michal_k

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #40 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.


abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #41 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

« Last Edit: March 16, 2011, 03:15:38 AM by abechap024 »
AC Sound - some DIY circuitboards

michal_k

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #42 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.

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #43 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

Niketouille

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #44 on: March 16, 2011, 09:30:37 AM »
I'm in for a pcb too... and ready to beta test !!

leadbreath

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #45 on: March 16, 2011, 11:44:15 AM »
im in for 1 set, ill get my mad scientist cap on!!!
f**k marlbro's and weed ill stick to smoking germanium and silicon

michal_k

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #46 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

abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #47 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)


« Last Edit: March 23, 2011, 07:43:22 PM by abechap024 »
AC Sound - some DIY circuitboards

abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #48 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
AC Sound - some DIY circuitboards

leadbreath

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #49 on: March 23, 2011, 07:10:54 PM »
so when will these pcb's be available??
f**k marlbro's and weed ill stick to smoking germanium and silicon


abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #50 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!
 :)
AC Sound - some DIY circuitboards

leadbreath

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #51 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.

f**k marlbro's and weed ill stick to smoking germanium and silicon

abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #52 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.
AC Sound - some DIY circuitboards

abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #53 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

Boards should be here in a couple weeks...

-Abe
AC Sound - some DIY circuitboards

sahib

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #54 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.

abechap024

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #55 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
« Last Edit: March 30, 2011, 04:50:20 AM by abechap024 »
AC Sound - some DIY circuitboards

ptron

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #56 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 :)
No, you are correct; $30k for coffee and occasional BJs is considered a good bargain stateside.

http://www.facebook.com/tronmusic

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #57 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.

strangeandbouncy

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #58 on: March 30, 2011, 02:40:34 PM »
Hi,


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


   ANdyP
. . . . RUH ROH . . . . .

MicDaddy

Re: PYE Compressor/Limiter PCB: FEELER
« Reply #59 on: March 30, 2011, 03:07:50 PM »
Interested in pcb

Looking forward to seeing a new generation of PYE compressors   :o


 

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