[Billy]

Good to hear it’s sorted

Funnily enough I was going to mention your test box I’ve had problems with mine in the past and we couldn’t fully see it then I thought nah!

I could tell you a few stories about my test box and audio probe failures but I won’t haha

I’ll just say it took me over a week to suss an audio probe failure which resulted in an amp being taken apart

I used an old guitar cable to make the probe plugged it into one of the amp inputs and it wouldn’t go in so after trying to force it in I used the other amp input and the probe still didn’t work

Long story short after stripping the amp down thinking I had a jack socket problem and finding I didn’t, I eventually looked at the probe / guitar cable  where the jack tip had snapped off and stuck in the amp input socket

I more or less accidentally looked at the cable end to find a problem I’d never have looked for I mean you don’t expect a metal jack tip to break off do you?

So we’ve all been there in my case more than once

[Billy]

It’s very difficult to make your resistor colour bands out even zooming in

I’m not 100% on your Q5 pin numbers post voltages as Collector Base and Emitter for clarification

What PNP transistor did you use for Q5

The original pedal is just a shade below unity

Some of your solder joints do look slightly crumbly and dull and there’s a few ball like joints that may be dry inside so I’d try reflowing those

The pot just controls the oscillation speed so as you say won’t affect volume

Post voltages for all ICs and transistors that may indicate your problem area

If you have an audio probe, probe IC1 pin 6 and both sides of R17 and 18 and the base of Q5 to see if there is any noticeable difference in signal level

 

[Billy]

With your IN jack insert a jack and trace the connections round to their solder lugs like this to make sure it’s connected correctly

If you’re not using a battery just leave the ring unconnected

 

[Billy]

Did you test it prior to adding the buff and blend

Some of the solder joints on the buff n blend pcb look like they need more solder particularly the ground connection 3rd from the left

You could also try increasing the value of R5

[Billy]

It’s very difficult to make out any of your resistor colour bands even zooming in, you’d need to take a well lit picture without your hand covering some of the pcb so that colour bands can be clearly seen and all wiring traced

I can’t see most of your resistor 4th multiplier bands it’s difficult to see whether they’re brown, red or orange etc

Have you tried reflowing the IC socket solder joints

What voltage readings do you get on the IC pins and TR2 middle pin

Your soldering does look good but there’s always the possibility of a dry solder joint even if they look nice and shiny especially if they look ball like,  they could be dry inside

Just a note when audio probing you don’t always get a good connection with the probe I’d usually always check beyond where audio stops you’ve got audio at the IC input pin 3 and nothing on the output pin 1, I would normally check the input pin 5 just to make sure

 

 

[Billy]

I wouldn’t think so it’s more likely to be a dry solder joint or something similar in that part of the circuit

I’d reflow your solder joints from R16 to R14 / 15

Do you have an audio probe

[Billy]

Looking at the schematic It either switches in an extra gain stage or bypasses it continuity check all your switch connections

You’d need to work out which position fails boost position would switch volume lug 2 to R16 and R14/ 15 to out jack tip

In the other position volume lug 2 to out jack tip

This is how I think the switch is connected you want to check the middle common row connects to the top row in one position and middle to bottom in the other position but not both at the same time

Here’s a PDF if you’re unsure with continuity checks

https://drive.google.com/file/d/176vVBWeRaSQ0QvZlnozjKHE6AeHsvxFP/view?usp=drivesdk

 

 

 

 

 

 

 

[Billy]

Yes you can leave it out it’ll just go through C1 looking at the schematic

[Billy]

That’s correct just wire your in and out jacks to the pcb

The spdt just puts either C2 or 3 in paralell with the input cap C1 giving you full mid and treble range

Leave that in the middle off position

[Billy]

Damn I checked the guides page for the latest build doc too

Guess I’ll stick to the shop docs from now on

Twice in a week

I’ll give myself a slap

[Billy]

Although its fairly difficult to see it looks like your diode D1 is the wrong way around the cathode striped side should go the other way around

Easy enough to confirm check what voltage you get on pin 8 of IC1 I’d suspect little to nothing

What may be happening is with the diode the wrong way around power will conduct through it straight to ground rather than into the circuit via IC1

 

[Billy]

As long as all your caps have a sufficient voltage rating 18v will be fine

If I’ve ran out of stage 3 mini pcbs

I usually just build a quick duende boost if I need to increase output and I’m in a hurry

http://tagboardeffects.blogspot.com/2013/04/escobedo-duende-jfet-jhs-minibomb.html?m=1

I’ll use a trimmer instead of a pot so I can set and forget and just add it at the input or output of my main pcb depending on what it is

In your case I’d probably put it on the output

 

[Billy]

Looking at the schematic one side goes to repeats 3 the other side would go to TR1 lug 1 with the small dot

You’d then be bypassing the trimmer when you press the switch as detailed in the build notes

You could definitely implement it or something similar to any PT2399 delay

What you’re actually doing is reducing the resistance going to repeats lug 2 if you look at a standard deep blue delay schematic it’s normally 2K you’d reduce that to 1K for infinite repeats when the feedback pot is fully CW

[Billy]

Apologies I’m looking at an older build doc where it’s 47K must have been changed in the latest version

I’ll need to update all my gpcb build docs on my PC

I should know better that used to be our mantra here  ‘are you using the latest build doc?’ haha and here I am not

I’m doubtful increasing its value will make much difference

You could try it or wire a pot as a variable resistor and try that

[Billy]

You’re correct right resistor wrong transistor I’ll edit it

It’s Q4 source resistor R10 47K

[Billy]

Now I’m not 100% fets aren’t my strong point but I’m thinking changing Q4 source resistor R10 to a higher value might increase output the logic being less signal will get dumped to ground through it

I’d socket it and try 100K in there

It also might mess up the biasing but you should be able to re adjust that via TR3

How much it’ll mess up the circuit I don’t know it being between a gain stage and the eq section but changing only 1 resistor it’d be easy enough to change it back

Let us know if you try it

 

 

[Billy]

There are differences between the two but looking at the schematic I’d think you could use almost any N channel FET

I’d err on the side of caution myself and use a 50K to 100K trimmer for T1 that’ll give you plenty of resistance in case you need it to bias it correctly

Afaik that part of the circuit from volume 2 is an added boost circuit some of the old fuzz circuits suffered from low output

[Author]

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