Does it mean that L2i-SE can reach a same lowest noise level when used in preamp mode by switching off the power stage and related supply units inside (AMP off)?
It will be close, but not 100% of the L2 Signature Preamp. Why? Because when the AMP button is switched OFF in the L2i / L2i-SE, this is only
disabling the current output stage of the L and R power amplifiers (essentially, grounding out the gates of the current output stage mosfets) so they
do not amplify the signal. But the power amplifiers' power supplies are still receiving power / kept warmed up. This way, there are no added
switches in the signal path or power path, which eliminates the influence of any added parts in the signal/power path and maximizes reliability (e.g. one less switch that can eventually fail years from now).
Having said that, since much less current would be flowing through the power supply for the power amplifiers when they are disabled (they are not driving speakers when disabled), the noise from their power supplies will be minimal, and the L2i-SE makes for sensational preamplifier via its single-ended or balanced preamp outputs.
The L2i-SE gives you the most bang for your buck compared to the L2 Signature Preamplifier, but *IF* you were *ONLY* going to be using it as a preamplifier, the L2 Sig Preamp would still be my 1st choice. Since you want to use it as both a preamp *AND* an integrated amp, the L2i-SE makes the most sense.
I hope this clarifies things.
Also, it may be interesting for me to test both gears (L2i-SE and Ayon CF PA) for bi-amping my speakers
If you were to do this, you'd want the gain of the L2i-SE be set when we build it to match that of the Ayon CF PA. Otherwise, the unit
with the higher gain will dominate the freq. range it is connected to. For example, if the Ayon has higher gain and you use it for the tweeters
when bi-amping your speakers, the treble is going to be boosted and could dominate (and vice versa)...
You can also use the L2i-SE in a bi-amp system with the L2 Signature Monoblocks!
It's only money, after all...
I thought the Dynaudio Special 40's sounded pretty bad with my Lio Integrated. Guess a 15k upgrade was all I needed..lol
Lol - It's a totally different story with the L2i or L2i-SE running the show. I really don't know how any
speaker can sound bad with them, unless
the speaker used (and/or the room they are used in) have fairly substantial issues going on.