Transients hurting my ears on hifi solid state amps

Here's where I'm at currently: I'm leaning toward class A, despite my worries about power consumption and heat. This is based on the hypothesis regarding transients and dynamics, but also other reasons, related to the distortion characteristics and the sound signature, often associated with most class A amplifiers.

Looking at the options discussed, the Pass Labs INT-25 is on the top of the list at the moment. I'm trying to be open to higher budgets given the options discussed, but even ex demo or used units remain perhaps too pricey. But the smooth, warm, liquid sound that many reviewers note could be exactly what should work for me. I would likely be underpowering my current speakers, but in a way, that might be a good thing.

In the case of Luxman, I think I would need to go to the 590 (similarly priced to the Pass), or perhaps 550. But even if it's considered smooth, it is a very different sound compared to the Pass Labs, a more neutral and balanced presentation, less forgiving of bad recordings, so I'm not sure if that's for me.

Reading about Sudgen and seeing reviews comparing it to Pass Labs, there seems to be more energy in the highs and there isn't the same smoothness and warmth. I wasn't convinced that was the one for me. There is also no standby mode, which I would ideally like to have.

Not sure about class A/AB amps, such as Parasound, given their high power ratings and reviews being less clear about the smoothness (the best proxy I have found for the sound I'm looking for).

Accuphase could be an option, both class A and AB, but they are expensive and their availability is limited, both new and used.

I would like to stick to integrated amps, just because of the need for an easy to use, that's the reason I feel the need to move from my current tube amp. However, I was wondering whether there are class A separates where the power amp can be turned on and off (or toggle the standby mode) from the preamp? I've seen mentions of this communication being possible, but haven't seen a pairing that does this. Space is not really the issue here. As mentioned before, First Watt amplifiers would be high on my list, but they don't fill the ease of use criteria.

The ideal would still be to find a class AB amp, but I haven't really found a way to judge which models could work for me. Higher end amps are usually very powerful and I worry that it translates to an overly microdynamic sound. Most reviews don't seem to find the options discussed (listed in a previous post) that easy on the ears, for example Stereophile says about the Croft:

the Croft didn't spare me the bad news of the peaky top ends that made cymbals sizzle overmuch, over-emphasized vocal sibilants, and suchlike.

Thanks in advance for any comments on these current conclusions I've drawn, as well as possible suggestions for alternatives to the Pass Labs, be it class A integrated or communicating separates, or class AB options that you think would fit with what I'm looking for.

But you already have the PrimaLuna and like it?
The reviews and measurements in stereophile look good.

If the main reason to move away from tubes was the heat, then I am not sure it will get better.

It seems like a sideways move to me.
But I’d probably trade my PrimaLuna for a Pass.

It is indeed in part a sideways move and that's why I would ideally find a class AB solid state option. However, heat wasn't the only reason to move away from tubes.

Other examples were the one-minute warm up time during which the amp is on mute, having to switch it to my preferred triode mode, having to keep it turned on in case I want to use it again in the near future, as each cycle damages the tubes and because you need to wait for a certain time before starting it up again to save tubes.

There are also security concerns with children and just the hassle of tubes: their long-term availability, searching for the ideal NOS tubes, finding the best combination, etc. Some people like tube rolling and the possibility to adapt the sound to their liking, but I would prefer an amp with no tweaking possibilities that can be just left as is. I'm being very negative here, but it's just to make the point regarding the accumulation of things that have been bothering me at different points. I do love my tubes in guitar gear (including in various pedals) and wouldn't ever imagine going solid state there, but it's just a very different use case.

The Pass lacks auto standby, which is its biggest drawback. But you can turn it on and off with the remote any time without needing to worry about hurting any component of it. And if its left on unattended, there's not the same danger as if a tube goes bad. But the current draw and heat at idle are definitely concerns on the Pass. To me, it would at least be a pretty good step in the right direction in terms of what my concerns are with my PrimaLuna, even though it's not ideal as you point out. In addition, I do believe, and hope for the price, that it would be a move up in terms of sound, as you also allude to.

You mention the Stereophile measurement look good, are there aspects I should look out for in measurements that could help me identify the amp that might work for me? I've never really tried to understand measurements.

Ok - WRT my contrarian and questioning post, it looks like you’ve thought it all through.

well done sir!

This is caused by higher ordered harmonics that are part of the distortion spectra of the amplifier. In this case, those higher ordered harmonics are not masked by the lower orders. The ear is keenly sensitive to the higher orders as it uses them to sense sound pressure. It also converts all forms of distortion to a tonality; the higher orders are interpreted as 'harsh and bright'.

@atmasphere 

You are obviously very knowledgeable about this, so I would like to ask you a follow up question about this:

Since the OP is referring to "transients", could it also not be due to his amplifier using excessive loop negative feedback, which might be causing Transient Intermodulation Distortion?