Using tube amp with electrostatic speakers.


Moons ago I started similar discussions and thought I had been given enough good advice not to approach the subject again. Here goes anyway. I've used Martin Logan electrostats for well over 30 years with quite a few different amps but have recently switched to a tube amp and dynamic speakers with which I am very satisfied.  It consists of the Cary Rocket 88R amp and Serie Reference 3 speakers. 

My brother was visiting last week and was so impressed with the sound that he decided that he might want to try a tube amp also (probably the same one as mine).  However, he is using a pair of SL3's that I gave him years ago and I'm concerned primarily about the current requirements of the Martin Logans as well as other concerns that I'm not thinking of.  I don't want him spending money on something that may not bring him improved sound so would appreciate more advice to pass on to him.  He currently uses a Rogue Audio SS amp with his SL3 speakers and, to me, it sounds very good. 
jimbreit
Tube amps or tube/FET hybrids, work best with electrostatics IMO.

I have never heard the Sanders.
atmasphere

Why do you keep pushing ZERO?

Are you PAYED BY THEM?

Most all tube amps use output transformers with impedance taps that work just fine into 4  or 6 or even 16 ohms!

The Zero is of NO VALUE to most tube amps!
Primaluna Dialogue HP integrated or separates.
Upscale Audio  should be able to answer your questions. They carry both the ML and the PL.

BTW: I have no affiliation with Upscale Audio

http://www.upscaleaudio.com/
Most all tube amps use output transformers with impedance taps that work just fine into 4 or 6 or even 16 ohms!

The Zero is of NO VALUE to most tube amps!
Don, the impedance of many electrostatic speakers, including most Martin-Logan models, decreases to very low values at high frequencies. The SL3 model the OP referred to, while having a nominal impedance of 4 ohms, is spec’d at 1.5 ohms at 20 kHz. Some other M-L models have impedances at 20 kHz in the vicinity of 0.7 ohms.

Most tube amps have effective output impedances on their 4 ohm taps that are comparable to or even greater than 1.5 ohms. The interaction of that kind of output impedance with that kind of load impedance variation will result in a greatly under-emphasized upper treble region relative to the response that would occur with a solid state amp. A Zero would either eliminate or considerably reduce that problem (note Ralph’s reference to avoiding high end rolloff), and I suspect it would also reduce amplifier-generated distortion.

Regards,
-- Al


P.S. to my previous post: The Audio Research V70 that was referred to in the post by Lostbears had a MUCH lower effective output impedance than most tube amps, due in part to very liberal use of negative feedback. Specifically, according to arcdb.ws it was spec’d as utilizing 20 db of overall feedback, resulting in a damping factor of 30 (the highest damping factor I can recall ever seeing for a tube amp), which theoretically corresponds to an effective output impedance on the 4 ohm tap of 4/30 = 0.13 ohms, essentially in solid state territory.

Generally speaking, Audio Research and also McIntosh tube amps tend to have lower effective output impedances/higher damping factors than most other high quality tube amps.

Regards,
-- Al