Should I buy a Class A Amp.

The 300 series ML’s are high biased class A/B, B after the bias runs out, they are not pure Class A.
Looking at the heatsinks I say about 20-30w Class A bias max, as Stereophile also said they weren’t too hot to touch, even after 1 hour pre-conditioning at 1/3rd power.
If they were pure Class A they’d be the size of a very large coffee table with heatsinks big enough to warm the whole neighborhood.

Stereophile full power tests on the No.334 are at 1% THD!!!.
8ohm = 139.9w
4ohm = 243w
2ohm = 430w

Bottom of the page measurement chart
http://www.stereophile.com/content/mark-levinson-no334-power-amplifier-measurements-page-3#toJJo0Xxp6m0aqe4.97

Cheers George

What about older Rowlands, 8T and 9T, and even older 5 and 7, how were they doing in terms of class A? Gryphons, I think, were and perhaps still are pure class A.

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