DRIP EQ1 gen 3 voltage issues

wimmy7986 · Apr 12, 2018

Hey everyone,

I built this unit about 2 years ago, and it was working great until a few months back. I smelled something burning, and noticed the 470R 2W resistor was burnt. The unit was also barely passing sound, but it was still "EQing" when I would turn the dials.

I swapped the burnt resistor out, and now I get NO SOUND.
All DC voltages look incredibly high! Except, I get no voltage at the 290V test pad. (With and without tubes installed)

There isn't a ton of clear build support for gen 3, and there are so many "optional" parts and sections to this build it is overwhelming and confusing.
Anyone have any ideas where I should start?

Thanks,

Jimmy

Michael Tibes · Apr 13, 2018

A schematic might help to help you

Michael

furn1979 · Apr 13, 2018

Do you go for the diodes (1N4007) or the 6x4 rectifier in the power section?

Here are the Drip Pultec v3 docs I have (no schematics unfortunately):

furn1979 · Apr 13, 2018

And another Gen 3 doc.

wimmy7986 · Apr 13, 2018

Michael Tibes said:
A schematic might help to help you

Michael

Unfortunately my knowledge and ability to read a schematic and troubleshoot is lacking. I understand the signal flow and how to follow the path of the schematic, but I don't even know where to begin to isolate a problem.

furn1979 said:
Do you go for the diodes (1N4007) or the 6x4 rectifier in the power section?

Here are the Drip Pultec v3 docs I have (no schematics unfortunately):

I went with the diodes. That pdf you attached is the exact one I used for the build.

wimmy7986 · Apr 13, 2018

The original schematic (except for the power section) seems to match up exactly with the Drip build. The specific voltage thats missing leads right to the CT of the output transformer.

I just don't understand why it used to work, and now is misbehaving... Not sure what led to the resistor burning, but my guess is that I have now damaged something down that path.