darTZeel Audio NHB-108 - Manual (Page 6)

darTZeel NHB-108 model one Audiophile's technical manual Page 6 of 28
later, new ICs allowed further investiga-
tion, and we built several prototypes. We
quickly noted, however, that digital had
some limits when pushed hard.
We used a sample frequency of 500 kHz
at the time, corresponding to a theoreti-
cal bandwidth close to 250 kHz, far
higher than all competitors, even in the
analog domain. But – alas – even with
such a high sample frequency, the actual
measured bandwidth was strongly de-
pendant on the loudspeaker impedance.
Another problem, jitter, already well
known in labs at the time, was difficult to
cure, to say the least. The signal to noise
ratio was just above our minimum crite-
rion.
Since pure sound was the only goal, then
noise, if at acceptable level, could have
been tolerated by us. On the other hand,
interdependence between load imped-
ance and frequency response was not
our cup of tea. Not by a long chalk.
End of the digital trip.
It is interesting to note that several
manufacturers offer digital amplifiers,
with greater or lesser success. The theo-
retical limits remain the same, even if
better managed than in the '80s. Analog
fortunately does not have to cope with
such limitations.
After several months of deep thinking,
circuit designing, and circle squaring at-
tempts, the project was revived (in
1990) on brand new bases. The gear
would be fully analog, moderately pow-
erful, and as close as possible, philoso-
phically speaking, to the signal treat-
ment used in its digital ancestor.
Two new prototypes were built on the
basis of existing designs; even though
heavily modified to suit our tastes, they
produced unexciting results. Then we
asked ourselves what is the point of pro-
ducing nice looking gear if the sonics
bring nothing new under the sun?
In 1992, we decided to develop a revolu-
tionary design from scratch. This ulti-
mate quest (for ultimate sound) lasted
over 5 years, with more disappointment
than joy. But the fun was always here.
Countless schematics were studied, scru-
tinized and hooked together until we
obtained, in mid 1995, what we could
tained, in mid 1995, what we could call
the first theoretical design corresponding
to our aims.
From 1995 to 1999, on that first elemen-
tary circuit basis, dozens of different
versions were simulated, some of them
being built and listened to.
By 11 November 1999 the definitive cir-
cuit was built and assembled. This was
the very first darTZeel machine, the NHB-
108 model zero.
The results, sonically speaking, were
outstandingly better than expected. It
seems that this design was the right one.
So much so that most of our test listen-
ers said that this product must be put
into production, even on a very small
scale.
The darTZeel NHB-108 model one was born.
3. Criteria
Your darTZeel NHB-108 model one is not an
ordinary machine and this is no doubt
one of the reasons why you purchased it.
The entire concept is based on just three
criteria:
- Simplicity
- Purity
- Reliability
These words can often be deceptive.
Easy to pronounce, conjuring up ele-
gance and fascination, they nevertheless
constitute very tough technical chal-
lenges, since their respective meanings
are not at all easy to reconcile.
Nothing is eternal. As for the darTZeel
NHB-108 model one, not enough time has
yet elapsed for us to assert such a claim.
What we do assert is that everything has
been taken into account so that you can
benefit from your machine for a long
time. A very long time.
You will discover that more often than
not, simplicity means long lasting.
Sometimes, it also means purity,
whether of sound or of form.
Welcome to darTZeel.