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Home » VintageKustom.com » Replacement Part Suggestions » transistor for 250 (mosfit FS85677)
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transistor for 250 [message #27196] Wed, 06 February 2019 08:50 Go to next message
Jimw727 is currently offline  Jimw727
Messages: 4
Registered: February 2018
Location: Elk River
Junior Member
I am going to either sell my system (listed in the for sale), or possibly have it repaired. The local shop was at a dead end trying to find a mosfit transistor on the preamp side...need part # FS-85677. Searched the web for hours.

Shop said they can get "noise" through bypassing, but need the transistor. They already put in a few parts in the preamp side.

If you turn the volume up, and tap the head, you can hear the reverb echo, etc. So the problem is the preamp.

Any suggestions? Thanks
Re: transistor for 250 [message #27197 is a reply to message #27196] Wed, 06 February 2019 10:58 Go to previous messageGo to next message
stevem is currently offline  stevem
Messages: 4775
Registered: June 2004
Location: NY
Senior Member
A replacement for that FET is a ECG brand ECG221 or a NTE brand NTE 221

Also tell the repair tech that if it's the preamp with select tone that's not working, it's output goes into the first half of the IC chip on the other preamp board.
This all means that if that IC chip is bad that the selecttone channel will not work also.

[Updated on: Wed, 06 February 2019 11:04]

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Re: transistor for 250 [message #27198 is a reply to message #27197] Wed, 06 February 2019 12:15 Go to previous messageGo to next message
Jimw727 is currently offline  Jimw727
Messages: 4
Registered: February 2018
Location: Elk River
Junior Member
Thanks!!!
Re: transistor for 250 [message #27199 is a reply to message #27196] Wed, 06 February 2019 12:22 Go to previous message
stevem is currently offline  stevem
Messages: 4775
Registered: June 2004
Location: NY
Senior Member
Also the plug in connectors used in these amps and there Aluminum terminals are known for tarnishing up and making for intermittents and non working conditions.
Many times just unplugging and re- plugging them a few times will be all that's needed to restore connections.
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