tube amps and electrostatics

Frogman: You know I hope that most SS amps have a lower output impedance than most tube amps.

Here is a quote from Roger Sanders of ESL fame a white paper on Solid State v Tubes for ESL's.

"This impedance problem is relatively minor when dealing with conventional, magnetic speakers. But an electrostatic speaker is an entirely different animal. An ESL is a capacitor, not a resistor like a magnetic speaker. The impedance of a capacitor is inversely proportional to frequency. Therefore the impedance of an ESL typically varies from around 150 ohms in the midrange to about 1 ohm at 20 KHz.
A tube amp will be able to drive the high impedance frequency bandwidth (the midrange and lower highs) of an ESL with linear frequency response. However, at higher frequencies, the impedance of the ESL will drop below the impedance of the amplifier and the amp will then roll off the highs to some degree depending on the exact impedance mismatch and the frequencies involved.
I think you can now see why I prefer very high power, solid state amps without any protective circuitry for driving ESLs. This is because they can drive ESLs with linear frequency response, while tube amps roll off the highs."

You can read the whole White Paper here:
http://sanderssoundsystems.com/technical-white-papers/172-tubes-vs-transistors

Cheers George

Ive heard quad esl of cj tube amp. Very nice match!

Georgelofi, thanks for the link and I am glad that you found what works for you. So did I, and it's tubes with electrostats. This is an old story in our hobby and after many years enjoying it I have learned that one of the few things that I can consistently trust to tell me what's "right" is my ears.

"Frogman: Georgelofi, thanks for the link and I am glad that you found what works for you."

Like I said, I even liked the sound of tubes into ESL's, but when you hear the extension and dynamic presence that's missing with tubes once you've heard a "good" solid state BJT (bi-polar not mosfet) output stage amp into them with lots of watts and current, you will think hard about what's missing, but then maybe you like that subdued rolled off top end.

It's not what works for me, it's fact, and electronic maths made up of Ohm's and Kirchoffs Laws, there is no voodoo involved.

Stated by one of the masters of ESL's design Roger Sanders that I quoted from the white paper I gave the link to. Here again in case you didn't fully read it.
http://sanderssoundsystems.com/technical-white-papers/172-tubes-vs-transistors

Cheers George

OK, George, you win; clearly, I don't know what live music sounds like.

****It's not what works for me, it's fact, and electronic maths made up of Ohm's and Kirchoffs Laws, there is no voodoo involved.****

I will go back to sticking pins into my tube sockets now.

Interesting (appropriate?) moniker, BTW ;-)