Musical Fidelity A1 - Introduction:

The A1 was a somewhat controversial design from Musical Fidelity, originally launched in 1984 and produced until the early 90's. Some people even call it a 'classic'.

The distinctive top cover is used as a heat sink and typically runs at 55-60°C - too hot to touch for more than a few seconds. While they don't claim it outright, Musical Fidelity would let you believe that this is a Class A design. However, in common with most commercial amplifiers, it is a class AB amplifier - it simply has a rather high standing current in the output stage, which results in the first 8 watts or so being class A.

It does have a certain 'sound' that has earned it praise over the years, but whether or not this can be attributed to the alleged class-A operation is open to debate. It is undeniably coloured - some reviews draw comparison with valved equipment.

Objectively, it has a generous power supply, uses some decent quality components and is quite well-made. Reliability is a thorny issue, as there was no shortage of failures over the years. Facilities are minimal - you get an input selector and a volume control - apart from the power and tape-monitor switches, that's it. No other facilities are included - no tone or balance controls, no headphone socket or loudspeaker switching and don't even ask about remote control...

You don't even get much of a manual for your money - a single sheet of A4 folded in half... Click on the thumbnails below to view on screen. Alternatively, download both sides of the sheet in this 490KB zip file and print out your own copy on A4...

Please note: The copyright of this manual belongs to Musical Fidelity, and while I believe that the inclusion here constitutes fair usage given the historical value, please be aware that it may be removed at any time.

Model History:

This section is sorely lacking, as I only own one example! From old magazines and the booklet that Musical Fidelity included in Hi-Fi News a couple of years ago, I've been able to put together the following. I'd welcome any further information that anyone can recall - please, drop me a line...

The A1 was release in 1984 to rave reviews. Minor revisions occurred throughout it's life - early models didn't have ventilation holes in the side panels, and the top cover was in two sections. The power supply capacitors were "radial" (wire-ended) devices that lay flat across the PCB. There were also some component value changes at some point - the schematic that you can find on Geoff Moss's site shows the earlier values. My 1990 example is regarded as a MKII, and you can see the differences on the next page.

Opposite is an extract from a brochure, circa 1990. The price is the sale-price that I paid - normal retail price at the time was £300.

Shortly after the MKII upgrade, the A1 was upgraded to Mark 3 status. This involved a minor power increase to 25 watts per channel. The reviewers largely raved about it.

There were a number of special editions over the years. In 1991 Musical Fidelity released something called the Collectors Edition - of which only 24 were made. In the same year, they also released the Final Edition, another limited production run of 200. Please note that these dates were taken from the Musical Fidelity booklet referred to above - I thought that the Final Edition wasn't released until much later - 1994-95 was the time I had in mind.

The Collectors Edition and the Final Edition had an external PSU, and the latter had an increased power output of 40 watts per channel. Amusingly, the Final Edition is actually a B200 - a completely different circuit with a MOS-FET output stage. Just about the only thing in common is the case!

In parts of Europe, the A1 was called the A1-X. I've been sent some pictures of this, and I can't really tell any differences apart from the model designation. Also, there was a version in Germany called the "David". This was a tuned version, apparently.

There are a number of other Musical Fidelity amplifiers that are related to the A1 - more details later...

On to the next section - technical matters...