B&W Nautilus 803 & Musical Fidelity A3

Thanks for the tips.
In these days I'm evaluating a new amplification: pre-ampli with tubes, made by a local expert (japanese - $10.000), and a power unit NET, MK105M, (105W, Dual Mono, MOSFET, $1.500).
Well, the improvements are very impressive. The soundstage, the micro-contrast and the dynamic have been very improved. In comparison, the A3 field is very flat and far from listener. Its 85W are not sufficient. In the test I've also switched between the pre, A3 and tubes. I've understood two things:

1. The pre-ampli is very important: it gives the main characterization of sound.
2. For the power unit is not important the absolute power, but the "quality" of watts.

However, the weak of system is in the tonal balance: too low bass frequences and too much medium. The high frequency are not so "clear". I'm going to test the MF Tri-Vista 300. It can be the right trade-off?

I have the N802s and found that the placement of the speakers is critical for the best sound stage & imaging.
Currently, mine are at least 4 feet from the rear walls, about 8' apart, angled to face the listener (around 30 degrees from straight on) and I sit about 10 feet from each speaker ... needless to say it is a trial and error approach until you have them focussed.
It is best done by 2 people.

As to amplication, I drive them with 2 Belles 350A monos (800 watts) and a Belles 21A pre-amp.
My current room is too small (13 by 17)... they like a big room 16+ by 20+ ... and they love power ...

Don

I'm continuing the experiments.
I've found the main cause of weak bass and poor soundstage: it is the source: the CD player, a Musical Fidelity A3.2!
I've tested it in another (excellent) hi-fi system and the result is very eloquent (the other system has MYST mechanic and Conrad-Jonhson P9 DAC). It seems that some harmonics are missing; the sound has little body and it is very poor in the bass part of spectrum. That disappointment!
I'm going to change this component first. After, will be the turn of the cables.

Finally I've a new cd source: the Teac DV-50, an universal player. It extracts from CDs al lot of information that before I never listen to. The bass estension is excellent, so the micro-detail and the dynamic. I have also new cables, Aircable, that improves details and dynamic.
Early I'm going to change the amp, probably the MF Tri-Vista.