QED MA-34 Passive Pre-Amp

Sadly now discontinued this little gem of a box would have set you back a mere £60. I have always been a big believer wherever possible in keeping things simple which is exactly what the QED MA-34 does.

Almost all active pre-amps apart from the very best add some colouration due to their design. The QED is passive ( no power), it has four sets of gold plated phono sockets at the rear (one set are not used ?), a high quality switch with silver plated contacts, and a high quality Alps blue potentionmeter to adjust the volume level and thats it. The dimensions of the box are 10cm x 11cm so all signal paths are kept to minimum. There are those who argue that the high impedience of passive pre-amps makes them unsuitable and that active is best. Well all I say is listen and make your own mind up.

So how does it sound ? In truth it does not really sound at all - that's the beauty of it, it is almost totally transparent and thus allows the power amp being used to produce more detail and depth that would previously been muddled or lost by the pre-amp section.

The pre-amp is designed to sit between your CD player and power amp, and initially I used a Quad 67 CD player and an couple of integrated amps that had been modified so that the power and pre amp sections could be used indepently or just wired together depending on preference.

The first amp tested was a Audiolab 8000A Mk II. The difference between the original integrated Audiolab 8000A sound and the new QED passive and Audiolab 8000A power amp section was staggering. The Audiolab 8000A pre-amp section without doubt was considerably coloured and it was obvious from the very first listening tests, it was like a veil had been lifted off the top end range of the amp.

Maybe this was just a one off, so I wired up my Cambridge Audio A1 mk II Special Edition amp which although very impressive for a £120 amp and whilst having quite a nice warm sound always sounded a little confused at the best of times as an integrated amp. This amp had also been modified so that the power and pre-amp sections could be used separately. As the boards are clearly marked it is very simple to drill 4 holes (2 for power-in and 2 for the pre-out) in the back above the loudspeaker terminals and wire them up to the suitable connectors on the board.

Once again with QED passive pre-amp, the Cambridge Audio A1 mk II Special Edition took on a new level of transparency which added to its warm sound made it comparable to amplifiers costing five times the cost. Why Cambridge Audio chose to put tone controls in this amp I will never know because they add unnecessary colour to a fine sounding amp.

To sum up this pre-amp is a truly great piece of kit that is worth every penny, its just a shame it is no longer in production, however for those DIY enthusiasts, it would not be a very difficult task to build something similar and well worth it as the sound quality or the lack of sound quality really does put pay to some people's thinking on passive pre-amps.

This entry was posted on Saturday February 4th, 2006 at 9:09 AM and is filed under Amplifiers, Classic. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response.

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