Review: Quicksilver 8417 Tube amp

Category: Amplifiers

I have been in the tube arena for only a year now, but have had the chance to listen to some noteable stuff. It is easy to take a lot of pride in recent purchases and over-rate them, you know how it is getting something new and something that is obviously quality equipment - it sounds soooo good, the best of all no doubt. Well, that's what my quicksilver mono blocks sound like - the best ever. Sure, 8417's are hard to find brand new (luckily I have 4 matched pairs on top of what's in there now - funny thing is, people think tubes are like gasoline, you have to have a constant steady source or the amps are not worth anything - well I don't agree. I'm an electrical engineer, and although I don't work in audio nor am I intimately familiar with tube type circuits, I can stand behind the fact that while tubes do age in their own way, it's not like you have to re-tube all the time. I've listened to old Heath W5M monoblocks with original tubes and they sounded pretty good to me, but not excellent.) The 8417's sound great to me, and quicksilver builds a really quality product. I drive 2 pair of klipsch heresy speakers in parallel, so I drive 4 ohm loads, and I like how the system sounds in this configuration, and my intuition tells me that the amp is a better performer this way as well. The highs are crisp and clear, with smooth and solid lows throughout the frequency band. I just love the way it sounds. Tube type systems with good, efficient horn loaded speakers are just outstanding in my opinion. I couldn't be happier...of course until I get my next piece of equipment I'm sure.

Associated gear
Klipsch Heresy speakers, modified PAS pre-amp - also with solid state pre's. mmf 2.1 turntable also with dual ortofon cartridge.
You can easily change the bias potentiometer range so you can use any of the standard tubes - 6550s, KT88s, EL34. The amp works very well with 6550s - the specs on this tube are very similar to 8417, except for gain sensitivity - the input stage has to work a bit harder to drive 6550s to full power than the 8417s. I replaced the stock pot with a Bourns mil-spec 10 turn job and have been using 6550s for years.


Hello Halltyler. You have a pair of very fine sounding amplifiers.The 8417 versions are a good deal more musical than the later Kt-88 versions of the same amps.Very stable driving low impeadence loads due to their terrific out trannies.One of a handful of tube amps that will remain stable even down as far as 2 ohms.The 8417 output tube is a far better sounding, and more linear tube than any 6550,KT-88, KT-90 or el-34... including the famous genelex kt-88.I am still kicking myself for selling mine a few years back.With a couple of spare pairs of 8417's for back up... I think your set for a hell of a long time.For the cost of modding them for the kt-88,you can surely just buy another pair of nos 8417's with a little searching. Leave them alone and Enjoy! Cheers
Chiming in on an almost 13-year-old thread, however, has anyone continued to have good results running the 8417 amp with different bias pots, and 6550 tubes? Sounds like an answer to a problem, if it doesn't stress the input stage of the amp too much. Anyone have results? Thanks.