Thoughts on Quad 989 amp selection?

I always heard that Quad electrostatics are best driven by Quad amps. This is the "can't go wrong" option.

Hello Sea2,

I've owned several Quads (though not the 989's) and both own and sell Sound Lab full-range electrostats. In amplifiers, I sort of specialize in models that do a good job on electrostats, and have several Quad owner among my customers. I have customers who have been very happy driving their Quads with amps from Atma-Sphere, Wolcott, InnerSound, and Parasound (the JC-1's). I sell these amps, but by no means are these the only options out there. For instance, the Thors mentioned by Thorman would also work quite well - for a while I drove a pair of original Quad ESL's (the "57's") with a pair of TP30s, which was about as big an amp as those speakers could handle.

Since you are open to tubes as an option, my suggestion would be to go with a lively-sounding tube amp (either OTL or with a high quality, wide bandwidth output transformer like the Wolcotts or Thors).

My 'Quad' room is 19x21' with a ceiling that rises from 6-1/2' to 12'. I listen to large-scale classical and film music and movies too, as the 989s are the LRs, but not nearly as loudly as I hear some of my friends play their audio systems. I heard the 989s demonstrated driven by a pair of Manley parallel-SET amps that the fellow said had about 25 Watts of power; they sounded jaw-droppingly excellent.

I drove them first with a tubed 70WPC c-j Premier Eleven-A (from the default 4-Ohm tap) and had plenty of power and quality. Then I got a pair of Chinese-manufactured unknown-brand 100Watt monoamps that used 4 KT88s and also had a triode switch. I'm now driving them in triode with what I suppose is about 40 Watts per channel. I've never overdriven them (ie caused the speakers to 'clamp' their input signals), and I never feel that I don't have enough power or dynamic range.

It sounds to me as if you need something like 50 - 100 Watts of tubed power, unless you listen at LOTS higher levels than I. I'd try a c-j Premier Eleven-A; there usually is at least one here on A-goN for about $1600. If the Eleven has enough quality but not enough power, you have at least 2 options, the easiest one of which IMO is to buy another Eleven and run both in mono. I think you'll NOT find a more-affordable option for c. 150WPC of very-high-quality tubed power. (FULL DISCLOSURE here--I'll have my 2nd Eleven for sale soon. E-mail me if you're interested.)

BTW, the one clear aural advantage of solidstate amps, their very-high bass-damping factor, doesn't apply here, as a 'stat's diafram is NOT 'controlled' by the amp's output stage the way cones are.
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Not sure of your price range but I remember a "thread" somewhere that the person was really happy with the TPA60 Thor Audio monoblocks driving the Quads. I have the TPA 30s ( kharma 1.0 ) and wish I could afford the 60s.If I could I would buy very quickly!