Musical Fidelity A1 Black

In Hi-Fi, the Musical Fidelity A1 has become one of the most classic designs " inside and out. First released back in 1985, it quickly made waves for being an absolute beast when it came down to driving some of the most difficult speakers of that time, even though it was actually a rather low powered integrated amplifier. But: it was all done in pure Class A with excellent and expertly laid out discrete symmetrical circuitry topology and using only highest quality components. The A1 showed people that there was more to amplifiers than just high power.

Based on its huge success, the A1 has gone through multiple reissues and new versions over the years.

Now for 2023, for the first time since its initial release we have actually kept all specifications, the appearance and circuits of the 1985 rendition for those who missed out the first time. With an updated transformer, power supplies and modern low noise components we've revitalized the formula and are proud to reintroduce the fresh original " three decades later.

Technical Talk The A1 is built around a completely discrete and symmetrical Class A topology. It‘s able to output 25W of pure Class A power @ 8 ohms load with 25A of maximum output. While the numbers here might seem rather low, the ability for the output stage to drive difficult speakers is a small miracle in itself. The amp design being dynamic class A, and if Class A standing current is exceeded, it will automatically allow more. It therefore "slides" (NOT "switches") smoothly into class B style operation, temporarily allowing the further current draw needed.

Power Supply The new A1 has received an updated transformer from shared (1985 original) to more efficient "dual mono split rail" windings. The amp stages are supplied by fully independent left and right power supplies for better power handling and stereo imaging and each power amplifier now has double supply capacity resulting in reduced ripple and noise.

The transformer‘s noise and heat dissipation are reduced due to better efficiency and updated components. The main supplies are filtered for better regulation and reduced switch on surge.

• 25W Pure Class A power @ 8 Ohm

• Discrete symmetrical topology

• Planar Audio transistors with 25A maximum output

• Dynamic class A, slides (NOT switches) smoothly into Class B, allowing more current as needed

• Therefore drives difficult speakers with no problems

• Updated transformer to "dual mono split rail" windings

• Fully independent left and right power supplies

• Each power amplifier now has double supply capacity

• Transformer noise and heat dissipation reduced

• Filtered main supplies

• Gain block before volume control totally bypassable using "direct" switch

• High quality and updated ALPS RK series potentiometer

• Low noise TL071 JFET preamplifier circuitry

• Discrete current-mode MM/MC phono input stage

• Low noise current to voltage converter for further amplification and RIAA equalisation

• Automatic input impedance matching (1K nominal) for MC along with increased gain

• Original (1985) A1 appearance and circuits with modern improvements

• Remote control added for volume

• Modern updated low noise components

AMPLIFIER:

Power: 25 Watts per channel into 8 Ohms

Voltage: 42.5 Volts peak to peak

Current: 25 Amps peak to peak

Damping Factor: 150

Gain (volume max): 32dB (Direct Mode), 42dB (Normal Mode)

Output devices: 2 per channel

Signal / noise ratio: 82dB

Channel separation: 85dB

Frequency response: + 0, "1dB, 10Hz to 40 kHz

Line level sensitivity: 300mV rms nominal, 8V rms max

Line level inputs impedance: 25k Ohms

Tape Out impedance: 220 Ohms

Pre Out impedance: 100 Ohms

PHONO PREAMP:

Phono RIAA response: +/- 1dB

MM sensitivity: 5mV nominal

MM capacitance / impedance / gain: 100pF / 50k Ohms / 40dB

MM signal / noise ratio: 75dB

MC sensitivity: 450μV nominal

MC impedance / gain: 1k Ohm / 60dB

MC signal / noise ratio: 70dB

Inputs: 1x phono RCA MM/MC, 5x line RCA

Outputs:

• 1 x line level RCA fix TAPE OUT

• 1 x line level RCA var PRE OUT

• 1 x 4mm banana/binding posts SPEAKER OUT

GENERAL INFORMATION:

Dimensions (WxHxD): 440 x 68.3 x 283.3 mm

Main voltages: 230V/115V Internally set or 100V optional

Max. Consumption: 130W, 0W in standby (=Power Switch OFF)