Troubleshooting – darTZeel Audio NHB-108 B version User Manual
Page 14
darTZeel NHB-108 model one
User Manual, version B 1.0
Page 14 of 35
8.2. Troubleshooting
While setting up your NHB-108 model one, it is
possible that you may not obtain the desired results.
Hereunder we list the most frequent problems you
are likely to encounter. If the problem cannot be
solved, please do not hesitate to contact us directly
at:
8.2.1. Eyes Closed
The eyes are closed – I beg your pardon, extin-
guished - while the Power Nose (3) button is ON.
Please check that the AC power cord is correctly
connected at both ends, and that the mains AC volt-
age is present. Just test with a table lamp. If AC is
present, it means that both primary fuses have
melted. Please go to point 7.1. "Fuse(s) replace-
ment".
One Eye only is not lit. This means that you have to
change the corresponding channel fuse.
8.2.2. Blinking Eyes
Blinking Eyes indicate that the output DC offset
value has exceeded the permitted limit. If such an
event occurs, please read the following:
A) Eyes blink at cold power ON. If your listening
room is at a temperature below 65°F (18°C),
this could be considered as normal, provided
that this behaviour disappears in the following 3
to 5 minutes.
In a room at a temperature above 65°F (18°C),
blinking eyes indicate that your NHB-108
model one
could do with some tuning. How-
ever, if this behaviour ceases after 3 to 5 minutes,
and especially if you can put up with it, no ad-
justment is mandatory.
B) Eyes blink after several hours, when the ma-
chine is hot, or even very hot. If your room tem-
perature is above 90°F (32°C), this can be con-
sidered as normal behaviour, and normally the
eyes should stop blinking as soon as the ambient
temperature returns to "human being" levels.
Please also check that your darTZeel NHB-108
model one
is properly ventilated, as indicated
in chapter 5.2. "Location" and that you are not
using it at quasi-permanent power clipping lev-
els with 3
Ω loads.
If the ambient temperature is under 90°F (32°C)
but the Eyes blink, your machine needs some
tuning.
To cut a long explanation short, NHB-108's eyes
should not blink in ambient temperature ranges
from 65°F to 90°F (18°C to 32°C). If they do, the
amplifier needs some adjustment.
In all cases it is important to know the working
environment in which you will use your darTZeel
NHB-108 model one
.
If you live at the South Pole or on the Equator, a
slightly different setting could be necessary, espe-
cially when the DC compensation offset is off.
If you need to know more about this topic, can you
guess what? Yes, read the technical section…
8.2.3. Amplifier ON, no sound
Please check first the Eyes’ illumination state, as
described in point 6.2. “darTZeel’s Eyes”.
A) Idle state. No signal is present at the input of
your NHB-108 model one. Be sure that the
source (SACD, CD, Tuner or whatever) is cor-
rectly selected and connected to the preamplifier
feeding your machine.
Please also verify that the Input Impedance
Selector (9) of each channel is not at the upper
position ("Zeel 50
Ω") when you are not using a
darTZeel NHB-18NS
preamplifier.
B) Signal presence. The input source is correctly
connected and routed,
but the loudspeakers are
not hooked to the Speakers Terminals (6)!
We
remind you that this is totally forbidden. Okay,
no trouble for this time. You are lucky enough
that the Crowbar circuit did not melt one fuse or
two…
C) No sound when using XLR inputs. Please check
that the Input Impedance Selector (9) of each
channel is at the lower position ("XLR Bal.").
8.2.4. Warped sound
You are using the RCA input (4), but the Input
Impedance Selector (9) of one or both channels is
in the upper position ("Zeel 50
Ω").
Your present preamplifier not being a darTZeel
(this will change one day), its outputs cannot drive
50
Ω loads.
So please switch the Input Impedance Selector (9)
to "RCA Hi Z" mode (mid position).
8.2.4. Sensitive fuses
Fuses have the bad tendency to melt much too of-
ten. Why, then, not replace them by a higher value
rating?
Please
never, ever
do such a thing!
Improper fuse ratings could produce a
fire!
Please
carefully read the technical section at the end of this