Back in the seventies, Denon was Nippon Columbia's hi-fi brand and the PM-850 its biggest, boldest statement. David Price puts it to the test.

In 1979, the princely sum of £445.54 would buy you Denon's biggest integrated. Not so much money these days, but considering that a new Ford Cortina 1600L would set you back £4450, one tenth of modern Mondeo money puts it at about £1500 in real terms. Some may be surprised by this, but lest we forget, Denon used to be (and in Japan still is) associated with high end, semi-professional and professional kit. The company has an obvious presence in recording and broadcast studios, with its DL103 Moving Coil cartridge in use by Japanese state broadcaster NHK since the fifties!

Back at the end of the seventies, Japan Inc. was in a historically unique position. The country's manufacturing industry was as advanced as anywhere in the world and thanks to its excellent education system, its engineers were extremely able. As a result, its hi-fi industry could produce incredibly expensive, beautifully designed and manufactured audio equipment - and still sell it reasonably affordably thanks to the low value of the Yen (which was around one quarter of its value today). Only then could this happen - by the early eighties the cost-cutters had arrived.

This explains the PMA-850's quality - the example you see here looks and works like new. It weighs a tonne, and feels far better built than a modern Mercedes car. Open it up and it's pure Japanese high end, massive pressed steel chassis, enormous top hat sized toroidal transformer (with separate windings for left and right channels), funnel-sized smoothing capacitors and dual mono construction with discrete circuitry throughout.

From the phono input(s) through to the final output, all amplifier stages use complementary transistor pairs. The preamplifier section even lives in a totally enclosed, separate box with most controls and switches wired directly to the PCB for shorter signal paths.

Even though it cost twice as much as a Linn Sondek, the PMA-850 was still just about affordable to Britain's well heeled audiophiles. The fact that the hi-fi market was larger and more vital then also helped, and the result was that a surprising number of such products found their way into people's homes. Unlike the British price rivals of the time, big Jap integrateds came with every feature under the sun as standard and attracted a different kind of buyer. 

So this amp isn't short of knobs and switches. How does three phono inputs (including one MC, complete with gold plated phonos around the back) sound? Or two tape monitors with switchable dubbing in any direction? Stereo, mono and stereo reverse? High and subsonic filters? Two pairs of speakers, tone controls, balance, muting and even a 'direct coupled ' mode? Get the picture?

Ah, that direct coupled mode. Switch this in and the fripperies get switched out - the signal goes straight to the power amp via the volume control. It's a common feature these days ('Source Direct'), but back then it was rare as a Ford Capri without go-faster stripes. It's also what makes this amp worth buying for audio purists nearly twenty five years on.

Going via all the bells and whistles, the Denon sounds like most Jap high end amps of its time. There's muscular, powerful bass, a sweet - almost saccharine - treble and not an awful lot in-between. Hit the DC button and it's 'hold onto your flares' however - you really start to enjoy its 85W RMS per side. 

The sound gets far smoother, tighter, cleaner and more open. Suddenly a soundstage appears - instead of it all being in your face - and you can hear this amp's true character. It's deep, dark and smooth sound with oodles of drive and surprising musicality. The only downside is just a touch of upper midrange grain which unfortunately CD accentuates. 

Its three phono stages are great - incredibly quiet and clean, although not quite as engaging as, say, a Michell Dino. The good news is these Denon's haven't withstood the ravages of depreciation as well as similarly priced UK esoterica, and you can pick one up (metaphorically) for under £150. At this price, it will trounce anything new or nearly new, and probably outlast it too. Just make sure your car's suspension is up to the job of carrying it home.