[Billy]

Yes that’s correct comparing the pcb and schematic the square + pads for both C8 and 12 connect to ground

[Billy]

Another nice looking build Steve you’re churning out some great looking builds

[Billy]

What’s the 074 pin voltages with it both in and out of socket

Did you take your transistor voltages with all pots CCW what transistors did you get with the kit

Measure across D3 with no power to the circuit in both directions it should only conduct in the forward direction as you know

Your Q2 and 3 base and emitter voltages are very low compared to those in the build doc so I’d suspect a problem prior to Q2 base which in turn will effect the current going up to pins 1 and 16 of the LM13700 state variable filter the thing that makes it wah explained here by My7of9 (Barry)

https://revolutiondeux.blogspot.com/2012/07/mad-professor-snow-white-auto-wah.html?m=1

As Playsforfun says you can’t see the resistor colour bands clearly so it’s very difficult to be 100% on those so check every resistor value by colour band if you haven’t already to make sure they’re the correct value

 

 

[Billy]

All your component values and orientation that I can see look correct

The most likely culprit as Barry says is dodgy J201s there are a lot of fakes around

[Billy]

Try lifting the ground side of the 4u7 capacitor C7 and if you like it install an SPST on / off switch to connect/ disconnect it from ground

[Billy]

R14 is the LED current limiting resistor in the older docs it was usually 1K8 for a pretty bright LED

Both values are starting points I’d personally consider 3K3 too bright,  for a standard LED I’ll use 10K

So it’s a personal preference depending on how bright you want your LED

[Billy]

Your TC1 will show it as a BJT indicating the pins or you can Google the transistor type pinout although it may be in Russian it’s fairly obvious which pin is which

If it’s the GT308 or P416 the pinout is here

(**) Germanium PNP Transistor Single (N.O.S.)

[Billy]

I’m not 100% on what you are trying to do

I’m assuming you want the boost first going into the main pcb and you don’t want to use the boost independently just the main circuit with or without boost

The way you’ve got it with the boost active LED left side illuminates bypass the boost and right side illuminates but you’d obviously need the bypass switch active for either side of the LED to light up

 

 

[Billy]

Looking good I think NostalgiTones are taking over the world nice

 

[Billy]

I can’t clearly see some of the resistor colour bands and the odd one partially hidden behind transistors etc even when I zoom in, which might be an age thing, the image is a little bit dark in places I’ve checked all your polarized components which all look correct apart from D3 which I can’t see

Here’s the audio probe PDF for when you find yours for a little refresher

https://drive.google.com/file/d/1T9OsJ0riQhm1QFWPfNQ5q5guikuFKDRN/view?usp=drivesdk

I’d personally start at the first send pad on the left with only the first circuit active if it’s OK there probe the return pad to make sure it comes out of the circuit OK I’d do this for all 3 circuits individually

Once you find a volume drop you’ll obviously know your problem area and its just a case of probing that particular circuit

In the meantime as Barry says post voltages that might indicate where the problem is

 

 

 

[Billy]

Low volume could be caused by a few things

As Barry says using an audio probe is probably the quickest route to finding your problem area

I’d start at the input jack tip to its 3PDT lug to circuit in 3PDT lug, circuit in pad etc to make sure audio’s getting into the first circuit at a decent level then do the same for output to next circuit input and so on

Hopefully that’ll narrow it down to whichever circuit is causing it or if it’s something external to the circuit

[Billy]

That’s a really pro looking build it looks great

[Billy]

We need much clearer pics of your wiring it’s very difficult to trace anything

Post a pic looking down on the pcb so that all the wiring can be traced to the in and out jacks, DC jack etc

We can’t clearly see the DC jack wiring

A lot of your solder joints look like they may be potentially dry inside you don’t want any dull, grey or ball like joints

Some of your images are out of focus so it’s hard to see if there’s any damage to the pcb

Make sure you aren’t plugging your in cable to out jack and visa versa with the enclosure the wrong way up it’s a very common beginner mistake you’d still get bypass but no effect signal

All of your component values and orientation that I can see look correct

 

[Billy]

Very nice work it looks great

[Billy]

Very nice indeed looks fantastic better than some manufactured pedals I’d say

I’m just waiting for mine to arrive when it gets here it’s definitely jumping the queue

I’d better get my building A game on there’s been some really great looking builds posted for this circuit

[Billy]

That looks the business

I like the sound of it I’m gonna have to pull the trigger on one your description makes it sound like a must have pedal

 

[Billy]

Unfortunately it could be anywhere in the circuit, post a nice clear in focus image of your pcb so we can clearly see the component values, orientation and offboard wiring

I know I’ve checked faulty builds visually numerous times and still missed incorrect values etc

If you don’t know resistor values by colour band use this to check them

https://samstechlib.com/610938/en/

[Author]

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