Victory v1 Copper help

Started by yalesmith, November 27, 2023, 05:43:25 PM

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yalesmith

Howdy. I am troubleshooting the Cobbler Preamp ( Victory v1 Copper clone) and I think the voltages are way off. the input voltage is 9.44 and drops to 9.41 after the d100 diode... ok so far (I think) Followed by R100 a current limiting resistor in series. There is no continuity between the negative d100 diode and the r100 resistor...... I physically bridge the resistor leg to the the Diode and now only get 3.4 volts to pin 1 of the ic100 charge pum (tc1044scpa) . Something must be wrong? The voltage should be something near 8.5 volts?  Any help would be great full! See schematic here:

https://docs.pedalpcb.com/project/Cobbler-PedalPCB.pdf

antonis

"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..


duck_arse

your IC2 appears to be upsidedown in its socket.
" I will say no more "

antonis

I think you killed IC2 (reverse polarity power supply) resulting into significant current draw (about 60mA, judging from voltage drop across 100R resistor)..

Take IC2 out of socket and take new measurements.. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

duck_arse

Quote from: antonis on November 29, 2023, 05:49:44 AMTake IC2 out of socket .....

..... take it to the back door, and throw it as far as you can. then get another TL.
" I will say no more "

yalesmith

Hello.  I wish it was that easy!!! I was swapping them out and I put them in backwards... but thanks for noticing!! I did get some sound but it was static, similar to a fuzz pedal that is not biased correctly but only worse... I hit a chords and static comes out a second later.   I did take some voltages as follows:
Ic100
1 - 5.60
2 - 4.89
3 -1.56
4 - .154
5 - .769
6 - 5.18
7 - 4.56
8 - 4.62

Ic1
1 -2.97
2 -2.56
3 - 1.60
4 - .762
5 - 1.04
6 - 4.13
7 -  3.48
8 - 4.53

Ic2
1 -2.83
2 - 2.27
3 -1.54
4 - .760
5 - .804
6 -3.85
7 - 4.2
8 - 4.53

Does this make sense at all?  Thanks!!

antonis

Quote from: yalesmith on November 30, 2023, 06:59:35 PMDoes this make sense at all?

Unfortunately, No.. :icon_wink:

Take both op-amps (IC1 & IC2) out of sockets and take measurements on IC100..
(Black probe permanently on GND and Red probe on respective pins - beware of measurements negative signs..)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..