Audio Note M2 Line - Manual (Page 6)

Congratulations on your purchase of the Audio Note (UK) M2 Line Pre Amplifier.
It has been specifically engineered for sonic performance rather than technical
specification, and fulfills all Audio Note (UK) Level 2 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 M2 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 M2 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 M2 Line Pre Amplifier features a
6SN7 line stage and a valve rectified power
supply incorporating a 6X5 and an ECL82.
M2 LINE PRE AMPLIFIER