Lowrider - Missing first octave down

[Pietrus]

Hi guys,

i got some problem with my lowrider. I apologize for my english, it isn't my native language, if something isn't clear, please ask.

General description of the problem:

I just finished my lowrider and my clean, octave up, second octave down is working. I like the sound of this pedal, it's very nice But I got some trouble with my first octave down. If I turn everything else all the way down, and doct1 all the way up, I get just some very quiet noise. This noise doesn't depends on the input.
I found this is an interesting problem, because according the schematic, the second down octave is generated from the first down octave. So I don't get, how the second work, if the first doesn't.

Steps that I have taken to try to resolve the issue

I checked the pads, and if I found a questionable one, I heated it up, and soldered again.
I checked the pinout of  q2 and q3, because I use 2sk30, and it's pinout is different, than the PCB's. I twisted the pins to the correct configuration.
I checked the contacts between the parts and the pads, in case of the parts of first octave down (according to schematic.

List any substitutions you used for parts/values

Instead of 1n34 diode, I used OA1182 germanium diode.
I used 2sk30 fet for Q2 and Q3.
I omit c12 and used 1n for c10.


I would be very happy, if someone can give some advice, where should I search.

Thank you.

[midwayfair]

Try audio probing, following the first octave down path. I suspect a bad connection somewhere AFTER the first octave is split off from the octave generation, like a dry solder joint on a pot or something.

[Pietrus]

I found the missing octave I share the problem, I hope, it can help somebody.
I tried the audio probe, and when I toched the Doct1 pot's middle pin with the multimeter, I could hear some noise. This noise was different from the earlier, it was louder. So I found out, my potmeter was dead. I don' know how and why, but after desolder it, I couldn't measure any resistance between any pins of the potmeter. I will buy an other, and try it.

Thanks for the idea. 

[garfo]

I found the missing octave I share the problem, I hope, it can help somebody.
I tried the audio probe, and when I toched the Doct1 pot's middle pin with the multimeter, I could hear some noise. This noise was different from the earlier, it was louder. So I found out, my potmeter was dead. I don' know how and why, but after desolder it, I couldn't measure any resistance between any pins of the potmeter. I will buy an other, and try it.

Thanks for the idea. 

Hi Pietrus. Were you successful?
I'm having exactly the same problem with a Boss OC-2. Everything works except first Ocatve down.