VAC doesn't reply to emails.

Ditto the effectiveness of Deoxit into switches and knobs.  I recently dripped Deoxit into the series-wired mini-switches of my Atma-Sphere MP-1 preamp, which had become noisy to the point of frustrating dropouts in the balanced signal phases.  After standing the preamp on end, dripping a fairly generous amount of liquid into each switch, then exercising the switch a few dozen times, the problems are all gone and good to go for another twenty years...      

I do mods to widgets in another hobby. I’m the only person who provides this service in the country. I don’t consider this a business so much as a service. I don’t advertise but my reputation spreads by word of mouth. I get inquiries on a forum devoted to that hobby. I try not to give out my phone number or email since I’ve learned that people will want to chat with me continuously. I answer questions about installing the upgrade but generally ignore or shut down idle chatter. I get a lot of messages that would like to go on-and-on. A couple of guys have gotten my phone number and called frequently just to chat until I learned not to answer their number.

My point is a businessman working 60 hours a week can get 59 hours or work done and spend 1 hour a week answering questions or he can get 40 hours of work done a week and spend 20 hours a week answering questions.

Generally you’ll get better answers to an email that is one paragraph long, has a simple greeting, a well-worded and clear question, and a thank you. If you write a novella, he may not even get around to reading it.

One thing I have noticed is that most customers act like they are the only cutomerer out there.  they assume you remember everything they ever told you, even though 40 others may have chatted with you since then.  they often don't even put a note in the box telling you who they are, what their symptoms are, or what work they want done.

Jerry

Sometimes l/r balance is affected by oxidation/dust, I prefer cleaning.

Cover off, it appears that the volume control is deep/covered/sealed, perhaps also blocking heat from nearby tubes.

Like many designs, there is another removable cover on top of the front controls.

I would remove both covers myself, to know what’s what: is it possible to spritz some cleaner/lubricant into the control? Sometimes there is a small hole in the front of the control that you find after you remove that inner top cover. Then decide: me, someone local, VAC?

If you find a way to spray or drip. I sometimes spray aerosol into a small cup, it collects into a small puddle, use a small artist’s brush and gravity to get it somewhere before it evaporates, spinning the control this way and that. Next, some compressed air, they sell cans of it if you don’t have a compressor.

Volume controls: clean and lubricate combo (not contact cleaner without lubricant).

Sometimes a small piece of material (felt/foam/...) is put in place around a shaft, as a final dust shield, (or light leak shield). Caution: remove it, clean the control, re-install, even then it may have simple age deterioration. You can ask VAC or improvise, I used a shoelace as a dust/light leak barrier around the edge of my tuner’s glass face to replace the foam strip that had simply disappeared over so many years.

Left/right balance is not affected. I rotated the knob multiple times back and forth, and it became noticeably better - less noise and the noise is less loud, though it wasn't really loud. I only use the range from 9 to 10 o'clock.

I am not sure I feel comfortable enough to open it and try to fix myself.