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Help with fixing Kustom L795RV [message #28847]

Wed, 16 November 2022 18:59

Smilan
Messages: 3
Registered: November 2022

Junior Member

Hi,
I have on the bench a Kustom L795RV that came to me disassembled with burnt resistors at the power amp.
I replaced the faulty resistors and installed new 2N3055 transistors.
Now there's no smoke.
The voltages from the PSU seems to be right.
But what is going on is that as soon as I'm turning the amp on the amp start to squeal and the bulb on the current limiter starting to light bright.
When I disconnected the driver regulator board and connected the signal generator straight to the primary side of the output transformer with the signal on the RED wire and the BLUE wire grounded I got an output signal on the speaker.
When I disconnected the preamp and fed it with 25DCV from external PSU I got output signal on the wire that goes to the driver regulator board.
So it seems like the problem is with this board.
I replaced the three electrolytics on the board and tested all the transistors outside of the board and everything tested good.
Since I don't have a schematic for the L795RV I worked with the "Ross organ amplifier schematic" that I found on EL34 website that is pretty much identical to the driver regulator board and the power section of the L795RV.
What else can I do to make this amp works?

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