I must say, that Croft is outstanding power amplifier. Grand piano in its creation with K1000 and deeply modified ASL Twin-Head is the best I've ever heard, better than with Orpheus or Stax 009. So I don’t searching anything else, although First Watt F1 is very interesting alternative. Such alternative is not AKG K701, which I don’t like. They are good with both Leben's amplifiers, but far, far away behind my K1000 setup.
Next month I will be able at last try Ancient Audio Grand Silver Mono, which I know with speakers, and question – is this distortion problem attached with my setup or K1000 itself – will be probably solve.
+1 on K701.
Let us know what develops. I find this very interesting.
I have never heard either Orpheus or 009 ( any Stax below that, Jecklin ES, etc etc ), but from your descriptions I understand you must have very acute hearing and understand why you prefer dynamic K1000 to the (best?) electrostatics on piano - and why you listen to K1000 without the inner grills. Are you a pianist, producer, recording engineer or "just " a piano lover ?
Still, I would strongly suggest to measure the Croft (or any other amp ) for clipping as I have described; peaks register far above what we perceive as loudness, in piano music it is the high notes that go far above average levels and can sound as you have described with clipping. If you find any example of piano that causes this on youtube, please post it.
I know that sound quality on youtube is what it is ( always remember not to forget to set the highest resolution available) , but there are decent sounding recordings of piano to be found:
Is the comment for this video by fredericfranc really true for Polish conditions ? I have recorded the same piece in one of our churches 4 years ago - and it seemed like the most
appropriate thing to do, acoustics were just about perfect.