I own the ARC LS16MKII. It replaces the line stage of my ARC SP9MKIII (I still use the phono stage from that unit with my Linn K 18 cartridge). The ARC LS16MKII has much better resolution than the ARC SP9MKIII, but also is better and quieter (on music material) than a LS 22 that I tried out. Driving an ARC VT 100MKII in balanced mode into moderate efficiency speakers (Linn 5140), it is dead silent when no music signal is on. What is more important is the comparative absence of "noise" when playing what were previously heard to be noisy CD's (a certain Best of the 60's CD), and the increase in micro-dynamics, relative to both the ARC SP9MKIII and the LS 22. The bass sounds (compared with the LS 22) a bit "dry" or overdamped, compared with an LS 22, and some might consider the top octive to be "whitish" rather than (as I do), delicate and defined. Depending on the quality of your power line signal, the preamp will sound better with a line conditioner (I use Monster 5000). In my home, without a conditioner, the sound can be slightly strained in the mid-range and the unit can sound a bit out of breath with tough CD cuts such as "I can see clearly now" in the Holly Cole Trio, Don't Smoke in Bed, CD. I suspect that reflects limitations in power supply regulation, that more expensive units such as the LS25 may not suffer to the same degree.
The gain level seems just right in relation to the power amp used, and the speakers used, in the context of the acoustics of my (long) listening room, but if used with a power amp with less gain, or with high sensitivity speakers, there might be a noise problem: its noise level is specified as being higher than an LS 25 (but it is a more recent product, and that may reflect changes in advertising policies or measuring techniques in the interim; see the noise specs on the Reference II compared with the LS 25 for confirmation of that.
I hope this helps.
The gain level seems just right in relation to the power amp used, and the speakers used, in the context of the acoustics of my (long) listening room, but if used with a power amp with less gain, or with high sensitivity speakers, there might be a noise problem: its noise level is specified as being higher than an LS 25 (but it is a more recent product, and that may reflect changes in advertising policies or measuring techniques in the interim; see the noise specs on the Reference II compared with the LS 25 for confirmation of that.
I hope this helps.