Manufacturer Repairs? What is a reasonable time?

Three months is a long time, but it's not outrageous. Before going nuclear make an effort to clearly express your displeasure to the proprietor and offer them the opportunity to make it up to you. A firm return date is what you're looking for. If he won't provide that, or misses the date with no explanation, then do what you have to do.

It's worth noting that if we try to put out of business every audiophile company that screwed up something with a particular customer there wouldn't be any audiophile companies left standing.

Quality of service and turnaround times for service can vary widely. Hard to say what is reasonable, although less hard to identify which companies have the best reputations for customer service over the long term however. You identified at least one or two that I could vouch for.

At a minimum, its reasonable to expect any vendor should be able to provide a reasonable estimate of the time required to complete a particular repair and keep the customer up to date if that changes.

I'm curious as to how you know that "one channel not working" is a "minor repair"? It is not as if the company has their employees just sitting around playing card games. If they have a long queue of repairs, it is typically, first in first out. So, they get to it when they reach a stopping point on the products in front of you. Now they can hire more technicians, but first, they must train them on repairs of their equipment and to hire full time assuming that the back log will continue may be a problem. To me, as long as they pick up the phone and acknowledge they have the equipment and give me a timeline for repairs, I'm good. It is when they don't pick up the phone. Then I have a problem.

Varied opinions, which is what I expected, hence the secrecy regarding the identity of the manufacturer. Sure, I dont know how minor the repair, nor does he, since he hasnt looked at it yet. Ignoring e-mails is also annoying, but he does pick up the phone to tell me that he is too busy to do the repair and will be done in "a few weeks" (since March). I give him the benefit of the doubt, but if I dont at least get a date from him, then I will do what I have to do - believe you me, it's not my intention to put anybody out of business, but fair is fair. All I asked for was a firm date or estimate, not endless procrastination.

I think its fair to allow a vendor to revise their initial time estimate once or twice, but more than that would be a red flag for me. Generally, three strikes your out is a pretty decent rule....

To some vendors, good customer service is a cornerstone of their brand and business model. Others, perhaps not so much. Some might operate under the assumption that the customer is locked into them as the only qualified service option and has no recourse other than to do things on their terms. It all depends....