Since originally writing this review, my system has now become

Linn Karik iii transport on a block of foam underneath
---> QED QNECT 75 Ohm digital cable
Monarchy Classic DIP with the clock upgraded by Lawrence at Excel Stereo
--->QED QNECT 75 Ohm digital cable
Monarchy M24 tube DAC with PCM 63 K DAC chips and Amperex PQ white label 6922 tubes
M24 DAC plugged into a Chang Light Speed

---> 0.5 m silver Litz interconnects similar to Luscombe's

Musical Fidelity A308cr preamp
---> AudioQuest King Cobra analog Interconnects
Musical Fidelity A3.2cr power amp
--- AudioQuest CV-6 speaker cables

and of course N804's.

Since the B&W FST midrange driver and Nautilus tweeter is so accurate,
it really helps to have output tubes in the digital source.

Tweaks are critical to getting great sonics from a source.
Lawrence's clock mod, to the Monarchy Classic DIP, is well worth the $100 upgrade.
Also, foam underneath the transport makes a noticable improvement.

Good job - looks like you put a lot of effort into this. I'm not a B&W owner, but if I was, I'm sure I'd find this useful. Should have been titled: "Uunderstanding Nautilus 804s."

cheers,
ben

There is a clarification I should make here:
Most DAC's are sensitive to the quality of the transport they are used with. Higher quality transports have lower bit error and have less bit jitter.
So using a quality DAC, like a Monarchy DAC, with a cheap transport, will not yeild good results.

However, bit stream jitter can be significantly be reduced by adding a circuit called a PLL - Phase Lock Loop - between the transport and DAC. Monarchy makes a PLL they call a DIP.
Adding a Monarchy DIP, to a Monarchy DAC, will make a massive inprovement.

As such, I recommend using a Monarchy DIP & 22C DAC with the N804's. The Monarchy DIP & 22C combination has great warmth, dynamics, noticably good channel separation and instruments are quite focused. Very importantly, using the Monarchy DIP and 22C, the N804's do not have any hint of harshness or fatige.

Since originally writing this review, I tried Kimber 8TC speaker cables connected to the mid/tweeter of the N804's.
8TC's are good cables, but IMHO are not right for this application.
For biwiring the N804's mid/tweeter, I much prefered AudioQuest CV-6's.


My reference test CD's are

Brubeck - Time Out

Mozart - Piano Sontas K.310, K.331, K. 533/494
Murry Perahia
Sony SK 48 233