MOSFET's vs Bipolar's


All else being equal, can one truly hear the difference between power amplifiers driven by MOSFET or Bipolar transistors? If there audible differences, are they due more to circuit design and other parts quality? Thanks to all who reply.
nordic587
I own mosfet amps(B&K)and bipolar amps(Acurus). Both have their strengths and are both very enjoyable to me. Mosfets tend to be a bit warmer with an emphesis on the midrange while bipolars are usually punchier down low and a bit brighter up high.(these are my experiences) Some may say that bipolar designs handle low impedences better but with my experience with B&K's, they do just as well when designed properly.

Bill
Unless you are comparing 1 specific mosfet vs 1 specific bipolar, I really don't think this question can be answered. There are definately several examples of both that are incredible amps. It seems today many use fets on the front end and still use bipolar on the output. It comes down to circuit design. Power supply and parts choices, just as much as Mosfet or Bipolar.
I think the heart of the answer is in your second question, the circuit design.

I'm a big fan of Nelson Pass's designs and he uses Mosfets but I have a Bedini 45/45 amp that uses bipolars and it's very sweet also.
I have often read that Mosfets are often the choice of transistor amp designers who mean to emulate certain tube virtues.... Hmm.

One can also read that fuzziness, softened transients, smoothness/warmth and a small degree of thickening are also hallmarks of Mosfet Mist.

While I have owned Mosfet amps for which the above is certainly true - it would not be right to characterize all Mosfet amps that way.
Lateral power Mosfets from Exicon can be drop in replacements for many types of devices supplied by Toshiba and Hitachi. The Exicons supply 30% greater current have much greater speed and lower capacitance. In my particular amp they increased resolution and impact while reducing the overall grain structure of the whole sonic picture. Tom
http://www.irf.com/technical-info/guide/device.html

I don't know suitability for audio but........the opposite of 'lateral', which BTW, the majority of devices appear to be.

Also, Carver used IGBT from these guys in his Sunfire line....at least part of it.
No more than the difference between night and day in my neighborhood though some will say otherwise.Its a hell of a hobby as long as you dont obsess,cheers,Jack
Belles uses Exicon lateral power mosfets..Luminance Audio used the Hitachi lateral power mos fets. Tom