how much tube power is needed?

In response to user35@ibm.net, I fully agree that a 60 watt tube amplifier will drive the Acoustat 2's to 105dB peaks, but maybe only in the midrange. As this is a discussion forum so that others may understand the issue, the Acoustat 2's, a "full-range" electrostatic which were first introduced in 1980, have an efficiency of 85dB/watt/M. It would take a 100 watt signal to drive these speakers to 105dB, and since a tube amplifier typically has 2 dB peak headroom, the 60 watt tube amplifier can drive the Acoustat at some frequencies to exactly 105dB peaks. This of course, as with all tube amplifiers, with the inevitable high distortion, limited damping and bandwidth, noise, unreliability, inability to match impedence or drive reactive speakers, etc. The 105dB peaks at 20Hz and 20kHz with low distortion that a true "high fidelity" system SHOULD produce are just not possible with user35's system, and that is also a fact. As for testing, a square wave is much more revealing of sonic flaws such as bandwidth limiting or reaction to capacitance, and a spectrum analyzer would allow simple measurement of harmonic distortion and noise. However, the sound of user35's system obviously is his preference, and I certainly respect his right to love his system! But I digress, and to answer zkis' original question of "how much tube power is needed?" my answer is: NONE!!!

I recently heard a set of 93 dB Sound Dynamics RTS-P100s driven by a Rogue 88amp(60wpc/8ohms/120wpc/4ohms)Nearly knocked my eardrums in when I twisted the volume. I really agree- it is the first 3 volts that count.

You might want to audition an Audio Note SORO SE (about 17 or so watts a side single ended). It's an integrated. I have one but am not selling.

The answer is dependent partially on the design of the speaker. If the speaker is a Maggie or Soundlab, the answer would be different from a horn or cone speaker. The reason is that some speakers require more voltage than wattage, and some require more damping and/or control. You must decide what type, design and brand of speaker, and then look for the amp. I have owned solid state and tube amps in all price ranges, and some combinations are created in heaven and some (unfortunately) in the other place. The argument between solid state and tube has a great deal to do with personal preference and the experiences of the user. Most people don't argue or cling to a belief to be difficult. Most are certain of their decision based on their own sound system and what has worked for them. We are all after "perfect" sound, that cannot be obtained.