T+A M 10, Руководство пользователя

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Circuit design
The  M10 features an overall circuit design which is
unique in the world: all the voltage amplification is
carried out with the help of valves (tubes), and all the
valves operate in Class A mode, resulting in a superbly
harmonious sound image. The input stage takes the
form of a symmetrical differential amplifier based on an
all-valve cascode circuit. The subsequent voltage
amplifier stage features two parallel-wired 6SN7 valve
systems with high cross-flow, which enables it to drive
the following current amplifier stages with very low
resistance. The result is that the whole amplifier offers
excellent bandwidth and speed.
The current amplifier stages at the input end feature
MOS-FET driver transistors, whose response curves
harmonise superbly with the 6SN7 triodes. At the output
end the current amplifiers are equipped with no fewer
than twenty extremely high-performance ring emitter bi-
polar transistors. These transistors satisfy the most
demanding requirements in terms of current delivery
capability and bandwidth.
All the amplifier stages of the M10 are designed in such
a way that they are totally linear and undistorted in
operation. Achieving this performance required the use
of nothing but the best possible components; these
parts are carefully matched to each other and calibrated
in-house for each machine using sophisticated selection
processes.
The level of linearity and bandwidth achieved with the
M10 is so high that it has been possible to avoid the
use of overall negative feedback completely.
Double output amplifier –
bi-amping
Another special and unique feature of the M10 is the
duplication of the output current amplifier (power
amplifier). Each of these output amplifiers is connected
to a pair of loudspeaker terminals. The two output
amplifiers are normally wired in parallel in order to
increase current delivery capability. In HighCurrent
operation mode (see below) the two output amplifiers
can be switched to bi-amping mode. In conjunction with
loudspeakers with bi-wiring terminals the bass and
mid/high frequency circuits of the speakers can be
driven separately.
Even if the loudspeaker connected to the amplifier is
not fitted with bi-wiring / bi-amping terminals, the two
loudspeaker outputs can still be connected to the
loudspeaker terminals using separate cables. In this
wiring arrangement all the internal and external speaker
leads are wired in parallel, and all four loudspeaker
relays present in the
M10 also operate in parallel. This
results in extremely low dynamic internal resistance,
and optimum damping for the loudspeaker. The
outcome is excellent control of speaker cone travel,
maximum possible control in the bass range, and
superb detail resolution in music reproduction.
Mains section
The M10 features a total of three independent mains
power supply units with three high-quality torroidal
transformers with low leakage fields. A high-voltage
mains section with extremely sophisticated stabilisation
measures powers the valve circuits of the voltage
amplifier section. The constancy of the valve operating
voltages is better than 10 ppm!
The two power amplifiers are fed by two high-perfor-
mance transformers, each rated at 1000 Watts, and
with a total reservoir capacity of more than 180,000 µF.
This guarantees more than adequate power reserves at
any time, capable of coping with any imaginable load
situation. Another truly unique feature is the facility to
switch the operating voltage of the
M10 output stages
between the values +/- 50 V (High Current mode) and
+/- 100 V (High Power mode). Selecting the lower
operating voltage more than doubles the idle current in
the output stages, with the result that the current
amplifiers of the
M10 generate up to about 40 Watts in
Class A mode. We particularly recommend this
High Current mode of operation if your system features
high-efficiency loudspeakers, and for general listening
at normal volume levels.
The High Power mode enables the amplifier to generate
a maximum output of well over 1500 Watts (into 2
Ω ).
This mode of operation is especially recommended for
use with high-impedance loudspeakers (impedance
higher than 6 Ohm), and for general use when high
power is required.
Protective circuit
The M10 features a micro-processor controlled
protective circuit which shields the amplifier itself, and -
wherever possible - the connected loudspeakers, from
damage.
The protective circuit monitors the mains voltage, the
internal operating voltages and the operating temperature
of the
M10 . The loudspeaker outputs are also
monitored for D.C. voltage errors, short-circuit and
overload situations.
If overloading or a malfunction occurs, the protective
circuit instantly switches the loudspeaker outputs off. At
the same time the operating voltages and idle currents
are reduced in order to promote rapid cooling. As soon
as all the operating parameters have returned to the
permissible range, the
M10 switches itself on again,
and operating voltages and idle currents are re-adjusted
to optimum values for high-quality sound.