I don’t think it really matters whether the amp is tubed or class A design. What really matters, is that you pick an amp that is designed well and will give you the sound you’re looking for. Some very well made amps will have a clean, detailed sound and other will lean on the very musical side. Ultimately, you would want an amp that matches well with your system and gives a magical, musical experience. I have 5 amps sitting on my floor at the moment in which I frequently rotate in an out. I like the sound each one gives and I have a log book I use to keep track of which speakers, speaker cables, power cords sound best on each amp. This consist of, a 50watt class A SS, 100watt EL34 tube amp, 22watt 300b amp, 18watt 300b mono amps and 9watt 300b mono amps. Each of these amps are very special and give a glorious sound. Point is, stick with an excellent class A SS or tube design and you’ll be fine.