If you might be considering Musial Fidelity, I have an MF X-AS100 power amp that's been in storage for the last ten years or so, owned from new. Pretty neutral to these ears, perhaps a tad warmer than ATC or Bryston integrateds which I compared at the time. Primare A30.1 about the same for 'warmth' and muscle but the power amp gave me more options than an integrated.
100W Class AB, bit of an MF classic. Would be £300 or so, pretty mint. Used to run it into Kef Ref 201s back in the day (£2k in 2001), it drove them beautifully - my first foray into fairly high-end audio. Worked well with valve preamp (MF Nu-Vista) and SS pre (MF X-P100). Was more neutral with the X-P100 but the Nu-Vista was fairly euphonic. You could turn the X-AS100 into a monoblock for more current but the differences were small, I sold the second one I had. An A3.2 preamp had more detail but seemed to suit the power amp less well - a backwards step. My take on the MF lineage around that time was A1 series = very warm and soft, XA series = just warm side of neutral, A3 series getting cooler... the A308 series I didn't enjoy. I do like neutral valve pres and class A power amps though!
All subjective of course.