Tube Amp for Green Mountain Audio Callisto

thanks for all the excellent responses.

using a radio shack SPL meter, i turned the music on as loud as i care to listen with the following results:

~88-90db from the listening position (the big peaks sometimes hit 95), which correllated to ~90-92db 1m from the driver (big peaks hitting 97).

on paper it would seem that i could get by with around 8 watts, as that would equate to 99db.

i also called Roy - he so amicable - and he confirmed that with as little as 15 watts, the callistos will sound great.

i was thinking an atma-sphere S-30 would not have enough juice to get my speakers singing, looks like i was wrong. i'll also look into the 300B, Jolida and Cary options.

thanks for all the suggestions!

Blue Circle gear has great synergy with GMA speakers. Disclosure: I am a Blue Circle and GMA retailer, Departure Audio. The DAR and FtTH ate hybrid integrated amps in the Blue Circle line. The new GDC integrated, while not a tube piece, is a terrific value at less than 2K and also a great match with GMA speakers. All of these have more than enough power to get everything out of the Callisto's. Blue Circle is one of the few lines GMA enthusiastically endorses with their speakers. Roy and I will be demonstrating these systems at some upcoming shows.

Srosenberg,

95 dB peaks at that distance is a far different story than 80 dB - in fact, you need about 32 times the power! So, forget what I said about a 300B and definitely forget about the 2A3! :)

(I know you didn't indicate you were looking at SET specifically but I thought I'd throw that out there.)

IF you are interested in SET, an 845 or 805 design would still serve you well. Or, actually paralleled 300Bs for around 20W.

I have a Response Audio/JoLida 60 wpc tube amp, as well as a Mapleshade-modded 18 wpc Scott. Both sound fantastic with my Callisto. With it's 90 dB rating, most any amp over 10 watts will drive it. Basically, it comes down to quality versus quantity with this speaker- although more power is always good for speakers IMHO. enjoy!!!