McIntosh technical support has deteriorated quite a bit over the past couple years because they lost some really good employees who actually understood the tube amplifiers.
If you have a question about your tube amplifier you’ll call up McIntosh and then someone will get on the phone referring to the literature because he has no knowledge of the actual amplifier it’s really really disappointing. Maybe tech-support is being farmed out to a third-party service at this point. Basically a call center