darTZeel Audio NHB-108 B version - Manual (Page 26)

darTZeel NHB-108 model one
User Manual, version B 1.0 Page 26 of 35
We also placed inputs connectors directly on the
input PCB, themselves very close to the entry audio
PCB points, altering as little as possible the still
unamplified incoming music.
Dozens of other small things have been thought
about and implemented. We would need too much
space to describe all of them; furthermore, such a
description would be much too boring. Please be-
lieve us, we have done our best to look after the
precious and delicate musical signal, leaving as
little as possible to chance.
T5.4. Symmetrically balanced?
The following could seem contradictory sometimes.
It is mainly due to the terms "balanced" and "sym-
metrical", or "unbalanced" and "single ended".
In French, these terms lead to even more confusion,
since both "balanced" and "symmetrical" are trans-
lated by "symétrique".
So, you will not feel less comfortable than our
French-speaking friends. Feel free to contact us at
[email protected] if you need explanations in
greater depth.
It is absolutely fascinating to note that some techni-
cal choices only serve fallacious sales arguments,
and to our regret, audio is no exception to the
rule…
Most high-end power amplifiers, especially flagship
models, offer balanced inputs, described as being
the very best, technically and sonically speaking.
As often as not there’s no option as regards bal-
anced inputs: in fact there’s nothing else!
For the darTZeel NHB-108 model one, our ap-
proach has been almost the opposite. To minimize
the cost? Could you even believe that?
Maybe the time has come to refresh our memory to
some extent…
T5.4.1. From the microphone…
A balanced line is in fact a transmission line with-
out reference to ground. Imagine that instead of
transmitting the signal between one wire and
ground, we use two wires. A 3
rd cable, earmarked
for ground, is of course also present, even though
not necessary for the signal right now.
This transmission mode finally leads to external
noise and disturbance cancellation.
In pro audio engineering, balanced lines are de
rigueur and massively used. Unbalanced links are
very rare indeed! The reason is very easy to under-
stand:
Microphones generate very tiny electric signals, and
very long lengths of cable run from the studio to the
mixing console. In these conditions, it is primordial
for the signal to be free of any hum and/or noise.
Also, in concert performances, mixing consoles are
generally located quite far from the stage, and bal-
anced lines are welcome. A technical trick, using
that 3
rd , ground wire, also makes it possible to carry
the phantom power supply feeding electrostatic
microphones.
So now you have understood that balanced links are
used especially in professional applications.
T5.4.2. To the loudspeakers…
Let us quit the studio and come back to the high-
end, musical world.
Basing themselves on what they consider to be the
real benchmark, audio companies equip their flag-
ship machines with the balanced lines described
above, using the well known XLR connectors.
Most of the time they offer "fully active balanced"
topology from input to output, claiming that the
sound will remain unaffected since it is immune to
external disturbances.
Technically speaking, fully balanced topology is
relatively easy to achieve. It suffices to double the
entire electronics, in a mirroring fashion, assigning
a new channel path for the inverted signal. Of
course this simplicity has a price, in fact double the
price. Finally, the balanced signal is amplified and
routed to the loudspeakers.
Come to think of it, are loudspeakers balanced or
not balanced? That is the question!
T5.4.3. And into the air…
Once in the air, the musical signal is travelling on
its last trip before delicately tickling your eardrums.
How exactly does music propagate itself in the air?
Music is a matter of vibration, and propagates in
the shape of waves. Any wave, to be propagated,
needs a medium. No medium, no wave, no sound.
Just try playing trumpet on the Moon. Not an easy
task, even if your name is Armstrong…
What about radio waves? What medium do they
use, in the vacuum of inter-sidereal space? Well,
write us, and we will send you the Physicist man-
ual, as soon as we have got round to writing it…
As for acoustical waves, it is a much easier phe-
nomenon to describe, and especially understand,
since it is part of our daily life.
The medium can be water in the case of mermaids
singing… er, sorry, when whales sing. Or when
more human, technological things such as sonars,
hydrophones and the like generate and detect acous-
tical waves.