The Audio Note (UK) M2 Pre Amplifier has been specifically engineered for sonic performance rather than technical specification, and fulfils all Audio Note (UK) Level 2 criteria: –

Pure Class A operation
Zero negative feedback
Single Ended circuit topology
Valve rectification
Materials and component quality
​
The M2 Line and M2 Phone are phase inverting.

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 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 „perfect measured response‟.

As a result, the M2 was designed for maximum linearity and minimum transient distortion, and avoids the need for detrimental „corrective‟ measures, such as inherently error-prone feedback loops.