2. amps-preamps
  3. 1085115335

How to track down bad tube and what can it mean?

I recently changed the tubes in my preamp and all but the driver tubes on my amp, but these tubes didn't work out. I replaced these with the stock tubes which had been good before. Now I get distortion from the left channel which sounds like a buzzing that comes and goes with the music. It increases with the volume. I've checked all the tubes and they are placed OK. At one point with the volume loud but not too loud the system turned itself off which had never happened before. My speakers are efficient and it was not putting out more than 10 wats max when this happend.

So how can I track down a bad tube if I have one? I suppose I could replace the tubes one by one with the new ones I tried, but this is extremely tedious and makes me dream of SS. Any idea what this problem, this sound indicates?

Any help is appreciated. My sick system depresses me. Thanks.
budrew

Showing 2 responses by pbb

pbb
1,140 posts
 
I don't think my local ARC dealer's service dept. would have figured out the ficus tree syndrome! Glad you found the source of your woes.
pbb
1,140 posts
 
With my ARC PH-3, I had a situation were I replaced all the tubes with NOS JAN Philips and everything seemed ok for a while. Then, problems with the right channel. My intention was to put back the original Sovteks one by one until the unit worked, but after substituting just one the situation seemed ok. Short while later, problems with the right channel again. So I brought the unit in to the local ARC dealer for an inspection. Turns out the mute switch was bad. They checked the two sets of tubes I had and they elected to put back the original Sovteks, declaring them way better than the just recently bought NOS. Moral of the story: NOS may not be the best road to go down (conversely, ARC dealers may be averse to using anything other than what ARC sells???) and more than one problem can surface at once making diagnosis/repair best left to qualified techs. Good luck.
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