Pro-ten green side very little gain

[Jonnytexas]

Blue side sounds absolutely glorious. 10/10. Green side has almost no gain. Volume and tone work as expected. I have built a few of these, so I know something is amiss. Really scratching my head. I believe all components are correct except a few I didnt have: 2n5457 instead of j201, 100pf instead of 120 above IC1, 6n8 caps instead of 8n2. Used a b100k for volume with a 100k resistor across lugs 1 and 3 to make a 50k pot. The 5k1 resistor is soldered on bottom side of board...long story. I tried using a 250k pot for the gain and it made very little difference. All 4 4148 diodes measure around .56 in circuit. Pictures and IC voltages coming shortly when I get home.
IC1....All 4.3, except pin 4--0, pin 8--8.7

 

[Jonnytexas]

 

[Jonnytexas]

 

[Jonnytexas]

Anybody have any thoughts? I got a shipment in from BLMS, so now have the proper pots in. The pedal works perfectly except for not having any appreciable gain on the green side.

 

[szukalski]

Is the pinout on the 2N5457 correct? Some manufacturers have different pinouts..

 

[Jonnytexas]

Is the pinout on the 2N5457 correct? Some manufacturers have different

 

[Jonnytexas]

Thanks szuk, it appears they are the same. I also have j112 and j113. Im fairly limited in my knowledge, but I believe it is not part of the distortion matrix, maybe a buffer?

 

[szukalski]

Yes, but if it's dropping signal, then the gain won't be so high to induce distortion.
Time to break out the ole audio probe..

 

[Jonnytexas]

Yes, but if it's dropping signal, then the gain won't be so high to induce distortion.
Time to break out the ole audio probe..

Where would I probe?

 

[szukalski]

Start at the start. Follow the schematic.

 

[Jonnytexas]

Not sure where to probe. Anybody have any ideas? It's very close to working, just cant get any gain out of the green side.

 

[Jonnytexas]

I will give this one more try. Can anybody offer any guidance?

 

[jesuscrisp]

It's really hard to make out the values from the pictures, maybe start with cross-checking whether all of them are correct.

 

[Jonnytexas]

It's really hard to make out the values from the pictures, maybe start with cross-checking whether all of them are correct.

I went through all caps and resistors and could not find any mistakes.

 

[Jonnytexas]

Maybe this is a better picture.

 

[music6000]

No Power connected!
Test these matching colour circles for Continuity with DMM:

 

[Jonnytexas]

No Power connected!
Test these matching colour circles for Continuity with DMM:

View attachment 56989

Thanks so much for taking a look! Have continuity between colors.
Edit: have continuity within colors.

 

[Kroars]

I might try reflowing your solder joints. Very strange as the Blue side has far less gain than the Green, when working properly. Something definitely seems off. What temp is your iron set? Mine is typically around 800 F and solder flows nicely.

 

[Jonnytexas]

I might try reflowing your solder joints. Very strange as the Blue side has far less gain than the Green, when working properly. Something definitely seems off. What temp is your iron set? Mine is typically around 800 F and solder flows nicely.

Thanks for the reply. My iron sits around 790. The green is producing no gain. It works like a boost pedal.

 

[music6000]

Thanks so much for taking a look! Have continuity between colors.
Edit: have continuity within colors.

What happens when you rotate from 0 to 10 with the Gain pot?

Can you confirm what Colour Bands are on the highlighted resistors: