Repair question for Audio Note CD-2

I'm hoping someone with some tech knowledge can help, since I have no expertise in this area. My player has been losing output in the right channel. It's been gradual, but now there's a severe imbalance. I've changed tubes, so it's not that. It still has a very sweet sound.

I'm wondering if someone could tell me (your best guess) what the most likely source of trouble is, and some sort of ballpark figure as to repair cost.

Thanks in advance.
Try an outboard DAC if you can...I had the same problem once, and found that an outboard dac fixed the problem, so obviously the dac inside the CD player was the problem.
Contact Nick Gowan at True Sound. True Sound is the authorized U. S. service center for Audio Note. You can find his contact info at True Sound Inquiries.

The CD-2 is a fine sounding CD player that despite being around for 10 years still compares very favorably with newer designs in my opinion. Personally I'd look into having it repaired if cost effective.
Look to what is driving the output tube - both the power supply feeding it, and the upstream components in the output section (voltage regulator, etc.).

Cost will be dependent on that. I would think $250 on the low end, and potentially 3 - 4 times that on the other end of the spectrum. I know that's a wide range, but I don't know how Audio Note components are constructed. Whether discrete components or an entire board(s) needs to be replaced determines a lot, as does the time/labor involved.

As Davidbigeye said, the unit should work fine through the digital out. And, as Rbrowne said, contacting the service rep is the right move.
Should you need to send it for repair, Nick Gowan is the man to contact. He gets my highest recommendation!
I have contacted Nick. He requested photos which I provided. I haven't heard back yet. He seemed surprised it wasn't the tube. Very nice man.

Please continue providing alternate theories.

Thank you.