Hiss at addition in system LAMM L2

I had BAT Rex in my system recently, paired with BAT 75-SE, and it was "dead silent"- I could only hear very low level ground loop- type cycling humm with my ear literally 1" from the tweeter, which I'm positive, was related to my power lines, rather then Pre/Amp themselves.
So, I guess hiss is a byproduct of less, then perfect design, and not inherent to tubes or mosfets for that matter.

Just for reference, I had the lamm pre in a system with Coincident Total Victory, Revel Studio and Verity Parsifal. There was some degree of small hissing with all but none really annoying except one combo: Coincicent TV with Antique Sound Labs 1009 60 watt monos. The hiss was very audible.
I had a 200 watt Edge NL 10 in that system that was fairly silent, surprising considering the power difference.
Currently the Lamm M1.1 are paired with the Verity and the hiss is only audible if you put your ear to the tweeter.
So in my experience it appears to be a amp gain speaker sensitivity issue.
The lamm pre is the longest surviving component in my system and is the last one that will leave.

My system:
Mark Levinson ML-390S
Preamplifiers LAMM L 2
amplifiers LAMM M 1.2
Dunlavey SC-V
Purist Audio
I always thought, that Preamplifiers and amplifiers one manufacturer
Will well incorporate …
However hisses strongly … even on distance 15.
Can change L 2 on LL 2???
What Preamplifiers LAMM L 2 or LL 2 hisses less??

In response to Tvad's comment:

"I often wonder if some of us are more sensitive to hiss than others, and were we to listen to the same system at the same time if some of us would object to hiss we hear whereas others would not."

Absolutely true.
I am one of those that can not stand hiss, (usually introduced via tubes), that is audible from one's listening position. I have sold all of the tube preamplifiers (and tube phono preamps), that I have tried becasue of this. That eventually led me to use the (solid state) Ayre K-1xe preamplifier, and its phono boards, in order to get as deep, dark blackground as posible. (FYI: I am very happy with the results, and doubt I will ever go back to a tube preamp.)

And what is funny is that I can ignore pops and ticks from records, which is how I listen to 90% of my music, but not low level hiss. (Well, a limited amount of pops and ticks anyway. Too much of course spoils it for me.)

However, I do realize that I like how tubes make the music sound, so I have managed to interject a nice touch of tubes via my Lamm M2.1 monoblocks. They only use one 6922 tube in the driver section of the amp, but it is enough to make the music come alive. (I will state that I use NOS Amperex pinched waist tubes, because I want the absolute best of the tube sound, and since I only need two, the exorbident cost of these tubes is somewhat mitigated.) And yes, it does introduce a very small touch of hiss, audible only by putting one's ear to the speaker, but it's not audible from my listening position.

If you can find that you can live with the hiss, you're probably better off in the long run, as the Lamm L2 reference is a wonderful preamp, and incredible musical, and one of the better preamps around. (Assuming you can live with the hiss, and its lack of a remote, (which was the deal breaker for me).

Good Luck!