No sound from compresor

[Guybrush]

Hi all

I've just finished populating a Keely compressor board from Fuzzdog and all is not well. When hooked up to my test rig I am getting no sound whatsoever when the pedal is engaged. No ground hum, no intermittent signal no nothing. Bypass works fine.

I have used an audio probe to follow the signal up to IC1 but not being the greatest at reading schematics I have got a bit stuck.  Schem below:



I am getting signal at the IC at pins 2 and 3 but nowhere else. Could anyone tell me if this is correct?

Voltages as follows:

EDIT: I made a mistake in reading the voltages . Please se my next post for the correct readings

1 - 53.5
2 - 4.82
3 - 4.83
4 - 0.00
5 - 8.71
6 - 9.44
7 - 7.30
8 - 56.2

Any advice on what might be the issue or on how I can proceed with the audio probe would be enormously appreciated.

Thanks

[selfdestroyer]

Looking at the datasheet for the 3080:
https://www.intersil.com/content/dam/Intersil/documents/ca30/ca3080-a.pdf

You should have output at pin 6. So if you have signal pin 2 & 3 but not 6 then your IC socket could be bridged somewhere or a bad IC, maybe.

Just some thoughts.

Cody

[Scruffie]

How can you have a higher voltage on pin 6 (OTA output) than the supply at pin 7? Also you have way too higher voltage at pin 5... if the chip wasn't dead it probably is now, test without the chip in.

[Orbis_Ignis]

How can your voltage be that high on pin 1 & 8? That does't seem possible

[Guybrush]

Oh balls. I've read the pins in the wrong order 

Correct order is as follows:

1 - 53.5
2 - 4.82
3 - 4.83
4 - 0.00
5 - 56.2
6 - 7.30
7 - 9.44
8 - 8.71

Apologies for the confusion! Do these voltages shed anymore light on the issue?

Looking at the datasheet for the 3080:
https://www.intersil.com/content/dam/Intersil/documents/ca30/ca3080-a.pdf

You should have output at pin 6. So if you have signal pin 2 & 3 but not 6 then your IC socket could be bridged somewhere or a bad IC, maybe.

Hmm.. Deffo nothing at pin 6. I've checked for solder bridges and everythng seems good. Possibly a dodgy chip?

Thanks again.

[lincolnic]

Are you sure about those voltages at pins 1 and 5?

[m-Kresol]

Are you sure about those voltages at pins 1 and 5?

I guess those are mV instead of V. autorange setting most likely