Marantz PM8003 integrated amplifier review

In common with most of the rest of the world, Marantz seems to be updating its ranges more rapidly these days than a few years ago, but certain aspects of the Marantz PM8003 integrated amplifier look familiar from mid-range Marantz models of yore.

The use of HDAM (Hyper Dynamic Amplifier Module – effectively an op-amp circuit, but built with discrete components and optimised for audio duty) circuits certainly comes under the heading of 'if it ain't broke, don't fix it' and we'd swear we've seen some corners from the rest of the circuit before too.

Power supply

In terms of new design, Marantz is keen to emphasise that there has been considerable influence from its upmarket amps, which act to some extent as technology proving grounds for more mass-market designs.

The power supply starts with a large toroidal transformer, which feeds a bridge rectifier made up of high-speed diodes mounted on the main heatsink.

A rectifier diode seems an awfully prosaic component to tweak, but regular ones have been shown to create high-frequency interference which, while not necessarily directly audible, seems to cause some mild degradation of fine detail in delicate audio signals.

High-speed ones reduce that and mounting them on a big heatsink is even more beneficial as it 'swallows up' most of the radiated field from the diodes.

Clearer bass

The next stage after diodes is smoothing capacitors and here again Marantz has done the listener proud with unusually generous provision.

This is another of amplifier design's near-intangible issues, but there is substantial accumulated evidence to support the argument that larger capacitors are very much a good thing, tending to give a fuller and also clearer bass.

As for the main circuitry, there is less evidence of tweaky construction here and indeed most of the passive components (resistors and capacitors) are thoroughly mundane types. They are assembled to a circuit board that in today's high-tech age looks frankly retro, with wire links and not a surface-mount component in sight.

Volume control

About the only real concession to modernity is a solid-state switch for input selection, a familiar part which we've found in the past to offer good performance: it also avoids a weakness of some such parts with regard to high input levels, which it accepts without complaint.

The volume control is the noted Alps 'blue velvet' type, a component not found in many mass-market products, motorised for remote control convenience. Although it has good sound quality credentials, we did find it a bit twitchy to use over some of its range.

Finally, there is a phono stage, suitable for moving magnet (high output) cartridges only. Assembled on its own circuit board as far as physically possible from the mains transformer, it is quite a deluxe-looking affair built from discrete transistors rather than the usual single op-amp afterthought.

Robust build

Physical build of the amp is good, with decent-quality connectors, nicely weighted switches and some very chunky output terminals, a little pretentiously finished in 'faux metal' – they're actually plastic on the outside.

From them issues a healthy output: Marantz's rating of 70 watts is conservative and we got more like 90 watts, with admirably low distortion and impressively flat frequency response from line and phono inputs alike.

Lacking detail

Having been used to high standards from Marantz amps over recent years, we were just very slightly underwhelmed by PM8003, which seems to lack some of the insight we've found in previous models.

The sound is large-bodied, tonally full and never less than pleasant, but it doesn't seem to have quite the level of detail that the PM7001Ki offered.

Now to be fair, we were very impressed with the 7001 and it set a high bar for future models. In addition, the newcomer seems to be more tonally neutral, having lost a slight chestiness which we found in both standard and KI 7001 incarnations.

We also continue to approve wholeheartedly of the family likeness in the way these amps handle bass. This is where performance goes beyond expectations of mid-price hi-fi, approaching a high-end standard indeed.

Lowering hi-fi prices

We've said many times that hi-fi value for money has been on an upward trend for years.

While it's also true that high-end achievement has also been increasing, products like this do suggest that the gap is in many ways not that vast and the extent to which the 8003 can grab hold of a woofer and vibrate it with precision, conviction and attack would really not disgrace an amp at a considerably higher price.

We tried all the usual 'trouble tracks' everything from church organ to plucked double bass, piano, kick drum and more: in every case, we were rewarded with tight, but always tuneful extension and a highly convincing sense of realism.

Lively performance

The treble is also highly commendable, perhaps not quite a strikingly fine, but still very good for the amp's price.

The big problem with high treble reproduction (and this seems to hold for amps, sources and speakers alike) is combining extension with that sense of air and space around the sound that is so essential to the lifelike replay of delicate treble details. In this case the extension is indisputable, while the space is very good, certainly among the better examples we've heard in this class.

And as already mentioned, midrange is neutral with excellent vocal quality as a result. We've found some Marantz amps in the past a little more partial to male than female voices, but this one seems very even-handed.

It's also very lively, again by our reckoning rather more so than previous models: it's a little tempting to link this to the improved neutrality, as coloration can have an odd effect on one's perception of rhythm and dynamics, especially in A-B comparisons. Whatever the cause, this amp really does seem to enjoy bopping along to lively tunes and has a good deal of that sought-after 'foot-tappingness'.

Underwhelming Marantz amp

Which really only leaves that niggle about detail. For less then two-thirds of a grand we aren't asking for the sort of analysis that allows one to identify the make of guitar pick being used, but we have experienced some very high standards in this area recently and on one of our favourite test discs.

For instance, we had rather more trouble identifying which instrument in the orchestra was playing which line than we'd expect and also found the imaging of the choir less clear than we've heard. Imaging and detail often go hand-in-hand and certainly here the former loses some depth and precision, though there's still plenty of width on offer.

Perhaps we are asking for the moon on a stick. Bass and treble extension this good are worth making a little sacrifice for and detail isn't everyone's top priority.

We're more than happy to recommend the Marantz PM8003 amp on grounds of tonality, liveliness and unusually clear-sounding phono stage: and with Marantz's usual good looks and ergonomic operation, it's a welcome arrival.