Info wanted on Krell KMA 400's

The KMA 400 B's are amongst my all time favorite amps. Dynamic as all get go, clear, transparent with just a hint of warmth. Reprince, the last pair of KMA 160 B's I saw sell here on Audiogon went for about $2100.

They've come down in price over the last 4 years! Wish I'd seen that, I might have gone for them for my bass modules. Still a very good sounding amp, particularly with hard-to-drive speakers.

In the MDA series of amplifiers, you would commonly find the MDA-300 and MDA-500 come up for sale... occasionally. What you would never find or maybe once in a blue, blue moon, is a pair of MDA-600s coming up for sale (only one pair has ever appeared for sale in the used market as far as we know). Being that only two pairs were ever made - One pair for Fabio and the other pair for Dan D'Agostino himself, good luck with ever finding another pair for sale. What is even rarer than the MDA-600s is this pair of MDA-400s that Dan specially built for a long time friend of his. This could be the only pair in the World (as far as we know)! And is probably even rarer than digging up a red diamond. Only the MDA-600s and this MDA-400s has the blue power output meter on its front that are similar to the uber high end KAS amplifiers. The MDA-300 and MDA-500 do not have them.  
Here's someone selling the MDA-400s
https://www.ebay.com/itm/Krell-MDA-400s-Class-A-monoblocks-1-of-a-kind-Re-capped-and-serviced-28-000...

steffo
Info wanted on Krell KMA 400’s

Don’t believe for one minute they are 400w Class-A, having the 400 figure, they would have been conservatively rated at 400w Class A/B into 8ohms, bench tested usually a Krell will be more, like 450-500 Class-A/B. They do this on purpose (underrate) because then the true 4ohm figure looks like it doubling, to give an even better illusion of current.

As for the Class-A bias, with a rail voltage high enough to give approx 500w into 8ohms, those heatsinks then are only capable of doing 30-40w max of Class-A into 8ohms, as this amp does not have "Plateau Biasing" it’s a fixed bias amp.

If it were just a 100w amp into 8ohms (no more) then those heatsinks "may" support it biased into Class-A maybe all the way to 80-100w. But it’s not and the heat factor goes up exponentially as the rail voltage goes higher for more Class-B output.

EG: The Mark Leveinson ML2 monoblocks are just as big/heavy, and have comparable heatsinks, but are only 25w into 8ohms but it’s all class-A.

Cheers George