I had to post this as I feel that credit should be given when it is due.
I recently bought a used ARC LS-7 preamp that is a wonderful little line stage, especially for the price. I wanted to reduce the gain so I called ARC about it. I got a guy on the phone who immediately asked me for name and address and said he would send me a drawing. I was pleasantly surprised to find in my mailbox a few days later, a large envelope containing not only instructions for the gain reduction, but a complete schematic and parts list, four new resistors, and even a small coil of solder. All this for a preamp that is almost 10 years old, and totally free of charge! I know that four resistors and a little solder costs less than a buck and the postage isn't much more, but still, IMO this is definitely "going the extra mile" and I feel that customer service like this ought to be held up as an example for all to see.
i've had my sp9, ls5 and bl1 serviced, inspected or upgraded by arc with identical results. fast, exact, inexpensive and supportive. maybe we should keep quiet about this to reinforce the mystique of unreliable or fussy tube gear so as to keep prices for used gear cheap. regards, jon