Are class A tube amps similar to class A solid state ...

The issue has to do with the efficiency of the speaker and its impedance.

As for the latter there is a simple solution, a device called the ZERO that will allow tube amps to drive the low impedances at high frequencies that are often seen in ESLs.

The efficiency issue will then have more to do with the specific model of ESL, the room and your listening preferences.

Keep in mind that an 80 watt amp will only sound about twice as loud as an 8-10 watt amp (10 db increase to double perceived volume).  A lot depends on the power supply driving the whole thing and what the dynamic headroom is.

8 watts to 80 watts is 10 dB?  

8 watts to 80 watts is 10 dB?

Yes, it is.

The ratio of two power levels, expressed in db and with the two levels denoted as P1 and P2, is 10log(P1/P2), where "log" is the base-10 logarithm.

It doesn’t matter whether the higher or the smaller number is placed in the numerator (P1) or the denominator (P2). The magnitude of the answer will be the same either way, with a sign that is positive if P1 is larger than P2, and negative if P1 is smaller than P2.

10log(80/8) = 10 db

10 log(8/80) = -10 db

Elevick is also correct that a 10 db increase in volume will be subjectively perceived as "twice as loud." As a good approximation, at least.

Regards,
-- Al

elevick
Keep in mind that an 80 watt amp will only sound about twice as loud as an 8-10 watt amp (10 db increase to double perceived volume). A lot depends on the power supply driving the whole thing and what the dynamic headroom is.

The first time I heard this was from the shop that sold me the 6 x 9 Jensen triax speakers, with Pioneer AM/FM Cassette deck that I put into a z28 Camaro. 1979? ... I was around 17-18?
Nothing has changed re: needs to be 10 times the power to sound twice as loud. My taste in cars did change. American, to Japanese to German.

The first time I heard this was from the shop that sold me the 6 x 9 Jensen triax speakers, with Pioneer AM/FM Cassette deck that I put into a z28 Camaro. 1979? ... I was around 17-18? 
Nothing has changed re: needs to be 10 times the power to sound twice as loud. My taste in cars did change. American, to Japanese to German. 

Oh God, me too!  I had a Nissan Z at the time (Datsun)  I loved that system.

Happy Listening.

 had a Nissan Z at the time (Datsun)  I loved that system. 

:^)   3 Datsun Z cars. incl '71 with 3 weber carbs last one was Nissan 300 zxTT. I had the first g35 coupe with the brembos. Damn ..I think I have had more cars than amplifiers....no that's not true.  

Not this week.

I took Ralphs (Atmasphere's) advice and ordered the Zeroformer from Paul Speltz. Hope this helps in whatever tube amp i decide to get . I assume it will help with lower power tube amps .

Hello , I have received the Zero's , unfortunately i do not have a tube amp yet to give them a try . A couple missed buying opportunities and a small used market at the moment . Hopefully i can get one in house to try before the return period is over on the Zeros . Will keep you posted .