PYE Compressor/Limiter Thread *boards shipping* BOM up!

[prescott]

Is it possible to feed (somehow) a stereo pair from only 1 oscillator?

 

[Dr_J]

Hi Abe,

boards arrived well, thanks!!

Now i'll have finish my mouser card 

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

Let's get build these beauty...  ;D

ROCK-ON!

 

[Patrick from Davis]

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

 

[Jeremy.Starseed]

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.

 

[Patrick from Davis]

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

 

[abechap024]

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!

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...

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

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

 

[abechap024]

Is it possible to feed (somehow) a stereo pair from only 1 oscillator?

Thats a very interesting idea.... Probably! But then again the channels might feed into each other strangely...haven't tried it.

 

[abechap024]

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.

 

[abechap024]

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.

 

[abechap024]

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.  but they do seem to have less parts then the clx.....hmmm

 

[abechap024]

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

 

[Patrick from Davis]

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.

 

[prescott]

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?

 

[Patrick from Davis]

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

 

[abechap024]

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

 

[abechap024]

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.

 

[Patrick from Davis]

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

 

[abechap024]

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!)

 

[Rob Flinn]

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

 

[Patrick from Davis]

Most everything you need should be in this post

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

Patrick