Should I buy a Class A Amp.

All high bias Class A/B I think except for an early massive Gryphon which was suppose to be pure class A to clipping into 8ohms.

You just have to look at the old huge ML25 monoblocks which were 25w pure class A only into 8ohms. The heat factor goes up exponentially the more watts there are, because the rail volts have be to increased.

So for two amps, one 20w class A that’s all.
And the other 100watts class A/B still with only 20w of Class A bias, this amp will be 4 x hotter. Even though their both only 20w Class A.
This is why I had to water cool the amp I made 4 posts back because I wanted 150w and Class A all the way.
Cheers George

I see.
What happened to your built amp or you still use it?

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?