MUSICAL FIDELITY A1

Integrated class A amplifier. Power 2x25W into 8ohm. Discrete symmetric circuit topology. Low noise JFET preamplifier stage. Selected, high-level components. Polypropylene capacitors and metal film resistors. Alps volume potentiometer. Toroidal transformer with dual mono windings and independent power stages for the left and right channels. 5 RCA line inputs. Phono MM/MC input. Pre out output. Remote control.

Amplification

Discrete symmetric topology, for unique sound and dynamics

25W of pure class A power into 8 Ohms

Planar audio transistors with a maximum output current of 25°

Dynamic Class A, if the quiescent current is exceeded, another one is automatically added. In any case it never switches to class B, but only shifts for the period necessary to drive demanding speakers without problems

Supply

Updated transformer, with separate “dual mono” windings for better efficiency (in the 1988 model they were shared)

Separate and completely independent power supplies for the left and right channels, for better management of power and stereo image

Each power stage today has double power supply capacity, resulting in reduced ripple and noise, benefiting performance

The noise and heat dissipation of the transformer are reduced due to its improved efficiency and the use of upgraded components

The main power supply is filtered for better regulation and to reduce overcurrents at start-up

Preamplification

The gain stage before the volume, completely by-passable with the direct button (-10dB)

The RK series volume potentiometer from Alps, updated and of higher quality

JFET preamp stage, same design with TL071 used in the 1980s

Filtered and regulated power supply for the lowest possible noise

Phono Stadium

Discrete current input stage, to better amplify the MC and MM cartridges while keeping the noise low

Low noise current/voltage converter for RIAA equalization

Automatic selection of input impedance (1K nominal) for MC cartridges, resulting in gain optimization

Characteristics

Aesthetics and circuitry faithful to the original A1 (1988) with modern improvements

Adding remote control for volume only

Updated components all with low noise impact

Improvements over the original 1988 model

The efficiency of the transformer, with separate “dual mono” windings

The RK series volume potentiometer from Alps, updated and of higher quality

The gain stage before the volume, completely by-passable with the direct button (-10dB)

All transistors, including those in the output stage, are carefully selected modern equivalents

All capacitors on the signal path are made of polypropylene (PP)

The resistors are metal film and low noise

Particular attention was paid not to modify the technical specifications of the components used, compared to the originals, but to update them with equivalent models with greater reliability and durability

The layout of the boards also faithfully follows the original, with the same separate circuit sections

Some circuits have been better laid out, in particular the separate power supply areas and final power stages

Additionally, the phono stage and preamp sections have been improved to reduce noise and hum.

The remote control was introduced, not included in the 1988 model