Build Your Own Clone Message Board

After 30+ hours of troubleshooting (using all of the other great threads with the same issue), im finally posting to try to figure this out.
When engaged, light goes on, clean signal passes through. Mix knob seems to be the only one that does anything– when turned all the way to the right, volume goes up a bit. And yes, I turned the trim pot slowly, no effect. i will follow up with pictures shortly, but wanted to highlight something i noticed while using a signal tester that was not mentioned in any other thread.

The signal goes dead on the left leg of the Q7 (leg closest to left edge of board), and the top leg of R28 (resistor right below Q7) also is dead here. Signal works everywhere else.

Schematic:
http://byocelectronics.com/schematics/p ... ematic.pdf

Other tidbits....
IC pins voltages look relatively close to where they should be
Reflowed all joints multiple times

Any immediate thoughts on what to do from here?

The left leg of Q7 is the collector, which is also the junction of R27 and R28. If you didn't have any signal there, you would not get any signal at all through the pedal in effect mode. I'm not sure why you are loosing signal there.

A better test is this - what does the signal sound like at the junction of R24 & R26? They connect on the left side of each resistor. This is after the wet & dry signals are mixed. Do you get any phasing there?

How about the middle lug of the depth pot? Don't test for signal there, but does the voltage fluctuate? Does the speed of the fluctuation change with the speed pot?

_________________
MasterDelayer/Reverbrador/Ampaholic/TopJacker

At work now, but will check that a little later today.

Forgot to mention it in my last email, but confirming that the middle lug of the Depth Pot oscillates– will need to play with the knob and measure to see how it fluctuates.

Confirming the left sides legs of R24 & R26 are passing dry signal.

Edit–
When I the speed is turned all the way down, the middle lug of the depth pot oscillates at a lower voltage,
-Rate Knob all the way up, speed all the way down: 2.9 volts about, no oscillation
-Rate knob all the way up, speed all the way up: 2.9 volts about, no oscillation

Thoughts on what to do next?

Based on past threads, seems like it may be the LFO portion of the circuit.

Referencing your post below and checking all of this now.
"Okay, so time to work on the low frequency oscillator (LFO) portion of the circuit. This section is currently not working and you will not get any phase until it is working.

The LFO consists of IC1, IC2, the depth pot, the speed pot, R32-R36, and C14-C15.

Visually check all of those component values, orientation of IC2 (underneath the pcb) and C14, and check/reflow those solder connections. Voltages from IC2 wouldn't hurt. You should have similar voltages as the other ICs EXCEPT that pins 1-3 are usually weird because they are left unconnected and pins 5-7 will oscillate when the LFO is working."

--
pics:
https://drive.google.com/file/d/0B8_fOf ... V4WjA/view
https://drive.google.com/file/d/0B8_fOf ... VwQk0/view

Can you revisit this? Rate all the way up, speed all the way down... Those are the same pots. Did you mean depth for one of them?

_________________
MasterDelayer/Reverbrador/Ampaholic/TopJacker

Apologies- yes I meant depth when I said rate.

Thanks. So yes, that means your LFO is not oscillating and you won't get and phasing.


This should apply to your build. Things look okay from your photos, but your soldering does look like it could use a little cleaning up. The most common issue by far is simply a bad joint hidden in the build somewhere. A lot of the joints look a bit uneven, some are different degrees of shiny, and there is a lot of flux splatter on the pcb. Here are a couple of references:

http://www.byocelectronics.com/board/viewtopic.php?f=9&t=52188

http://www.byocelectronics.com/board/viewtopic.php?f=9&t=52211

_________________
MasterDelayer/Reverbrador/Ampaholic/TopJacker

Thanks, Morgan! Somehow, I fixed this. Still not sure what did it.

Now I want to mod it do reduce the clipping...