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Forum: Repairing Kustom Amps
 Topic: K150-6 pumps out DC voltage when powered on.
Re: K150-6 pumps out DC voltage when powered on. [message #27684 is a reply to message #23707] Tue, 25 February 2020 07:20
stevem is currently offline  stevem
Messages: 4254
Registered: June 2004
Location: NY
Senior Member
Forgive my oversite here, but you have a early model K150, and I have been looking at the schematic for a late K150 model with the 5033 board.

The early model 150s like yours still use the K100s +8 and -8 volt regulator sections and preamp section, so besides Q5 maybe going bad as the issue, something in that + 8 volt regulator circuit could be the bottom line on your issue maybe?

To narrow this down when the amp acts up check to see if your + 8 volts ( red wire to preamp boards) is still 8 volts when you have that 27 volts on the output.

By the way you do not need to keep a speaker load hooked up once the issue starts, this will save your ears and speakers!

[Updated on: Tue, 25 February 2020 07:22]

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Re: K150-6 pumps out DC voltage when powered on. [message #27685 is a reply to message #23707] Tue, 25 February 2020 09:47
corybrown is currently offline  corybrown
Messages: 27
Registered: August 2015
Junior Member
Yeah, I unplug the speaker any time the hum comes back. I really only have it plugged in when I'm checking to see if it's working and how long it will work.

I got some better rated test leads and will check those when I get home this evening.

Thanks again.
Re: K150-6 pumps out DC voltage when powered on. [message #27686 is a reply to message #23707] Tue, 25 February 2020 12:17
stevem is currently offline  stevem
Messages: 4254
Registered: June 2004
Location: NY
Senior Member
The wires that can give you a wall line voltage shock are the white and black ones and the white ones with a black strip.

If you go across the green and red wires on the main caps then you can a 90+ volt shock .

The 40 volts out of each main filter can will not harm you.



Current Time: Tue Feb #d 13:14:37 EST 2020
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