What amp do I need to power my Acoustat 1100


I have had my 1100's for quite a few years. I stopped when the fried my (don't laugh, I was young!) carver tfm 35 amp. do you guys recommend a brand or price range I should be looking in. I have been looking into the krell amps I've seen for sale as well as the Parasound A21 but don't know whether that's bringin a Knife to a gunfight. Please give a novice some help.
stlrfn

Showing 5 responses by nsgarch

If you want an SS amp that won't freak out when faced with electrostats, consider the one from Roger Sanders (formerly of Innersound) http://www.sanderssoundsystems.com/

If you prefer tubes as I do (for driving electrostats) I recommend one (or possibly two as monoblocks) McIntosh MC275's. The McIntosh Unity Coupled Circuit provides as much current per watt as just about any amplifier made, so it's well suited for driving electrostats.
If you want a great stereo (actually 'dual mono') SS amp for around $2500+ look for a Mark Levinson 23.5 (not a 23, a 23.5!) 200W @ 8 ohms, and worked beautifully into 0.7 ohms! of my MartinLogan CLS's.

If on the other hand you want a great tube amp which puts out a very "current rich" 90W/ch you can't go wrong with a McIntosh MC275 Mk IV or Mk V; which are now selling used within your budget.
You don't mention your pre, but tubes would be nice there, and would give you the ability to tweak the system's presentation to suit your tastes.
I think this has become a popular misconception. If you want to roll tubes to tailor the sound of your system, you need a tube amplifier. In a preamp (with the exception of a PHONO preamp), the tubes aren't used for amplification, and therefore have little effect on sonics other than adding a certain amount of tube hiss to the signal (even in the more expensive units.)
.
Rodman, I don't know which ARC preamps you've owned, but the later ones with onboard phonostages (like the SP-14) use a single tube for gain in the phonostage only. The other tubes in a "tube" preamp provide source input buffering -- thus leveling the (input impedance) playing field for the various sources. This makes it easier for all the sources (including phono after being amplified in the phono section) to drive an amplifier.

Further, because tubes are high impedance devices, many "tube" preamps actually use solid state output stages because of their low (versus high for tubes) output impedance. Why? Because the lower a preamp's output impedance compared to an amplifier's input impedance (1 to 100 is considered excellent, 1 to 10 is absolute minimum) the more faithful the frequency response to the original source signal, and the farther the distance over which you can run interconnects (even single-ended interconnects) without signal loss or noise pickup.

So Rodman, if you've "found tube rolling worked wonders in quite a few pre-amps over the years" I'm not saying you're wrong, but I'd like to know two things:

1.) What do you mean by "wonders"? For instance, rolling an ultra quiet tube in place of a noisy tube is not a "wonder" it's just common sense. The sonics really won't change because a preamp if it's any good will remain neutral. The sound will come through against a blacker background if the tubes are quiet; for a REALLY quiet background, a quality SS preamp is just the ticket IMO.
2.) Where in the ARC preamp circuit is/are the tubes in question? If they are in the phonostage, they don't count for this discussion, because that exception has already been noted. If they (actually "it") is in the power supply, you have to be talking about an SP-8 (introduced in 1981) which did have ONE tube in an otherwise solid state electronically-regulated power supply. All other ARC preamps before and to the present, had/have ss power supplies.

Certainly in some of the 'all-tube' (except power supply) ARC preamps, there is ample opportunity to try different brands/types of tubes, but even ARC is always talking about better performance in terms of lower noise tubes, not in terms of better sonics (i.e. frequency distribution, detail etc.) Of course ARC has the (dubious) reputation for making the most SS-sounding tube equipment there is ;-)
.
Rodman, I've no desire to split hairs with you because first, you obviously have walked the walk, and second, you're a tube guy, and that's all good in my book!

But I'd like to express my POV more succinctly while at the same time addressing the OP's rather colorful inquiry as to whether he's "bringin a knife to a gunfight"!

So let me put it this way:

One can enjoy far more sonic variety (assuming that's what one is after) rolling the gain stage tubes in a tube amplifier (regardless of whether the preamp is tube or ss) than one can ever have rolling the tubes in a tube preamp and using a ss amp. And I think it a common misconception when people assume the effect can be the same either way. Further, a (decent quality) tube amplifier is just as quiet as any ss amplifier; whereas I have never heard, in my own necessarily limited experience, a tube preamp that was as quiet as a decent ss preamp. And so, the bottom line for me personally (and in the words of the Divine Miss Midler) is "why botha?!" with tube preamps.

As for the part about "bringin a knife to a gunfight", well, yes, one better bring a gun (e.g. a Krell or similar beast) if using a ss amp to drive an electostat; because stats will always try and eat even modest output ss amps. While a knife, in the form of a modest output tube amp, will generally do just fine driving even a large(ish) stat panel; and the worst thing that will happen if a tube amp isn't quite up to the job (probably under 100W) is it'll clip softly -- but not go into oscillation and then cardiac arrest!

And finally, as everyone who knows me knows by now, I just happen to think tube amps sound best with stats ;-) And I now realize a lot of other people think so too!
.
Another best-of-both-worlds hybrid amplifier, which gregadd is planning for his new MartinLogan CLX's, is the latest Moscode hybrid from George Kaye http://www.moscode.com/

And while I feel this is a great way to bring some tube signal preservation to voltage hungry speakers like Maggies, I'm still not sure I'd want a ss output device driving stats, despite the ability to tailor the sound with the driver tubes.