Marantz PM-40SE Amplifier
Despite some recent changes in the administrative structure, the special relationship between the parent company Philips and Marantz continues to allow Marantz UK, in particular, a fair degree of autonomy. Dealers and audiophiles alike will be reassured to know that Ken Ishiwata remains firmly in charge of product refinement and that his special way with subjectively selected components, connectors and wiring layout will keep the Marantz brand name well up in the high performance ratings. Perhaps we associate his wizardry more with the relatively expensive high-end Compact Disc players and amplifiers, from which he used to conjure up "limited edition" samples by after-manufacture modifications. But he has also applied his talents to Marantz budget units and produced SE (Special Edition) versions built in Japan to his specifications for audio enthusiasts who put sound quality before everything else.
Thus the PM-40SE integrated amplifier reviewed here is a reworking of the existing PM-40 which raises the power rating into 8 Ohms from 40W to 50W and subtly improves other key items in the specification, whilst leaving off the tone controls and switchable subspeaker connections. In appearance the PM-40SE closely resembles the taller and more powerful PM-50. The rather plain front panel is even more sparse in terms of controls but is enlivened by a "Special Edition" label in gold lettering. A horizontal channel runs the full width of the panel and has five very tiny red LEDs set into it to show the status of the push-switches below them, namely Power on/off, Source Direct (bypassing the balance and tape monitor controls and effectively producing a 'passive' preamplifier, with only the volume control coming between the source and the power amplifier stages), Tape 1, Tape 2 and Tape Copy 1-to-2. Also below the line are the goldplated headphones socket, changeover switch for moving-magnet or moving-coil pick up cartridges, and balance. The only controls above the line are the rotary source selector for phono/CD/tuner/auxiliary and the larger volume control with a scale indicating attenuation in decibels.
On the back panel are four pairs of phono sockets for the source inputs, the phono and CD being gold-plated, plus the usual ground terminal for anchoring a turntable earth wire. Alongside are four more pairs of sockets for Tape 1 and 2 record/replay. There are no facilities for listening to one source while recording another and tape copying is restricted to dubbing from Tape 1 to Tape 2. Note, however, that it is perfectly possible to monitor off-tape when recording on to a three-head machine simply by pressing the appropriate Tape 1 or 2 playback button.
Next come two pairs of substantial loudspeaker terminals, designed to accept 4mm plugs or bare wires. However, rather surprisingly, unless you are tuned in to Ken Ishiwata's predilection for audiophile tweaks, these two pairs of speaker outlets (labelled A and B) are actually wired in parallel and are intended to facilitate bi-wiring of loudspeakers with separate tweeter and woofer input terminals. It would be possible to connect up two separate pairs of loudspeakers but these will not be separately switchable, and they must all be of at least 8 Ohms impedance to keep the overall load above the 4 Ohms mark.
Internally the amplifier presents a neat and workmanlike appearance, with the high-grade components, including damped copper styrol coupling capacitors, and 'minimum path' philosophy well in evidence. The main printed circuit board occupies the middle area, with the left and right channel output transistors mounted along each side on large multi-vaned L-section heatsinks which act as partitions. The left-hand section houses the mains transformer, protection fuse, etc. Hefty 10,000μF capacitors are used in the Marantz Linear Drive Power Supply circuit whose low-impedance wide-bandwidth feed to the power stages is claimed to produce "realistic dynamic performance even when driving difficult loudspeaker loads".
Compared with the basic PM-40 unit, higher rated 10-Amp power transistors have been selected in a three-stage Darlington configuration. The left and right ground paths are laid out independently throughout to minimise cross-channel interference. The right-hand section contains the phono preamplifier board and indeed all sensitive low-level circuitry. An ultralow-noise op-amp is used for the moving-magnet input and low-noise FETs provide the additional gain for moving-coils. The latest IEC/RIAA equalization curve is followed, with its controlled roll-off at subsonic frequencies.
How it performed
One thing about testing a minimalist amplifier from a reputable manufacturer is that there are few fiddling features or distractions to get in the way of the serious business of just listening to sources of known excellence through good quality loudspeakers. The PM-40SE fairly galloped through my measurements sequence to produce a ruler-flat frequency response on the line-level inputs and very precise tracing of the lEC-RIAA phono curve. The claimed power, distortion and noise figures were comfortably reached. Residual noise at the loudspeakers was totally absent with the source switched off and the volume control wound full up. The amplifier ran only mildly warm after hours of use and seemed impervious to external vibrations or electromagnetic interference. It is also a pushover to use and the only slightly tricky business of tape dubbing and monitoring is very clearly explained and tabulated in the five-language booklet.
Extended listening tests began with Compact Disc and could hardly have been more encouraging. With all Marantz's talk of "long and rigorous listening tests in both Japan and Europe", "research into the sound of components and the effects of vibration" and "sonic improvements in higher resolution imaging and musical detailing", one might be brain-washed into expecting a clinical, 'chromium-plated' kind of sound. Not so: if anything, the bottom half of the spectrum came over as more impressively detailed than the top.
For instance, I have played the opening of the CBSO/Rattle recording of Mahler's Resurection Symphony (EMl CDS7 47962-8, 10/87) innumerable times but have never heard the double-basses more richly sonorous or the very wide dynamics more effortlessly handled. Another disc I often use in listening test s is the AAM/Hogwood version of Beethoven's Ninth Symphony (L'Oiseau-Lyre 425 517-20H, 11/89), partly because I was lucky enough to attend the recording sessions and have a good recollection of the actual sounds in Walthamstow Assembly Hall. The live experience was closely recreated at home, with solo voices crisply detailed yet set back at a sensible distance, and the chorus and orchestra well balanced in a warmly natural acoustic. The stereo stage had the expected integration in terms of both spread and depth. I also played a selection of LPs and tapes with equally satisfactory results. On low level moving-coil (the Ortofon MC-70) a slight lift in volume setting was needed but noise remained below audibility and the sound was superb.
Marantz UK have done a good job in producing this "Special Edition" amplifier. Careful listening is the only way for an intending purchaser to assess whether Ken lshiwata's subtle enhancements add up to real sonic benefits. If you are in the market for a moderately priced transparent-sounding amplifier, I suggest that you take some favourite CDs or LPs along to your nearest Marantz dealer and let your ears decide. I don't think you'll be disappointed.
