SOLVED Caesar is ill

Phasma888

Phasma888

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Have a nice day, everyone!
Please help if you can - the Caesar chorus part is not working.
Try to ignore the voltage and op amp names in schematic - it just fits.:)
I hope it will be easier than 23 wounds.

3207 voltages
1) 0.00 8) 3.95
2) 4.20 7) 3.95
3) 1.06 6) 4.17
4) 8.06 5) 8.64

All LEDs (and 3mm) work as they should, 5mm are temporarily not soldered. The flashing frequency is successfully adjusted by pots.

UPD: the blend pot works like a reverse volume - at the max the sound disappears, at low values - quite loudly.
 

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Betty Wont said:
Have you biased the trimpot? There is only a tiny part of the rotation that makes chorus.
Click to expand...
Yes, and once again now. From 9 to 12 volume increase, from 12 to 3 no changes. 8-9 and 3-4 o'clock with no sound.

And also the blend pot works like a reverse volume - at the max the sound disappears, at low values - quite loudly.
 
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Did you make this board yourself? Has it been verified?

Where did you get your BBD and clock? Your LFO is working, but it sounds like you can't bias in the BBD. The MIX knob is working as a reverse volume because you're not getting signal from the delay line.

EDIT: Recheck IC2 pin 6 -- it's not possible to have no sound at the non-inverting input but have signal at the output. Did you mean that you just have dry signal?
 
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The blend is working correctly, at minimum you have 100% dry, and at maximum you have 100% wet. Sounds like your delay line is not working. Betty's suggestion is the right place to start. With the blend maxed (100% wet) try adjusting the bias trimmer and see if you get sound.

If not, check the pin 2 and 6 of your 3207 with the frequency setting on your DMM. This will verify your clock is working. If that is fine you will need to audio probe the delay signal path and determine where you are losing it.
 
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benny_profane said:
Did you make this board yourself? Has it been verified?

Where did you get your BBD and clock? Your LFO is working, but it sounds like you can't bias in the BBD. The MIX knob is working as a reverse volume because you're not getting signal from the delay line.
Click to expand...
Yes, NextPCB. Unfortunately, the only way to verify this is to assemble and then hear a beautiful sound(

In different local stores - there was no alternative.
 
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There could be a number of issues in that case. You'll have to verify the delay block of the schematic and board, including all components. If that checks out, you may need to try a different BBD/clock pair.

Since you're not working from a verified board, there isn't much more help I can give.

EDIT: I missed @Bio77's post above. Definitely follow that instruction.
 
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Bio77 said:
The blend is working correctly, at minimum you have 100% dry, and at maximum you have 100% wet. Sounds like your delay line is not working. Betty's suggestion is the right place to start. With the blend maxed (100% wet) try adjusting the bias trimmer and see if you get sound.

If not, check the pin 2 and 6 of your 3207 with the frequency setting on your DMM. This will verify your clock is working. If that is fine you will need to audio probe the delay signal path and determine where you are losing it.
Click to expand...
Well, I just tried to trim again as slow as possible, and there was the sound of working pedal ! just for two seconds. It was about 3,5 - trim almost maxed. But I can not repeat(
 
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benny_profane said:
There could be a number of issues in that case. You'll have to verify the delay block of the schematic and board, including all components. If that checks out, you may need to try a different BBD/clock pair.

Since you're not working from a verified board, there isn't much more help I can give.

EDIT: I missed @Bio77's post above. Definitely follow that instruction.
Click to expand...
I checked all my docs for 5! times before order, and checked PCB using PedalPCB schematic. I can't buy any other pairs of 3207-3102, that's why I'm here.
 
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Bio77 said:
The blend is working correctly, at minimum you have 100% dry, and at maximum you have 100% wet. Sounds like your delay line is not working. Betty's suggestion is the right place to start. With the blend maxed (100% wet) try adjusting the bias trimmer and see if you get sound.

If not, check the pin 2 and 6 of your 3207 with the frequency setting on your DMM. This will verify your clock is working. If that is fine you will need to audio probe the delay signal path and determine where you are losing it.
Click to expand...
And I think that the adjustable flashing of the LEDs indicates that clock IC is working correctly, doesn't it?.
 
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Bio77 said:
Can you post the complete schematic? I didn't realize it was a different PCB.
Click to expand...
I added pin numbers to bdd and a clock to make it more readable. For both op amps, I used Eagle's TL072 because the pinout is the same. VPP = Vref, VEE = Vref_B (voltage net names doesn't matter)
 

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Bio77 said:
Can you confirm you have a 50k trim? If so, maybe try a 100k to give you more range to bias.
Click to expand...
Just thinking about the same! The 50k (that's for sure) trims that I have divide the resistance to 48k and 0, a few degrees before max. Maybe there are values I need somewhere nearby...
 
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benny_profane said:
It’s a voltage divider…would that really give more range?
Click to expand...
Perhaps a smaller value trim pot will give a larger usable angle?
UPD: I thought well about it and came to the conclusion that I'm dumb
UPD2: I thought great about it and decide to use 3296 trim with 25 turns of effective travel
 
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Do you have a Layout with actual resistor values on the PCB?
I would be checking your resistor values again!
Are they 100k 4 colour Metal film resistors????
 
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