how does a magnetic field power amplifier work?

I recently acquired a Carver M-200t 'magnetic field power amplifier'. These as i understand are highly recommended. I heard somewhere that they are supposed to emulate a tube-amplifier sound? i would really like to know how it works as opposed to other solid state amps. I opened it up to check out a buzz fom the transformer (see my post in the repair section--know where i can get a transformer?) and i noticed it has some very business like transistors, but not much of a heatsink array...

anyway, if anybody who knows how these amplifiers work can clue me in, it would be much appreciated!

thanks,

emmett

I'm no expert (former drip under pressure ) but what I do know is that instead of having huge capacitors to store energy for high demands and a medium sized transformer, magnetic field amps use a huge transformer that can supply all the power the amp could possibly use at one time then the input to the x-former is current controlled (not voltage) so that it only uses what it needs at any time. More efficient and way more powerful!! It controls the current going into the transformer by means of a triac and optocoupler arrangement that switches on and off twice each cycle of AC. That's how it controls the current and maintains a constant voltage.

I'm no expert (former drip under pressure ) but what I do know is that instead of having huge capacitors to store energy for high demands and a medium sized transformer, magnetic field amps use a huge transformer that can supply all the power the amp could possibly use at one time then the input to the x-former is current controlled (not voltage) so that it only uses what it needs at any time. More efficient and way more powerful!! It controls the current going into the transformer by means of a triac and optocoupler arrangement that switches on and off twice each cycle of AC. That's how it controls the current and maintains a constant voltage.

That sounds about right. It only borrows what power it needs from the outlet when needed. That's one of the reasons they run so cool. They are not holding all the current in the capacitors, therefore not as much heat is generated. I love the design. It's funny how the lights will flicker when you really start using a lot of power from the amps. You can actually see the light strobe with the power peaks.

As far as the tube sound goes, there is an interview with Bob Carver (you can do a search and find it on the net) where he says, basically, getting the tube sound amounts to adjusting the output impedance to around 1 ohm. He said that 90% of the tube sound is due to the output impedance.

I have NO idea what any of that means but it SOUNDS good.

BDT

I've serviced some Carver and Yamaha amps with this design. audioguy1 bout nailed it