Aiwa M-301

“Refined to the essence of hi-fi perfection”, or so said Aiwa’s 1980 brochure for its M-301 microsystem. “The 35 Watt System: Refinement. Ingenuity. Performance”, it continued. It’s easy to laugh at the marketing hype, but look beyond this and it’s actually a rather impressive bit of kit. This is largely because when it was launched, the market for (what the Japanese call) miniature components was absolutely cut-throat – and pretty much every consumer electronics giant of that country was fighting it out against one another.

Lest we forget, this precise moment was a vibrant time for hi-fi, and the market had come along in leaps and bounds over the previous decade. From 1970 to 1980, the demand for high quality consumer audio equipment expanded exponentially, and every big Japanese brand wanted a piece of it.

By the end of the seventies however, the focus was on miniaturisation – especially in Japan’s home market. Every major manufacturer began to slim-down its products, keeping the ‘full width’ aspect but often only making them half as tall. In 1979 for example, a typical Sony amplifier looked dramatically different to the model range of just three years earlier – whilst retaining almost all the features. One spin-off of this push to downsize was the growth in popularity of mini-components, what we in the UK called ‘micro systems’. It’s important to point out that these weren’t simply the swish-looking, all-in-one ‘lifestyle systems’ that we have today; they were effectively full-size hi-fi separates that had shrunk in the wash, so to speak. They gave little away in terms of features to their full size brethren and were often actually more expensive to buy. Competition was intense to deliver high performing compact stereo systems, with all the features that people had come to expect from full size designs – and Aiwa was at the forefront.

The stars seemed aligned for the company to succeed. Although notionally independent, it had been 52% owned by Sony since 1969, so there was a lot of cross-pollination in terms of component usage and engineering resources. Aiwa had come to be known for its excellent tape decks – first open reel and then cassette – and was now living through its halcyon days.

In 1979 it seemed to be on top of the world, with ultra sophisticated products like the AD-6900 three-head cassette deck AT-9700 FM synthesiser tuner and LP-3000 parallel tracking turntable. These were close to the best that money could buy, at least in terms of engineering sophistication. Aurex – with its System 10, 12 and 15 – was the strongest performer in the ‘microsystem wars’, but Sony was in the game with the Precise P7 and FH-7, and even Mitsubishi produced mini components. Then Aiwa really got stuck in, producing the L22 system (including, variously, the S-A22 integrated amplifier, S-C22 preamplifier, S-P22 power amp, S-R22 tuner and SD-L22 cassette deck). This also appeared under the BASF, Metz, Uher and Wega brand names, and there was even a ‘Boots Audio’ badge-engineered Aiwa microsystem sold in the UK.

The excellent Aurex microsystems created a halo effect for the breed, but the Aiwa did most of the heavy lifting in sales terms. The former was very expensive (typically £800 in 1979, around £4,500 in today’s money), whereas the latter cost less than half this – and sold in far higher quantities. The M-301 system that you see here was the L22’s direct replacement for the 1980 model year. It comprised the SA-C30U preamplifier, SA-P30U power amplifier, ST·R30U tuner and SD·L30U cassette deck – plus a range of options including fancy cases, turntables and loudspeakers. Although less well known, it’s a meaningful step-up in quality over the L22, and something of a rarity in relative terms.

The nerve centre of the system is the SA-C30 preamplifier. Despite being so tiny, it has a range of inputs including a moving magnet phono section sporting specially selected polypropylene capacitors and metal-film resistors, said to hold RIAA phono-equalisation to within ±0.2dB from 20Hz to 20kHz. It uses one high gain IC and several ultra low noise transistors to give a signal to noise ratio of a 87dB, according to Aiwa. The selector switching is contactless for better longevity, and the tone controls are defeatable. Like all the other components here, its 210x71x228.5mm casing is all made from aluminium and beautifully finished; it weighs in at just 1.75kg.

The really clever stuff begins with the matching SA-P30U power amplifier, which has a quoted output power of 2x35W RMS into 8 ohms, both channels driven with no more than 0.05% T.H.D. Back in the day, that was as much as most audiophile integrated amplifiers were putting out – things like the A&R Cambridge A60 for example. A Class AB design, it sports three-stage complementary DC construction – and uses discrete transistors rather than power ICs. Aiwa made a big fuss about this in their promotional literature at the time, adding that specially selected high speed devices had been used. There’s even a toroidal transformer fitted, and pair of large-capacity 10,000μF electrolytic capacitors. Being Japanese, sturdy protection circuitry was built in, plus the obligatory largely useless LED power meter.

Measuring 210x71x210mm, it weighs 4kg. Aiwa got to demonstrate its prowess with tuners with the ST·R30U; it’s important to remember how rare it was in 1980 to have quartz-referenced digital synthesiser tuning. There’s a digital frequency display, and the front end has a high-stability cascade junction MOSFET. The IF detector stage boasts an excellent quoted selectivity figure of 70dB within 400kHz, by the use of specially chosen ceramic filters. Stereo separation is quoted a superb – for that era – 45dB at 1kHz. Input sensitivity is also very good for its period, meaning users in urban areas could get away with the so-called ‘wet string’ indoor aerials. Finally, a decent AM stage was fitted, too. Vital statistics were 210x71x254.5mm and 2.1kg.

The system’s pièce de résistance is the SD·L30U cassette deck. It’s a simple single capstan, two-head affair but is very well engineered. It sports a hard permalloy record/replay head that gives a claimed 25 to 16,000Hz with either chrome or the (then) new-fangled metal tapes. A Hi-B double gap ferrite erase head was fitted beside it. Wow and flutter was quoted at a good 0.09% (WRMS) thanks to its DC servo motor with decently sized flywheel, and signal-to-noise ration is a good 60dB (Dolby on). A five-segment peak meter cluster is fitted, immediately to the right of the front slot-loading cassette door, which sits over mechanical piano key transport controls. Scores on the doors are 210×72 x229mm and 2.8kg.

The M-301 system was highly sophisticated for its day, giving away little to full size mid-priced separates of that era. The cassette deck is particularly sophisticated for something so small, and turns in a claimed measured performance that’s easily the match of any decent grown-up machine; you had to go high end to do noticeably better. The tuner will have seemed like a technological marvel to many at that time, and the power amplifier shows sound audiophile best practice – despite it being dinky. So there’s a lot to respect about this system, despite the diminutive dimensions.

Build quality and ergonomics are hard to fault; generally the four components feel really classy and are slick to use. The main drawback for what’s effectively an all-in-one system, is that each different component has its own captive mains lead and plug, meaning that a four-way power adaptor is essential. The mechanical transport keys of the cassette deck would have been a disappointment to some at the time – after all, the Aurex decks had full logic control – but again most cassette decks on the market hadn’t progressed to this luxury feature by 1980. For true ‘soft-touch’ operation, you’d have to invest in Aiwa’s M-606 microsystem, which was much closer to Aurex money.

Given that most people’s expectations of such a small system as this will be commensurately tiny, many will be in for a shock. Given a decent pair of loudspeakers, the M-301 is capable of turning in a seriously good sound, even by today’s budget standards. Its pre-power amplifier combination is quite the star, sounding open and musical with a good degree of grip in the bass, and bite in the treble. At the same time, the power amp doesn’t seem breathless until you really ramp up the volume close to the end stop, and it’s generally a tactile and communicative listen. The tuner and cassette deck front ends do not let the side down by any means, yet it’s still possible to do better by plugging a decent turntable in should you so wish.

I found Change’s A Lover’s Holiday to be rather fun via the Aiwa. This record is tonally quite warm but has lots of super-snappy percussion, and the M-301 system really caught this well, without machine-gunning it out at the listener. The M-301 system has that classically Japanese light and spry sound, but never falls into harshness. The energy and grip of the bass, allied to the precision and detail of the midband and crisp treble, make for an enjoyable yet quite refined performance. Play some classic rock like Watcher of the Skies by Genesis, and you’ll detect a slight lack of detail and insight in the midband, and the sound staging isn’t as three dimensional as you’d hope for. Still, it’s quite impressive for a forty year old design that’s half the size of most hi-fi systems. The overall impression is of a system that’s full of life and energy, yet far less rough around the edges than you might expect. Modern full size budget equipment does better, but not by that much…

By 1983, the microsystem boom was largely over in Japan. The Next Big Thing was of course CD, which was first sold as a high end medium, and as such it deserved full-sized, grown up ancillaries – or so people said. The M-301 system struggled to repeat the original formula of the L22, because there were now so many rivals competing for buyers’ money. Yet this is an altogether superior product, with better specs, more features, a crisper sound and subtler styling. As such, it’s hard not to like.

By 1982, Sony’s stake in Aiwa had risen to 55%, and we were witnessing the saw the slow demise of the Aiwa brand, as it began to lose its unique identity. Aiwa had been king of tape, but digital audio was just around the corner. By 1990 it was making cheaper and more plasticky mini-systems that lacked the charm and engineering depth of those early Aiwa ‘mini compos’. The good news for buyers in 2020 is that there are still quite a few of the former around, and they’re ideal for kitchen, bedroom or office systems. With rough examples going for just £50 and tidy ones at twice that, keep your eyes peeled for these small systems because they’re huge value for money.

Buying secondhand
The good news is that there are more of these little systems around than you think, but you’ll still have to actively keep your eyes open to find one. Those who have owned them know just how good they are, yet those who haven’t, don’t. Build quality is of a very high standard, which means that this system will easily last half a century if properly serviced. The main ‘consumable’ is the main drive belt on the cassette deck, but replacements are relatively easy to find online. At the same time, the SD-L30U’s main record/replay head is made of permalloy, and therefore wears out faster than other types – so check for a tape-shaped groove scored into the central head. If so, you can knock the seller down on price, and/or buy a replacement head to get fitted by a local specialist. The only other issues are of switchgear and socketry oxidising over time, so a good clean with Caig DeoxIT or Kontak is highly recommended. Generally though, this is a reliable and well made system that proves less can sometimes be more.

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