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.
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.
The low noise preamplifier circuitry is the same as the original 1985 design and, as we have highlighted above, greatly benefits from the improved, fully smoothed and regulated power supplies.
Among the discernible alterations, one that immediately catches the eye is the addition of a new direct switch at the preamp stage. With this switch you can totally bypass the gain block before the volume control, resulting in roughly 10dB less gain. This feature proves particularly advantageous when working with modern or high-output digital sources, enabling fine tuning the range of your volume potentiometer and accommodating sensitive loudspeakers.
Furthermore, a notable upgrade has been made to the volume potentiometer itself, now replaced by a premium ALPS RK series potentiometer. This high-quality component ensures superior performance and enhanced precision. Additionally, the potentiometer is now motorized, granting you the convenience of adjusting the volume from the comfort of your couch, courtesy of the new included remote control.
The A1 employs a discrete current-mode input stage for lowest noise amplification of MC and MM cartridges. A low noise current to voltage conversion stage is used for further amplification and RIAA equalization. Automatic input impedance matching for the selected MC input, along with increased gain increases the versatility of the A1's phono stage.
The A1 has a sweet, warm, full and exciting sound. No harshness. No grain. Just pure music. It doesn't get muddy, and despite its lower power, drives difficult speakers with ease. It remains clean right up to its power limit. To hear what the A1 does is to hear what Hi-Fi is supposed to do: it makes music, pure and simple.
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 RIAA response: +/- 1dB
MM sensitivity: 5mV nominal
MM capacitance / impedance / gain: 100pF / 50k Ohms / 40dB
MM signal / noise ratio: 75dB
MC sensitivity: 450uV nominal
MC impedance / gain: 1k Ohm / 60dB
MC signal / noise ratio: 70dB
1x phono RCA MM/MC, 5x line RCA
1 x line level RCA fix TAPE OUT
1 x line level RCA var PRE OUT
1 x 4mm banana/binding posts SPEAKER OUT
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)