Should I buy a Class A Amp.

After 20 years of use even though all metal parts were aluminium, electrolysis started, it started to get corrosion, it was getting dangerous, so I rebuilt it into a normal big amp with big heat sinks hi bias first 30w Class A  and sold it.

Cheers George

george,

Thanks for taking time to research the specifications of the amplifier and for your professional decorum. I actually have an original copy of the Stereophile Magazine with the article. Due to the age of my unit, I had it serviced just over a year ago and returned to factory specifications.

I agree with your statement above. A/B application. 
An important aspect of the design was the implementation of a new sliding-bias output-stage topology which Madrigal calls "Adaptive Biasing." The design goal was for the 300 series to function as a true voltage source for any loudspeaker load between 8 ohms and 2 ohms. (The No.33 Reference extends this ability down to 1 ohm.)
"As discussed in one of the company’s white papers, an amplifier rated for this range of impedance loads needs a high level of output bias to minimize crossover distortion and to avoid any possibility of reverse-biasing an output device. In a traditional class-A design, this leads to a large quiescent current draw, hence the production of a lot of heat. Madrigal’s solution was to modulate the bias level as a function of the input signal, using an algorithm that includes both the input signal and the level of output current being demanded by the loudspeaker."

All the best,
N

To bpoleti in copy, I would like to reiterate that I never stated that I was operating the no.336. Nor that I was drawing 50 amperes from a 120hz outlet.

Madrigal states in my manual "...Because of this "Voltage Source" characteristic, the 300 series amplifiers double their output everytime the loudspeaker impedance is cut by half. For example the no.336’s continuous output is 350 watts per channel @8ohms, 700 watts per channel @4ohms and 1400 watts @2 ohms- assuming the electrical circuit in the wall can support these extraordinary power levels. A "continuous" 2ohm test of the no.336 at maximum power would require 50 amperes at 120v..."

Could it be said that Class A amps, like Pass for example, play better on certain types of music? Better classical than rock, for instance?

Most Pass Labs amps are also high biased A/B amps, and yes if you were to play a piece of music that was very mellow like slow blues, some Class A/B amps may stay in Class A. But maybe with a full blown orchestra that same amp may go into class B.
Also an A/B amp may stay in Class A  if the speakers impedance stays at say 8ohms, but if that same speaker dips to 1,2,,3 or 4ohms somewhere in it's impedance curve then that same amp may go into class b.

Cheers George      

I was a Krell dealer and also a Musical Fidelity in the days when use to have big amps like the 270 and 370 which were class A. The ones I liked best were a pair of Stax 100 watt As through Quad 63s. I don't have any As now and find good ABs sound good are more flexible and far less trouble. I am using a CJ 350 and Gamut D200 which are not cheap but I got the Gamut for less than a good Class A