Are Carver TFM's good amps for driving Electrostats?

[CharlieM]

I have a couple of Carver TFM 25's bi-amping my home built hybrid ESL's and the treble sounds a bit anemic on the upper end. I read somewhere that Carvers may not be so good at driving ESL's and I'm also wondering if upgrading the speaker trannys to 75:1 toroidal type ($$$) would would correct the weak upper treble. Before I go spending more money on components, I really need to understand whether the treble issue has to do with the speakers' step-up trannys or their interaction with the Carver amp. The trannys are 100:1 wound on EI type cores that I bought online from a guy who builds and sells ESL speakers and components (they are claimed to be good to 20kz but who knows and, again.... could be interaction with the amp). Really, the ESL's sound fantastic with the Carvers except for the anemic upper treble.
Everyone please share your thoughts on:
a) Suitability of Carver TFM 25's for driving ESL's
b) what might be causing the anemic upper treble

thanks y'all,
Charlie

[AMV8]

Hi
I do have three Carver amps similar to your amps. I have two 500 watt amps and a 75 watt amp. I have not tried to drive ESL's with them but I have used them on a number of other speakers. I can tell you what I have found but hopefully you may get a reply from someone with more direct knowledge of driving ESL's.

I find that they struggle on extreme bass and treble and particularly on percussion notes. I think this to do with the power supply.

They appear to be amps with high power reserves. However in pratcice I find the power is insufficient when trying to reproduce percussion notes such as low piano notes or a triangle or trumpet. I do not know for certain why this is. However my guess is that it is because of the way the power supply system operates on the TFM amps. A full description here would be long winded but you can find one if you check diyaudio or google. However effectively effectively the primary supply to the transformer is passed through a triac and both channels "share" the power supply. The theory is that it makes more efficient use of the transformer. For many applications I guess that is true. However for high level audio I find the power supply seems to have low reserves to meet short term demands such as transients. In addition the use of the triac seems to introduce distorsion that passes to the power amplifier channels.

I believe that is what you are hearing. Someone with more knowledge of the amplifiers may explain that I am not correct. In that case I will be pleased to find out more about the amps as well so that I can improve mine. Currently I am considering converting my amplifiers to conventional power supplies and conventional channels with only one power supply voltage to each channel.

Don