Audio Note M5 Phono Signature - Manual (Page 6)

Congratulations on your purchase of the Audio Note (UK) M5 Phono Signature Pre
Amplifier.
It has been specifically engineered for sonic performance rather than technical
specification, and fulfills all Audio Note (UK) Level 3 criteria: -
Pure Class A operation
Zero negative feedback
Single Ended circuit topology
Valve rectification
Materials and component quality
It is well known that the accurate reproduction of music, not just sound, requires the
purity of the incoming signal to be preserved. It is therefore not difficult to conclude
that, in order to achieve this goal and to retain the musicality of the original
performance, the complexity of the circuitry itself must be kept to a minimum.
In response to this, the M5 Phono Signature Pre Amplifier uses a single-ended, zero
feedback circuit topology. This is simply the most linear design possible, demanding
pure Class A valve operation and removing the need for a phase splitter, which
introduces unnecessary crossover distortion.
In contrast to the majority of the audio industry, we design our circuits with the aim of
minimizing non-harmonic and time base anomalies, rather than producing
vanishingly small harmonic or low intermodulation distortion measurements. These
non-harmonic amplitude and time base distortions have a highly perceptible and
adverse affect on the signal waveform, and it is far more important to address these
factors than participate in the increasingly irrelevant numbers game that chases
‘perfect measured response’.
As a result, the M5 Phono Signature was designed for maximum linearity and
minimum transient distortion, and avoids the need for detrimental ‘corrective’
measures, such as inherently error-prone feedback loops.
The M5 Phono Signature Pre Amplifier features an ECC82 and 5687 line stage, and
uses a 6X5 valve rectified power supply based on the M10’s Galahad PSU. This
power supply also incorporates an ECL82 for voltage regulation and an OB2 as a
voltage stabilizer. Audio Note (UK) Copper wiring, tantalum resistors, SILMIC
capacitors and Audio Note (UK) copper foil signal capacitors are used throughout the
circuit, along with in-house designed and manufactured, custom Audio Note (UK)
output transformers which feature IHiB c-cores and copper windings. The M5 Phono
Signature also has a correctly designed and implemented balanced output circuit.
Additionally, it incorporates an exceptionally fine Moving Magnet phonostage which
uses three GE 6072a / 12AY7 valves, Audio Note (UK) copper foil signal capacitors
and its own dedicated, valve regulated and rectified power supply.
Rather than using separate controls for volume and balance, the M5 Phono
Signature is equipped with a dedicated Audio Note (UK) stepped attenuator for each
channel. This not only brings the enormous improvements in sound quality expected
from the now legendary Audio Note (UK) stepped attenuators, but also provides a
level of channel balance accuracy that is impossible to achieve with conventional
volume and balance potentiometers.
M5 PHONO SIGNATURE PRE AMPLIFIER