Stereo Amplifier

Review: Denon PMA-350 II Stereo Amplifier

One beneficial result of the long recession which has hit our audio industry harder than most has been the opportunity to examine customers requirements in greater detail. In the case of the Japanese companies who previously went their own way almost regardless, the slump in demand has forced them not only to pay attention to their foreign personnel but actively to invite their cooperation. To be fair, a number of the more enlightened Oriental manufacturers had started to listen to European voices when the first sign of an easing in demand was but a small cloud over Mount Fuji. As a result we have seen a number of successful products from them in which the British involvement in design has been Considerable. There is little doubt that in the amplifier field Pioneer's A-400 led the way. Its almost instant success and runaway sales soon had contemporary Japanese companies tripping over one another to get on the same path. Without a doubt this has resulted in some excellent products reaching our market and I doubt if any Japanese manufacturer will ever revert to their former insularity; to do so would be inviting market disaster.

The Mark II indicates what is almost a completely new model, but it would not be seen as such from outward appearance. Other makers have followed Pioneer in hatching minimalist designs - omitting tone controls, loudspeaker selection, headphones sockets, and in some cases phono inputs. Perhaps unkindly, Denon call these 'stripped down' designs and suggest that a majority of users now want them back if it can be done without compromising quality. However, as a sort of two way bet they, like some others, now provide a Source Direct switch which enables the user to by-pass the tone control circuits if so desired.

Not unexpectedly Denon's PMA-350 II looks more or less exactly like a hundred others of its fellows: black anodized extruded aluminium front panel with white legends, black-painted sheet steel casework with ventilation slots as needed and the seemingly essential drum feel. The layout of controls is equally predictable. On the left the Power On/Off switch; alongside a red LED indicator; below it the headphones socket with loudspeakers A and B relay operating latching buttons adjacent. Three small round knobs adjust Bass, Treble and Balance, each with centre detents. A lever knob selects one of six inputs and there are three more latching buttons enabling tape-to-tape copying, tape monitoring and the tone control option already mentioned. Lastly, the large knob at the right controls volume and is arbitrarily calibrated from 0 to 40. At the rear are a group of 16 phono sockets below a ground terminal and four pairs of rather nice loudspeaker terminals, large enough to lake hefty cables but rather closely spaced for easy access; however, each has 4mm centre sockets which makes life easy if you remember that the terminal has to be done up tightly for reliable contact when using the latter. There is a permanently attached two-core mains lead approximately 1250mm long.

Dominant features of the internals are a large steel pot containing the power transformer, which we are told is of toroidal construction, and a substantial vertical heatsink located over ventilation slots in the base and to which the two pairs of complementary output transistors are bolted. The majority of the small components are incorporated on a single large main printed circuit board. There is plenty of room to provide a well separated layout and allow symmetrical placement of the left and right channels. The input selector switch is adjacent to the input sockets and operated from the front panel control by a flexible link. The relatively small amount of wiring is of generous gauge and that in the signal path is Sumitomo OFC (Oxygen-Free Copper). All the components appear to be of good quality and some coupling capacitors and the main supply reservoirs are exceptional. The use of by-passed Cera fine capacitors for the latter is easily justified when one applies inverted thinking and accepts the output transistors as a sort of musically operated tap passing power from them to the loudspeaker.


It came as no surprise to find that the usual series of measurements tallied closely to those given in the specification. Power output easily exceeded that quoted reaching 72 watts at mid frequencies into 8 ohms and over 60 at the extremes of 20Hz and 20kHz. My sample gave up at a little over 70 watts into 4 ohms but I later noticed that the supply mains had dropped a few per cent below the nominal 240 volts, so it may not have been an entirely fair measurement, Everything else checked out all right but I would draw attention to the unusual tone control arrangement, whereby their effectiveness is progressively diminished as the volume control is advanced beyond the half-way point until at its maximum there is no response from the tone controls at all. This may be no bad thing as it prevents excessive boost from being applied at high volume levels, although even in the operational range the controls are quite modest.

Listening sessions using loudspeakers and sources of the highest quality soon proved that the effort put into this design had not been wasted and consequently after making a few' direct comparisons I have found no need to return to my usual reference and probably won't until the time comes to return it or replace it with the next candidate in the continuing inquisition.

Fine sounding amplifiers were once the exception but now more and more of them are surfacing at a variety of price levels and it would be nice to think that British influence has a lot to do with it. Some-but certainly not all-of the comparatively expensive amplifiers have a certain fluidity and confident athleticism in the way they carry the music along which young pretenders like this Denon constantly strive for. It is only to be expected; but there can be no doubt that for a modest £220 one can both see and hear exceptional value in the Mark II version of Denon's PMA-350 II.