Audio Note M5 Phono - Manual (Page 6)

Congratulations on your purchase of the Audio Note (UK) M5 Phono 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 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 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 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 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 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 PRE AMPLIFIER