There are speakers that present a difficult load at both ends of the (frequency) and impedance range. Soundlab Ultimate Ones are are an example I am familiar with. The are about a 30 ohm load in the deep bass, but only 2.5 ohms in the extreme highs. The power provided by most solid state amps is "halved" at each doubling of the load above 8 ohms. A 400 watt transistor amp at 8 ohms, would (in theory) produce 200 watts at 16 ohms and 100 watts at 32 ohms. This 100 watts of power this transistor amp is reduced to is made worse, as it is in the "power hungry" region of deep bass. In addition to that, the electrostatic panels are capacitive in nature, and have a fair amount of reverse electrical feedback that the amp must tolerate. A good tube amp, OTL or transformer coupled will often out drive even a huge transistor unit in this situation. I am able to play my Ultimates to almost live level in a large listening space, with a 25 watt SET tube unit. My point is the same as Redkiwi was making, there are situations that prove the exception to the rule.
Tube vs Solid State - Comparable Output?
I know this is a terribly general question -- and maybe off the wall -- but is there any difference in a tube versus a solid state amplifiers' with comparable power ratings ability to generate high current? This relates to amp selection for current hungry low impedance speakers. Is 200w the same whether its created by tube or solid state? Someone recently told me that a 100w tube amp (Audio Research) was comparable to a 200w solid state amp in this regard. True or no? Thanks in advance.