Does Class A amplifier artificially smoothen sound

It is hard to generalize among class A amps. There are class A amps that are still flat, strident, and dull.

Moving from a class AB to a class A topology, you might experience:
Increase in dynamics. Music is more energetic, punchy, rounded.
Less compression of the soundstage width and depth.
Better delineation of details with less strain or harshness.

I know this because I had an amp that could switch between A and A/B. The difference is not even close. It is like going from mono to stereo. I would not say that class A resulted in an artifically smooth sound, but there was more ease and less strain.

As said, there are great Class A amps, and inconsequential Class A amps. But keeping everything else constant except the A and A/B designation, the A should have a more satisfying sound.

The Pass XA.5 has a warmer midrange with more textural and harmonic richness compared with many SS amps. I would say that is more by design throughout, than due purely to class A.

Perhaps, it's more likely that Class AB amplifier(s) artificially roughen sound.

I am trying to come across neutral, that people would be more comfortable voicing either positive or negative comments about class A amplifiers. Personally I don't think it's an artificial compensation by Class A to make the sound more pleasant as some of us tend to suspect. I wrote because I want to see more people benefited from such healing effect of music; and I was so glad to have stumbled into Class A amplifier design that allows the sustained listening without having the headache and the disappointment I have had for years beforehand. What use is music if you cannot listen to it for so long. So I raised a case-and-point contrasting between DVA-A and CD reproduction both by Pass XA60.5. Nor do I think there is something wrong with the disc player which is Meridian 808. We all know that Meridian has spent a lot of effort to polish their DVD-A technology, and they receive nothing but compliments for their work. Personally I think the XA60.5 monoblocks transmit whatever they receive. If the source is good, then it's good. If the source is not ideal, then I am going to pay for it with a headache. Yet all of this is just my personal view. Any difference in opinion is more than appreciated.

No matter what the topology, all amps have artificial artifacts. Some are simply more true to the source than others. I think Rtn1 is correct in that specific design is what ultimately dictates the result. I own 3 class A Bedinis, a 25/25, 100/100, and a 250/250MKII. It's well known that the Bedinis are the SS amp that's trying to be a tube amp. They all have an upper mid-range "hump". The 25/25 is fabulous with extremely fine transients and upper detail. The 100/100 sounds similar as all Bedinis do, however it"s fatiguing with just too much upper-mid. The 250/250 is the best all-round balance with great bottom-end and flat response and I think that's the key. I have a couple of A/B amps as well which are extremely flat and sound very similar to the 250/250, only faster with better bass extension. Flat response is what reveals the source material. If all your source material has the same sonic characteristics, then I would say your amp is leaving something to be desired. Also, in my opinion, an amp with a slew rate of less than something close to 50 is not going to be satisfying and fatiguing. The 100/100 is just that, too slow. My Meridian Super Class-A is very fast, detailed and flat. Definately not fatiguing. However I do all my listening through my Leach Superamp mono A/Bs, which have a slew rate of 80. Even though their soundstage characteristics are not as good as the Class A's, their linearity and speed make them more pleasing.

We've made class A amps for a long time and one thing that has always been an issue is the revealing nature that class A can bring to an amplifier. If your digital gear does not have its ducks in a row, it can give you a headache. So I'm with Stanwal on this one.

Its hard to use digital as a reference. IOW if it gives you a headache with analog too I would be a lot more suspicious of the amplifier, although if you are suggesting that its the Pass, I don't buy it- they make some of the best transistor amps made.