2. amps-preamps
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How are tubes to be purchased in general?

I have never had a tube power amp. Although I have a tube preamp (AI3) it is relatively unfussy with tubes. If a power amp has a matched quad set of tubes, how do you replace them if only one goes bad? Most are sold in matched pairs. How many do I have to keep around for emergencies? Do all four ever go bad at once, or can I just pop in one or two. I talked to the manufacturer (Rogue) but the rosy picture of tubes lasting years finds me a little bit skeptical. Of course if this question is like an owner of a gas guzzler car wondering if he can afford the gas (tube replacements) please tell me so or to go get a SS amp. It's just that a cheap pair of matched KT88's/6550 go for about $70.00 new, two monoblocks mean 8 tubes so that is $280.00 investment.
drjjpdc

Showing 1 response by weiserb

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weiserb
477 posts
 
You need a auto ranging multimeter to check the bias on the power amp tubes. If your lucky whan a tube starts to go you will hear a little distortion . With the multimeter you can see which tube has a bad bias reading, which cannot be corrected with the bias adjustment. Then you replace that tube and your set.

If the tube blows it may take out a fuse or a safety resister depending on the amps design.If the resister goes you need a trip to the shop to replace it.

I prefer tube sound so I thinks its worth the extra cash, and hands on attention... for the next step closer in Musicality.
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