VintageKustom.com
VintageKustom.com is your source for literature and information on the tuck-and-roll vintage Kustom amps from the 60's and 70's, as well as their related products such as guitars and organs . We provide a webboard for help with kustom gear history, technical information and repairs as well as discussions with other collectors.
Home » VintageKustom.com » Repairing Kustom Amps » K100-2 Hiss but no other output (Need help troubleshooting)
Show: Today's Messages :: Polls :: Message Navigator
Return to the default flat view Create a new topic Submit Reply
Re: K100-2 Hiss but no other output [message #21187 is a reply to message #21183] Fri, 15 August 2014 22:47 Go to previous messageGo to previous message
Jerrybass1955 is currently offline  Jerrybass1955
Messages: 45
Registered: August 2014
Location: NC
Member
IT's ALIVE....mostly.
I had to replace all three of the first transistor in the preamp. I used 2N3904 and 2N3906 and they work nicely. Pretty quiet too. I may replace some of the carbon comps with metal films to see if the noise drops further.

A few issues remain, and any assistance would be appreciated:

1- Reverb doesn't work at all, but very noisy when the reverb is turned up.
- Tank actually appears good visually - all springs connected. I can probably test it on another amp.
- Any thoughts on common failures or troubleshooting advice appreciated.
- With the tank connected, tapping or rapping the tank causes no sound at the output.
- Will modern transistors and metal film resistors in the reverb circuits help reduce the noise (assuming some of it stays after I get it working? If so, suggestions appreciated.

2- Tremolo works but needs a bit of tweaking:
- I can hear a ticking of the tremolo when turned all the way down. Planning to replace the .47uF cap for good measure.
- I notice on one schematic there is a 10K resistor in series with the intensity pot - it has been crossed out and 15K written above it. Could this be a tick fix?
- When I crank the speed up near all the way I hear it going unstable and squealing at the high end of the speed range. Any thoughts? Perhaps there is a known component tweak to fix it? My first thought is perhaps that .47 uF cap could be tweaked in value to reduce the range of the high end? Any other ideas. I don't really use tremolo so much, but it will bug me if I don't fix it!
- Moving the wires to the foot switch jack around seems to help both problems somewhat, but doesn't fully cure it.
- Also, seems a bit odd to me that the tremolo wire and the reverb wire are twisted together going to the foot switch jack. Perhaps I should use some coax there for each connection since lead dress seems to be contributing to the problem.

Thanks for helping me get this far!
Jerry

Report message to a moderator

[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: trem-vib distortion on my k150-8 and k100-8
Next Topic: Do I actually have a Frankenstein??
Goto Forum:
  

-=] Back to Top [=-
[ Syndicate this forum (XML) ] [ RSS ]

Current Time: Thu Sep 26 00:44:03 EDT 2024
.:: Contact :: Home ::.

Powered by: FUDforum 3.1.3.
Copyright ©2001-2023 FUDforum Bulletin Board Software