Musical Fidelity A

Musical Fidelity: Integrated A1 amplifier

Amplification

• Symmetrical discrete topology, for unique sound and dynamics
• 25W pure class A power on 8 Ohm
• Planary audio transistors with maximum output current of 25°
• Class A dynamic, if the rest current is exceeded, automatically another is added. However, it never switches in class B, but moves only for the period necessary to fly without any problem challenging speakers

Power supply

• Updated transformer, with separate “dual mono” windings for better efficiency (in the 1988 model they were shared)
• Separate and completely independent power supply for right and left channels, for better management of power and sterephonic image
• Each power stage, today, has a dual power capacity, resulting in reduced ripple and noise, for benefit of performance
• The noise and heat dissipation of the transformer are reduced thanks to its best efficiency and the use of updated components
• The main power supply is filtered for better regulation and for reduction of overcurrent to ignition

Preamping

• The gain stage before volume, completely by passable with the direct button (-10dB)
• The volume potentiometer of the Alps RK series, updated and of higher quality
• Preamping Stadium in JFET, the same design with TL071 used in the 1980s
• Filtered and regulated power supply for as little noise as possible

Stadio Fono

• DC input stage, to better amplify, keeping low noise, MC and MM cartridges
• Low noise current/voltage converter for RIAA equalization
• Automatic selection of input impedance (1K nominal) for MC heads, resulting in gain optimization

Description

• Aesthetics and circuitry faithful to the original A1 (1988) with modern key improvements
• Adding the remote control exclusively for volume
• Updated components all with low noise impact

Improvements to the original 1988 model

• The efficiency of the transformer, with separate “dual mono” windings
• The volume potentiometer of the Alps RK series, updated and of higher quality
• The gain stage before volume, completely by passable with the direct button (-10dB)
• All transistors, including those of the output stage, are carefully selected modern equivalents
• All capacitors on the signal path are polypropylene (PP)
• The resistors are metal and low noise film
• Special attention has been paid not to modify the technical specifications of the components used, compared to the original ones, but to update them with equivalent models and greater reliability and durability
• The layout of the cards also faithfully follows the original, with the same separate circuit sections
• Some circuits have been better arranged, especially separate power zones and final stages of power
• In addition the sections of the phono stage and preamplification stage have been improved to reduce noise and buzz
• The remote control was introduced, not included in the 1988 model