LED / Voltage issue after upgrading output caps. [resolved]

Julyan9 · 1175

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Offline Julyan9

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Hello!

I know that giving troubleshooting advice is easier when the kit is stock and not fiddled with.

I have a speedballed crack with 157M choke installed.

Today I decided to install some mundorf Mcap 100uf 250V caps to swap out the stock output caps.

There was no problems with the speedballed crack with the choke installed on the PS before this.

All LED's on the small board are lit, and the voltages there are
OA 73
IA 240
B-A/B 0
IB 241
OB 72

Also the LED's on the 9pin socket are both lit and both tubes/both halves are lit.

On the big board however I'm getting ~240V DC to all of the measuring points OA/OB/G/B+

Yours: Julyan
« Last Edit: January 19, 2019, 05:37:14 AM by Paul Birkeland »



Offline Doc B.

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Reply #1 on: January 18, 2019, 11:38:11 AM
Sounds like you have disconnected something on the big board when you installed those caps. G is ground and should be 0 volts, not floating at B+. So start by checking that connection.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Julyan9

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Reply #2 on: January 18, 2019, 11:40:19 PM
Yeah fair enough I was sure I checked all the wires but the black wire from speedball going to the terminal strip had broke off. All works now. I have some fresh tubes coming in next week. In a sense its sad that there is not many mods left to be done on this so now I have to decide between crack-a-two or the mainline and save money for some hd800(s).

Thanks for help and I really really love this amp and the service you provide.