I've got a nOrh se18 tube amp. So far, two gripes:

1. The transformers play music! That is, I can hear faint music playing out of them when not listening to my headphones. This was also mentioned about someone's se9 not too long ago too. Not too much of a biggie at the moment since it doesn't (seem to) affect the sound to my AKG K1000's.

2. More importantly, the right channel volume is way below the left. Left side is fine. I don't have a schematic from nOrh yet to indicate which tubes affect what, but it is my current understanding that the EL34 driver tubes affect output - correct?

I've swapped around EL34 tubes, as well as the various 12ax7's just for giggles, with no changing affect on this symptom. The se18 does not have a rectifier (power?) tube. I think that part of the amp is solid state, but I do not have any more technical info (no owners manual)

BTW, I've isolated this problem to the amplifier section, after swapping out sources, music, cables, and changing to other inputs on the preamp section. All result in no change.

I've emailed Mr. Barnes, but don't expect a reply until next week. Anyone here have any ideas?

weird, i've been having the same balance problem

mine is pretty slight though. i tried changing tubes around and using different tubes but to no avail. i hope you figure yours out and let me know.

maybe an unbalanced volume pot? Does it get more balanced as you go up in volume?


Mitch

actually i think it does. i thought i just noticed it more at lower volumes.

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Not in my case. There is definitely a quality difference, as well as quantity (ie. volume) difference). Left side is smooth with plenty of volume. Right side is thiner with a bit more grain.


/edit: Things seem to be a bit better after playing more music tonight. Right channel seems closer to the left now, less grain. I admit that I didn't hear this diff when I first fired up the amp a few days ago. It's a bit hard to tell now. *shrug*

Could this just be tubes settling in? They are the original stock, but I am not the original owner. I think the amp is just a few months old, if that. And it was just shipped cross-country.

It should not be the tubes settling in.

Are there any tubes that you were not able to change?

Also, in some circuits the signal from both channels may go through the same tube. If the triodes in a 12AX7 were badly mismatched, you could see that symptom if both channels went through the tube (particulary if one side was on the verge of going bad). Can you get your tubes tested?

i've witnessed phenomena like this before with equipment. i've found it's usually warmup thing. back with my rkv and hp-1's, i almost really lost it one day when i swore i heard my new expensive headphones had a problem with the left side.. turned out to just be the rkv warming up.

recently i actually had a moment like that with my stax setup, and i think it was my cary getting warmed up. sort of funky, but it does happen to me from time to time.