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The unit appears to power up properly. All LEDs are lit when expected (“Tap” LED pulsates, so something is happening internally). There is a thru signal in op mode and in bypass but no tremolo. There appears to be a VERY faint trem, but questionable. I saw that someone else had a similar problem related to the FET. Is there some way to check this? Any other suggestions would be welcomed.
Does it respond to the tap foot swtich?…(with the multiplier knob set to 1:1) Can you tap out a tempo?
-Brach
Yes
Another thing I notice is that although your owners manual says “volume” has unity gain at about 12:00, this actually appears to be at the lowest volume setting. That is the volume with the effect bypassed is approximately equal to the volume with the effect on at the minimum volume setting.
Did you build this from a kit or was it built by us, at ZDL? What is your serial number?
Just to be clear, you are saying that the pedal works fine, when it is either bypassed or engaged, but when it is engaged the effect doesn’t seem to be working (there is no tremolo), just a louder guitar signal. Is this correct?
About the volume issue, set the volume knob in the center and adjust VR10 until the gain is set to unity.
-Brach
This was built from a kit. The serial number is ZD3803. I don’t know if you can say the pedal works fine if there is no effect, but, yes, there is sound out both when the effect is engaged and when the effect is bypassed. Yes it is louder when the effect is engaged, but no effect heard. I am assuming the loudness is just gain which can be adjusted.
Yes, I agree…the loudness is probably just the gain pot over adjusted.
When the pedal is engaged, does it sound different than in bypass (other than it being louder)?
On the middle pin of depth knob…Are you getting a variable DC voltage between 0 and 5V as you turn the knob?…or is it always at some low voltage, close to 0V?
Are Q1 and Q2 installed properly?
Are you hearing both channels (high and low) fine in calibration mode?
-Brach
I have adjusted the gain, that is fine now. Sound appears to be the same with effect engaged or unengaged. On the middle pin of the depth control I have 0 V all the way counterclockwise, increasing to 5 V at full clockwise rotation. Q1 and Q2 appear to be installed correctly rounded side toward the optocouplers. In calibrarion mode I have basically the same sound with harmonic mix all the way over either direction.
Don
Thanks for checking that stuff. That is good information to have.
Are you sure the jumpers are jumped correctly? JP1 and JP2 aren’t connected, are they?
My understanding of page 48 step 4 is to connect JP1 to JP2 and JP3 to JP4. Is this not correct?
OK I get the jumper thing. Have reworked those, now the high band is working but not the low band. Have reflowed the solder on the low band jumpers twice, no change.
High band is working but I’m still not having any luck getting the low band tremolo to work.
In calibration mode high band sounds good low band is dead. Only thing I can figure from that is that low band optocoupler is not working. So what do we do to test that or have I already tested adequately and it is toast in which case it needs to be replaced?
Make a tiny incision on the heat shrink in the back of low side optocoupler (with your xacto knife), near the the leads of the opto’s led. No longer than 1mm long. In calibration mode, with the harmonic mix knob on the low side, look to see of the opto’s green led is lighting up. If not, turn the low side trim pot all the way up (clockwise 20 times) to see if you can see it light up. If it does light up then you have a problem with the analog signal path, if it does’t light up there is a problem with the led or it’s driving circuit.
Let me know what you find.
-Brach
I just ran your test, at first no light, after I turned the trim pot full up (20 turns) there was light, but still no output from the low band tremolo.
