Pork Barrel Voltages Way Off

[LedZepp007]

Hi,

My PB build isn't working. I have checked the solder joints and voltages. Voltages (with 9.36VDC supply) listed below:

4558:
1: 7.58
2: 7.55
3: 1.0
4: 0.0
5: 3.75
6: 5.51
7: 3.55
8: 9.1

BL3102:
1: 8.38
2: 2.8-3.0
3: 8.4-8.57
4: 0.3
5: 4.39
6: 0.0
7: 4.3
8: 8.97

BL3207
1: 4.32
2: 4.32
3: 4.36
4: 8.99
5: 8.3
6: 3.0
7: 4.3
8: 0.0

TL062:
1: Varies
2: 4.5-4.56
3: Varies
4: 0.0
5: 4.5-4.58
6: 4.54-4.58
7: Varies
8: 9.09

Any help appreciated.



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[Govmnt_Lacky]

Is this a Rev 1 PCB? If so... did you read the note at the end of the build doc?

Did you jumper properly for the 3102/3207 combo?

What is your R7 value?

What happens when you turn the trimmer?

[LedZepp007]

Is this a Rev 1 PCB? If so... did you read the note at the end of the build doc?

Did you jumper properly for the 3102/3207 combo?

What is your R7 value?

What happens when you turn the trimmer?

It's rev 1 and shouldn't need the modification.

I believe so.

R7 should be 10k, but I'll check it when I get home along with the trimmer.

Thanks.


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[LedZepp007]

Okay. Checked values last night. Some of the resistors were measuring a little low, but all within tolerance I think.

I found a cold solder joint was responsible for the weird 4558 voltages. So, now the TL062 and the 4558 are good. The 3102 and 3207 voltages are still the same. With my test rig, I was able to get some extremely soft effected sound. It was about 1/10th the volume of the bypassed sound and with a lot of static/white noise. The trimmer pot reduced the noise a bit, but the volume was still extremely quiet. Any explanations for why the BBD chips have such strange voltages? I did notice that R41 (33R) is not surprisingly not dropping the voltage to the 3102 much (about 0.1 VDC).


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[LedZepp007]

Okay: I believe the 3207 voltages are good now. But, the 3102 remains very high on pins 1 and 8.

Any help would be very much appreciated.


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[LedZepp007]

Anybody? Bueler?


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