Audio Note M3 Line - Manual (Page 6)

Congratulations on your purchase of the Audio Note (UK) M3 Line 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 M3 Line 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
minimising 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
ʻperfect measured responseʼ.
As a result, the M3 Line was designed for maximum linearity and minimum transient
distortion, and avoids the need for detrimental ʻcorrectiveʼ measures, such as
inherently error-prone feedback loops.
The M3 Line Pre Amplifier features an ECC82 and 5687WB line stage, and uses a
6X5 valve rectified power supply based on the M10ʼs Galahad PSU. Audio Note (UK)
copper wiring, a mix of Beyshlag and Audio Note tantalum resistors, SILMIC filter
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)
copper wound output transformers. The M3 Line also has a correctly designed and
implemented balanced output circuit.
Rather than using separate controls for volume and balance, the M3 Line 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.
M3 LINE PRE AMPLIFIER