Soundlab Speakers - Budget Amp Suggestions


I have tried to read as much as possible about different types of amplifiers capable of driving electrostatic speakers. Thanks to everyone for the great articles and discussions. In particular, I am looking for a ss amplifier that can drive Soundlab speakers. The Soundlabs have a low impedance at high frequencies and a high impedance at low frequencies. A high power ss amp that can drive difficult loads appears to be the ticket (I'm not interested in tube amps). High current is needed for the high frequency/low impedance (but not necessarily high power) while the high voltage (albeit at lower power) can drive the high impedance at low frequencies.

While looking for speakers I came across the Soundlab speakers and really liked the sound. I basically blew my budget on them, which for me is not a bad compromise because I don't want the speakers to be the weak link in the chain.

So this is what I have:
1. Two Soundlab A-1 speakers (1992 vintage)
2. One Soundlab B-1S subwoofer (pre 1990) - This is a stereo subwoofer having two separate inputs to drive each interior panel.
3. The A-1s have the toroidal and impedance upgrade.
4. I had all the speakers reskinned with the px mylar.

There will be some type of crossover between the A-1s and the B-1S (the frequency and type of crossover is undetermined at the moment)

I believe that having the B-1S reduces some of the constraint of having the highest power amplifier to drive the A-1s (e.g. 500-600W) since a lot of the bass will be coming from the B-1S. I was told to limit the power to the B-1S to a 400W or less ss amplifier. I am thinking that perhaps I could get away with a lower power amplifier for the A-1s because of this scheme. Please let me know if I am wrong.

As I said my budget is limited. I have about 1.2K and perhaps up to 2K to spend on an amp. The amp I have targeted is a Sunfire Cinema Grand Series II 5-Channel amplifier that outputs 425W a channel. The channels driving the B-1S won't be delivering a lot of power as the impedance is 16 to over 30 ohms. The amp should be able to drive the A-1s adequately. As a side note I have a couple of amps (Crown K1 or Citation 7.1 which output between 300-400W) that I could use to drive the B-1S if needed.

Are there some vintage or other budget amps that I should be considering. Is my analysis wrong? Any suggestions on crossover frequency? I appreciate any and all input. I want to thank every one in advance for their thoughts.

Regards,
GWHO

gwho

Showing 3 responses by rrog

If you want a good amplifier for driving electrostatic speakers without breaking the bank look for a used Acoustat TNT 200.
"Have the changes in amp designs been so significant that I would hear a substantial difference even with my twenty year old speakers?"

Absolutely not, but not all amplifiers will sound good with electrostatic speakers. All electrostatic speakers that I know of have the impedance characteristics you mentioned in your Soundlabs with a low impedance in the high frequencies and a high impedance in the low frequencies. This can bring out a lean sound with certain solid state amplifiers. However, this never seems to be a problem for tube amplifiers. Unless an amplifier is designed for use with electrostatic speakers like Innersound or the TNT 200 I mentioned I would not buy an amplifier without being able to audition it with your speakers.
I have not compared the TNT 200 to an Innersound amp. However, I compared the TNT 200 to my Levinson 23.5 and VTL Ichiban amplifiers and the TNT 200 sounded better on electrostatics speakers. I tried many many amplifiers on Martin Logan CLS and I can tell you there are very few solid state amplifiers that will sound good on electrostatics. Has anyone mentioned Quad amplifiers?