Pre amp fault - diyAudio
Go Back   Home > Forums > Design & Build > Parts
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 5th January 2008, 07:29 PM   #1
Addolff is offline Addolff  England
diyAudio Member
Join Date: Jan 2008
Default Pre amp fault

Need some help here please.

I have a Krell KSP 7B pre / KSA100S power amp which has recently been giving me problems

When I turn the combo on, most times it is fine, everything quiet. After a while though a high pitched 'white noise' type sound is heard - even with the volume muted.

In addition, sometimes there is a hum, apparent on all sources, but worst with the phono stage. It will be virtually silent, then this too suffers with hum.

When I use another pre amp, no problem.

Any help would be really appreciated.
  Reply With Quote
Old 5th January 2008, 07:56 PM   #2
diyAudio Member
analog_sa's Avatar
Join Date: Aug 2002
Location: Cascais
These symptoms are not sufficient to pin-point a simple cause. What level of experience/abilities in electronics do you have?
  Reply With Quote
Old 6th January 2008, 11:02 AM   #3
AndrewT is offline AndrewT  Scotland
diyAudio Member
Join Date: Jul 2004
Location: Scottish Borders
one channel or both?
does it change channels when you swap interconnects?
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote
Old 6th January 2008, 01:25 PM   #4
Addolff is offline Addolff  England
diyAudio Member
Join Date: Jan 2008
Thanks for your reply.

Very little electronics knowledge - I can use a multi meter to test the simple stuff and can use a soldering iron.

I just wondered if the symptoms may have been a dead giveaway to an experienced hand for a particular fault - leaking capacitors or something.

The thing that is intriguing me the most is that the 'white noise' I described is apparent even with the volume muted.
  Reply With Quote
Old 6th January 2008, 01:55 PM   #5
diyAudio Member
Jan Dupont's Avatar
Join Date: Apr 2003
Location: Copenhagen, Denmark
Send a message via MSN to Jan Dupont
What your reply to Andrews question ??
It could brings us closer to the problem.....

Your volume sits in the front end of the circuit, so no mystery there......

I would first suspect a bad soldering, and properly a soldering to ground since you sometimes get hum.........
Free Schematic and Service Manual downloads, Spare time company (just for fun):
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
fault with my lanzar 50c amp pulsarhks Car Audio 1 4th March 2009 03:40 AM
M&K Subwoofer Amp Fault, Help Anyone? GES1407 Chip Amps 16 7th August 2008 07:02 PM
nad 304 annoying fault sollerbeen Solid State 14 17th November 2006 06:51 PM
cd6000 fault goodlife Digital Source 11 28th April 2006 06:31 PM
sorted out amp fault leander Solid State 0 22nd September 2005 06:00 AM

New To Site? Need Help?

All times are GMT. The time now is 09:01 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2