Hiss at addition in system LAMM L2

Guys,
Who had raised(increased) Hiss (noise) from speakers at addition in system LAMM L2?
My system:
Mark Levinson ML-390S
Preamplifiers LAMM L 2
amplifiers LAMM M 1.2
Dunlavey SC-V
Purist audio Venustas
Can bad lamps influence on strong Hiss?

This sounds like what I had when I owned a L2-ref preamp. Bought used off a dealer it exhibited the same behaviour as yours. Discussed the issue with the dealer who said some hiss was normal and he could hear some hiss sitting over 15' away from his set-up so my sitting 8' away would make sense that I would hear some as well. Mine was more predominant in the left channel. I bought new tubes, rebiased everything and still there was hiss. Swapped cables, rack location (maybe there was EMI/RFI issues?), removed preamp from rack to get it away from digital gear - you name it I tried it and still there was hiss. Drove me nuts enough that on Lamm's advice I sent in both the control unit and power supply - two 40lb. wooden crates overnight to Brooklyn. I had Lamm change out all the toggle switches at the same time as one was sticking, but I digress. Lamm checked it out on the bench and in their system and said all was OK. Got it back - overnight freight again - ouch and still the hiss was there. Loved the preamp in terms of what it did but couldn't take the hiss. Possibly it was a system synergy issue as the new owner mated it to Lamm amps and all is well.

And I do know what "normal" tube hiss should typically be as I've owned Rogue, ARC and Hovland preamps in the past and this was not the norm.

So maybe yours does require a check-up @ Lamm as it may not be the same thing that mine had or maybe its a synergy issue with your remaining gear (amp)?

BTW I was able to audition a LL2 deluxe and there was no problem with it and it was extremely enjoyable in my system.