in another thread by someone who claimed to have measured the originals. Gonna get a higher ratio tafo and see if it changes anything. I've been messing with this for almost a week and the circuit behaves as it should. But the ratios are way off.

None,
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 04:14:44 PM
I mean the base of TR11 (the PN3640).

I suspect that my ratios are screwed because of the sc trafo. I'm currently using 1:2 as was suggested in another thread by someone who claimed to have measured the originals. Gonna get a higher ratio tafo and see if it changes anything. I've been messing with this for almost a week and the circuit behaves as it should. But the ratios are way off.

Lots (limit)
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 04:15:50 PM
I mean the base of TR11 (the PN3640).

I suspect that my ratios are screwed because of the sc trafo. I'm currently using 1:2 as was suggested in another thread by someone who claimed to have measured the originals. Gonna get a higher ratio tafo and see if it changes anything. I've been messing with this for almost a week and the circuit behaves as it should. But the ratios are way off.

Only a week?
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 20, 2017, 04:22:21 PM
Only a week?
Best,
Bruno2000

Ok, This puts things in perspective....

Thanks for pics!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 04:30:30 PM
Ok, This puts things in perspective....

Thanks for pics!

My pleasure.
Hooked up to the AP.  Anything else?
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on February 20, 2017, 04:39:27 PM
My pleasure.
Hooked up to the AP.  Anything else?
Best,
Bruno2000

Not anything important I can think of right now. Maybe only this - what THD reading are you getting in the 1:1 mode?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on February 20, 2017, 04:51:36 PM
Not anything important I can think of right now. Maybe only this - what THD reading are you getting in the 1:1 mode?

About 0.2% at 0 dBu out
About 2% at +20 dBu out.
w/extra Neve gain stage (+10 dB)
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mrclunk on April 05, 2017, 05:26:02 AM
Hi folks,
i'm a bit late to the party but does anyone have the full 80 4060 schematic/service doc with the extra output stage included?
As per the clip below.

I see Mr Sowter now does the output transformer for it. http://www.sowter.co.uk/acatalog/E_A_Sowter_Ltd_VINTAGE_RECORDING_AMPLIFIER_TRANSFORMERS_5.html
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on April 05, 2017, 06:09:02 AM
Hi folks,
i'm a bit late to the party but does anyone have the full 80 4060 schematic/service doc with the extra output stage included?
As per the clip below.

I see Mr Sowter now does the output transformer for it. http://www.sowter.co.uk/acatalog/E_A_Sowter_Ltd_VINTAGE_RECORDING_AMPLIFIER_TRANSFORMERS_5.html

This pic basically shows the whole output stage. The input/sidechain are roughly the same. Sowter did the transformers, but I'm not aware if anybody actually tested them in this design.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mrclunk on April 05, 2017, 07:02:53 AM
Thanks, i think i see the changes now.
Here's the console version schem for folks.
I didn't spot it in this thread.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 15, 2017, 08:36:17 AM
Hi All,

i've taken the plunge to try and get hold of a couple of these pcbs from Abe, i love Eddie Kramer so i need to get me a decent stereo pair of these for the studio!!
prepare yourselves for when i get stuck!!!

Happy Easter btw everyone.

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on April 15, 2017, 11:00:35 AM
I've spent ridiculous amount of hours trying to get this compressor to work as it should. And I finally nailed what was the problem - one shorted trimmer on R44 position!
It has been very frustrating but it was worth every minute IMO.

Just follow the build guide and BOM provided by SR1200 and reference to the schematic file PYE3 14SCHB.PDF and you'll be good. They are both somewhere in this thread.

I've built dual unit and after I realized how transparent it is, I've replaced pots with switches on input and output.
Not it is tracking so precisely that it doesn't have to be in stereo link mode to maintain accurate stereo image.
It is definitely a mastering grade compressor!

If you get stuck, I can pull out my unit and do a voltage map. That may help.

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 15, 2017, 01:19:16 PM
thats very kind Luka, i will start getting all the bits together as i think i have a lot of the bits left over from other units ive built, i will probably wind my own inductors and transformers as well.

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 16, 2017, 05:31:09 AM
Did I read that a line balancer can be used on output?

Could a 500uA meter be used? Or other meters?

I have a few choices of transformers that I can use for input and sidechain.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 17, 2017, 03:12:25 PM
I built mine with the recommended parts/values and had no problems. I'd say stick with what's recommended.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 18, 2017, 04:29:10 AM
Ive ordered the correct 1ma Meters and decided to go with the TLC555 pcb.
Few other resistors and caps I will have to order but should have pretty much everything else.
Looking forward to this build!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 18, 2017, 05:05:05 AM
is there a specific schematic available for this build?
i have found a schematic with 2 x 52mH inductors shown but not one with the 12uH and the 50mH
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on April 18, 2017, 06:13:27 AM
I think it's somewhere in this thread, but on a quick search I couldn't find it.

So here it goes (again)

schematic PYE14SCHB
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 18, 2017, 11:22:19 AM
perfect thanks!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 19, 2017, 07:56:56 PM
If you haven't done so, I'd also recommend reading the thread from start to finish just to get some perspective on it.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 20, 2017, 02:10:19 AM
Yes, I need to find out about how to bypass the unit! Should I wire input to output true bypass or wire a switch to disable sidechain?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on April 20, 2017, 07:00:11 AM
Disabling sidechain would require lifting one leg from the switching transistor. That would be messy on this board. Also, you would probably have to lift send to interstage transformer.
Way more neat would be to do true bypass via relay on the in/out connectors
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 20, 2017, 11:35:46 AM
Has anyone done a schematic and pcb layout for the relay true bypass?
If not im up for doing one and putting it up here.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 20, 2017, 10:19:47 PM
When the bypass boards (if you're using the same ones) are powered the circuit is in. When they lose power(bypass on), the nc contacts pass in directly to out.

https://www.facebook.com/photo.php?fbid=208395312989103&set=a.191092941386007.1073741829.100014559074906&type=3&theater
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on April 20, 2017, 10:36:19 PM
When the bypass boards (if you're using the same ones) are powered the circuit is in. When they lose power(bypass on), the nc contacts pass in directly to out.

https://www.facebook.com/photo.php?fbid=208395312989103&set=a.191092941386007.1073741829.100014559074906&type=3&theater

:(

I get "The link you followed may have expired, or the Page may only be visible to an audience that you aren't in" for this.  Is there a special, elite group that I need to join? ;)

Thanks,
A.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 20, 2017, 11:11:38 PM
It's no big deal really. Just a pic of the layout and bypass boards with power on.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on April 20, 2017, 11:20:42 PM
It's no big deal really. Just a pic of the layout and bypass boards with power on.

Cheers, thanks for that.

The OCD person inside me would like you to fix up that fourth transformer please ;) ;)

Cheers,
A.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 21, 2017, 12:15:16 AM
Well, it's quieter in that position.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on April 21, 2017, 01:02:34 AM
Well, it's quieter in that position.

It's OK, I was only kidding :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 21, 2017, 03:32:00 AM
would be good to have a detailed schematic of this relay pcb, could anyone shed any light on this please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 21, 2017, 03:36:45 AM
ok ive done some digging and found this!

https://groupdiy.com/index.php?topic=29770.0

or this

https://groupdiy.com/index.php?topic=44049.0
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 21, 2017, 07:39:52 PM
A relay is a relay; isn't complicated...all the hookups are labelled on the boards no/nc. Boards were off of Ebay...

http://www.ebay.com/itm/Two-DPDT-Signal-Relay-Module-Board-DC12V-Version-for-PIC-Arduino-8051-AVR-/130690277968?hash=item1e6dbf6250:g:1asAAOSwk5FUv7Nz
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on April 21, 2017, 09:27:54 PM
i'd rather build my own pcbs
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: touane on April 22, 2017, 03:04:07 AM
I've spent ridiculous amount of hours trying to get this compressor to work as it should. And I finally nailed what was the problem - one shorted trimmer on R44 position!
It has been very frustrating but it was worth every minute IMO.

Just follow the build guide and BOM provided by SR1200 and reference to the schematic file PYE3 14SCHB.PDF and you'll be good. They are both somewhere in this thread.
Luka

Great to hear another success story with this one! I've been following this thread for a while, and had a go myself but not 100% happy yet with the build. It does sound good, but craps out with max ratio, where I get a nasty thump as compression kicks in. Also, never gets to compress more than 10-12dB, despite what meter shows.

I'd love to ask you a few questions regarding calibration, in case you have a minute:

R23-->recommended 22R. Both in simulation and reality, it all sounds horrible with this value, and I ended up setting it around 68R, which is also the value appearing on the original schematics. Could you mention how you set this one?

Oscillator: I imagine you also used the 555. Could you mention which freq. and which duty cycle you ended up with?

Would love to hear more (if you recall) how you proceeded to set it up.

Thanks!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on April 22, 2017, 06:56:51 AM
R23-->recommended 22R. Both in simulation and reality, it all sounds horrible with this value, and I ended up setting it around 68R, which is also the value appearing on the original schematics. Could you mention how you set this one?
I did readjust this one a lot, but after I found out my problem was elsewhere I set it back to around 22R. Since I have dual channel unit, I set those to match channel-to-channel gain exactly.
What I found out is that this trimmer simply sets the gain of the unit. But if you go with too much gain it can run the channel into shutdown. So you don't have unlimited range of gain setup.
Be aware that this compressor is feedback topology. If you raise the gain on R23 it affects the gain in the sidechain and that consequently changes the compression amount.
I think that you can set it at whatever resistance you feel it sounds good as long as sidechain is behaving properly!

Oscillator: I imagine you also used the 555. Could you mention which freq. and which duty cycle you ended up with?
I never had problems with oscillator. I built it with 555 and first I checked if it is getting proper supply voltage (in my case few mV higher than -12V). Then I used my cheap chinese Hantek to trim chopper pulses to the specified 250kHz. It was no big deal. Once done, I never had to go back to it.

Would love to hear more (if you recall) how you proceeded to set it up.
Problem with my dual unit was, as I mentioned somewhere before, with shorted R44 trimmer on one channel. It was manifesting as low output gain on that channel. I first went and tested main signal path on both channels. For it to be tested, I had to disconnect entire sidechain. It was messy since I didn't socket my transistors in the first place and solder pads on this pcb are very small with narrow holes. Disconnecting sidechain is done by lifting mid leg of the chopper transistor PN3640 and disconnecting interstage transformer's primary. That way you can test your input-to-output signal integrity.

I found out that when using BC550A on TR12, as recommended by Abe, is crap. I used 2N4124 as recommended by SR1200 and it performed well. As well, I did my first mistake not taking care when stuffing board in the first place so I put BC550C on that position! 550C has way too much gain. But then I got 550A and it didn't perform well either. When using 2N4124 it was all good.

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: touane on April 22, 2017, 08:53:40 AM
Much appreciated @ Luka, I'll take note for next time I decide to open that box!
Cheers,
M.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on April 23, 2017, 12:19:14 AM
i'd rather build my own pcbs

Yeah! I guess if you have the time it's a cool idea. Mdainsd sussed out most of the issues with this circuit and abe predefined everything as it should be. If people stick to what these guys did and found previously, you shouldn't have any problems.

If people start changing things, I'm assuming they will run into issues that are difficult to figure out. Also, there is no known calibration procedure. Abe spent 3 years? fooling around with this circuit, so rolling with the pre-trimmed values seems a wise idea.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on May 07, 2017, 02:02:41 PM
Wanting to know some inductance figures for the input transformers and side chain if anyone can help please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on May 10, 2017, 04:23:11 PM
Looks to me like the 1:1 input transformers need to be nickel lams or mix of nickel/steel?
Have ordered two pcbs about 3 weeks ago and nothing arrived yet and no word from Abe? :(
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on May 10, 2017, 06:12:41 PM
I think the PIE PCBs are probably still being manufactured, since the pre-order only finished recently.   That's probably why you haven't received them yet.  You may have to wait a few weeks, or even months.   I too am waiting for a set of PIE boards.  I'm sure they'll turn up eventually.  My CLX PCBs took a few months from pre-order to delivery and there was no problem there.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on May 11, 2017, 07:43:55 AM
I think the PIE PCBs are probably still being manufactured, since the pre-order only finished recently.   That's probably why you haven't received them yet.  You may have to wait a few weeks, or even months.   I too am waiting for a set of PIE boards.  I'm sure they'll turn up eventually.  My CLX PCBs took a few months from pre-order to delivery and there was no problem there.

Update: the web site says they're in stock, so I expect my pre-order is on its way now!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on May 11, 2017, 05:57:52 PM
That's good to know as I'm very keen to complete this build as I'm using the plugin but I'm sure the real thing kicks more butts!!
Hopefully next week the pcbs and other bits will arrive.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: trashcanman on May 14, 2017, 07:05:48 PM
Does anyone know if the acsound store is still filling orders? I bought a couple of pre-order Pye boards a few weeks ago and now I've realised they've been shutdown for years or something. Has anyone received anything from them recently?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on May 14, 2017, 07:20:28 PM
Does anyone know if the acsound store is still filling orders? I bought a couple of pre-order Pye boards a few weeks ago and now I've realised they've been shutdown for years or something. Has anyone received anything from them recently?

The pre-order only finished recently, so they've only just been in stock for a few day/weeks at most.   That's might be why you haven't received them yet.  AC Sound is single-person operated amateur DIY, where things often take weeks or months, not a high volume commercial multinational company with dozens of employees where you might get overnight delivery and an instant response to your emails...

I too am waiting for some PI boards - I'm sure they'll turn up eventually.  I bought two CLX PCBs late last year and they took a few months from pre-order to delivery so they're most likely still open and operating.

Cheers,
A.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: trashcanman on May 14, 2017, 07:25:36 PM
The pre-order only finished recently, so they've only just been in stock for a few day/weeks at most.   That's might be why you haven't received them yet.  AC Sound is single-person operated amateur DIY, where things often take weeks or months, not a high volume commercial multinational company with dozens of employees where you might get overnight delivery and an instant response to your emails...

I too am waiting for some PI boards - I'm sure they'll turn up eventually.  I bought two CLX PCBs late last year and they took a few months from pre-order to delivery so they're most likely still open and operating.

Cheers,
A.

Cool, I just saw the posts above about other people ordering them. I should probably read threads before replying.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on May 21, 2017, 11:24:30 AM
Good to see people still chugging along with this project. It is worth the time and effort for sure.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on May 28, 2017, 07:23:09 AM
been well over a month wait for the pcbs now, i have emailed and tried to contact but nothing back?
starting to get worried now!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on May 28, 2017, 07:40:04 AM
been well over a month wait for the pcbs now, i have emailed and tried to contact but nothing back?
starting to get worried now!!

Sadly I am in the same boat - nothing in the post, emailed a couple of times to say hello but heard nothing back :(

But I am the patient type, so I guess I'll just see what happens.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on May 28, 2017, 03:07:02 PM
Heres hoping your boards arrive, soon hopefully. The level of support for this project has been woefully inadequate from the git-go. But that is Ok in a way. It forced some of us building these things, to get busy figuring them out rather than just following an assembly manual. I learned a lot on this build.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on May 28, 2017, 06:22:50 PM
Heres hoping your boards arrive, soon hopefully. The level of support for this project has been woefully inadequate from the git-go. But that is Ok in a way. It forced some of us building these things, to get busy figuring them out rather than just following an assembly manual. I learned a lot on this build.

Yes - I've read this thread a couple of times and it's great to see how you lot worked through issues collaboratively and in public.  I think often that sort of thing is done by the smart/experienced/highly-motivated guys, but behind the scenes, so use mere mortals never see it in action.  Thanks!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 04, 2017, 05:04:46 PM
Made some substantial progress on this project. Here's a what I've found:

In order for the compressor to operate correctly you HAVE to make the discrete oscillator. The interaction of the original blocking oscillator with the rest of the circuit is quite large and there's no way you can just drop in a 555 circuit and hope it will work out fine. With discrete oscillator the circuit requires almost no tuning, all ratios and the threshold are correct. Threshold seems to be in dBV, not dBu.

For those who chose the 555 chip as an oscillator. Check your ratios! You may have to fine tune the PWM mark-space ratio to get the ratios correct. The threshold will probably be off as well.

Now, here's the curious problem that I have both with the 555 and discrete oscillators. When the compression kicks in, there's a strange looking waveform, almost as if some low frequency modulation is going on. This only happens when the compressor goes from no compression to compression (when the input level increases). I'm including the picture of the waveform. You can see that there are two places where compressor starts to work. They both look different, but conditions were absolutely the same.

I wonder what other, brighter then me, members of this forum can suggest.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: headstack on June 05, 2017, 01:22:36 AM
Are these the Pye boards from AC Sound?
Sent them money last year and have now sent a few messages to check with no response.
Looking for the website finds it down.
I am hoping this is not an illness, or someone disbanding a business and walking off with monies.
Word was that the boards were to ship in March or April as memory serves.
Apologies if I'm totally off base here.

Thank you,

John
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on June 05, 2017, 01:30:49 AM
Are these the Pye boards from AC Sound?
Sent them money last year and have now sent a few messages to check with no response.
Looking for the website finds it down.
I am hoping this is not an illness, or someone disbanding a business and walking off with monies.
Word was that the boards were to ship in March or April as memory serves.
Apologies if I'm totally off base here.

Thank you,

John

Nope, you are on the money... excuse the not-very-funny pun there  :-\

Before the AC Sound store went down, the PYE boards changed status from pre-order to available for a few days.  For a while the whole main AC Sound web site redirected to a completely different company, but then it came back.  But the store has been down for a while now.  I'm not getting response to my emails either, so waiting is really the only option at this stage.

I'm desperately hoping that the issue is something like faulty boards from the board manufacturer, and so they've taken down the store and stopped selling for a while until they sort it out.  But who knows.

Cheers,
A.

[edit: stupid grammar stuffups!]
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 05, 2017, 02:15:00 AM
be nice to just have one reply on email to one of us to let us know!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mrclunk on June 07, 2017, 11:43:42 AM
Are these the Pye boards from AC Sound?
Sent them money last year and have now sent a few messages to check with no response.
Looking for the website finds it down.
I am hoping this is not an illness, or someone disbanding a business and walking off with monies.

In the same boat too...
I've bought pcb's from Abe before without issue.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on June 07, 2017, 02:44:50 PM
Made some substantial progress on this project. Here's a what I've found:

In order for the compressor to operate correctly you HAVE to make the discrete oscillator. The interaction of the original blocking oscillator with the rest of the circuit is quite large and there's no way you can just drop in a 555 circuit and hope it will work out fine. With discrete oscillator the circuit requires almost no tuning, all ratios and the threshold are correct. Threshold seems to be in dBV, not dBu.

For those who chose the 555 chip as an oscillator. Check your ratios! You may have to fine tune the PWM mark-space ratio to get the ratios correct. The threshold will probably be off as well.

Now, here's the curious problem that I have both with the 555 and discrete oscillators. When the compression kicks in, there's a strange looking waveform, almost as if some low frequency modulation is going on. This only happens when the compressor goes from no compression to compression (when the input level increases). I'm including the picture of the waveform. You can see that there are two places where compressor starts to work. They both look different, but conditions were absolutely the same.

I wonder what other, brighter then me, members of this forum can suggest.

I also had problems with thumping on the attack of a fast transient.
Unfortunately, I didn't pinpoint the solution to an exact component or setting.
What I know is that this occurred during the tests with one transistor that was ill behaving (TR12) and I managed to completely mistune all the trimmers. So what was going on I'm not sure.
I was obsessing with getting equal signals on both channels so I went to replace most of the transistors with pairs of hfe matched ones, and I also removed trimmers R41, R42 & R44 on the channel that had problems. So after that thumping on trasients stopped, but my troubles were still in other areas.
After a lot of headache, final fix was replacing shorted trimmer on the other channel. That made them behave exactly the same.
And to be matched, I also replaced pots with stepped switches.
Now they're working.
And I'm using 555 on the oscillator! No problems with that.
:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 11, 2017, 04:36:38 AM
I also had problems with thumping on the attack of a fast transient.
Unfortunately, I didn't pinpoint the solution to an exact component or setting.
What I know is that this occurred during the tests with one transistor that was ill behaving (TR12) and I managed to completely mistune all the trimmers. So what was going on I'm not sure.

Thanks for your input. Unfirtunately, changing those transistors to low hfe type didn't change anything for me  :(. Still looking for what's wrong with the unit
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 11, 2017, 12:01:06 PM
anyone able to get any response from Abe?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mrclunk on June 12, 2017, 11:37:52 AM
anyone able to get any response from Abe?
Nope.
I ordered over3 months ago.
Think i'll have to contact my CC company unfortunately.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 12, 2017, 03:37:25 PM
is anyone else able to produce these pcbs?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 12, 2017, 05:35:32 PM
Collective Cases did it for a while, I thought.  Perhaps he has an inside track on contacting Abe.  I received my boards, but they were in the initial offering.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sebastianzetin on June 13, 2017, 01:27:26 AM
is there a link to buy pcb and a bom? this sounds like it could be cool
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 13, 2017, 02:50:05 AM
Isn't that Dan at collective cases? I have his email.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on June 13, 2017, 09:21:47 AM
Collective cases still offers PCBs for sale, although I'd ask them first if they're on stock before ordering.
http://collectivecases.com/?product=ac-sound-pi-3141-vintage-pwm-compressor-circuit-board (http://collectivecases.com/?product=ac-sound-pi-3141-vintage-pwm-compressor-circuit-board)

Personally I'm going for PPH board now.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 13, 2017, 10:00:26 AM
Hi All,

yes i fear the worst with Abe and AC Sound, i will be getting in touch with the small claims court and pursuing my moneys as regards Abe, i do suggest everyone else owed does the same.
In the mean time i have ordered two pcbs from Dan at Collective Cases, very nice man.

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 13, 2017, 10:54:57 AM
I've finally ironed out everything and planning to release the module for my system within a couple of months. There will be an extensive guide (like other guides for the existing modules) with detailed test and calibration instructions.

http://www.rackneve.com/PYE_compressor_announce
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on June 13, 2017, 06:59:12 PM
I've finally ironed out everything and planning to release the module for my system within a couple of months. There will be an extensive guide (like other guides for the existing modules) with detailed test and calibration instructions.

http://www.rackneve.com/PYE_compressor_announce

Great news!  Count me in for a pair (PCB only), thank you.

When you have a chance I'd be interested to hear more about your design (e.g. discrete oscillator details, input/output transformer requirements, maybe even a demo...)  Or I could just wait for you to actually release it, I guess ;)

Cheers,
A.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Patrick from Davis on June 13, 2017, 07:05:47 PM
Yes, Dan at Collective Cases, I feel a little stupid for not including that.  I feel bad for Abe, something happened, and it didn't sound like it was anything good.  That being said, I never heard what happened.  However, you can't accept money for these things and not send them, so hopefully you can get your money back.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 14, 2017, 02:10:43 AM
I've spoken to Dan and he has about 40 pcbs left.

http://collectivecases.com/?product_cat=pcb
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 14, 2017, 05:11:34 AM
Great news!  Count me in for a pair (PCB only), thank you.

When you have a chance I'd be interested to hear more about your design (e.g. discrete oscillator details, input/output transformer requirements, maybe even a demo...)  Or I could just wait for you to actually release it, I guess ;)

Well, there's nothing revolutionary there. Cinemags input/output and Edcor on the sidechain. Discrete oscillator details will be provided with the boards. There will be an option for 555 oscillator as well, but discrete is the preferred type. GR meter is also behaving differently with different oscillators.

I'll leave a note here when I have the boards in stock.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 19, 2017, 10:22:30 AM
Hi All,

I picked up this project that need some love recently. I got both channels passing audio and some slight compression with the threshold control cranked (about 4db of compression).In comp mode it has plenty of gain and is virtually noise free.  I read through this thread but didn't see these issues I'm having so maybe someone can help. Here's my issues in BOTH boards.

Both meters sit zero in comp mode and function with light compression in most rotary switch settings. As soon as I engage Limiter mode the hairball meter drops to around 16 and volume goes waaayy down. Also in the 1:1 ratio setting in comp mode  the meter goes down and slowly rises back to zero after a about a minute.

I have messed with the calibration settings noted here but have not set the chopper calibration yet. Wanted to get over this hurdle first.

Any ideas would be greatly appreciated!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 19, 2017, 10:31:24 AM
I have messed with the calibration settings noted here but have not set the chopper calibration yet. Wanted to get over this hurdle first.

Set all trimmers to the recommended preset values (refer to schematic) and start from there. You need to check the chopper, but this is not that critical for initial tests (if it's in the ballpark).
1:1 should work fine and pass the signal with no gain reduction. I can't speak about Abes particular PCBs, but people reported not connected trimmer pads on the PCBs. So check for those.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 19, 2017, 02:28:52 PM
Thanks for the reply! All the trimmers have been bridged to the middle bottom pad and I started with preset values. My main concern is the lack of compression and the limit mode dropping signal and moving down on the meter. It's almost as if its not fully connected. I have triple checked the header connection to the rotary switch board. Running out of ideas. I wonder if there's a component around the limit section that may have failed or isn't connected properly...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 19, 2017, 03:53:29 PM
Thanks for the reply! All the trimmers have been bridged to the middle bottom pad and I started with preset values. My main concern is the lack of compression and the limit mode dropping signal and moving down on the meter. It's almost as if its not fully connected.

To me it sounds like in limit mode your unit is going in high gain reduction for some reason. Don't bother with the lack of compression until you solve the limit problem. I'd start with the sidechain. Check R5 and R69 values. Also scope the output of the 555 oscillator (at D1 cathode).

What happens when you switch to 1:1 mode? What interstage transformer are you using?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 19, 2017, 04:48:56 PM
Thanks for the tips! I'll check that out

I haven't even fussed with the oscillator yet, just moved the trimpot on that around but noticed no difference in the limit behavior so put it back to where it was roughly

I'm using an Edcor wsm 600:10k for the side chain and output, cinemag on the input
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 22, 2017, 03:15:47 PM
R5 and R69 verified correct values. I notice the 2 pole 6 position switch was placed wrong on the decay rotary switch. There was a bridge connecting the pole where it should have gone. I desoldered it and orientated it where the 'A' pole goes to the slot where there is a track on the circuit board and left the 2 empty poles blank ... After doing that I still have the same problem with limit mode but now the channel is thumping when it compresses and is much noisier. Yay...

Tried moving trimpots to no avail.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 22, 2017, 03:40:31 PM
Aren't all switches there 3-pole except decay? At least from the schematic it seems so...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 22, 2017, 09:19:25 PM
Yep they're all three pole except decay which is one pole. I just verified all rotary switch controls to themselves and headers with a continuity meter so the issue is not on the switchboard.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 23, 2017, 01:47:21 AM
I should mention when I switch to 1:1 ratio the meter behavior is the same as when I switch to limit mode even while in comp mode.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 23, 2017, 04:53:57 AM
I should mention when I switch to 1:1 ratio the meter behavior is the same as when I switch to limit mode even while in comp mode.

In 1:1 and Lim modes the only common thing is not connected emitter of TR18. Check that. Also measure voltages at the D5/D6 cathodes junction - which values do you get on different ratio settings and in Lim setting?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on June 23, 2017, 06:15:37 AM
Check your transistors are correctly installed TR15-18, especially if you used 3906 on TR16 and 18.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 23, 2017, 12:58:33 PM
So I checked all the transistors(diode tested each leg) and they are all good. 2n3906 were used and orientated backwards along with the 2n4124 like the manual says to do. I reflowed all solder joints. Checked electrolytic capacitors for capacitance and all are good. Resistor values are spot on. I am at a loss for why I can't get limit mode to engage and the 1:1 ratio mode. It's like those connections are not present when switched in if that makes sense.

To boot I have to crank the threshold control all the way up to get 3-5db of compression in the other settings. Sidechain transformer is orientated correct via the manual instructions, I even flipped to see if any change and I got no compression that way..

Running out of ideas
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 23, 2017, 01:06:31 PM
Running out of ideas
Have you measured the voltages I talked about?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 24, 2017, 11:19:24 AM
my pcbs have arrived!! time to get building!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 24, 2017, 12:08:34 PM
On the cathodes of the D5/D6 I get  -6 volts Not sure what the voltage is supposed to be here? All the main voltages everywhere else line up with the schematic(-12V and -15 to -22V)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 24, 2017, 12:18:05 PM
On the cathodes of the D5/D6 I get  -6 volts Not sure what the voltage is supposed to be here? All the main voltages everywhere else line up with the schematic(-12V and -15 to -22V)

You need to measure the voltages at different ratio settings, otherwise it's meaningless.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on June 24, 2017, 02:38:42 PM
Gonna chime in with what I get approx on my PPH board (no x-former or 3640 installed ):
1:1 =0v
2:1 =-8.3v
3:1 =-8.1v
4:1 =-7.6v
Limit = -6.1v

Plugging in my 2nd switchboard varies those measurements by 10mV max.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on June 24, 2017, 03:39:58 PM
my pcbs have arrived!! time to get building!!!

Dan or Abe?  Hoping for Abe, since that means mine might be close behind :D

/edit/ Damn, just saw your comments about Dan having all the stock now.  Off to my credit card company I go for a refund, then :(
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: orangechili on June 24, 2017, 08:58:34 PM
Ok,

I had thought I had the switchboard wired header assembly right but it was indeed off by one side. Doh!

Here's my measurements on those diodes now
1:1 =0v
2:1 =-8.33v
3:1 =-8.14v
4:1 =-7.71v
Limit = -6.14v

So the channel I was working on was thumping/oscilatting on its own after I reset the trimmers to where the manual recommends. Turn it on hours later and thumping is gone and the channel acts normal as it should. Whatever... I'll take it

Meanwhile the other channel gets no compression at all now. On to some more fun debugging there.

Thank you guys for your help and ideas. If I hadn't traced the emitter of TR18 I wouldn't have discovered that header error so great suggestion!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 25, 2017, 05:08:20 AM
Ok,

I had thought I had the switchboard wired header assembly right but it was indeed off by one side. Doh!

Here's my measurements on those diodes now
1:1 =0v
2:1 =-8.33v
3:1 =-8.14v
4:1 =-7.71v
Limit = -6.14v

That sounds about right. Glad you figured the issue. Now that you have one channel working you can compare it to the faulty one and find where they differ.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 25, 2017, 05:22:24 AM
following the 1.1 BOM and v1 schematic, is there other information i need, or do i have do go through the whole thread?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on June 25, 2017, 09:53:24 AM
following the 1.1 BOM and v1 schematic, is there other information i need, or do i have do go through the whole thread?

Your pcbs are marked v3.14 no?
That schematic has some corrections compared to v1 posted somewhere on the first pages.
Also someone posted a longer BoM + build guide for v3.14.
I can reupload them unless you're a search wizard. Never hurts though to read through it all at least once.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 25, 2017, 01:09:37 PM
If your able to email to

[email protected]


That would be great, otherwise I'll see if I can find.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on June 25, 2017, 01:28:10 PM
The schematic: (note theres a missing connection from pin6 of the switchboard connection to the B- of the sidechain but that should be there on the pcbs)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on June 25, 2017, 01:30:32 PM
And the BoM with a few instructions, cant remember who made that one but thanks anyways.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 27, 2017, 07:04:06 PM
do any of the transistors have to be hfe matched?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 28, 2017, 02:27:41 PM
Also the silk screen for the 470uf are a bit confusing?
Anyone know the correct orientation please ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on June 28, 2017, 05:46:05 PM
Also the silk screen for the 470uf are a bit confusing?
Anyone know the correct orientation please ?

Use the Build Butler!
https://buildbutler.org/build/pi-3141-rev3-chip-version#_470uF_25v
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 29, 2017, 08:22:43 AM
thanks shot, i thought it was to the right, as this would then line up with pretty much everything else.

Im going to try and wind myself the input transformer, its a 1:1 but no other info which helps me wind it:

http://cinemag.biz/line_input/PDF/CMLI-15-15B.pdf

it doesn't give DC resistance or inductance so im a bit of a loss at how to interpret this info, could anyone pitch in please?

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on June 29, 2017, 10:09:06 AM
Im going to try and wind myself the input transformer, its a 1:1 but no other info which helps me wind it:

http://cinemag.biz/line_input/PDF/CMLI-15-15B.pdf

it doesn't give DC resistance or inductance so im a bit of a loss at how to interpret this info, could anyone pitch in please?

Well, at roughly 50$ CMLI is a very good value. You'll spend a lot more (both in time and parts) trying to produce your own. Do you stock the lams, wire and mu-metal cases? If yes, this might work. If not, I'd say don't bother.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on June 29, 2017, 11:14:35 AM
yes i have access to all the parts as i have friends in the industry, just down the road actually, Brian Sowter and Best Windings are my local transformer people, just trying to not hassle them as i have winding machine and can go and pick up the bits.
Also the whole point of being on here is to DIY, the first thing i would do if i couldn't be bothered to build something is go and buy the right thing, its all about learning, i don't mind messing stuff up as long as i learn a bit about it.
Ive ended up winding a couple of 1:1 with some M6 which should do the job nicely, just would be nice to have some better info about the cinemag's or similar TXF.
And anyways what everyone forgets is it maybe $50 but i would have to pay at least that again for shipping then i would get stung with a customs charge for the same again, so i'd be looking at $200, not so cheap now!!

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 07, 2017, 09:52:04 AM
right, well i've completed the build and fired it up today, and no smoke so far!!
Ive set the DC voltage to -20v but no signal on output yet, haven't had time really today and its really hot here today, so going to leave until i've read up on setup procedure , if there is one!!!
getting good signal at T4, and getting something at the output pot but doesn't look very nice!!!
Ive linked the units but i'm going to just try and setup one first of all, then i'll pop the other in, one i know i've got them both going.
Need to have some ideas for bypassing it?

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 07, 2017, 03:20:28 PM
Ok I have a few questions now.
The schematic doesn't show output txf connection?

Is it in series with the output xlr connection?

Could someone explain to me the side chain please, I thought a side chain was taking the signal and being able to adjust frequency wise what part of it is effected?

Regards

Spence

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 08, 2017, 04:38:29 AM
will wait until someone replies about these problems, but i'll try and explain what i've done so it makes it clearer:

I've had to use leads for the decay, limit and rated switches, only lengthened them about 10mm, so this could potentially have wrong wiring so will double check this, although there is some movement on the meter when switching in out etc, and the waveform does seem to respond.

Im using OEP transformers for Input and side chain set to 4:1 ratio, output TXF is about 1:1

I've used 2N3906 and 2N4124 and have reversed them.

On the OUT XLR pins i have run these to the output TXF and then from the TXF to the XLR output sockets.

Is the schematic laid out so that if you use the transistors not in the brackets you use the resistors not in the brackets?

My B- rail is -15.44V and on the other rail it is -11.41V

I am getting good signal up until TR5 middle leg, but nothing on TR6 middle leg?

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on July 08, 2017, 06:01:46 AM
Check R23 Trimmer, I get good sound with it being set around 68R, if you didn't pre set the trimmer it might be way off and can cut out the signal. Also as far as meter behaviour and overall responsiveness I found that R52 makes quite a difference so play with that as well once you get signal going through.
Output transformer hookup is straightforward, fromt the connection marked 'output xlr' on the schem to the primary leads of the XF and secondary to the respective + and - of the XLR connector, might have to swap leads for phase on the secondary (at least my Edcor seems to be labelled wrong in that regard)
As for schematic I stuck with all the values as indicated not using any of the values in brackets, the notes in the upper left corner of the schem state also what these values represent. I used 2n2222 in TR12 as well which works fine (my supplier had no 4124 and i wasnt gonna order just from somewhere else for a couple of transistors).
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 08, 2017, 07:15:55 AM
ok thanks, i will set trimmers as you have said, and yes i have all resistor values not in brackets.
I will report back once done,.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 08, 2017, 07:42:47 AM
i took the R23 trimmer as 22R or 100R trimmer, so ive put in a 200R trimmer and i get signal through the unit now!!

could you help suggest where the controls need to be for setup please, as all the documentation seems vague.

I have had a play around and limit seems to work but general Vu metering doesnt seem to be right.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on July 08, 2017, 08:13:56 AM
Lots of people have had trouble calibrating the Meter, mine doesnt sit at 0 either but it is also the cheapest 1ma meter i could get.
Like I said R52 seems to have an effect on the Meter and the release time as well, initially my needle would sit pretty far down and not move much, playing with R52 made the unit come alive and the meter now sits just below 0. Just play with it while feeding it some material like a drum loop, it will become pretty apparent what it should sound like.
As far as I understand Threshold is fixed at -10db and the Input pot just works as attenuator, I find that I have to run a pretty hot signal though to get things going even with the Input all the way up.
I'm running the sidechain transformer at 1:4 as well, 1:2 was a bit tamer. Lastly I hope you calibrated the oscillator. Mine runs dead quiet so far and its not even in a box yet.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 08, 2017, 08:45:46 AM
how do i calibrate the 555?

I have a scope and  MM.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on July 08, 2017, 08:58:25 AM
Probe the Output of the 555 (pin3), set it with the trimmer to 250khz.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 08, 2017, 11:55:36 AM
Probe with what?

My scope? Multimeter? What do I set it to?

Sorry never done this before!!!!

Regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 08, 2017, 02:13:20 PM
Spence,

Are you doing a single channel or dual?
If you're going with dual, it would be smart to check first if audio path is performing well. Since this is feedback type of compressor, you would need to disconnect the sidechain to measure if everything is ok on the main audio path. To do that, just take out TR11 (or at least it's base leg). Then go and check voltages around transistors. Follow the pye14schb.pdf schematic - it's the upper part of the circuit. While you have TR11 disconnected, it's smart to check also in the sidechain for any significant drops.
Disconnect the 7pin "switchboard" connector and check with resistance meter if everything is ok between pins 1-2, pins 3-6, pins 4-5 and 4-7. Just follow the schematic of the switchboard (lower left corner). That way you'll know if your switchboard is wired properly.
In one earlier post you mentioned that your B- rail is -15v. That's a bit low! It should be from 18 to 20 volts. Trim it with VR1.
Also check what's the supply voltage on the sidechain. It should be close to -12v. If it's too off than it's probably bad zener D8.

That's few things I can think by just looking at schemo. Can't compare it to my unit since it's in the studio.

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 08, 2017, 03:25:46 PM
Also check what's the supply voltage on the sidechain. It should be close to -12v. If it's too off than it's probably bad zener D8.

These zeners are 5% tolerance so even as low as 11.4V will be within spec.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 08, 2017, 03:26:28 PM
Ok thanks for the tips Luka, how do I setup 555?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 08, 2017, 10:27:36 PM
Ok thanks for the tips Luka, how do I setup 555?

You'll need an oscilloscope or at least DMM with the ability to measure frequency.
This actually pushed me to get my first oscilloscope - a cheap chinese Hantek

Oscillator board has four legs. One on the top and three on the bottom.
Attach your ground probe to the middle leg or right leg on the bottom and signal probe to the left bottom leg (the one next to D1 diode). Actually if you observe the schematic it should be logical - top pin is connected to the voltage supply and we have no interest in it now. Two signals are connected to ground - probe one of them with ground probe. All that you have left is the output signal!
On this leg you'll get a reading of the frequency. If you're using oscilloscope you should se nice asymetric square waveform (short tick). Digital oscilloscopes have "auto" function that should be able to find your waveform period, stabilize it on the screen and they read at what frequency it is. When you turn the trimmer on the oscillator board the frequency of this waveform should go up or down. Adjust to 250khz and you're done!

Oh, and as a sidenote - for this project I bought myself an oscilloscope. I went with the cheapest option avaliable. And I regret it now! It's full of bugs, software is hard to install and measurements are all jagged. Since then I got me one oldschool analog scope and it measures much better, but it's too big and it's a drag to read values by counting blocks on the screen. I got an oportunity to try PicoScope (https://www.picotech.com/oscilloscope/2000/picoscope-2000-overview) and this one is great! That will be my next buy. It's suitable for all the audio measurements we need (assuming you're not into digital multichannel stuff). That is if you're not into spending more for "real" standalone scope with screen.

:)

Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 09, 2017, 12:30:03 AM
I have old anologue scope which only has gnd and tip on each channel and I have two channels.
It sounds like your saying there is 3 connections I need to make?
Sorry I'm still not understanding how to connect and how to set my scope and how to read 250khz?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 09, 2017, 03:16:11 AM
I've taken the lorlins off now and i've drawn out how they should have been wired and rewired them, now none of them function!!!

I have 1mA meters from hairball i think, not joking when they say this build is hard!!

anyone have any info on how to set this thing up correctly please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 09, 2017, 09:16:33 AM
I have old anologue scope which only has gnd and tip on each channel and I have two channels.
It sounds like your saying there is 3 connections I need to make?
Sorry I'm still not understanding how to connect and how to set my scope and how to read 250khz?

Spence,
You just need to probe one signal! That is the output from the oscillator board (lower left pin on schematic). But to have scope show you the correct measurement, it needs ground also. Usually scope probes have small wire with alligator clip on them for ground connection. Take the ground from the nearest possible pin (usually lower mid pin).
It takes just one channel of your oscilloscope!
On an analog scope, you have to manually set the TIME to be small enough to show you the waveform. If you convert frequency to period, 250kHz is 4 uS (microseconds). Set the time on your scope to a close value and adjust volts/div to scale it vertically. And that would do it.
If you want to be sure your scope is working properly, you can test it with a regular audio signal first! Just use some testgenerator plugin to send a sinus signal from your audio interface output and probe the tip and ground of the output cable with your scope. You should see a nice sinus on your scope, and you'll get a grip how to set time and volts/div parameters.
Oh, and be sure to set your scope to AC signal measurement!
:)
L
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 09, 2017, 09:20:42 AM
I've taken the lorlins off now and i've drawn out how they should have been wired and rewired them, now none of them function!!!

Don't just test it in your unit!
You must check if you get correct resistances referring to the schematic.
That is the easiest way to check if everything is wired correctly
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 09, 2017, 02:05:02 PM
Ok I think I understand how to set the timer now!! Thanks very much for explaining.

I took off the lorlin Pcb and checked it with MM and everything is per schematic.

The only trimmers so far that do anything are the 100R trimmer but I've put in 200R as that the smallest I have.
The other trimmer that does something is the 5Meg but I have put in a 2Meg.
The other trimmers do very little to nothing?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on July 09, 2017, 03:07:43 PM
I'd leave all the trimmers alone for now, however if you have tweaked them I'd advise you to set them at the following values as a starting point before further troubleshooting:
R23 =68R
R48 = 1m8 (you can install a fixed resistor here)
R42 = 5k1 (fine tunes the meter adjust, leave it alone until last i suggest)
R44 =220k
R52 = not indicated on schematic, i measured on mine to get good results approx 900R with junction of R51 (and consequently 100R with junction of 4148)

Now as mentioned earlier you need to tweak VR1 in your PSU to get anywhere between -18 to -22V as your B-. Do this first.
Then I suggest you go measure if all your Ratios are behaving right, Ilya pointed this out 2 pages back.
For this connect your switchboard and measure the voltage at the cathodes of D5/D6 under each of the ratio settings.
Typical results are mentioned on the 2 previous pages.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 09, 2017, 03:33:50 PM
Ok sounds like a plan! Will report back once I've done.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 05:29:53 AM
Have set everything as you have ask and get nice signal through but no compression?
Also my meter is all the way over to the right?
Must have it wired backwards?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 05:39:04 AM
Incidentally the input is 2 seg per div and the output is barely 3/4 of a segment.
I've changed the meter now so it sits at the correct side but controls do nothing apart from input and output pot?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 05:47:35 AM
Adjusting R48 to lower value brings back a good sized waveform which matches input signal.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 05:58:02 AM
Oscillator isn't oscillating, that's my main problem I think!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 10, 2017, 06:09:49 AM
Oscillator isn't oscillating, that's my main problem I think!!!

Try to measure AC (and DC while you're at it) on the output of the oscillator with DMM. If it works, it should show some value.
If it's idle it should output zero.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 07:39:28 AM
ok, i'll do a DC voltage sweep across all the transistors and the oscillator, report back.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 08:00:36 AM
oscillator 1 is on channel 1 = DC = - 0.299 at CW and AC = -0.407v
oscillator 2 is on channel 2 = DC = -0.302 at CW and AC = -0.400v

I'm going through the transistors now, going to make a chart.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on July 10, 2017, 08:31:53 AM
Did you probe the voltage at cathodes of D5/D6 under the various ratios?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 09:39:15 AM
d5/d6 on pcb 1 = pos1 = 0v, pos2 = -8.37, pos3 = -8.17, pos4 = -7.73

im gonna check my wiring again on pcb 2 as the voltage doesnt change at all!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 10:16:10 AM
voltages on audio path:

TR1
E = -16.64
B = 17.4
C = -17.96

TR4
E = -6.82
B = -6.18
C = 0v

TR11
E = 0v
B = 0v
C = 0v

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 12:11:04 PM
i've managed to work out how to set the frequency to 250khz now but nothing seems to have changed, doesnt seem to operate?
vu meter doesnt  move?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 10, 2017, 12:26:41 PM
Forget the VU for now. Do you have an audio path working? Is it clean? You need to use component values NOT in the brackets - this is important!

Put a scope probe on the base of TR11 and set any ratio except 1:1. Feed an input signal and observe the waveform on the scope. Increase the volume of input signal and see if there's any change in the waveform at the base of TR11. If everything works correctly, you should see how spikes become narrower when you increase the volume of input signal.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 12:53:27 PM
channel 1 the audio path isnt clean, but i have had a play with all the trimmers again so they could be set to anything!!!
but there does seem to be movement to the wave form when using the controls, not a lot but something.

channel 2 seems better audio path but no movement to audio waveform.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 10, 2017, 12:58:03 PM
R23 is the only trimmer in the audio path, you need to set it so that there's minimum distortion. Other trimmers are in the sidechain and it's better to set them to the pretrimmed values indicated in the schematic.

Don't move contols. Change the input signal volume and see if there's any change at the base of TR11. Set your threshold to the lowest possible setting to make sure you're hitting the threshold.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 01:09:14 PM
both channels have good waveforms up till TR7 base.

at TR8 base looks bad.

tested TR11 base and only getting top part of waveform.

I have used all resistor values not in brackets.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 10, 2017, 01:31:02 PM
TR11 waveform has nothing to do with the input waveform. It's a control waveform that turns the transistor on and off, so it shouldn't resemble the input waveform at all.

Now,  TR7 is a buffer that feeds the sidechain transformer. What do you get at the emitter of TR7? You may also check the emitter of TR5 and see if there's any clipping (not symmetrical) or rectification going on. If it is, the DC bias at the base of TR5 is incorrect and you may need to adjust it with R20. The same logic applies to TR7, but here the DC bias is set by the previous stage (TR5).

If you get crap at TR8 this means the signal corrupts somewhere earlier. I suspect the TR5-TR7 region is the culprit.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 10, 2017, 03:33:58 PM
When you fiddle to much with R23 it can cause shutdown of audio signal. Maybe Spence has set the value of this trimmer to off and that is why it's not passing audio anymore.

Spence, did you happen to desolder this (or any other) trimmer and later solder it back?

My situation was that one trimmer was burnt. They are very fragile and too much heat can burn them.
And specifically this pcb has very narrow holes for components so taking components out is a hassle and requires a lot of heating. Maybe that's the way you've burned it.

As a precaution, I would take all the trimmers out, throw them in trash, get new ones and set them to preferred values before soldering them in. At least trimmers are cheap and it's a half'n hour job

And once you do that DO NOT rotate trimmers anymore. That way you'll know that the problem has got nothing to do with them. Then you can go searching for problems elsewhere! See, trimmers on wrong values can cause a domino effect on other components. You'll never know what is wrong unless you know you got your trim values on a correct spot.
After you get all your audio passing and compression going on on all ratios and speeds, only then you start calibrating meter and overall responsiveness of the unit (read: rotating trimmers)

:)
Luka
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 06:41:08 PM
the trimmers are fine as i can put my MM on them and when i turn them they function.

Channel 2 now seems to pass audio nicely but channel 1 waveform doesnt look right.

Im not getting compression, i do not have a bypass switch either as i dont think its possible?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 08:01:25 PM
channel 1 is good up until Tr7 emitter and R27 / C15.
Tr6 is all good along with Tr5.
Ive changed TR8, TR9 and TR 10 and its still bad waveform.
Ive tested all resistors around the output back to the output pot and all are good.
I'll draw out a diagram to show how ive connected the lorlins just to make sure i havent cocked all that up!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 10, 2017, 08:24:14 PM
this is very crude but this is how i figured it would work!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 11, 2017, 03:39:33 AM
this is very crude but this is how i figured it would work!!!

There's an error - Pins 6 & 7 are swapped!
Third switch (ratio) section B resistors need to sum to pin 7 and section C resistors need to sum to pin 6

And also you have first position of the decay switch doing the longest time. Pin 1 on that switch should be 100ms and pin 6 be 3200ms.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 11, 2017, 04:17:56 AM
Ok, I've either wired it wrong or drawn it wrong either way I'll correct and report back!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 11, 2017, 05:16:20 PM
Found 39R resistor which should have been 39k, changed and I'm now getting signs of compression and meter is moving a little, this is on channel 1, channel 2 was good but not now I need to test again as it seems low output compared to channel 1.
Testing all voltages does seem to help me track down what area is off as I can compare to channel 1 now.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 12, 2017, 01:21:48 PM
Got both channels passing audio good now.
Couple of mistakes with resistors!
Channel 1 seem to compress a little and meter moves but it's all the way to the left, can I adjust the meter?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 12, 2017, 01:24:46 PM
You need to make your unit compress properly. Do you have your sidechain tx connected correctly? It should be connected in 1:4 step-up ("4" side goes to diode bridge in the sidechain).
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 12, 2017, 08:58:34 PM
does this look right?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 13, 2017, 04:27:45 AM
Yes!
Though on Abe's board switch A (decay) has position 1 on 100ms and position 6 on 3200ms.
But that's just orientation. Either way it will work.

Why are you doing it by yourself? You don't have that board in your set?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 13, 2017, 05:33:18 AM
i have to run wires so i can fit the lorlins in the 2U, its a bit pushed for space due to the big VU meters.
I do seem to be getting decay (release i'm thinking this is?) working now on both channels.
Limit switch and ratio dont seem to do anything yet?

limit switch does do something when ratio switch is set to 2nd position, but nothing on 1st position and 4th position.

looking at voltages on bottom part of circuit TR20 is looking good.
TR12 on its collector has 0v and on other channel -0.585v
TR13 has CH1 = E = 0v, B = 0v, C = -11.01v
CH2 = E = -0.052v, B = - 0.532v, C = -10.95
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: shot on July 13, 2017, 05:14:05 PM
When limit is engaged, ratio should do nothing!
Either you compress - then you select the ratio - or you limit!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 13, 2017, 06:22:32 PM
well this is starting to grind me down!!!!, as i seem to now have everything correctly connected but its not operating correctly?

i do understand how the unit operates as i use the plugin version, just very frustrating when i dont understand the circuit or really know where to look. Its been a busy week and i will have another look at this next week, as i have a bit of time away from it, when i come back hopefully i will find the problem.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 19, 2017, 12:06:49 PM
Anyone provide some working voltages for all transistors please?

There's a voltage chart in pyebook on Abes site. But you'll have to do some cross-referencing because original designators are different
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 19, 2017, 12:19:14 PM
the site is down as far as i can tell, does anyone have that info please?

really need to fault find this build!!!

Is there a voltage guide available?

Anyone provide some working voltages for all transistors please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 19, 2017, 12:25:59 PM
Here's that page
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 19, 2017, 12:36:08 PM
ah, spot on dude, thank you.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 20, 2017, 03:45:16 AM
right had another look today and error on wiring sidechain transformer!!! i'd connected pins wrong way round then put txf in mumetal can!!
controls now working as should and both channels seem to be working within very close range.

next step is getting meter working correctly!!!

any ideas please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 20, 2017, 05:33:51 AM
right i'm starting to get there now!!! meter now working, had it wrong way round.

distortion present with compression or limiting, ok when on 1:1 but this is bypass right?, so gonna wait for my frequency meter to turn up then i'm gonna try and set it up correctly.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on July 20, 2017, 05:40:42 AM
I'm glad you're debugging this build, SLH - my boards just turned up (purchased from Collective Cases) so I will start my build soon, hopefully learning from all your mistakes and discoveries :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 20, 2017, 09:24:43 AM
yes, most of my mistakes so far are down to not taking enough time on everything!!
difficult when balancing work, family life!!!
i've just got to get rid of the distortion now, everything seems to function correctly apart form the compressed sound!!!

good luck mate!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 21, 2017, 09:50:41 AM
Im getting saw tooth waveform at R41 / R43, distortion present in both channels, think im ment to get rectangle waveform?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 21, 2017, 07:23:15 PM
I’ve taken some voltage readings with 1:2 ratio and slow release

TR20
E = -11.55
B = -12.65
C = -21.65

TR12
E = -11.41
B = -10.82
C = -1.718

TR13
E = -.143
B = - .649
C = -10.82

TR15
E = -.821
B = -.1.398
C = -11.55

TR16
E = -11.55
B = -1.890
C = -1.379

TR17
E = -8.30
B = -7.70
C = -1.850

TR18
E = -7.10
B = -1.371
C = -.756

any ideas?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 23, 2017, 09:02:07 AM
is this voltage chart off the original schematic?

I think it would be good for everyone to have a full voltage chart as I'm really stuck on where this distortion is coming from!

I'm only getting distortion when it is compressing, clean signal otherwise?

And when I put sinewave through waveform looks clean with compression, when I put bass guitar through I get distortion, could this point to the input txf?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 23, 2017, 11:10:09 AM
That voltage chart is from one of the original Pye manuals. I have a different one from another old Pye manual, but the callouts are similar.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 23, 2017, 04:31:53 PM
Im getting saw tooth waveform at R41 / R43, distortion present in both channels, think im ment to get rectangle waveform?

The waveform depends on the compression and turns the transistor on and off. Your sawtooth is probably fine. You're getting distortion somewhere else. I suspect the first block before the output pot. Check R19, R20 and R23. Try adjusting R23 and see if it makes any difference.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 23, 2017, 04:59:49 PM
And when I put sinewave through waveform looks clean with compression, when I put bass guitar through I get distortion, could this point to the input txf?

This could point to anything, really. It depends on the input level. This comp is very easy to overload. Both input and output stages. Especially if you're on 16V. You need proper measurement tools to read THD value, even 1% THD sinewave will look fine on the scope, you won't spot the difference with your eyes. So make measurements and tweak the resistors I wrote you earlier. This should make a difference in THD. You can measure THD in different places of the circuit and see which part adds more distortion, so you can zero on that particular spot.

Are you using a proper threshold switch or two separate pots?

Voltage chart is for 16V rail. If you feed your comp from 18V rail, voltages will be off. The sidechain voltages will remain valid though because it's regulated separately to -12V.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 23, 2017, 05:28:11 PM
Threshold switch?

Have you built this pi 3141?

It sounds like your talking about something else, no mention of threshold switch on BOM or schematic?

I'm on -22.54v giving me -11.55v rail.

I had conflicting info, it's been said that I should run it at -22v and you seem to say if should be run at -16v?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on July 23, 2017, 07:22:06 PM
I run mine at 16V.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: mdainsd on July 23, 2017, 09:21:53 PM
I run mine at -22V
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 24, 2017, 12:50:04 AM
Bruno and mdainsd,

Could you take some voltage readings and post please?


ive wound mine down to -16.20v now and no difference, have put output from protools through and getting loads of distortion, sounds like its just on the low end, so could this possibly be the output transformers?

well i've got no idea where the trimmers are now but i've tweaked and tweaked and have a pretty sound now!!!
R48 seemed to help the most, also the 10k trim, i will take readings from all trimmers once i've tweaked both channels!!
Finally starting to work and sound good!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 24, 2017, 03:30:46 AM
Threshold switch?

Have you built this pi 3141?

It sounds like your talking about something else, no mention of threshold switch on BOM or schematic?

While I haven't built these exact PCBs, I used the same circuit from the PYE service manual.

I suggest that you read this thread from the beginning. There's a discussion on the threshold switch. This part is important for the correct gain staging inside the compressor.

EDIT: original unit ran on 16V. I'm running mine on 18V because of better performance. Other people answered you earlier.

May I also suggest that if you want to post something in addition to your previous post, you'd rather edit that post so we don't have half a page of your posts with just a couple of sentences in each please.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 24, 2017, 07:31:08 AM
i will consider my hands well and truly slapped!! lol, thanks for all your wise words, i will edit my posts and read again this post from the start to understand about the gain staging.
The compressor now is sounding really good, think i just have to move the txf nearest the psu as i can hear a little hum on that channel.

thanks everyone, sorry about all the posts!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 25, 2017, 01:53:36 AM
I have just read on page 3 of the thread that the gnd should be tied together to B+?

At the moment there is nothing from B+  to IEC but i am getting continuity.

Just to confirm though, would it be better for B+ to goto IEC gnd or XLR gnd?

and could this be why i'm getting some hum?

and Yes i'm getting loads of mobile phone interference!!

and to reply to the previous comment about the threshold control, i think i understand now, the input and output are put onto a switch pot, i dont have this, i have 2 x pots.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 25, 2017, 11:14:19 PM
Im getting a lot of hum!, both channels , would someone be able to  explain the correct gnd scheme please?
and also does anyone have any info on how to make the stepped attenuator,
 i have a couple of 24 switch 4 pole switches i could use, just need to know layout of resistors.

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on July 26, 2017, 08:59:25 AM
Im getting a lot of hum!, both channels , would someone be able to  explain the correct gnd scheme please?
and also does anyone have any info on how to make the stepped attenuator,
 i have a couple of 24 switch 4 pole switches i could use, just need to know layout of resistors.

regards

Spence.

Email sent w/ r values for switch.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 26, 2017, 09:08:42 AM
Im getting a lot of hum!, both channels , would someone be able to  explain the correct gnd scheme please?

You need to connect IEC ground to chassis (metal enclosure). Then connect B+ to this point. B+ is the ground reference. Take B+ from the PSU filter cap and connect it to the chassis, this should cure your hum issues.

Ian (ruffrecords) has an excelent paper on grounding that's worth reading:
http://www.customtubeconsoles.com/diy
Theory folder.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 26, 2017, 11:11:32 PM
thats perfect, thank you, i also need to change my stand offs to plastic, once ive done i will then attempt the attentuator!!

Also Just to clarify, im using 2 x 18v 30VA transformer which is powering both channels, is this too little?

Only getting hum on the right channel, clean as a whistle on left channel?

Could someone explain the whole threshold switch and gain control please.
As on the original schematic the gain pot just looks like a dpdt switch?

Update(27/07/2017)
also today after doing the gnd from the C10 cap, the right hand channel seems to have hiss as well as a little low end hum, where as the left channel is silent.
when i match the level of hiss on both channels, the right hand channel is down about 15db on the mixer, so its quite loud!!

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 27, 2017, 02:24:24 PM
Im going to run each pcb from 18v - 0v rather than having the secondaries in series and daisy chaining, hopefully this will fix the hum and hiss?
also could be a dodgy transistor, will do some voltage comparisons and see if i can spot it!!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 27, 2017, 03:11:29 PM
Im going to run each pcb from 18v - 0v rather than having the secondaries in series and daisy chaining, hopefully this will fix the hum and hiss?
also could be a dodgy transistor, will do some voltage comparisons and see if i can spot it!!!

It's not clear how you're powering the unit. 30VA should be plenty. Each channel consumes about 0.12A, which translates to roughly 2VA at 18V. 4VA for 2 channels.

The hum in just one channel tells that you probably have a ground loop. Make sure that each channel has only a single connection to a common ground point. They shouldn't share any other ground except this one point.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 27, 2017, 03:57:49 PM
The only gnd points I have are on input which attaches to xlr socket,  c10 + is linked to both pcbs to star gnd and input pot and output pot both have gnd.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: marcn on July 27, 2017, 04:11:05 PM
Missed the output xlr gnd connection by any chance ?
Also the pcb provides 3 connections for the input XLR, i assume one of them is gnd, if you connect the gnd on the input XLR socket to the chassis then dont use the gnd connection on the pcb (assuming the shield wire connects to the xlr socket gnd)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 27, 2017, 04:17:13 PM
The only gnd points I have are on input which attaches to xlr socket,  c10 + is linked to both pcbs to star gnd and input pot and output pot both have gnd.

Maybe that's me but I still don't get your power and grounding scheme.

Input/output XLR's pins 1 should tie directly to chassis ONLY. You don't bring that connection to your clean audio ground. Now, are you powering 2 boards from a single PSU or what? Or do you link each C10+ to your common GND? What does "input pot and output pot both have gnd" mean? Of course they should have GND, but they should have connections to your audio GND, not common point.

You may also compare voltages in the hissy channel agains the clean one and see if they match. Maybe it's not a ground issue at all.

Missed the output xlr gnd connection by any chance ?

This is probably not a huge deal in the transformer balanced outputs. The GND on the XLRs is used for shielding only, it isn't (and shouldn't) used as a common GND reference between the devices as in unbalanced connections. So if the shield is not connected to chassis, you loose a protection of the screen, but I doubt that this can make a hiss in one channel 15dB louder than in another.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 28, 2017, 06:45:54 AM
sorry yes, i have both the output and input pin 1 to star ground.

input xlr shields goes to gnd on pcb

star ground to C10 + on pcb 2 then daisy chained to C10 + on pcb 1

Im now going to change the mains transformer so each pcb gets 18v feed rather than windings in series.

then i will check transistors, as i suspect its the transistor making the hiss.

regards

spence.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on July 28, 2017, 07:08:15 AM
now i have changed the mains transformer to feed each channel with 18v/ 0v there is no hum, just some hiss now to try and track down.
The hiss difference is about 4db now so i'm very nearly there.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on August 06, 2017, 01:29:01 PM
Its seems I’m not out of the woods with this compressor, channel 2 has a sawtooth sound at 700hz, I’ve check the sound using a signal generator and it sounds exactly like a sawtooth rather than anything else, its maybe triangle but not sure.
Channel 1 is ok, bit of hiss but i would expect this without the correct gain/threshold control which i haven’t done yet.

I will go through all the transistors and see what voltages look like now on bottom of circuit to see if anything looks off?
I have set the oscillator to exactly 250khz now as i have a meter for setting this.

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: peskado on August 18, 2017, 10:06:12 AM
sent payments for 4 boards 6 month ago
didn't get it yet(
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: aladan on August 20, 2017, 05:52:52 AM
sent payments for 4 boards 6 month ago
didn't get it yet(

Apparently Abe gave all the boards he had from the most recent PCB runs to Dan from Collective Cases in order to cover his outstanding debts to him.  I lodged a claim to get the payment I made to AC Sound back from my credit card company, and received a refund which I then used to buy boards from Dan instead.

http://collectivecases.com/?product_cat=pcb

I know this is not ideal, but I suspect it's your best option - I don't think you'll see your order fulfilled by AC Sound in the near future :-(
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on September 10, 2017, 12:55:39 PM
Has anybody tried to use the link option for stereo linking? Nothing suspicious happened?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: JeromeMason on September 13, 2017, 05:33:09 PM
Has anyone used or does anyone know if there would be any major issue of running a 1:2.8 tranny instead of the 1:1? Or reversing and stepping down? I found some LL1521's for a good price and I'd rather use them if I can. I know 1540's will work, but they're harder to find and more expensive. I'd much rather have Lundahls on the inputs. I was going to etch out an adapter board to go from the CLMI to the LL1521. Not a fan of wiring in PCB mounted trannys.

Thanks folks!

Jerome
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on September 14, 2017, 01:59:03 AM
You can use this transformer, although I wouldn't recommend doing so. It will shift your threshold level (which may be not a huge problem if you're using 555 oscillator- it shifts the threshold as well). If you connect it in step-up, you may easily overload the circuit (especially if you're running it from 16V). In step-down it attenuates the signal too much, so you'll have to drive the input much harder.
You can modify the circuit and adjust the threshold level, but this is not obvious and requires some experimentation.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on September 24, 2017, 09:14:32 AM
How difficult would it be to change the attack time for a PYE.

I know it has 0.5ms and 1ms, if i could get a 10ms or longer attack time, this unit would get a lot more use!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on September 24, 2017, 12:36:39 PM
There were a million records made that people loved that used the given settings...all of a sudden it doesn't work anymore? Use a different unit for the task at hand!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on September 24, 2017, 07:49:05 PM
A longer attack time would let drum transients pass and would probably sound amazing. Nothing wrong with how it is now, I was just wondering if i could make a capacitor somewhere switchable to change the attack time from stock to a bit longer
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on September 25, 2017, 04:00:32 AM
A longer attack time would let drum transients pass and would probably sound amazing. Nothing wrong with how it is now, I was just wondering if i could make a capacitor somewhere switchable to change the attack time from stock to a bit longer

According to the service manual you may have luck adjusting R59 (refer to schematic here: https://groupdiy.com/index.php?topic=43351.msg727799#msg727799). Increasing it should increase attack time. Please report back what you find.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on September 25, 2017, 10:27:26 AM
So I found that passage in the service manual. It appears the R59 is bypassed unless the unit is in LIMIT.

I did remove R59 and insert a resistor box, when in LIMIT the attack appears to be slightly slower when I change the resistance to >= 10k. However, the gain reduction dB goes to almost zero. It sounds like less compression instead of a slower attack (meter still moves quickly).
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: eddie_ruff_ on September 25, 2017, 11:05:38 PM
I am happy with this  :)

Not sure if it is actually a slower attack, but the sound is much more punchy and appears to be letting more of the transient through while still compressing the tail. This mod only works when LIMIT is ON. my decay was set to 200ms.

https://youtu.be/bcxRlfuIBv0

...AND youtube compression totally ruins this video demonstration haha.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on September 30, 2017, 03:33:54 AM
Going to try and set my PI-3141 up today and produce a document which details exactly what to do with voltages of transistors etc.
Still haven't got to the bottom of exactly what each trimmer does, and it's seems everyone else is a bit vague as well!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on September 30, 2017, 08:38:42 PM
Cant find the original schematic anywhere as all the links on the thread are out of date!!

anyone got one please?

also on every version of the compressor i have seen a gain control, i started with input and output pot, release and ratio switch and limit switch but no gain control, i have now implemented the dual gang switch which has the input and output pot on one control, but do i still need a gain control?

also i need more info on how to bypass the compression properly?

thanks in advance.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on September 30, 2017, 09:12:33 PM
In the original (ACSound) Pye there was a 10dB gain loss through the unit.  I added a Neve style output section with 20dB of gain, with a 20dB, one dB per step 21 position attn circuit.  Thus the center position made the total circuit unity gain with a +/- 10dB output "trim".
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on September 30, 2017, 10:33:33 PM
I may not be explaining myself right, or i may have not wired the input/output pot correctly (but i think i have!)
there seems to be a threshold control or gain control as well as the  input/output pot?

with my unit as i increase the input/output it goes from nothing to very loud, i know this may sound silly but i dont have any control over output or threshold with this?

what should i be getting as i turn up the input/output pot?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 01, 2017, 12:22:30 AM
I kept mine as in the original alternative design. Split. The input(gain) increases clockwise and the threshold is wired to increase counter clockwise. The unit sounds fantastic...and both channels function identically.

When I switch mine 1:1...i get a large jump in gain...as the input is cranked up due to threshold, usually. I included a true relay bypass like Mdainsd that seems to play much nicer with the 'in' circuit volume.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 01, 2017, 06:27:38 AM
Could anyone repost the original schematic please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on October 01, 2017, 06:32:51 AM
I seem to recall that somebody posted the schematic in the documents section of the forum.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 01, 2017, 07:01:59 AM
yes its in the technical docs section thank you.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 01, 2017, 07:40:58 AM
Well im starting to get confused again and need some clarity.
I'm not understanding all the controls.
I first had it wired, 10k input pot, 10k output pot, decay lorlin, ratio lorlin.
Now I have dual gang pot wired one way 10k for input and opposite 10k for output.
I have no threshold control?
Is the threshold control the input/output control?
If so what is the gain control?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 01, 2017, 07:52:10 AM
My confusion maybe because of using the plugin.
The plugin version has threshold, gain, decay and ratio controls.
Does this equate to threshold = input, gain = output, decay = release, ratio = compression ratio?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on October 01, 2017, 10:13:14 AM
The threshold is fixed. Threshold is input gain....gain is makeup gain. On Abe's, the input and makeup were separated to allow more control.

https://www.youtube.com/watch?v=RxyLcNF9-JI
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 01, 2017, 10:25:42 AM
Ok I think I understand it now, and think I'll go back to having both controls separate as it's much more flexible.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 02, 2017, 07:36:42 AM
Ok, today i have twiddled a bit and Im still not able to setup then unit so it sounds good.
Ive set 2:1, 100ms, input and  out off and taken some voltage readings, the previous voltage chart is absolute garbage and means nothing, would be good to provide a up to date voltage sheet from a bonafide working unit.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on October 02, 2017, 07:48:39 AM
Well, I told that the voltage chart hat different transistors references. You can't use it on Abe's unit directly.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 02, 2017, 08:05:50 AM
do we have something we can use then?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on October 06, 2017, 08:17:55 AM
do we have something we can use then?

Not anything I'm aware of. It's possible to cross-reference the components, but somebody has to devote quite a bit of time to this.

P. S. As promised earlier, I'm announcing that I've got PYE PCBs and front panels for my 4-channel module system in stock.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 07, 2017, 04:10:13 AM
Seems my problems where a combination of wrongly wired transformers and when testing my patch bay!!!
Need to check all connection leads to patch bay!
Have one channel sounding nice and quiet and great compression in acoustic guitar , going to take voltages and try and repeat on other channel.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on October 11, 2017, 12:57:58 AM
Could anyone take some voltage readings on the transistors please as I’m nearly there and just want to verify everything, I get quite a big thump on release at fastest!
My R23 is set to about 24ohms, I have the 1.8M resistor, 220k and 1k trim set to 30ohms. Test point that have been suggested are vague so better understanding of this would be good.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on November 08, 2017, 05:28:26 PM
Does anyone have any useful data on T3, the oscillator toroid, other than the turns ratio?

I am pondering inductances, wire gauge, core material, etc ...

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: dandeurloo on November 20, 2017, 03:17:22 PM
I am finally gonna start working on building up my personal unit. I just read through the thread again and took notes.  Thanks to all the guys who have been so supportive in this project.  It seems like it should go together with the proper BOM and schematic. 

Thanks, I will post anything I can come up with that is helpful. 

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on November 24, 2017, 01:02:09 AM
Is there an updated build guide... I have had all my parts for over a year and am about to get to this build too!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on November 25, 2017, 06:02:21 AM
To complete this build I think a transistor voltage sheet is needed, my build works its just not setup correctly as I need transistor voltages.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: tommia on November 25, 2017, 11:15:38 AM
@ Spencerleehorton; Sorry I can't help you. Mine is not working like it should, but it is compressing.

We could all try to compress the same drumbeat , compare whitch is the best and than measure the transistor voltages.

No technical info on the net, so we have to improvise. Or is there somebody with the real thing out there?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on November 25, 2017, 11:28:49 AM
You actually don't need a voltage chart to make the thing work properly. All those trimmers are mostly not needed and stock values should be used. However, there's a big BUT: you have to use original oscillator, otherwise your threshold and ratios will be off.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on November 25, 2017, 01:29:46 PM
Mine compresses too, a bit too much actually, need to try and finish other projects to get some time to tweak again.
If I get the unit sounding good I will post all voltages.
I have IC oscillator.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: TubeMonkey on January 16, 2018, 11:25:05 PM
Hi all,

Can someone post the schematic/docs to this project. I bought a pair of PCB's a year ago and have since lost the docs and accidentally deleted my mouser cart :(   

Upon trying to visit the site, it looks like the domain has gone dormant since the last time i visited.

Thanks in advance!

EB
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Potato Cakes on January 17, 2018, 12:29:59 AM
Hi all,

Can someone post the schematic/docs to this project. I bought a pair of PCB's a year ago and have since lost the docs and accidentally deleted my mouser cart :(   

Upon trying to visit the site, it looks like the domain has gone dormant since the last time i visited.

Thanks in advance!

EB

All the documents should be on collectivecases.com site.

http://collectivecases.com/?product=ac-sound-pi-3141-vintage-pwm-compressor-circuit-board

Thanks!

Paul

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: TubeMonkey on January 17, 2018, 01:24:32 PM
All the documents should be on collectivecases.com site.

http://collectivecases.com/?product=ac-sound-pi-3141-vintage-pwm-compressor-circuit-board

Thanks!

Paul

Thanks Paul!

Exactly what I needed.  Do you have a space here in Nashville?

EB
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on January 20, 2018, 03:03:30 AM
Does anyone have a fully functioning unit where they could post voltages, preferably with IC version?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: bruno2000 on January 20, 2018, 12:10:00 PM
Does anyone have a fully functioning unit where they could post voltages, preferably with IC version?

emailed.
Best,
Bruno2000
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: opacheco on January 23, 2018, 10:45:17 AM
Rev 3 Boards :)

Thanks guys.

http://www.acsoundstudio.com/diy/Pye/rev314/REV314_BOM1.pdf
http://www.acsoundstudio.com/diy/Pye/rev314/rev314_pcbPNG.png

So boards are almost done and on their way to me, then I can ship them out! Thanks for everyone who participated, wouldn't of happened with you! Got a few extra so they are still available through the white market thread or store. Bring on the compression!!

Dear abechap024,

could you upload again the Schematic and BOM of this Project please??

Thanks anticipated
Opacheco
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on January 23, 2018, 01:00:08 PM
Dear abechap024,

could you upload again the Schematic and BOM of this Project please??

Thanks anticipated
Opacheco

Please look several posts up. There's a link to the other site with all the documents you ever need. Initial TS is absent for a long time. I personally won't count on his support.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 07, 2018, 02:15:18 AM
I’ve got the pye on the bench again to try and figure it out!
I’ve set my unit using some voltages that have very kindle been supplied.
I can post voltages to transistor if anyone wants them but I’m still not confident I’ve got the unit functioning yet!
First some questions:

Where should the Vu meters be set, in the middle or to the left? I’ve seen them all to the left but the original is sort of in the middle?

When slowing down the release should the needle move to the left?

The sidechain txf says 1:1 in Pcb but I’ve seen it say 1:4?

Input txf 1:1 or 2:1?

Output txf 1:2 or 1:4? Or use a preamp to boost?

True bypass info?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 07, 2018, 09:59:44 AM
right, well i've been tweaking and if i ignore the meter being at just left of half way on both meters, i've got a very respectable working unit.
Tiny bit of top end hiss but you would expect that from any unit.
i don't quite know what i've done yet but i've gone with the following:

input txf = 1:1
output txf = 1:4
SC txf = 1:4

i've used BC560C, BC550C, 2N3609 in replacement of BC550A and used 2N5088 and PA3640.

B- voltage is -16.55v

i've put the 1M8 resistor in, the 5k trim pot i've put in the middle somewhere, the R23 i think is about 220k, most of the tweaking was done on what i'm calling the input/output pot as it seems to me to be the most critical.

Im going to continue tweaking as i would like to get more compression out of it, as with input volume at max and output at half way the needle is only moving a a little and it could move double the distance.

will update once i find out more.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 07, 2018, 07:53:29 PM
reading through the thread again ive learnt a few more things:

going to set R48 correctly so to set zero on the meter

going to sort out the wiring and tidy everything up and bolt it all down

gonna change the L1 choke for lower ohm version, self wind

R23 = compression amount, probably threshold?
R44 = set to 220k
R42 = set to 5.1k
R52 = meter zero (max to one side to get near zero)
R48 = 1M8, lower if cant get to zero

going to change Vu Meter LEDs for something more powerful

my meters are hairball 1mA and im using input pot and output pots, i have stepped pots as well but will try on separate pots first.

getting slight hum on right channel but this would figure as psu part of board right next to toroidal, going to move into bigger case so should be much better.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on February 08, 2018, 08:09:22 AM
gonna change the L1 choke for lower ohm version, self wind

Any chance of doing an extra pair ?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on February 08, 2018, 12:15:01 PM
Hello folks,
I have finished stuffing my boards and am ready to install them in my case... I need to order a few more things from Mouser and am curious what to order for the rotary stereo link switch and the "On, In, bypass" switch. I still have to order my bypass PB's (the ebay seller is away) and the little step-down pub to power them. Very excited to get this one up and running!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 08, 2018, 07:57:55 PM
Rob,

sure mate, i'll wind you a couple, send me over your details and i'll pop them in the post.

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 10, 2018, 01:28:43 PM
Hello folks,
I have finished stuffing my boards and am ready to install them in my case... I need to order a few more things from Mouser and am curious what to order for the rotary stereo link switch and the "On, In, bypass" switch. I still have to order my bypass PB's (the ebay seller is away) and the little step-down pub to power them. Very excited to get this one up and running!

You can use any switch so long as it has enough positions...
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on February 10, 2018, 05:16:10 PM
You can use any switch so long as it has enough positions...
Thanks desol!

Could you post a few more pictures of your build for reference please? Sometimes a picture(s) helps me  :o

Kindest Regards,
rlucas
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 10, 2018, 06:38:36 PM
I've attached a pic of how I did my bypass switch. Basically, 1 pole is the 120 main and the other pole is the 12v supply main. I added a jumper so that when you move the switch from 'in' to 'bypass' 120v is always present and the unit stays on(meters, etc) whether in bypass or not....but also when you move the switch to bypass, it sends 12v to the coils on the relays(white wires) to power them from normally closed to the normally open position...which is XLR direct in to out(bypass).

The 1:1 ratio setting on my units does not account for makeup gain, so you get a massive gain boost if you turn it to 1:1 from say 5:1 heavy compression. The true relay bypass works to match heavily compressed vs dry signal levels better. Hope that helps. I'm no expert.

Makes me wonder what the point of the 1:1 ratio setting is?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on February 12, 2018, 12:09:52 PM
the 1:1 just gets the flavor of the transformers into the signal chain.  Mine is quite colorful so i could see someone wanting to maybe do that... but id rather squish things with it.  ;D
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on February 12, 2018, 02:02:15 PM
the 1:1 just gets the flavor of the transformers into the signal chain.  Mine is quite colorful so i could see someone wanting to maybe do that... but id rather squish things with it.  ;D
Hello sr1200!
Ive finally gotten around to this build, your help with my SB4000 was indispensable and I used your build guide for the PYE! Im waiting on a few more things to arrive and then I can power this one up... You happen to have any pictures of your build?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on February 12, 2018, 07:26:55 PM
I dont have any gut shots of it.  Ill be happy to remove it from the rack if you need to reference something.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 13, 2018, 10:54:18 AM
the 1:1 just gets the flavor of the transformers into the signal chain.  Mine is quite colorful so i could see someone wanting to maybe do that... but id rather squish things with it.  ;D

The transformer option I completely understand. It's just that I'm used to other (different) units that account for makeup gain when you bypass the sidechain. I have a good bypass on this unit and I see now why someone included it in the design. No biggy....
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on February 13, 2018, 02:22:41 PM

The original units are pretty transparent, so 1:1 was just intended to defeat the compression and eliminate the need for bypass. I used these daily for years and never felt like it needed a bypass switch. If I wanted to I could just pull the return jack out of the patchbay and let the jackfield bypass the unit, but like I say it was never really something I needed to do because switching the ratio to 1:1 sounded perfectly linear to my ears.

That said, I guess the Pye trannies had nothing lacking and the signal path is really very simple, so if you're hearing a lot of colour there might be something squiffy going on ...

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 13, 2018, 05:17:10 PM
Im in the final stages of the re wiring and changing the layout of my unit, need to find some other inductors to re wind L1 as well.

one question, should the output leads form the pcb to the output transformers be screened 1 core cable? or use 2 core not screened?

also ive seen someone put copper tape wrapped around the output txf, is this copper tape then put to GND?

regards

Spence.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on February 13, 2018, 05:33:36 PM
I'd have thought the output wiring to be non-critical, but original units had single-core screened leads.

Can't comment on the copper foil, but why wouldn't you ground it?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 13, 2018, 06:49:36 PM
The original units are pretty transparent, so 1:1 was just intended to defeat the compression and eliminate the need for bypass. I used these daily for years and never felt like it needed a bypass switch. If I wanted to I could just pull the return jack out of the patchbay and let the jackfield bypass the unit, but like I say it was never really something I needed to do because switching the ratio to 1:1 sounded perfectly linear to my ears.

That said, I guess the Pye trannies had nothing lacking and the signal path is really very simple, so if you're hearing a lot of colour there might be something squiffy going on ...

Thanks for your reply.  I'm assuming the units are working correctly, as they both appear to function and sound very much like what I've heard the actual circuit doing, but they haven't been measured, proven, etc. They were put on a scope and a few things looked at to the best of my abilities. The oscillators and trimmers were set as per the guide(trimmers are not labeled on the board, which I thought was a bit odd...but whatever).

They sound unique to any of my other units, so I'm a bit confused with the description of transparent. As soon as I turn it on(even on light settings), I can immediately hear it; as I increase the input, it seems to handle things really well, and musically.

Apart from jump in gain I get when I switch down to 1:1, everything seems to be working normally. I have to assume(by your reply) that you 'did not' need to lower the makeup gain before switching to 1:1. Has anybody else noticed this on their units?

As far as I know, the only things that were changed(more or less) were the additional input 'mike' stage(removed) and the oscillator component 'improved'. I know that the originator of this had messed with it for years before releasing this final version, and that he had units on hand to observe, listen to, etc.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on February 13, 2018, 07:37:11 PM
Apart from jump in gain I get when I switch down to 1:1, everything seems to be working normally. I have to assume(by your reply) that you 'did not' need to lower the makeup gain before switching to 1:1. Has anybody else noticed this on their units?

The originals have a dual-ganged, reverse-wired threshold control which decreases the output level at the same time as it increases the input level, thereby increasing/decreasing compression while keeping the overall gain at unity. Unless you are really smashing it, you don't hear that much of a jump in level when going to 1:1.

If your unit has separate input and make-up controls I guess it might explain the need for compensation, though.

When I say transparent, I mean that since the gain is at unity regardless of threshold, patching in at 1:1 should result in no change in response. I would guess that any tonal difference you might be hearing under these conditions is likely to be transformer colouration, unless something is wrong with the signal path circuitry. If the trannies have been tested for DC resistance with DC current, they might need degaussing. I remember a warning in the Pye manual about that.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 13, 2018, 10:35:20 PM
Ahhh..ok. That makes sense with the pots being unganged. I understood that they were separated, but I didn't connect the dots with the make up gain... it can be brutal if you're not paying attention and you switch it under certain conditions. I feel like locking that position out now, as I don't really see myself using the box in that manner.  Also thanks for clarifying what you meant by transparency Dan. I hadn't checked it for coloration at 1:1. I just powered it on, and started using it. :)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 16, 2018, 12:58:49 AM
Here is my layout
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on February 16, 2018, 04:23:03 PM
I dont have any gut shots of it.  Ill be happy to remove it from the rack if you need to reference something.


If possible. That would be great. Me and a friend here are getting close to finishing up. We just need to put in the I/0 & side chain transformers.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on February 16, 2018, 07:37:00 PM
Ill try to get some up this weekend.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Grummy77 on February 16, 2018, 08:58:45 PM
Ill try to get some up this weekend.


Choice. Me and a friend up here are getting close. We just want to see some innards of some others to check against to make sure we’re doing it right.

Here’s a photo of where we’re at.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on February 17, 2018, 04:59:43 AM

Choice. Me and a friend up here are getting close. We just want to see some innards of some others to check against to make sure we’re doing it right.

Here’s a photo of where we’re at.

Ideally your big brown caps should be flush on the board and not at angles.   If you have them how you have done it and they get a knock it can rip the track off the pcb . .........      I tend to  get all components sat down on pcb unless I know they will be generating some heat, then I stand them off to get some more air round them.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 17, 2018, 11:32:11 AM
Yep. It's good to make sure your parts order will fit the board. Lead spacings, diameters, etc. You'll want to make sure you're far enough away from the meters(in front) so that the meters aren't too cramped. Try to think of things in the future. ie: If I need to take this all apart, how difficult will it be? Keeping your pcb's and x-formers straight saves space and looks nice, but isn't always a reality. One of my output transformers needed to be placed at an angle to reduce hum(the channel closest to the pwr x-former).

Otherwise, the layout looks reasonable. Hope that helps.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on February 17, 2018, 07:18:22 PM
Anyone have a build guide once you have the board populated?  The build butler helps a ton with that but I need guidance on wiring the PCB's to the transforms and pots

Pictures even?

Thanks 🌝🍻
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 17, 2018, 10:18:27 PM
It's on page 18. I just spent about 10 minutes looking for it.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on February 18, 2018, 05:56:06 PM
You have a build document?  I somehow missed that can you post it here?  Or email it to me please.  [email protected]

Thank you thank you thank you 👍🏻🍻

oh page 18 of this thread.... this doc PI_3141_Build_Guide_1_1.pdf
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 18, 2018, 05:59:56 PM
Yes...

My recommendation(which is what I did), would be to first read this entire thread; all fifty pages. Go from there.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on February 18, 2018, 07:21:05 PM
https://imgur.com/fXTNOr1 (https://imgur.com/fXTNOr1)

https://imgur.com/XSxXkOJ (https://imgur.com/XSxXkOJ)

https://imgur.com/LgWYQlN (https://imgur.com/LgWYQlN)

Hope these help  ;)
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: stevenclements on February 20, 2018, 01:54:36 PM
https://imgur.com/fXTNOr1 (https://imgur.com/fXTNOr1)

https://imgur.com/XSxXkOJ (https://imgur.com/XSxXkOJ)

https://imgur.com/LgWYQlN (https://imgur.com/LgWYQlN)

Hope these help  ;)

Thanks a bunch these will go a long way to helping me wrap my head around it
cheers
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on March 04, 2018, 03:27:16 PM
So Ive completed my build and have this to report...

I used SR1200 build guide and bom

Upon power up I set each channel for 19.25vdc (it just stuck in my head to set it at this voltage)

Both channels pass audio and are VERY quiet.
both meters work but are at 4db  upon power up (they will zero out with R52 adjusted)
Both channels threshold out makeup gain are working great
Decay is working great too.
Channel one compresses as it should and sounds awesome.
Channel two is not compressing and sound like the daughter board/oscillator is not engaged.
BUT, when I engage stereo link both channels compress and track very well together !

now on to what is not working yet... and this is where I hope you folks will help me out...
Channel two is not compressing on its own and am wondering if TR11 is bad (TR11 is the oscillator transistor?) and I need to replace.
neither channel seems to engage the 3:1 setting 

Now on to calibration... My Fluke 179 DDM only measures to 100khz for the frequency. I have an old analog tektronix 2215 oscilloscope that was recently given to me (and a pulse tone generator) but don't know how to use it really. I can get the oscillator waveform to show for both oscillators on it but don't know how to calculate it (just being honest).  I have ordered a neoteck DDM that will measure up to 600khz so Im waiting on that to begin a formal calibration. And hopefully replacing the TR11 on channel 2 will get it compressing on in dual mono.
Going to try to upload some pictures of my build. Also I have held my iPhone 6 right on top of it with absolutely no noise or hum .
seriously thinking about build another one already!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on March 04, 2018, 03:29:08 PM
So Ive completed my build and have this to report...

I used SR1200 build guide and bom

Upon power up I set each channel for 19.25vdc (it just stuck in my head to set it at this voltage)

Both channels pass audio and are VERY quiet.
both meters work but are at 4db  upon power up (they will zero out with R52 adjusted)
Both channels threshold out makeup gain are working great
Decay is working great too.
Channel one compresses as it should and sounds awesome.
Channel two is not compressing and sound like the daughter board/oscillator is not engaged.
BUT, when I engage stereo link both channels compress and track very well together !

now on to what is not working yet... and this is where I hope you folks will help me out...
Channel two is not compressing on its own and am wondering if TR11 is bad (TR11 is the oscillator transistor?) and I need to replace.
neither channel seems to engage the 3:1 setting 

Now on to calibration... My Fluke 179 DDM only measures to 100khz for the frequency. I have an old analog tektronix 2215 oscilloscope that was recently given to me (and a pulse tone generator) but don't know how to use it really. I can get the oscillator waveform to show for both oscillators on it but don't know how to calculate it (just being honest).  I have ordered a neoteck DDM that will measure up to 600khz so Im waiting on that to begin a formal calibration. And hopefully replacing the TR11 on channel 2 will get it compressing on in dual mono.
Going to try to upload some pictures of my build. Also I have held my iPhone 6 right on top of it with absolutely no noise or hum .
seriously thinking about build another one already!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on March 04, 2018, 10:11:49 PM
If that osc is not calibrated correctly, i dont think you'll get the compression you would expect.  You may have gotten lucky with the one side but not the other.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on March 04, 2018, 10:18:21 PM
If that osc is not calibrated correctly, i dont think you'll get the compression you would expect.  You may have gotten lucky with the one side but not the other.
I’m definitely hoping once I get it calibrated correctly that resolves the issues! It’s been a cool project for sure🎉
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 08, 2018, 02:00:33 AM
Now I have my unit reworked I have both channels sounding good.
Both meters are not quite right, so I do want to look at other options to get them to 0.
Channel 1 is worse than channel 2, so really it’s just looking at why ch1 is off compared with ch2.
If anyone could point to where in the circuit to consentrate on please?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on March 08, 2018, 06:06:47 PM
When you find it let me know. Ive never been able to “0” the meters. I even went over it with Abe himself. No reason why they wouldnt act properly.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 09, 2018, 12:54:28 PM
When you find it let me know. Ive never been able to “0” the meters. I even went over it with Abe himself. No reason why they wouldnt act properly.

You can calibrate the meter empirically with a series R and a shunt resistor.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: sr1200 on March 09, 2018, 03:33:14 PM
would the shunt be relative to the series resistor in value?  To find the value i would think i could use a pot temporarily, figure out a fixed value... or can i just leave it there as a calibration point.... hmmmmm
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 09, 2018, 08:31:42 PM
ooh this sounds good, throw some values out there and i'll get on it in the morning!
And if you could let me know exactly where we should put these two resistors please?

Looking at the schematic R65 and R67 look to be ones to play with?
Also R52 seems to have a big effect on the meter, but i seem to have R52 all one way? which could imply  that TR13 has a big effect on the meter position? any thoughts?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 10, 2018, 02:48:01 AM
The shunt goes across the meter (between + and - ). The series resistor (maybe there is one already if you have a trimmer) goes ahead of it. Or between - and ground if you prefer.

By adjusting the two values you should be able to set a zero point and a sensible deflection range.

I cannot offer values, sorry. They will depend on your meter more than anything, but the shunt will probably need to be close to the resistance of the meter coil.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 10, 2018, 04:20:10 AM
Ok so we are probably talking about putting in 100R trimmers then and having a twiddle right?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on March 10, 2018, 05:49:46 AM
That's how I got my meters to zero, by turning r52...as it didn't seem to affect the sound of the unit. I tried dialing it down and up and listening while compressing heavy/soft, etc. Nada...didn't do anything that I could hear at all....but of course, that's subjective.

That's why I mentioned earlier in this thread that I wish he had labeled the trimmers on the board(obviously, there's other logical ways to deduce what does what, I just don't know how to do it).

All of my other trimmers were pre-trimmed to the suggested values and left, and it's been good ever since. I'd still like to know what's what tho...

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 10, 2018, 06:10:25 AM
Yes that’s what I have found, R52 doesn’t effect sound but seem to have the most influence on the meter position, but with mine I can’t adjust it anymore as it’s fully one way, so I need to change something to allow a bit more range to be adjusted?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 10, 2018, 06:41:47 AM
Ok so we are probably talking about putting in 100R trimmers then and having a twiddle right?

That sounds like a fair starting point.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 10, 2018, 07:22:55 AM
I wondering whether TR13 has effect on the meter position, as I have same values in both channels but one meter very nearly lines up and the other doesn’t?
I might test both and see if they are different?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 10, 2018, 10:29:20 AM
Looking at the schemo I have on file, I think TR12 is the one you're concerned with.

I've just spotted that there is a 1k5 resistor (R65) which is connected across the meter lines.
I would try reducing the value of this resistor, in order to bypass more of the drive current away from the meter. This might bring R42 into range. 😉

Transistor matching between channels is never a bad thing, though.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 10, 2018, 10:49:30 AM
Or increase R67.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 10, 2018, 01:49:01 PM
top darts dan, hopefully i'll get a minute and try this! will report back.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 13, 2018, 09:58:35 AM
HI All,

I have just changed R65 to 1k trim pot and this works well to dial down the meter to zero, so if you need to this works great!!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 13, 2018, 01:36:33 PM
Glad that fixed it for you.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 13, 2018, 02:46:10 PM
Yes thank you very much Dan.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on March 16, 2018, 02:57:30 PM
We still don't know what all the trimmers do, or at least I don't. Namely R52.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on March 16, 2018, 03:03:47 PM
We still don't know what all the trimmers do, or at least I don't. Namely R52.

R52 is decay time as marked on the schematic. It works on my unit just fine. Although it may not work correctly with 555 oscillator.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on March 16, 2018, 08:11:46 PM
I have calibrated the oscillators and and balanced the channels in/out... I was able to use R52 to zero my meters but do feel indeed it adjusts decay as well...  but it works for me. This thing sounds smooth and tight, it can really squish but is also smooth on the vocal tracks I have tried it on and it does indeed sound great on acoustic guitar... but it is especially groovy on the drum buss! I don't know that it will see my 2buss very often but it will get used in every mix from here on. it is very quiet too! Now on to the next build :o
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: MagnetoSound on March 17, 2018, 02:04:42 AM
R52 is definitely for calibrating DECAY time, but does have a slight effect on the idle position of the meter.

On the original Pyes, the meter always tends to sit about half a dB or so above zero when DECAY is properly adjusted. Just perceptible on an original unit, but possible to ignore once you know about it.

I strongly suggest calibrating the meter to zero first using R42 (and R65), with R52 (DECAY) all the way down. Then, to calibrate R52 go to the longest setting and calibrate recovery time if you can arrange a suitable test signal (drum samples with reverb tails of known duration are good for this). Alternatively, you can calibrate at the 100mS setting for the shortest undistorted recovery time (pick a signal with good LF content) if you feel the shortest setting is the most crucial.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on March 18, 2018, 09:22:47 AM
Hey, thanks for pointing that stuff out guys. Actually, I think I remember seeing the notes for the trimmers at some point on the schematic, now that someone mentioned it. I'll dial those decay trimmers up a few turns next time I have it open Magneto..thanks for that advice.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: vitopower on July 20, 2018, 02:40:59 AM
Is there anyone who is willing to describe the process and parts required for building the oscillator transformer?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Ilya on July 21, 2018, 09:04:27 AM
Is there anyone who is willing to describe the process and parts required for building the oscillator transformer?

The transformer is basically several turns of wire around a ferrite ring. You need to find the ring with the correct permeability to get the osc frequency you want. This can be done with some experimenting.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: vitopower on July 22, 2018, 11:26:06 AM
Thanks, Ilya!
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: kml23956 on December 09, 2018, 07:04:49 PM
Does anyone have the documentation for this project that they would be willing to share?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on December 24, 2018, 07:18:21 PM
I think the information is posted in the thread somewhere.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on December 24, 2018, 09:01:49 PM
http://collectivecases.com/?product=ac-sound-pi-3141-vintage-pwm-compressor-circuit-board
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on February 04, 2019, 06:49:16 PM
Has anyone else got a working unit? If so, what do you like it on?

I love mine on acoustic guitars, drums and drum buss, vocals too.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on February 06, 2019, 06:14:03 AM
I like mine on overheads and acoustic guitar, haven’t tried it on anything else yet
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: desol on February 09, 2019, 10:11:40 AM
Like any good, usable piece of equipment, Pye is a compressor known to pretty much work on anything.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rlucas41 on February 09, 2019, 01:11:09 PM
I second that desol! ;D

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Mmt50816 on March 12, 2019, 05:39:44 PM
Im gettin set to start wiring this puppy up and had a few questions. I attached a pic of how i think the pots should be oriented and the way i intend to wire the stereo link. Anyone want to check my work and give me the A-Ok?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 19, 2019, 09:07:38 AM
Have we got a working setup procedure yet?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 19, 2019, 04:10:28 PM
I got a problem with channel 2 now!!
Channel 1 passing audio and can twiddle in some approx settings
Channel 2 not passing audio?

Would be really helpful to have a proper setup procedure
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on March 19, 2019, 04:13:24 PM
Dis you see the attached doc
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 20, 2019, 03:12:15 PM
Thats great stuff Rob, i thought i'd revisit this unit and see if I could get it working a little better and understand the setup a bit more.
Channel 1 sounds pretty good, I have no idea what everything is set too!!! I just twiddled and looked at the waveform and tried to get the meter working to a decent level.
Channel 2 sounds good now but i get these big spikes!! so I need to revisit the setup and approach it as per your last post calibration.
I also have a trim pot for R65 which helps zero the meter.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Mmt50816 on March 20, 2019, 03:59:36 PM
I dont know if my pic posted with my last question, but I was wondering if someone could give me a little more clarity on the orientation of the pot pins to the board and the wiring of the stereo switch. The verbal instructions are not making much sense to me about marrying the pins
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on March 20, 2019, 05:03:23 PM
I dont know if my pic posted with my last question, but I was wondering if someone could give me a little more clarity on the orientation of the pot pins to the board and the wiring of the stereo switch. The verbal instructions are not making much sense to me about marrying the pins
1=anticlockwise
2=wiper
3=clockwise
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Spencerleehorton on March 21, 2019, 06:49:55 AM
Am I right in thinking that these peaks I see happening on Channel 2 are when the compressor is pumping?
Or is it that the threshold is t setup properly?
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on March 21, 2019, 07:45:46 AM
Am I right in thinking that these peaks I see happening on Channel 2 are when the compressor is pumping?
Or is it that the threshold is t setup properly?

Have you tried to set up both channels as per the doc I posted ? 

If you haven't then I would do this first & then start making comparisons.   If you have then I would say that if both channels are doing something radically different with the same settings then you have a fault on one channel.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Mmt50816 on March 21, 2019, 03:01:54 PM
1=anticlockwise
2=wiper
3=clockwise

I understand that is how the pins on the potentiometer are oriented. I am asking which pin goes to which spot on the pcb.  As in does pin 1 go to ground in both the input and output pot with wiper being the middle spot on the pcb?

Which spot on the output xlr is the + and which is - ?

And on the input xlr is pin 3 of the xlr go to the middle spot on the pcb?

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Mmt50816 on March 21, 2019, 03:04:06 PM
Ill post my wiring pic again. Let me know if all thse connections look correct, especially the stereo switch business
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Rob Flinn on March 21, 2019, 05:58:57 PM
I understand that is how the pins on the potentiometer are oriented. I am asking which pin goes to which spot on the pcb.  As in does pin 1 go to ground in both the input and output pot with wiper being the middle spot on the pcb?

Since they are both level controls it is highly likely that pin 1 goes to ground.

Quote
Which spot on the output xlr is the + and which is - ?

And on the input xlr is pin 3 of the xlr go to the middle spot on the pcb?

Since both in & out are transformer balanced it will not make a great deal of difference which way you wire them so long as the output is in phase with the input.

Check with your meter which of the input connections goes to ground & you will have found which connection is pin 3 on the xlr.

Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: JoBe76 on April 23, 2019, 02:16:15 PM
I was wondering does anyone have the full documentation for this project?
The Help docs on collectivecases.com has no schematic on the U7 Daughter Board, all other links I have found are dead.
I would be incredibly thankful for any additional documentation anyone could share.
Title: Re: PYE Compressor/Limiter Thread *boards shipping* BOM up!
Post by: Mmt50816 on May 04, 2019, 03:31:27 AM
1) I was wondering did anyone ever try to put the missing 100k resistor back in the circuit and did it change anything?

2) Are you guys grounding the case and shield of the input cinemag and did it help noise?