For QS 8417 owners, another option at QuicksilverAudio.com Q&A page:
http://quicksilveraudio.com/questions-and-answers/ √
Quote:
http://quicksilveraudio.com/questions-and-answers/ √
You no longer have 8417 tubes, what do I do with my 8417 Mono Amplifiers?
Quote:
"For $250/pair (plus cost of new tubes), we can modify your amplifiers to use EL34 output tubes by changing the front end circuitry and the bias circuitry. We also replace the 12BH7 with a 6922.This modification must be done at Quicksilver and comes with a one year warranty. For original owners of Quicksilver 8417 amplifiers we will give you $900 trade-in toward a pair of new Mid Mono Mono Amplifiers. Returned amplifiers should be complete, with tubes, but do not need to be in working condition.",unquote.