Plinius SA amps

For those owning Plinius SA amps. I got a question.
I bought SA-102 back when brand new, together with CDLAD.
I liked the sonics and the way they came on doing what they did.
Though, i found the CDLAD to be quite bad as it was so thinn sounding. What i never got rid of was the high background noise. I aquired a SA-250mk4 and to my ears it was the same.
I later moved on, same issue in the new apartment. We brought the SA amps to a very good friend. Same in his system. Later on, i had an, at home demo with Krell 600c and KPS 25sc. These sounded pretty different, and also very silent (no noise). I contacted dealer and importer about my Plinius units.
I never got them to bettered really, even though they were sent back to Plinius facility. Well, they lowered gain, but it was still a noise. How do you solve this issue as i have noticed no-one here even mention this.
I had at this period, a speaker manufacturer at my home, bringing two set of speakers. He was as me, annoyed of the very audible noise and suggested a change of amps. This was apperent mostly, in the tweeters. Sounding similar to pink noise or running water.
Speakers had, from 87-94 db sensivity. I tried some rfi filters but it never helped much. I ended up selling both the SA units. I still liked what they did, but i could never come over the noise issue.
What i wonder, is this same with the SA-103 an SA Ref and SB-301?
I don't know if it has anything to with the gain of 32 db ove rca/ 38 db over xlr?
Anyone that can clear this up?