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Musical Fidelity A1 Integrated Amplifier

Musical Fidelity A1 Integrated Amplifier

Regular price £1,499.00 GBP
Regular price Sale price £1,499.00 GBP
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The original A1 was, I think it’s fair to say, an icon. It was a design launched in 1985 that had futuristic looks that were in part a necessity due to the unusual design choice of output stage, with the entire ‘lid’ acting as the heatsink. The circuit was penned by the late Tim de Paravicini and was a solid state pure class A design, which was, and still is, something of a rarity due to the low power output and high heat generation. In essence, a pure class A design biases the output devices to be ‘on’ all the time, this removes crossover distortion and leads to the unusual trait that they actually run (slightly) cooler when playing music than when silent! It is the holy grail topology for many of us, and is one of the reasons we love valve amplifiers so much, as they generally lend themselves to this much better than transistors.

The 1980s were a time where speaker efficiencies were plummeting and power outputs skyrocketing, so producing an amplifier that generated ‘just’ 30 watts was a brave move in dark times, especially one where the custom metal work must have cost an absolute fortune to tool up for. It was however a great commercial success, and even now we look after many of the surviving originals as there’s still not much like them. Or should I say wasn’t much like them, as there is now a homage available. 

You can easily be forgiven for mistaking the for the original, the appearance really is very similar and just as timeless as ever. The heat is very similar too - it’s supposed to run cooler, but we’re not so sure having compared the old and new one side by side, it’s certainly still rather toasty and would benefit from a bit of open space around it, and is claimed to produce 25 watts in pure class A. The new casework is slightly larger, but not so you’d notice without the two being side by side.

Inside there is now split secondaries on the mains transformer to improve channel separation, and the power supply is uprated over the original. The true to original pre amp stage can be bypassed with the ‘Direct’ button, which moves the design over to a more contemporary passive input stage, this knocks 10dB off the overall gain, and to our ear improves the sound along with giving a more usable range of the volume control. A remote volume control is a welcome addition and the potentiometer is a high quality Alps one, removing one of the weaknesses of the original design.

A switchable MM and MC phono stage is included, made with discrete parts (not opamps).

Not only does it look very similar, it sounds it too - this is really a remarkably faithful reproduction considering the time elapsed. It has a similar sweet and natural presentation that will familiar to anyone that knows the original. If you’re looking for a punchy sound then there are other Musical Fidelity products to consider, but that misses the point of the A1, with its refined, smooth and fluid sound being faithfully recaptured and in some respects enhancing the original and making it something of an outlier in the often samey world of transistor amplifiers.

Specifications:
-POWER OUTPUT (8Ω) 25 W
-AMPLIFIER VOLTAGE OUTPUT 42.5V Peak to Peak
-AMPLIFIER CURRENT OUTPUT 25A Peak to Peak
-OUTPUT DEVICES 2 per-channel
-CHANNEL SEPARATION 85 dB
-DAMPING FACTOR 150
-SIGNAL TO NOISE RATIO 82 dB
-THD +N Typical < 0.05 %
-PHONO INPUT MM and MC Input
-PHONO STAGE IMPEDANCE (MM) 50 kΩ
-PHONO STAGE IMPEDANCE (MC) 1000 Ω
-PHONO INPUT GAIN (MM) 40 dB
-PHONO STAGE GAIN (MC) 60 dB
-RCA LINE INPUT(S) 5 Stereo RCA Pair
-FIXED ANALOGUE OUTPUT(S) 1 x RCA Pair
-VARIABLE ANALOGUE OUTPUT(S) 1 x RCA Pair
-MAXIMUM POWER CONSUMPTION 130 W
-DIMENSIONS (W X H X D) 440 x 68.3 x 283.3 mm
-WEIGHT 10.5 kg
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