Essentially, a preamp is used for several
things:
- As a way to switch between multiple sound
sources (i.e. CD player, tape, etc.)
- Be able to provide a way to adjust volume
- Contains a circuit that has enough current
to drive certain amps (sometimes digital sources do not have enough current in
the analog output circuits).
You can add a preamp into the mix, but it
is not really needed with the NFB-28.28.
The NFB already has a volume control.
You can attached multiple digital sources to the unit as well as one
analog source (the IN5 RCA inputs). The
current in the NFB should be fine to drive any amp you attach. The Yamaha studio monitors will have a preamp
type circuit inside because it needs an active analog circuit for the crossover
to separate the woofer amp and the tweeter amp.
In your situation, the only reason to add a preamp is if you felt the
NFB was lacking in some way. For
example, if you had a CD player that was very bright/harsh sounding, you could
get a tube preamp or a warm-sounding preamp to put in between. This would further modify the analog waveforms
from the DAC to calm down the sound.
Honestly, I think the sound quality of the Audio-GD
is high enough that you would have to spend a lot of money on a preamp to get
something better than what is already output from the NFB (like $2,000 or more).
You are correct in the understanding that a
DAC converts digital data (0s and 1s) to an analog waveform. Anything coming from satellite TV or CD or
bluray is going to be transmitted in digital format, so there has to be a DAC
somewhere. Many satellite receivers have
a DAC inside because you will usually see left/right analog RCA outputs, but
the quality is going to be poor compared to Audio-GD. The conversion from digital to an analog
waveform is where the sound quality of the Audio-GD is superior. The power supply and DAC / analog circuits
are significantly better. You can always
get better than the NFB, but it will cost more.
Just look at the NFB-27.77. The
chassis is twice as large. Three
separate power supplies (one for digital and two for analog). Fully balanced analog circuits. Over twice as expensive.
It’s not that the DAC chip should be described
as powerful. You want to get a DAC that
is clean/accurate. Large capacity linear
power supply, fully discrete analog circuits, good design approach, etc.
On the Blue Jean 1694A, select “Digital
Audio” for the application for sure. They
use specific RCA connectors and the RCA connectors are different for other
purposes (such as subwoofer, stereo, etc.).
The cable color doesn’t really matter.
I usually just get black, but you can get anything you want. Obviously, get the “RCA/RCA” connectors. Remember, 6 feet long (to avoid short cable
signal reflections).
There might be a small chance that the
satellite receive does not have COAX. In
that case, you will probably need to use a toslink digital cable. The lifatec toslink cables are the best for
the money that I know of. The length
doesn’t matter.
http://www.lifatec.com/toslink2.html
Hopefully, I’ve answered everything.