Channel Imbalance Mystery


I’ve been experiencing a channel imbalance for awhile now that I cannot seem to solve. I’m only running a turn table so I cannot troubleshoot with a digital source. I have ruled out the TT and cart as the problem because I had it tested in another system and it sounds great there. I’m running a Herron VTPH-2A phono pre into a Cronus Magnum II integrated amp with brand new KT120 power tubes. (The imbalance was present with older power tubes too). My channel imbalance is left leaning. When I swap the tt inputs into the Herron preamp the imbalance is fixed. Vocals are dead center but my stereo orientation is flipped. No problem, just swap my preamp outputs to get me back to the correct channel orientation but doing so shifts the center image back to the left a bit but soundstage is correct. It’s not nearly as bad as when my tt inputs were in the correct L/R positions. What the hell is causing this?! I’ve tried different interconnect cables with the same results so I don’t think it’s a cable issue. Could it be unmatched signal tubes in the Herron? Signal tubes in the integrated? Super frustrated. Thanks for any help. 
paulgardner

Showing 2 responses by ghdprentice

Swap the tubes and find out. I have all tube components. Whenever something odd like that happens it is a tube and swapping will quickly identify it as tubes are split along channels.

I also always have an extra set of tubes around as backup. They don’t fail or act strange often, but it is good to have if the do.
I find a little logic and a very few minutes of swapping tubes sufficient to identify tube issues. For instance I had a channel a bit weak not that long ago (new equipment). I reseated the tubes and it went away… 15 seconds of work.

Also, I noticed the Tung-sol site basically says the best way to test a tube is in the equipment. There are all sorts of testers and none really guarantee performance in the equipment.

Although I am attracted to instruments (I have 4 pollution sensors). I admit I am lazy and don’t want more junk around the house when it comes to audio. 

http://www.tungsol.com/html/faqs7.html