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Old 2nd April 2016, 06:03 PM
A.N. Beal A.N. Beal is offline
Join Date: Feb 2006
Location: Leeds, West Yorkshire, UK
Posts: 59
Default Re: KT88 Intermittent problem

Dear Friends,
Thanks for the further suggestions. I can't give more feedback because I have been away a bit and also the problem is not happening enough at present to warrant the time to try to fix it. However I am not convince that the problem is a noisy potentiometer - it always adjusts volume smoothly with no crackles or other problems, so I am reluctant to squirt anything into it (alcoholic or otherwise) at present unless the evidence starts to point more firmly in that direction.
To recap, the first sign of the problem is if slight crackling occurs on the right channel during warm up; this disappears after a short time and both channels are then as quiet as normal. However when the amplifier is fed a signal, the right channel seems to be louder than usual and the left channel is quieter than usual but still clearly audible and undistorted. Changing sources or turning the volume control up and down a bit has no effect but a quick turn up to full volume and back down again clears the problem: the left channel comes up to normal volume and right channel reverts to normal. My guess at present is that the cause is a marginal connection or short-circuit which usually works OK and is cleared by a blast of full volume when it gives trouble.
As it isn't bad at present it may be a few weeks before I have another go at solving it but I shall let you know if and when I have more news to report.
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