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

Help Support GroupDIY:

Rob Flinn

Well-known member
Joined
Jun 3, 2004
Messages
4,527
Location
Sussex, UK
I think if you look at the original PYE diagram you will notice that the solid line of the electrolytic caps is drawn as the +ive side. i.e vice versa to what you would normally expect to see. Just look at the caps that are connected across the power rails.
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
I think if you look at the original PYE diagram you will notice that the solid line of the electrolytic caps is drawn as the +ive side. i.e vice versa to what you would normally expect to see. Just look at the caps that are connected across the power rails.
Thanks Rob
So are you saying the positive side of C7 on the PCB should be the negative side
And C7 is shown incorrectly on the org schematic?
 

Rob Flinn

Well-known member
Joined
Jun 3, 2004
Messages
4,527
Location
Sussex, UK
Thanks Rob
So are you saying the positive side of C7 on the PCB should be the negative side
And C7 is shown incorrectly on the org schematic?
I am not saying anythung about the pcb. I was just saying the the 2 diagrams you have show the caps the same way round. i.e you were misreading the orientation of the caps on the original Pye diagram.
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
Thanks Rob
So are you saying the positive side of C7 on the PCB should be the negative side
And C7 is shown incorrectly on the org schematic?
I just looked at the neg rail on the org schematic, and it has all the electrolytic caps connected directly to B- to negative of the cap (solid line) they are not shown reversed symbol wise
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
I just looked at the neg rail on the org schematic, and it has all the electrolytic caps connected directly to B- to negative of the cap (solid line) they are not shown reversed symbol wise
Did you install C7 in reverse on your build?
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
I am bringing this up because someone on this forum mentioned there was an error on the pcb board that the + side of C7 wasn't correct.
See post #387
 
Last edited:

Rob Flinn

Well-known member
Joined
Jun 3, 2004
Messages
4,527
Location
Sussex, UK
You need to confirm this for yourself comparing it to the diagram. The last time I looked at this was more than 5 years ago, so I can't remember.
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
You need to confirm this for yourself comparing it to the diagram. The last time I looked at this was more than 5 years ago, so I can't remember.
Yes, I think this was a bad Idea doing this build, no one is doing this build anymore, might have to install an eye hook and use it for my boat anchor ☹️
 

JMan

Well-known member
Joined
Oct 26, 2019
Messages
312
Location
Chicago
If it helps, I'm following the thread and am happy to help in the rare moments where I am able. I would like to finish mine up at some point, I just can't spare the time to work on it right now. But I hope you won't give up! If you've already got the components and everything, why not give it a whirl and see if you can get it working? I mean, don't get me wrong, these older projects with incomplete/confusing documentation where the threads have gone quiet are a little intimidating, but on the other hand, you might discover something that helps out the next guy (maybe me! 😅 ).
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
If it helps, I'm following the thread and am happy to help in the rare moments where I am able. I would like to finish mine up at some point, I just can't spare the time to work on it right now. But I hope you won't give up! If you've already got the components and everything, why not give it a whirl and see if you can get it working? I mean, don't get me wrong, these older projects with incomplete/confusing documentation where the threads have gone quiet are a little intimidating, but on the other hand, you might discover something that helps out the next guy (maybe me! 😅 ).
Hey JMan I am not giving up yet, just letting some steam off
 

sr1200

Well-known member
Joined
Dec 6, 2010
Messages
1,885
Location
Long Island, NY USA
I did. It was posted here but wasnt very detailed like a paint by numbers kind of thing. I really didnt have much trouble getting it going and not sure why folks are having a hard time with it. You do need some equipment to get the timing right on the chip, but everything else was pretty cut and dry. If theres something specific you need help with let me know.
 

sr1200

Well-known member
Joined
Dec 6, 2010
Messages
1,885
Location
Long Island, NY USA
Has anyone found a 1000uf,50v with a package size 10-11mm dia for C8, all I can find is a 12.5mm, won't fit properly on the pcb, the space layout is too small.
Tie a bigger one to the bottom of the board instead of the top and lift your board up off the bottom of the case w standoffs. There are a few quirky things w this that youll run into.
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
Tie a bigger one to the bottom of the board instead of the top and lift your board up off the bottom of the case w standoffs. There are a few quirky things w this that youll run into.
Thanks sr1200, I think I found the problem, I noticed in Abe's notes that TR12, TR16 and TR18 need to be reversed if you use the alternates, and I did use the alternates so I will reverse them later and see what happens. I did get the 555 chip to generate 250khz.
 
Last edited:

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
Thanks sr1200, I think I found the problem, I noticed in Abe's notes that TR12, TR16 and TR18 need to be reversed if you use the alternates, and I did use the alternates so I will reverse them later and see what happens. I did get the 555 chip to generate 250khz.
Success it's alive!! chopper is working and it sounds awesome. Meter now zeros also.
I ran a bass track through it and does compress. Much different than most compressors in a good way.
 

JMan

Well-known member
Joined
Oct 26, 2019
Messages
312
Location
Chicago
Success it's alive!! chopper is working and it sounds awesome. Meter now zeros also.
I ran a bass track through it and does compress. Much different than most compressors in a good way.
I am legitimately so excited that you got it working! Congratulations! I'm trying to finish up several other projects at once right now, but this gives me some motivation to come back to the PYE once those are done!
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
I am legitimately so excited that you got it working! Congratulations! I'm trying to finish up several other projects at once right now, but this gives me some motivation to come back to the PYE once those are done!
Thanks JR
I did have a small hiss when the output pot was cranked up, I soldered a jumper from the can of the CINEMAG 15/15B to the XLR input pin 2, and the hiss went away.
I did use the EDCORS XSM600/10K transformers for both SC, and outputs, the old BOM listed the EDCOR WSM600/15K for the output transformer, but it doesn't sound as good
as the XSM600/10K.
 

AW

Well-known member
Joined
Feb 15, 2021
Messages
111
How is the stereo link wired, I am guessing two wires from U8 board1 to U8 board2 via a DPDT
 

JMan

Well-known member
Joined
Oct 26, 2019
Messages
312
Location
Chicago
How is the stereo link wired, I am guessing two wires from U8 board1 to U8 board2 via a DPDT
Is U8 the stereo link connection? (I’m not looking at the board so I don’t know what the silkscreen says). If so, what you described is the correct procedure for this.
 
Top