Stereo Amplifier

Review: Denon PMA-450 Stereo Amplifier

According to the Denon leaflet, "Designed for the UK's unique 'budget audiophile' market. Nowhere else in the world does the sound of amplifiers at this price come in for such scrutiny... The PMA-450 is a totally new model which has resulted from many months of design, research and development in the UK".

Usually I am completely turned off by this effusive trumpeting of hi-fi products, particularly amplifiers, which are made in Japan or somewhere else in the Far East but reputedly designed at least in pan by British "consultants" for "British ears". All the UK distributors of Far East hi-fi seem to be at it: yet all too often we are simply getting something uglier than the version sold elsewhere in the world, with the tone controls and other facilities left off and the minimalist cult extended to any components and wiring which might degrade the sound!

However I am more than happy to make an exception of the Denon PMA-450. Although it is rather large and lumbering, with that ubiquitous all-black look, it was no sooner inserted into my hi-fi system than I came to recognise a whole range of sonic virtues. It comes in above the already successful PMA-250 and PMA-350 amplifiers which also claim British designer input. The 60 Watts-per-channel power rating into 8 Ohms gives some headroom in hand for even quite large domestic situations and there are separately switchable outlets for two pairs of loudspeakers.

The front panel has a minimum of controls, just the power on/off with red LED, headphones socket, loudspeakers A/B, friction locked two-ganged volume/balance control and identical rotary switches for source input and source-to-recorder selection. They both have six positions labelled Phono, Aux, Tuner, CD, DAT Tape 1 and DAT Tape 2. Copying from Tape 1 to Tape 2 or vice versa is perfectly straightforward and it is possible to listen to any source while recording another. The rear panel has the signal phono sockets grouped together at one end with an earth terminal close to the Phono input (moving-magnet, i.e. 2-5mV/47K sensitivity only). The two pairs of loudspeaker sockets are of superior construction and will accept 4mm sockets or bare wire. There is a high speed protection circuit which mutes the signal in the event of a short circuit or other faulty loudspeaker condition: this also introduces a delay of a few seconds at initial switch-on.

The UK design effort has led to the use of special 'audiophile' components, some of them sourced in this country and sent out to Japan for assembly. These include Ansar capacitors, the Alps precision volume control and a heavy duty toroidal transformer. The use of a single large printed circuit board means that signal paths have been kept as short as possible consistent with the pure symmetry design of the power and disc stages and the decision to place regulators close to the circuits they control. Loudspeakers A and B are relay switched independently of the headphone socket and lend themselves to bi-wiring operation or two-room applications.

Sonically this amplifier combines a good degree of transparency with well extended bass impact and treble clarity. I found that centre soloists and other front-row voices or instruments had a pleasing unemphasized presence and yet I could listen through these in depth and full-width well defined stereo. The Robert Shaw/Atlanta recording of Verdi's Requiem provides a good test of these criteria with its well placed soloists, ideally balanced chorus, large orchestra and wide dynamics. The Denon PMA-450 amplifier handled all this well, including the spaced brass and timpani, without congestion or loss of detail.

Adequate sound levels were obtained in a fairly large room but any attempt to wind up the volume to superhuman levels did increase the treble brightness uncomfortably. Any loudspeaker load could be imposed with confidence, however, making this an easy amplifier to install. In short I rate this as a serviceable neutral-toned 'black box' ready to produce clean sounding music of any genre in company with suitably high-performance source units and loudspeakers.