darTZeel Audio NHB-108 - Manual (Page 7)

darTZeel NHB-108 model one Audiophile's technical manual Page 7 of 28
4. Structural aspects
It would be all too easy to compare the
darTZeel NHB-108 model one and wrist-
watches, both being made in Switzer-
land. There are no springs, cogwheels, or
hands in a NHB-108 model one. Here, eve-
rything is a tad… bigger.
4.1. The case modules
The case of your machine is exclusively
machined from AW-5754-ALMG3 alloy alu-
minum, offering a remarkably even surface and
hardness.
Every item is CNC machined from the
billet in order to ensure a very high den-
sity and outstanding rigidity, thus con-
siderably lowering all unwanted reso-
nances.
The elements are finished in the three
hard anodized darTZeel colors, namely
electric blue, blazing red, and gleaming
yellow. This unique finish gives to the
darTZeel NHB-108 model one its inimitable
appearance.
The three main elementary modules are
the mother plate, the transformer plat-
forms and the heat sinks. They are
tightly assembled together with non-
magnetic, stainless steel screws.
Each basic module is first carefully hand
assembled, and individually tested. Only
then is it dated and signed before being
fitted.
If you dismantle your darTZeel NHB-108
model one, you will see that modules are
not assembled in a hurry. Some of them
are installed with several weeks elapsing
between construction and assembling.
In line with this non-stress approach, we
take all the time necessary to achieve
the best job we can. If our tests show
that a component is out of specification –
this can sometimes occur after its as-
sembling – the entire module is disman-
tled, checked, and reassembled before
being tested a second time.
The darTZeel NHB-108 model one housing
features a 25mm false bottom, sand-
wiched between the 6mm thick mother
plate module and the 4mm thick bottom
plate. All cables and wires are routed in
this sandwich, minimizing the influence
of electromagnetic fields.
Furthermore, such an arrangement is of
extreme rigidity ensuring exceptionally
good mechanical coupling between the
mother plate and heat sinks modules.
4.2. Divide to conquer
The inside of the darTZeel NHB-108 model
one is divided into four distinct volumes.
The left and right channels are insulated
from each other, as are their respective
power supplies. This unprecedented con-
struction allows extremely low crosstalk
behavior across the whole audio fre-
quency range. You are either true dual
mono, or you are not. The darTZeel NHB-
108 model one definitely is.
The two front compartments are devoted
to the power supplies, and are them-
selves divided into a two-storey struc-
ture. The Crowbar elements and the soft
start circuitry are located on the lower
level, while the suspended toroidal trans-
formers are fixed on the 6mm thick, up-
per decks.
We insist on the fact that in the final as-
sembly process, all parts are first care-
fully aligned before being tightly screwed
together. This additional precaution adds
still more rigidity, and the entire case
then behaves as a single block. As a free
bonus, the case is thus virtually dust
proof.
4.3. Eliminating vibrations
The fastening of the power supply trans-
formers was carefully thought out as re-
gards noise reduction and trouble-free
life. A specially developed suspension
ensures that even in case of failure, the
transformers will not fall off.
So, in 40 or 50 years, when the rubber
absorbers have become – perhaps –
worn out, they will withstand their last
trip to the factory for their replacement.
The same is true for the silentblocs used
for suspending the lighter audio and
monitoring circuits.
These various suspensions, tuned on
different resonance frequencies, are
coupled quite tightly to the chassis, ab-
sorbing especially the medium and high