2. amps-preamps
  3. 191958-170518

Tube power amplifier low static on one channel

Hi all I have an Audio Note Kit EL34 power amplifier. When the music is off I can hear a static sound from the right channel. It is not constant it gets louder then quieter then nothing then back again. I switched the non power tubes right to left and the static stayed on the original channel.  

If it was a tube it would have switched to the other channel correct?

If it was electro interference it would come out of both channels correct? 

Thoughts on what to check next?

Thanks

jh

johnah5
Post removed 
elliottbnewcombjr
5,471 posts
 

Don't trust your memory, make notes

All cables and connectors are good? IOW, make sure you are not hearing the random result of a poor connection elsewhere.

Switch L/R inputs 1st, that way, if the noise moves, it is coming from a different piece of equipment prior to the amp

Switch speaker wires, noise moves, it is that connected side, noise doesn't move it's perhaps in the speaker's crossover

How old is the unit?

If the noise does not move with the tubes (swap one at a time, keep track of original locations) it's time to check the entire unit, not just find one thing.

Another reason a simple tube tester is good to have. 

Power tubes get biased, how does your unit handle that?

johnah5 OP
235 posts
 

Found it!

It was one power tube which I isolated by switching channels and following the static. The power tubes are new stock so I didn't think it could be them but it was.  Thanks for the help.

jh

buellrider97
393 posts
 

 Glad you found the issue. FWIW I had a new pair of Gold Lion KT -77’s with about 15-20 hours on them. I started getting noise and before I could act boom ! The brand new tube let go and blew out the capacitors in the respective channel. You just never know. 

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