Tube amps - what 3 things…

Hello all,

I am close to purchasing a tube amp moving away from SS. So far I have listened to a pure sound, PL, and allnic. 

Question for all you experienced owners - if you could do it all over again, what 3 things/features would you look for in an amplifier and what 3 things/features would you not invest in again?




For me autobias isn’t critical as long as it’s easily adjusted. I’ve owned Unison, Allnic, Quicksilver and Audio Research. My favorite sounding was my AR which is a pain to bias but the others provided an accessible dial. Biasing once tubes are settled should be monthly. Stick with a company that has been on the market for a while and has a solid support network. Buy an extra set of tubes or two and you should be set for a decade provided the amp isn’t left on. Good tube amp hygiene, no turning on and off in quick succession and allow a 15 minute warm up or more before hammering the system.

Checking bias monthly is OK, but knob dicking the adjustment pots will shorten their life. Tweaking for the last fractional mA is pointless. Great amps were biased with moving coil voltmeters for decades before digimania took over.

The bias is going to shift slightly with line voltage, time on and ambient temperature variations. Home users would do better to check bias at the end of the listening session with the amp and components are fully warmed.

I have to say that I am enjoying this thread alot, and I am learning quite a bit, being a newcomer to tube amps (I have owned my first for a couple of months now), I get the feeling this rabbit hole runs deep!

If you don’t have huge power demands I’d recommend Dennis Had Inspire Fire Bottle KT88 SEP amp, and an Inspire LP 3.1 preamp. These products won’t break the bank, especially used, yet their performance is very difficult to top, especially at that price point. For $3k you can get outstanding sound for cheap compared to other products. I’ve had Inspire products since 2016, and happy to have discovered them. Audiogon is well aware of Inspire products!