Lowrider has clean signal coming out of the high out.

[Louie B.]

Lowrider board, only substitutions are standard POTs in the Fuzz and tone.

low and sub outputs sound fine.
Dry output is fine.
High output just sounds like the Dry out run through a HPF. Fuzz works fine. Tone doesn't seem to have much effect. A/B switch doesn't seem to have much effect.

Reading through the schematic, with as little experience as I have, it looks like the octave up is created around IC 2A & IC 2C? I ran through a voltage check and IC 1, 2, 3, 4 all look good. The numbers get crazy around 5,6,7. I can't figure out what these 3 actually do, but it looks to me like they're part of the Low and Sub circuits.

Also Q2 and Q3 are wierd, but again, these appear to be in the low and sub portions of the circuit.

I am  a bass player, and do not have any guitars to test this with. Both of my basses are Passive P-Basses.

Photos here:  https://photos.app.goo.gl/i3o4fiUNwLJzv96G9

[madbean]

So, the High part of the circuit works like a lot of analog octave up circuits in that it phase shifts one copy of the waveform then rectifies both signals with diodes and sums them to get the upper octave. IC2A is the phase shifted part. IC2C is just a simple buffer. Each half goes through the two germanium diodes and combines the two signals together.

If you are getting just clean signal through the High control, that means your phase shifting part or the buffer part is not working so rather than adding the two signals together to get the upper harmonic, you are getting just one of the outputs (most likely).

You need to look at two things: the outputs at pins1 and 8 of IC2 and your germanium diodes. The first thing I always suspect is a part. What type of germ diodes did you use and where did you get them? Is that a culprit? Next thing could be the IC itself. Do you have another one you can swap in? Does all your soldering look good...no bridges or excess solder blobs, etc etc.

[Louie B.]

Thank you so much for the informative response.

GE diodes are 1n270 purchased from Small bear.
Yes i did have another TL074 so I just swapped that in. no change.
IC2 Pins 1 and 8 are both reading 4.86v on my meter (this is what I get on all the points that are spec'd to have 5v)
D3 and D4 I am seeing 4.86v on both sides of each Diode
R18 and R19 are reading a good 100k across them.

Attached is a sample of the soldering (the section of the board in question) There's a couple of joints that may be considered a bit solder starved but nothing looks cold or shorted to me.

The last time I had issues with (someone else's) Pedal, their forum just kept coming back with "reflow your solder joints" "reflow your solder joints again". I ended up overheating and lifting pads to the point the PCB was ruined and the problem turned out to be a faulty stompswitch. That's why I'm reluctant to reflow these now.

I'll take it over to a friends tomorrow and try his strat through it and see how it sounds.

[Louie B.]

Update: Running my boss' strat through the circuit: playing open string or lower fret still sounds like a clean signal run through a HPF, when I get up passed the 12th fret I am getting some of what I would call ringing that is an octave up mixed with the dry. I'm thinking my expectations were wrong on what an Analog octave up pedal can do. I was expecting just the octave up without the dry mixed in, now that I'm reading your explanation I guess it's supposed to be a mix and maybe this has been working all along.

[madbean]

Analog octave up is a unique but very imperfect sound. You won't get anything like digital OU out of it. That said, it is very cool...when it works!

To test it, roll the tone knob down and play the g string between the 9th and 16th fret. That's were it gets really prominent. At least it will be able to tell you whether or not it is working correctly.

[Louie B.]

Thanks again, yes I think it is working. Sorry for my ignorance.