First foray into Class A amp -- recommendations

@audiolabyrinth, who wrote:

"if you go and audition a krell 400cx or 700cx, they will clearly out perform the pass labs amp you listened to, espeacially with high quality cables"

That much difference between the 300cx and 400cx? I thought the 300cx was a bit more dynamic than the Pass XA100.5s, but it wasn't a huge difference.

Now, the speakers being used in the comparison were Magnepan 3.7, which are apparently not the most dynamic speakers out there. But, there was no question that the Pass were better in sound stage and fidelity to the actual sound of instruments and voices.

"You're right, what would I know..."

I wasn't trying to be negative with you or say that you don't know what you are talking about. Its just that your post was vague and may unfairly lump together all class a amps with bs marketing. If you could point out specific examples, that would help a lot. And you may be right. Maybe the rest of us overlooked issues that you did not.

Mtrot, Hi, I own the 700cx modded, There is a huge substantial difference between this and the 300cx you are looking at, if my amp was not modded, there would still be a big difference, for one, the 300cx is the bottom of the cx line, and the 700cx is the top of the stereo line, which esentially is mono blocks in one chassis, where the 400cx and 300cx is not!, hope this helps, Happy listening.

If you have cold winters, than KSA200 is able to provide heat to the whole room.

@Zd, fair enough. I certainly wasn't criticizing Class A power as my Vitus runs in pure class A up to 25 watts true rms and can be manually switched to class A/B mode which delivers 100 watts true rms and is great for home theater duties. In Kl.A mode the Vitus can change to Kl.A/B mode at very high volume levels or under extreme load, but does so instantly without switching. That is what I meant by pure Kl.A. The Krell fanbois endlessly claim that their amps are pure Kl.A, when in fact they use a sliding bias scheme as confirmed by John Atkinson. Only a few pure class A amps have been built, including the Threshold T800 but they were prone to failure.

What I meant is, most customers want the marketing bs and claim they do not. Amps like Boulder and Rowland market Class A amps which in reality are highly biased class A/B amps. Vitus do not change the bias based on input signal amplitude – that has nothing to do with real kl. A. It's just a marketing gimmick. What Vitus's research has shown is that when the transistors they use has a core temperature of about 70degrees C then the music becomes REAL Liquid – listenable for hours – not the usual competitor “bleeding” ears after 30min. Some call it dynamics, “air” in the high freq – I call it a headache.

Moreover a lot of manufacturers routinely quote peak power figures, or don't quote "true RMS" power just to impress people. Vitus quote their power figures in "true RMS" which is a correct, but less impressive spec. Also, Vitus is using in-house designed UI-core transformers which are much more efficient than typical toroids used by most manufacturers and loses max 1.5v tested. That is another reason why specs on paper mean very little.