2. amps-preamps
  3. 192410-110112

Lower power on left channel

Hi all, 

Does anyone have any ideas or come across this before?

I have a Primaluna Evo 300 pre-amp with a Primaluna Evo 400 power amp, using G/L KT 88 tubes. The other evening I was sat there playing some music and suddenly thought that it did not sound right, as I stood up and walked towards the centre of my speakers I noticed the the left speaker was down on volume compared to the right speaker. As I went to turn the system off I noticed that the KT88 tubes where down on heat to what they normally are.

I can not do much now till after Christmas but any help would be much appreciated

Merry Christmas 

Steve.       

bigred71
immatthewj
3,300 posts
 

+1 @2psyop  .  I don't know your preamp, but I have a Cary SLP 05 that uses 6SN7s, and using a specific test tone on a test CD I have used the AC volts setting on my meter to check volts at my speaker terminals, and I have found that depending upon which tubes I am using in my balanced input sockets, the readings are not always the same from L to R speaker.  I have found that when I then swap my L & R balanced input tubes, the readings I get follow the tubes.  

bigred71's avatar
bigred71 OP
17 posts
 

When I can get to the back of the amp I am going to change the speaker cables over and see if the loss of power is then on the right hand channel.

 

immatthewj
3,300 posts
 

Good plan.  If it doesn't follow the speaker cables, I guess it's the speakers.  If it does follow the speaker cables, try swapping pre to amp interconnects, and if it follows them I guess it's in the preamp, and if it doesn't, I guess it's in the amp.

Good luck.

jond's avatar
jond
6,056 posts
 

It's almost certainly a tube or tube going bad you have some good advice above.

vicdior
60 posts
 

I had that problem a few weeks ago and it was the right channel with my pre amp that was causing the problem so I replaced it and all is good as new.

More to discover