2. amps-preamps
  3. 163493-5418

My really dumb tube mistake(s)

8 years ago, I bought a sweet sounding Line Magnetic amp for my office system which a few years ago died and had to go to the repair shop. $500 later it was back working, but then recently I noticed the sound was getting thin, I couldn’t bias the tubes and thought something else was wrong with it, arghh.

Then I noticed one newer tube was able to be biased and decided to replace all 4 KT-88 power tubes.
Presto, the amp sounded great again!

Like the boiled frog, the sound degradation had been so gradual my brain had gradually adjusted. But the new tubes brought it back to life.

So, then I thought, wow, maybe I should try the same thing in my primary system with my Primaluna monoblocks, switch out the Primaluna tubes for some new Gold Lions. Again - wow! What a difference. Like I bought new amps, much richer and fuller sounding.

Tubes wear out, even if they don’t blow out.
Yes, duh, it’s a good idea to replace them every 4 years or so and not wait eight.
cdc2

Showing 1 response by petg60

petg60
1,486 posts
 
When music turns lifeless, lacking, punch, drive, dynamics, air, bass, then is time to check which tube has gone bad, no need to blow if its an output tube. Or even if they cannot bias properly (output ones). For me it should be best to change all output tubes at the same time. A tube tester will not show when a tube is going to go bad but can give a good indication of its life. So if close to end of life readings, replace. Always have a spare set, you never know.

G
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