Yes, it's quite strange and very frustrating. At first listen on the Sopra 1s, I thought it was very good and I thought I liked what it was doing with the sound signature. After about 100 hours on it. It has become nearly unlistenable! It is is shrill, thin, metallic with a screaming, screeching treble that would wake up the dead. The midrange is recessed and distant, totally unexpressive. The bass has all but disappeared and when it is there it is loose and flabby. Very poor performance overall. Voices are literally transformed into a litany of sibilance unlike anything I've ever heard. Do you know of any songs without words beginning with S or T? I don't! In fact, this thing has transformed my well-known reference recordings from Steely Dan, Donald Fagen, Pink Floyd, Sade and Deutsche Grammophone classical composers into horrifying calamities of sonic agony. I still have trouble realizing how bad this really is.
So, what did I do? I changed 3 sets of speaker cables, interconnects and power cords. No effect. I rolled a full set of new production Gold Lions to no effect. I the purchased some expensive NOS Telefunkens and got no effect. I changed the source and it did nothing. I then connected some Sonus faber Concertinos and it was the same, all treble and no bass.
Even funnier, I recounted this experience on some McIntosh sites and FB groups looking for advice and suggestions. I was summarily banished as a heretic because I did not proclaim that McIntosh was made by God himself and that it made the very sound of angel's voices singing from on High. It was probably even worse than the Naim forum. It was inconceivable to these people that the MA352 could be considered anything less than a mysterious, magical box that makes heavenly, blissful sound.
I stand firmly by my impressions. The amplifier is overrated, overpriced and underwhelming. It performs poorly and is not musical at all. This is the first amplifier where I hear "confusion" in the musical signal. On complex passages, the thing gets lost, confused and drowns out details of instruments and voices and combines them into an unintelligible mush that really is just noise. Never heard such a demonstration of sonic incompetence in all my years, which are numerous at this stage.
Now I have an ungodly expensive chunk of dorky metal ruining any hope of listening to music. I swear a 50$ Chinese Class D from Aliexpress could do just as well...
Don't expect much from McIntosh except marketing, hype and frenzied fanboy zealots.