DRIP EQ1 gen 3 voltage issues

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

wimmy7986

Well-known member
Joined
Aug 31, 2011
Messages
45
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
 
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):
 

Attachments

  • eqp-1 psu NOTES AND COMMENTS-1.pdf
    798.4 KB · Views: 23
And another Gen 3 doc.
 

Attachments

  • pultec version 3 amplifier notes-2.pdf
    1.5 MB · Views: 23
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. 
 
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. 
 
Take precautions this is HV.
Make sure Pt is not shot..it can explain the hight voltages..did you installed the right fuse?
 
Back
Top