I got arround 250mV AC but have to check on monday with a better DMM with 6 digits 0.01% Tolerance.
Most cheap dmm have in AC measurement a high Tolerance.

Dear,

Try to change R127 Value by 4.7Kohm.


Best regards,
e-licktronic

e-licktronic wrote:Try to change R127 Value by 4.7Kohm.

Changing it to 18K seems to work. I guess the proof will be when it's all put together and I can do some audio tests.

Changing it to 18K seems to work. I guess the proof will be when it's all put together and I can do some audio tests.

Glad to ear you say

Best regards,
e-licktronic

Hmm... The closest I could get it is 180mV...

Have I gone wrong somewhere?

Yes, i appears so : Wrong value caps in C16, 18, and 20

Okay.... corrected my error but still can only get down to 160mV..

Okay, just went through everything, tested all values of resistors and checked values of cpacitors. All good. So still confused as to why I'm getting a different minimum mV value....

I too am having issues with trimming to the correct voltage on pin 1 of U24, the lowest I can get is about 250mV.

All components have been checked and rechecked and they appear to be correct.

However while checking for errors, I noticed that the resistor pictured for R127 does not match the one listed in the build guide. The image is of a 47K resistor as opposed to the listed 4K7 and due to my excessive voltage problem I'm wondering which value is correct? I currently have a 4K7 in R127.

Edit: I've just noticed that the original 808 schematic lists a 4K7 for R127, so that's likely the correct value (and the image must be mismatched). I'll have to look for the source of the problem elsewhere.