The Audio Note (UK) M6 preamplifier has been specifically engineered for sonic performance rather than technical specification, and fulfils all Audio Note (UK) Level 4 criteria: –
Pure Class A operation
Zero negative feedback
Single Ended circuit topology
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 M6 Line 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.
https://www.audionote.co.uk/m6 for details.