DPA DSP-200S/DPA-200S Preamp/Amp Page 2

The source selector of the DSP-200S reverts to its CD input at switch on; changing this involves a small button that skips through all five inputs in one direction only. Furthermore, while the volume control – a Japanese ALPS 'Blue' type – is as beautifully silky as these always are, the sensitivity of the CD input is excessive for a standard 2V RMS machine, making obtaining a low-level output for quiet listening difficult.

Something that I did appreciate was the care that had clearly been taken in ensuring that the units could be switched on and off in any order without generating ear-splitting crackles and howls through the loudspeakers. Any regular user of specialist equipment will know that this is not always the case. The well-engineered tape loop is another welcome addition.

sqnote Tim Listens
My first impressions of DPA's system were that despite the attempt to add extra prominence to the bottom end, the sound still has a dry character with a clear midrange lift. It is smooth without being excessively rich, and revealing without being obviously sharp. Neither the deep bass nor the high treble are especially extended but what is there is well ordered over a wide range of listening levels.

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The DPA-200S's two transformers [top] are contra-connected into a single stereo PSU [centre].

The DPA-200S can produce the sort of listening experiences one would expect from a 50W model. The amplifier's internal power supply seems to be the limiting factor, as it was the bottom end that got slightly muddied first as the limit was approached, but for general listening there is more than enough grunt available here. The combination's most impressive strength could be found at the opposite end of the output scale, though. There was essentially no noise audible through the loudspeakers at any setting of the volume control, which is quite a feat for a pairing of this layout. In fact, the only thing that broke the silence in my listening room between pieces was a buzz from the mains transformers in our DPA-200S.

Playing Tanita Tikaram's 'For All These Years' [Ancient Heart; WEA 2438772] revealed lots of space and a wonderful sense of breathy presence in the vocals, but this was set against a longing that the redesign had been still more generous with the bass. Subjectively the sound is still a bit cold, even when using material and loudspeakers which are not. System matching is therefore a matter that will require care with these amps.

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The fully discrete DH-OA32 hybrid op-amps were a feature of all Deltec/DPA amplifiers of note

A separates system brings the chance to further investigate tonal colourations like this and the results were interesting. The lean bass originates in the DPA-200S unit, whereas the DSP-200S contributes a subtle but clearly identifiable veiling of the upper treble by contrast with the units which I substituted into the system – an Aurex SC-M15 and SY-C15 [HFN Apr '16] used in passive mode. Simple acoustic material is not necessarily impeded by these traits; instead it lends the sound a simple clarity which can be really beguiling.

Dutch Courage
Orchestral set-pieces showed another side of DPA's compact duo. My work of choice was Beethoven's 7th symphony, performed by the Concertgebouw Orchestra in Amsterdam [Philips 420 540-2]. The soundstage was impressively expansive and the clarity around solo instruments almost forensic, but the shortfall in absolute bass weight, and an initially not obvious but eventually apparent dulling of the bite of the strings, meant I couldn't escape the impression that something was missing. That something was the excitement and dynamics of real music which makes a live performance (or a truly excellent system at home) such a joy to listen to.

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Dated February 1993, the first issue PCB of the DSP-200S shows LM317/337 PSU regulators [centre], 74HC4051 multiplexers for input and balance switching [far left] plus NE5534 audio op-amps [top left]

Raising the volume to a realistic level (something that the DPA-200S amp handled without fuss) narrowed the gap but it was never quite a 'close your eyes and be there' sort of sound. Substituting the preamplifier again and pushing the loudspeakers further into the corners of the room brought about a very worthwhile improvement; perhaps what the DPA-200S needs is a nice little passive preamp and a pair of something big and ported.

DPA's technologies succeed to a great extent in doing what the designers intended. The DPA-200S in particular is an excellent technical amplifier. Musically, however, the sound of this pre/power pairing is something of an acquired taste.

Buying Secondhand
The use of miniature surface-mount components makes any repair to the DPA-200S far more complicated that it is with a conventionally constructed amplifier. Not only are the parts tiny, they are also not all marked with type numbers so without a circuit diagram (something which is not in general circulation) it is very difficult to know what everything is and what to replace it with. Any example which is not demonstrably in perfect working order should therefore be treated with extreme suspicion – insist on a proper audition first.

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The DSP-200S [top] has four line inputs (phono was an option), a tape loop and two preamp outs while the DPA-200S [bottom] has inputs on RCAs and speaker outputs on 4mm binding posts. A toggle switched the amp into bridged mono mode

It has been noted that the internal heatsinks are rather small for the task at hand and therefore long periods of running at high power levels are not recommended. For the same reason a bridged system should still be used with a degree of restraint. The situation with the DSP-200S is a little better. As well as being less densely laid out, it operates at lower power levels and is greatly less likely to suffer from catastrophic failure.

Hi-Fi News Verdict
These cute and compact DPA amplifiers are technically clever and interestingly different in both interior design and outward construction, so represent a break from the pre/power norm. Careful system building will be the route to listening enjoyment, however, and whatever you do you must buy and operate the DSP-200S and DPA-200S with care, because most repairs will not be straightforward!

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