darTZeel NHB-108 model one
User Manual, version B 1.0
Page 13 of 35
7.2. DC voltage drift
Every single
NHB-108 model one
is lovingly
checked, tested and listened to before leaving our
workshop.
Output DC voltage drift normally does not need any
further adjustment, provided you use your amplifier
in a room temperature ranging from 59°F to 95°F
(15°C to 35°C).
Furthermore, the version
B
now features a built-in
DC compensation circuit. In order to fully benefit
from total lack of any overall negative feedback,
you can disable this circuit.
Please refer to chapter
6.4.
"
Jumper settings
".
If one – or both – Eye begins to blink, even though
your loudspeakers are properly connected
, a read-
justment is recommended.
This tuning procedure is described at the very end
of the technical section.
7.3. Cleaning
and
upkeep
The
darTZeel NHB-108 model one
has not only
been designed for providing you intense moments
of musical pleasure; it is also designed to withstand
the rigors of time, especially if you take proper
care.
This is undoubtedly one of the few, if not the only,
amplifier to be virtually dust-proof. The whole case
performs heat exchange, while the two lateral heat
sinks regulate and maintain the correct temperature.
This design avoids the need for any vent slot.
The only visible traces you will see in the long-term
will be located on the inner side of the smoked
glass, and will be due to some natural evaporation
of some plastic packaged components.
We suggest that you remove the cover glass once a
year, and use a soft cloth to gently wipe the glass
with an appropriate cleaning solution. Your
NHB-108
model one
will then keep its "like-new" aspect for
decades, and as time goes by, the less you will need
to perform this operation.
As for the external parts of your equipment, a soft
cloth or even a dust brush will be completely ade-
quate.
In case of fingerprints, a gentle rub with a cloth
soaked in isopropyl alcohol will be more appropri-
ate.
Just bear in mind, however, that the simplest things
are, more often than not, the most efficient.
We personally found that a spot of soap on a wet
soft cloth is the best method most of the time. Try
for yourself!
As you have certainly guessed, we confirm that it is
strongly recommended to
never use acid
to clean
your gear. Acid is very corrosive and could react
with the anodized coating. Furthermore, acid is
very
corrosive for the skin, too…
If you follow these few elementary rules, you will
be assured of having a very nice looking machine
for decades to come.
8. Some advice and tips
8.1. What not to do
Our advice and recommendations have been volun-
tary placed close to the end of this owner's manual.
This does not mean that they are of only minor
importance - quite the contrary.
We just thought that the following points are not
directly involved in the everyday use of your ampli-
fier.
However, the completely new concept of the
NHB-108
model one
calls for certain precautions.
These few but important warnings are the follow-
ing:
1)
Never, ever attempt to short circuit the
Speaker Terminals (6)
.
Repetitive shorts could lead to permanent dam-
age to the corresponding output stage.
When bi or tri cabling, be especially careful
when connecting the cables. If you inadver-
tently cross the polarity of one run regarding
the other(s), you will make a perfect short cir-
cuit. This can easily destroy the corresponding
output stage!
The warranty will be partially or totally
void in the event of non-compliance with the
above !
2)
Do not power ON the
darTZeel NHB-108
model one
when no loudspeaker is hooked to
the
Speaker Terminals (6).
In such a case the internal fuses could be blown
by the Crowbar circuit, especially if the DC
compensation offset has been disabled.
3)
Before connecting or disconnecting the audio
cables to/from the
RCA (5)
or
XLR (7)
inputs,
always flip, when possible, the
Input Impedance
Selector (9)
onto "
Zeel
50
Ω
" position. You will
thus avoid any of the resulting parasitic clicks
and bumps.
