darTZeel NHB-458 User Manual

NHB-458 Monoblock Amplifier

User Manual

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Table of contents

1. Preliminary notes _______________________________________________________ 5

2. Introduction ___________________________________________________________ 5

3. Brief description ________________________________________________________ 5

4. Warranty ______________________________________________________________ 6

5. Installation ____________________________________________________________ 6

5.1. Unpacking _______________________________________________________________________ 6

5.2. Location ________________________________________________________________________ 7

5.3. Connections ______________________________________________________________________ 7

6. The NHB-458 in detail ___________________________________________________ 8

6.1. Front panel ______________________________________________________________________ 8

6.2. Rear panel _______________________________________________________________________ 8

6.2.1 Fuse and voltage settings __________________________________________________________ 9

6.3. Remote control ___________________________________________________________________ 9

7. Activation key procedure ________________________________________________ 10

8. User parameters _______________________________________________________ 10

8.1. Main features ____________________________________________________________________ 10

9. How to set everything ___________________________________________________ 10

9.1. Power-on sequence _______________________________________________________________ 11

10. Full configuration and settings ___________________________________________ 11

11. Some advice and tips ___________________________________________________ 18

11.1. Cleaning and upkeep ____________________________________________________________ 18

11.2. What not to do _________________________________________________________________ 18

12. Assistance ____________________________________________________________ 18

13. Technical data ________________________________________________________ 19

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darTZeel NHB-458 monoblock amplifiers

User Manual

1. Preliminary notes

The NHB-458 cannot be user switched from a
different voltage setting than the one set at factory.
This is an operation that only your authorized dealer
can perform. Any attempt in changing voltage

setting will void the warranty.
Be sure that your AC wall voltage corresponds with

NHB-458s’ factory settings.

Your NHB-458 pair comes with a USB activation
key to provide the required identification data to
your NHB-458‘s internal CPU.

Usually, both monoblocks come already activated to
your name. If it would not be the case, you could use
the provided USB keys in order to program en
eventually unlock them. In such a case please
contact your authorized dealer.

Please refer to chapter 7, “Activation key
procedure” (page 9), for how to obtain your USB
activation-key data file.

Please read this user manual in its entirety.

As it is the darTZeel rule, we did our best to avoid

making you fall asleep. We hope to be successful in
that regard…

While already being pretty impressive out of the
box, your NHB-458 will require about 170 hours of
playing time before it approaches its full potential.

2. Introduction

Congratulations on your purchase of a darTZeel
NHB-458 monoblock pair.

The darTZeel NHB-458 is the most advanced
analogue monoblock amplifier yet designed.

Grace, Delicacy and Power are the words which
describe these musical machines the best.

The NHB-458 is the culmination, in terms of power
amplification, of more than 30 years of true love and
dedication to music reproduction.

Not only NHB-458s do joyfully distillate the
slightest “pianissimi” with unbelievable realism,
they also transpo rt you into the heart of the musical
event, effortlessly reproducing the loudest

“fortissimo” without any kind o f limitation but your
hearing threshold of pain.

Designed for uncompromising musical and
emotional performance, the NHB-458 will
nevertheless give its best when paired with the
darTZeel NHB-18NS, t he only preampli fier in the
world using true 50-ohm matched impedance links
as well as the unique and ultimate analog optical
“zero contact” volume control signal path.

With its fluorescent display, you will ha ve an easy
and comprehensive access to the various operational
menus.

With its ver y conservative ratin gs, the NHB-458 is
comparable to a never ending energy reservoir.
Bench tested at half a kilowatt under 8 ohms in
continuous mode, it can deliver twice this power
when playing music, and eve n much more tha n this
when using 4-o hm speakers.

So, please be careful when you will start to tame
these beasts. A single vinyl crackle can peaks at
more than 300-400 watts because of the
unprecedented speed and dynamics available.
Otorhinolaryngology medical consultation is not
included in the purchase price, so allow for your
hearing some time to adapt.

3. Brief description

Your NHB-458s are the result of all the research
and development we have brought to the audio
industry over the past decades.

Our passion and love for music and its reproduction
have been embodied in the NHB-458s.

The challen ging goals we set for ourselves were to
design and then build a power amplifier with no
sound either built quality compromises.

You are amon g the very few owning a ver y unique
design, and we at darTZeel are very proud to share
this experience wit h yo u.

The entirely newly-developed audio circuits will
drive any real-world load in a breeze, transfo rming
your loudspeakers into a new window open to the
music, anyhow they previously sounded so far.

With the NHB-458s’ more than 450 watts RMS into
8 ohms, and 750 watts RMS into 4 ohms, even low-

darTZeel NHB-458 User Manual, version 1.0 Page 6 of 19

sensitivity speakers will put out plenty of volume
during your most demanding – dynamically
speaking – listening sessions. When it comes to
music reproduction, power is not needed in a
sustained way; the n enters t he pheno menal dyna mic
power reserve.

Thanks to the huge 750 joules of energy available
from the enormous capacitor reservoir, short but
repetitive peaks in excess of 1 kW – yes, more than
1,000 watts – are delivered in a very clean way, and
much faster than the time of an eye blin k – here we
mean a standard, human eye…

From the technical point of view, there is no doubt
that the NHB-458 is a very special machine. Every
single part was carefully selected, from the first
resistor to the last power output transistor .

Adding to t he beauty, i n those “green” days, we are
proud to say the NHB-458 actually runs very c ool,
saving on your electrical bill.

Needless to say those extraordinary performances
deserve an e quivalent out standing dres sing. We use
our own al uminum alloy, mad e from custom made
extrusion forms, and then both finishing and
anodizing are performed by real artwork craftsmen.

When assembly time comes, our dedicated crew
lovely assembles every module day after day until
final comple tion; then our asse mbly chief engineer
carefully looks for irreproachable making before
bringing the NHB-458 onto the final 3-days bench
test.

This is why you waited so long in getting your
darTZeel NHB-458 monoblock power amplifiers.
Not that we like to make our esteemed customers
waiting for months but simply because love is also
lot of pain and efforts to cope with, needing time t o
smooth everything down.

We are indeed very proud to say that our “Never
Heard Before” motto plenty takes place when one

talks about NHB-458 monoblock power amplifiers.
As for the mos t imp or tant t hi ng yo u can as k for, and

we obviousl y mean the music, you will simpl y find
them… Enthralling.

4. Warranty

Your NHB-458s are guaranteed for one full year (parts
and labor), against any breakdown or component
failure, as is the tradition in Switzerland for such
equipment.

As we view it, any electrical component with no
moving parts either will fail within days, or will last
virtually “forever.”

This is the re ason all our machines a re thoroughly
tested and b roken in, before b eing lovingly packed
and sent on to you.

We are nonetheless aware that no component is
always flawless, and that a problem could arise after
the expiration of the warranty period.

In such a case, we will carefully examine all the
circumstances, with the aim of reducing the likely
repair costs to minimum levels.

You can always trust us for customer care, as you
already trust ed us when purchasing your NHB-458s.

The warranty is valid in the original country of
purchase only.

The warranty is transferable to a single second-hand
user within the first year, but only in the original
country of purchase.

5. Installation

5.1. Unpacking

Your NHB-458s are delivered in an industrial
wooden crate. We understand this is the less
appealing pa rt o f t he pa cka ge; ho wever it i s t he o nl y
way we found to safely ship your 70 kg/each
emotional music reproducers.

Hopefully you will no t ha ve t o b othe r unpa cki ng the
darTZeel NHB-458 monoblock power amplifiers;
your authorized dealer will be very happy doing this
for you, taking a chance to admire them while
installing. A separate sheet i s nevertheless provided
in order to explain how to proceed, in case you
would secretly want to install your machines by
yourself, during a dark, moonless night.

Please note that in case of future shipping, the
original crate must be used if you wa nt to avoi d any
possible damage.

Do no forget securing the po wer supply susp ension
screws before shipping. Any shipping damage will
not be covered by the warranty if blocking screws
are not installed.

The wooden crates should contain:

• Two NHB-458 monoblocks amplifiers

• Two USB keys

• Eight golden plated screws

• Eight suspension securing screws

• Two AC power cables

• This user manual