Noise & Hum Rating

I did switch to the 4 ohm taps, and they are quieter. Not silent, but definitely quieter. There also doesn't appear to be any difference in sound, which is good.

I was a bit disappointed in Cary's service for a number of reasons. I don't think they looked very hard at the amp, although they were quick to sell an overpriced capacitor upgrade, and to try to charge me $40 each for EH EL 34s that cost $13 from any number of sources. If I ever send it out in for service again, it won't be to them.

That's nonsense. My amp takes a dozen EL 34s. Cary tried to tell me that the tubes that were in it were bad. When I had them tested locally not only weren't they bad, they were actually very strong, and except for a little degradation in two of them, pretty well matched. Cary said they were all bad and needed to be replaced, and it simply wasn't true. They also said that the tubes were causing the hum, which also wasn't true.

The EH tubes they wanted to sell me are nothing special. Electro-Harmonix EL34s are an inexpensive tube. Tube Depot, Doug's Tubes, Amplified Parts - all of which were highly recommended by A-gon members - and a few others sell that same tube for $13 (or $27 a pair) matched and tested, and graded for early or late distortion - a pretty thorough QC process.

IMHO Cary was less than upfront about the state of my existing tubes, and trying to gouge me for replacements. Even if Cary does go through such a rigorous QC process themselves, that's not an excuse to triple the price of the tube, especially when the same service is available through some other reputable sources.