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k100-2 tremelo and reverb questions [message #16907]

Fri, 13 April 2012 15:30

natedriver
Messages: 35
Registered: March 2009

Member

I have a k100-2 plexi faced head with tremelo/vibrato and reverb effects.
when turning off the tremelo I get a momentary loss of signal
is this normal? also when the tremelo vibrato is on I get noticeable drop in volume. Also the reverb is weak barely noticeable. Any help would be great.
Nate

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Re: k100-2 tremelo and reverb questions [message #16908 is a reply to message #16907]

Fri, 13 April 2012 21:40

cassent5150
Messages: 341
Registered: August 2009

Senior Member

I'm not an official tech or anything but from my expirience with these Kustoms, I would say you have some caps drifted out of tolerance and or leaking. I think you can test most of the transistors in the circuit without pulling them. Make sure the reverb tank is good. They've been known to loose a spring or two from all the road abuse they've been through. I believe that would be a PC-1500 pre-amp and you can get a free schematic to download at this link : http://music-electronics-forum.com/t19128/

You'll need PC-1500a and PC-1500b

Steve C

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Re: k100-2 tremelo and reverb questions [message #16909 is a reply to message #16907]

Fri, 13 April 2012 21:44

cassent5150
Messages: 341
Registered: August 2009

Senior Member

looking back at your text I see you have a head. That would mean you only have tremolo and reverb. Is that correct? I think the tremolo/vibrato was only on the combo 100's. That would have a totally different schematic. Steve C

Steve C

[Updated on: Fri, 13 April 2012 21:46]

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Re: k100-2 tremelo and reverb questions [message #16910 is a reply to message #16907]

Sat, 14 April 2012 10:35

stevem
Messages: 4774
Registered: June 2004
Location: NY

Senior Member

Indeed you amp does not have vibrato, your drop in volume could be due to electrolytic type caps on the board in the Tremolo circuit that have drifted in valve up or down, or have shorted and/or gone up in ESR big time.
It could also be the fault of a leaky transistor.
In the least with the age these amps are at now I change out all the board mounted electorlytic caps during a reapir as a matter of rule, and this is where I would recommend you start with your amp.
Just note that these type of caps have a + and - lead and must go back in the way they came out. what I do is once I pull the cap out I mark the board with a fine writing tip marker so that If I walk away I have no question where I am at when I pick back up.
Note that the 35 volt rated caps in the 8 volt + and - regulator circuit can get blown out if the amp ever had a problem in that part of the circuit and in turn got the power supplys full 40 volts applyed to them.

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Re: k100-2 tremelo and reverb questions [message #16912 is a reply to message #16910]

Sat, 14 April 2012 11:49

cassent5150
Messages: 341
Registered: August 2009

Senior Member

stevem, do you have the schematic's for the two k100 heads (K100-1 and 2 models cause I have both of them and I sure would love to have a copy if someone could email me a copy to cassent5150@hotmail.com Thanks Steve C

Steve C

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