Mosfet amps A true compromise betw. tubes and SS?


I heard from several people that Mosfet SS amps are a nice compromise between tubes and SS amps.
There is one manufacturer in particular I am interested
http://www.wbe-audio.de,s croll down to Fusion 700 (its a German made amp, but he has an English web page) who calls his hybrid amp a Mono tube mosfet amp.
I would really appreciate if someone who has more insight would tell me a bit more of advantages and shortcomings of this design and if the claim: "sound of tubes with power of SS" is true or not. Also I would like to know if these are fast amps, as I plan to maybe use them with my ML Prodigy, should the Wolcott amps, I bought recently, not work satisfactorily.
tekunda

Showing 4 responses by zaikesman

Of course Tweeterman will take exception with me on this, but I don't believe that anyone can look at a web page, see what type of technology is employed in a piece of gear, and think they have even an inkling of what it will sound like - either in an absolute sense (if that even exists), or particularly in their system (the only place that it ultimately matters). By all means, audition some MOSFET gear if you are curious, but don't expect any more uniformity of sound between different amplifiers of this type than there is between amplifiers of the tube type. If that sort of thing were actually the case, then there would only be a handful of distinguishable amplifier "sounds" - one for each type of active device employed in amp circuits, and we all know that is not true. That's because everything matters, not just one thing, and the way the overall circuit is designed and implemented is generally regarded as being even more important than what type of active devices are used. If I were interested in trying out something new based on an idea about its technology, I sure wouldn't make it a "sound-unheard" purchase, off of a website, of foreign gear that no one in my country sells or services, much less has even heard of. Sure, the stuff *might* be great, but what would I be able to do with it if I wound up not liking it so well? (FWIW, the MOSFET amp I used to own sounded nothing like [and not as good as] my present tube amp.)

P.S. BTW Tekunda, mightn't you be jumping the gun just a little bit, plotting your next amplifier change before you even know if, in your words, your "recently" bought amps will "work satisfactorily"? Why not give 'em a chance - they certainly weren't cheap! You have my sympathy if Audiophilia Nervousa is really that advanced!
So, will you audition these amps in Germany, and if you do, let us know what you think? Good luck, Z.

P.S. Tweek, I must admit that in this thread as well as our previous encounter, I have had the darnedest time trying to follow you. Is it me? Or are you crediting me with saying things I don't think I said? (Or maybe you're just having me on - er, "Tweek"-ing me!) Oh well, I've got to admire your enthusiasm - say, maybe while he's in Germany, Tekunda can give a listen to those speakers you saw on that website (now, what were they called again?)!
Muralman1, are you certain that the Pass amps contain no resistors in the signal path? Also, I thought the 'Super-Symmetry' topology was implemented prior to the output stage. (I too have not heard of interstage coupling capacitors being referred to as "step-up" capacitors - though I believe they are sometimes called DC-blocking capacitors.)
Yes, resistors are passive, and so are capacitors (plus of course transformers, and wire). And both color the signal that passes through them (as do active devices like transistors), but both are necessary to construct circuits. Since an amp's power supply is actually in the signal path (the input signal to each amplification stage serves only as a 'template' to modulate a new larger one for the output, taken from the power supply), and since all conventional amplifiers contain capacitors in the power supply, we can't really say that direct-coupled amps contain no capacitors in the signal path - only that they contain no coupling capacitors.