Audio Valve Baldur 70 Owners manual
Class-A triode amplifier
OWNERS MANUAL
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List of contents
Page
PART 1 - Overview
1. The BALDUR 70 - silver and black 3
2. Introduction to AudioValve 4
3. Background to the BALDUR 70 5
4. The 6AS7G Valve and ABR circuit 5
5. The PCB 6
PART 2 Instruction Manual
1. Warnings and precautions 7
2. Unpacking & set-up 7
3. Connection 8
- To mains power
- To/From Pre-amp (or other source)
- To Loudspeakers
9
10
10
4. Operation 11
- Power Switch
- Operate Switch
- First Start-up
- Day-to-day Operation
11
11
12
12
5. Changing Power Valves 12
- IMPORTANT safety warning
- Automatic Bias Regulator - function & interpretation
12
12
6. Technical Data 14
7. Warranty 15
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Congratulations on your decision to become the owner of the Aud
ioValve
manual has been prepared to
help you understand the operation of your amplifier and to provide some
BALDUR 70 class-A triode power amplifier. This
information about its design and the variety of ways in which it may be used.
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PART 1 OVERVIEW
roducts are designed by Helmut Becker and feature
advanced, modern circuitry, combined with the warm sweet sound of
valves. Now it is no longer necessary to sacrifice one to get the other.
cut steel, every
amplifier we manufacture utilises double sided PC boards
lators to ensure a continuously uniform current flow
to and a perfect match between all the valves throughout their entire life,
Unlike other valve amplifiers, where a certain amount of guesswork and
erience is required to know when valves need to be replaced, with
AudioValve amplifiers not only do valves not have to be removed
prematurely (prior to burn out), but when burnt out does occur, only the bad
tomatically adjust and
AudioValve amplifiers always deliver nothing but the most advanced,
economical, high quality valve sound. Power output valves in most models
ong several different types with no modifications to the
units, so that an appreciable degree of sonic system matching and user
preference may be accommodated. No matter what combination of valves
ll experience at all
times the balanced and coherent sound of amplifiers working with brand
new, perfectly matched valves. The bonus is that there is never any need to
use a meter or screwdriver to adjust bias on any valve in any condition of
bias circuitry is the best and most
We
have designed and manufactured this power amplifier to faithfully and
h quality of components used and
that
you will enjoy the superb audio performance and pride of ownership,
1. Introduction to AudioValve
All AudioValve p
Combining the finest in modern valve technology with sophisticated smartbias circuitry, AudioValve brings you the best of both worlds - and more.
With contemporarily-styled chassis built from 4 & 5 mm laseramplifier and preand automatic bias regu
even as the various valves decay at different rates.
exp
valves need to be replaced. The amplifier will au
distribute the total current flow to optimally match the new configuration.
may be varied am
one uses (differing valves, new valves, old valves), one wi
operation. AudioValves smart unobtrusive available!
The BALDUR 70 power amplifier represents exceptional value for money.
accurately reproduce music. The hig
advanced valve operational principles employed in this design ensures
inherent in such a hand-crafted product as this, for many years to come.
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2. Background to the BALDUR 70
Las Vegas AudioValves customers and dealers
made it abundantly clear that there was a requirement for a smaller version
ce as
A triode monoblock
was rapid with its world
Germany later the same
achieves within a whisker the ideal that the customers and dealers
wanted. As you rarely, if ever, get something for nothing, some compromises
complement of 6AS7G valves of the 200 plus
still more than
enough power to satisfy the vast majority of users and at a significantly lower
00 of the BALDUR 200
Nevertheless, this is a class leading
performance, as the damping factor of competing valve amplifiers is not
their strongest feature. This combination of power and damping factor
appy driving a wide range of loudspeakers
whether dynamic, electrostatic or hybrid types. The high damping factor
ensures strong, clean, taut and sharply outlined bass accompanied by a
There is a clear family resemblance in the appearance of the two BALDURs.
The 70 incorporates all of the design and constructional elements of its
eliability,
durability, low maintenance and ease of use that are familiar to all owners of
AudioValve products since the first amplifier, the RKV, was launched over 20
de power output valves. This valve
was first used in the BALDUR 100 and is also used in the current BALDUR 200
plus. The 6AS7G is an exceptionally high performance triode when it is
conventional biasing circuit. As a consequence the valve is rarely used and
current to the valve. Any such adjustment can only be optimum for an
instant as valves, even selected ones or a matched set, cannot hold a
consistency of performance in the long term. Each valve will deteriorate
rily in the same way as others in that
set. A matched pair or quad will therefore only remain matched for a
In 2003 at the CES show in
of the BALDUR 200 plus. Ideally this would offer the same sonic excellen
the 200 plus but in a smaller, less expensive package.
AudioValves answer was the baby BALDUR 70 Classpower amplifier. The development of a baby BALDUR
premiere being at the High-End-Show in Frankfurtyear! It
had to be made, but these were surprisingly few.
The BALDUR 70 uses half the
which in turn halves power output to 75 watts per channel -
cost!
Damping factor is also reduced from the amazing 1
plus to 20 for the BALDUR 70.
means the BALDUR 70 is h
broad, deep soundstage and delicate, velvety highs that can only be
obtained from pure triodes amplification.
bigger brother and retains the Audio Valve hallmarks of safety, r
years ago.
3. The 6AS7G Valve and ABR circuit
The BALDUR 70 uses four 6AS7G dual trio
working optimally. However there are too many adjustments that need to be
carried out for optimum performance to be maintained over time using a
is relatively inexpensive.
Traditionally, valve biasing is performed with a screwdriver to adjust the bias
individually and, if in a set, not necessa
relatively short period of time!
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