Tube Amps

As Alex & Sdcampbell both said, the Quicksilver products are superb. Their Mini-Mono's have a very open sound, eerily close to that of SET (single ended triode), which has an intimate, holographic midrange. You can use a variety of tubes with them, and they are self-biasing. They would easily power your system in that 12 x 12 room, and if you like them, I would suggest trying them out with a more efficient speaker. It would be worth your time to hear them with an older Klipsch Heresy or Forte, especially on the music that you like.
There is a pair of Mini-Monos for sale at $525 here (they usually go for $700 or so). They are exceptionally good amps. You can pick up one of their preamps for around $500-600 used, and even if you play around with NOS tubes and upgraded power cords, you will be well under your budget.

Another superb amp is the Audiomat Arpege. Incredibly musical, and about $1250-1400 used).

Also, If you have not heard SET amps, and you like class A, I would recommend giving them an audition. Like many people, my wife and I became completely addicted to their holographic midrange. You will experience their full benefit with a more efficient speaker, particularly because many of them are between 3 and 12 watts, but they sound absolutely magical. We generally play our 7W SET with our 104db horns, but with our 95db Silverline speakers, Pink Floyd etc. sounds fantastic. However, it's with jazz, vocals and classical that they really shine.
Hope this helps.

Howard

SirJun.. if you can come up with another 400-500 dollars,you can get a used BAT VK-60 and that will set you home free for a long long time..good luck..

for 2000, you could have a VAC auricle, which has independently biased tubes and a built in meter. it's 55w and should drive your speaker fine in you sized room. jazz is fabulous with tubes and definitely through this amp. the midrange is particularly sweet with the el34, perhaps sacrificing a tiny bit at the frequency extremes. i have one and love it! plus if (and that is a really big if!!!) you ever have a problem with it, Kevin at VAC is fantastic (as is their customer service in general). though i must emphasise that i have never had any problem with the amp, it has been flawless in operation and a joy to listen to!

I just bought a used BAT VK-60 for $1800, and the sound is mesmerizing. Also the amp is self-biasing (automatically adjusts the current to the output tubes), so you needn't worry about that. The Quicksilvers are marvelous bargains and extremely well made, but I find the sound a little dark. Good Luck. - Jeffrey

VAC's Renaissance amps and CAT's amps are Class A triode designs. They all exceed your budget, however.

That said, you might be able to pick up a VAC 30/30 Renaissance Mk. III used for +/- $2,500. It is as trouble-free as a tube amp can be because (i) it is self-biasing, (ii) uses super long long-life 300-B output tubes, and (iii) has great build quality. It also has a "sentry circuit" that automatically shuts down an output tube if the tube starts to fail. It is only rated at 32 watts channel, but is much more powerful than its wattage rating suggests due to its very high quality power supplies and output transformers. It can drive most speakers to loud levels in average size rooms (it is a beast of an amp that weighs 85 lbs. - it can drive a 2 Ohm load). The styling is gaudy in my opinion, but the sound quality and build quality are truly supurb.

The only hassle to owning a good tube amp is that most put off a goodly amount of heat and you can't leave it on 24/7, meaning that you have to give it time to warm up before letting loose (it depends on the amp, but generally speaking, anything less than a half an hour of warm-up stresses the tubes and other internal parts). This requires that you "plan", to a certain degree, when you will listen to music, which some people find unacceptable.