Any Audio Amplifier is only as good as its power supply. This old truism has been said often, but is actually true.
An amplifier circuit of any kind does NOT really amplify the signal in the strictest sense of the word. Rather, it
acts as a signal-controlled valve that lets more or less of the power supply current flow into the following device
(hence the original English name of thermionic electron valve for the first "amplifying" device).
For the lion's share of mainstream audio equipment that employ thermionic electron valve circuitry, the use of
generic solid-state regulators and basic solid-state rectification circuits in the power supply section is prevalent,
often for reasons of cost or apathy or both.
AMR found this approach significantly degraded the sonic performance when compared to supply circuits that
do not use regulation. Instead, extensive multi-stage passive filtering has been employed to keep the supply
lines free from noise. We remain surprised that while regulators should theoretically result in improved sonic performance; in practice, the opposite is true. However, we have to accept facts as we find them.
In order to extract the maximum sonic performance from the thermionic electron valve circuits, AMR developed
the OptiPower®supply. Using extensive multi-stage passive power supply filtering incorporating both choke/capacitor type filters and resistor/capacitor filters, a level of mains noise suppression was attained that significantly exceeded
the most advanced regulator circuits and eliminated noise over the widest frequency range.
Realising that the power supply is in fact the signal, we use in the filter stages driving the actual amplifier circuitry
only the highest quality film capacitors, eschewing inferior electrolytic capacitors in all positions that are critical
to the sound quality. It goes without saying that several chokes and even more high-voltage, large value capacitors (including several film types) cost a good deal more than a handful of silicon chips.
Working in conjunction with AMR's patent-pending OptiMains®power conditioning, any type of regulation in and
around thermionic electron valve circuits has been ingeniously avoided.