2. amps-preamps
  3. 1061393832

Help Troubleshoot - Left Ch. Louder than Right Ch.

I need your collective troubleshooting assistance.

I just put together a new system (comprised of used gear, of course) and hooked it all up last night.

Unfortunately, the left channel is considerably louder than the right. Or - it could be that the right is much QUIETER than the left. Not to be facetious, but in actuality, the left channel seems more "appropriate" all things considered.

The amp is an Antique Sound Labs AQ-1002 (50wpc) and the preamp is a Counterpoint SA-1000. Unfortunately, I don't have any additional components to swap out and determine which piece is the culprit. Can you guys think of any other techniques that might help determine what's causing the problem?

Also, if the amp is not biased properly, could that cause one channel to play louder (or quieter) than the other? There are no Gain controls on the amp that I can see.

I need to figure out what's wrong so that I can either fix it, or seek recourse from the seller before too much time has elapsed.

Thanks guys!
gullahisland
gullahisland OP
83 posts
 
Well,

I switched the interconnects and the problem stays in the right channel. I switched the speakers as well, just to confirm that there's not issue with them and, again, the problem stays in the right channel.

Marakanetz - Should I just switch the placement of the tubes and see if the problem follows the tubes? The amp uses two 6550s for each channel. Is it safe to just switch them? I'm a tube novice and don't want to do anything catastrophic.

Thanks again.
newbee
4,093 posts
 
Try switching the drive tubes first - you don't have to worry about the bias settings on these.
gullahisland OP
83 posts
 
Newbee - Please forgive my ignorance, but I assume by "drive tubes", that means the 6550 output tubes? On the input side there are 4 12AU7s.

Thanks again everybody.
newbee
4,093 posts
 
No, I was referring to the small tubes, the 12AU7's. It is not unusually at all that when small tubes die that you start to loose volume before they go dead. The 6550's are usually referred to as the power output tubes.
piezo
302 posts
 
I have a transient problem with my VTL 185s that sounds kind of similar and i was wondering if this could be a tube thing as well. One amp will suddenly get louder and then start to hum, or will just start to hum without the volume surge. Toggling the on off switch gets rid of it...no need to let the sound die, just hit the switch. same problem with different ic's and in two different houses. Used to be i could toggle either power amp or the pre amp and the hum would quit but now seems to only work on the afflicted amp. doesn't happen often enough to spend the money to ship it to VTL, where it would probaly work fine. any ideas?
More to discover