Aiwa AD-WX727 Repair & Thoughts

Aiwa created the first Japanese cassette tape recorder in 1964. Up until the late 1990s they were a leading manufacturer of consumer audio equipment. Not the finest equipment you could buy, but generally affordable, well featured and well made, and sold by the boatload. The range encompassed everything from full-sized separates to mini separates, integrated component systems of all shapes and sizes, boomboxes, portable audio, microphones and headphones. Trouble hit the company in their later years though, and eventually they were acquired by Sony in 2003. Sony had a significant share in the company prior, though looking at the variability of of the quality of the later products one can’t help but wonder if the financial stake swayed the competition in Sony’s favour.

Aiwa Ad Wx727 Front

The AD-WX727 does nothing to assuage that view. It’s a large box filled with – well, not a lot. A single circuit board, with most of the functions integrated across a few chips, and a pair of cheap, flimsy tape mechanisms. The way the rear panel flaps in the wind when you remove the top is a sign of things to come, though from the front it’s a decent looking machine.

It does have some redeeming features including tape stabilisers in the doors, which most of Aiwa’s decks had. These were spring-loaded carriers that pressed the shell of the cassette into the mechanism, holding it securely in place to prevent movement. A bit of a gimmick perhaps, and worthless in this deck, though they were a welcome edition to the high-end models which were better across the board.

You get full logic control with autoreverse on both decks, recording only on deck B, and high-speed dubbing, not that you’d want to use it. There is a manual record level control, a headphone jack, simple counters and metering, and that’s about it.

Specs are good too with 20Hz to 18kHz claimed frequency response on metal tape and 20-16kHz for ‘normal’ tape, though no linearity figure is given. It has Dolby B and C which by this point only the most basic of decks omitted as Dolby became a single-chip implementation adding hardly any cost to the product in mass production. The electronics are based around the Hitachi HA12155NT audio signal processor and LC66408A 4-bit microcontroller, and there are calibration pots for most aspects of recording and playback.

The real downfall is the mechanisms. They are so incredibly cheap it’s a wonder they hold up as long as they do. The flywheels are plastic, the gearing is plastic, most of the framing is plastic. And not good plastic either. Thin, flimsy plastic that flexes, wobbles, grinds and bends. The mechanisms are vaguely similar to the Sony mechanisms used in most of their later full-logic autoreverse decks, though side-by-side the better quality of the Sony mechanism is quite obvious. The Aiwa is clearly built to a cost, and it suffers for it.

Aiwa Ad Wx727 Overal Inside

Nevertheless, changing the belts is relatively easy. Or at least it would be if the belts didn’t turn to tar after sitting unused for many years, as was the case with this particular example. The dreaded black goo, that anyone who has ever serviced a significant number of cassette decks will be familiar with, goes everywhere. It finds its way to every possible pulley, gear, groove and hole, and chances are you’ll have a significant amount of it on your hands, clothes, work surface and tools by the time you’re done cleaning it up. I forgot to take pictures of this bit, but Peter Vis has written an article on the same deck with more detailed shots.

Aiwa Ad Wx727 Close Up Of Back Of Tape B

Copious amounts of IPA later and the tar-like residue was removed. You can’t use acetone on any of the parts due to the quantity of plastic, nor any of the harsher chemicals that are typically used to remove this stuff. You can sometimes freeze the mechanism over night, which will solidify the belt residue and let you pick it off. But if you froze this mechanism you’d probably end up with a mess of cracked plastic.

I used belts from DeckTech, manufactured and sold by ManaTree. I have tried belts from every manufacturer I can find including WebSpareParts and other ‘premium’ brands, as well as the cheap bulk packs online. The DeckTech belts are the best I’ve found, precisely manufactured and they will last as long, and probably longer, than the originals. I’m tired of seeing so-called ‘refurbishes’ using those cheap bulk packs from Amazon and eBay, which are poorly manufactured, give horrible performance and don’t hold up in the long run. DeckTech belts are the only belts I will be using going forward.

Changing the belts is easy once you’ve cleaned up the mechanisms. You can change belts in these without removing anything but the top panel – you don’t even need to take the motor off. If you find one where the belts haven’t perished, changing them is the work of 5 minutes or less.

Aiwa Ad Wx727 Close Up Of Back Of Tape A

Unless the flywheels fall off the capstans, of course. The capstans are a simple 2 mm steel rod with a groove to take the front lock washer which holds the flywheels in place, as there is no rear thrust plate. Unfortunately as the plastic heats and expands with age, the tolerances (which weren’t very good to begin with) increase and the press-fit capstan is no-longer a tight fit in the wheel. A blob of epoxy sorts that problem, though you have to be careful to keep the shaft vertical in the wheel, and position the wheel so that there is a half a millimetre or so of play in the bearing for free movement.

When you do get it reassembled you’ll need to adjust the speed. The speed post are on the back of the circuit board fixed to the rear of each mechanism, right next ot the motor wires. Each mechanism has 2 pots for the 2 speeds – the one closest to the motor connections is normal speed, and the one furthest is the high-speed control.

First put the deck into service mode by holding the deck b tape detection button (the left-most switch on the top of the mechanism) while you power on the deck, and waiting for the display to indicate test mode. This can be finicky and might take a couple of tries. Adjust the normal speed first using a 3kHz test tape. Then, using the same tape, press the high-speed dubbing button on the front panel and the speed will double. Adjust the second speed pot for 6000Hz. Press the high-speed button again to return to normal speed and check your adjustment. Go back and forth, adjusting the two as necessary until you have them balanced. Repeat for the other deck, and exit test mode by pressing the standby button.

Aiwa Ad Wx727 Back Of Switch Board

Sound wise the AD-WX727 really surprised me. Speed stability isn’t great, though you only have to look at the flywheels wobbling while it plays to see that this is not a tape deck for the lover of classic or piano music. The mechanical instability is greatly exacerbated when you engage high-speed dubbing, so copied tapes end up with a noticeable warble. Playing pop and rock at normal speed, however, you don’t really notice. The sound is crisp and clean, with acceptably low noise and stereo imaging that is plenty decent. It’s a pleasant listen.

Autoreverse works quickly, and the obligatory music scan finds the gaps between tracks on the tape with ease. However it tends to miss the immediate start of the track. It attempts to cue the track perfectly but usually misses, so the first note or two of the track gets cut off. Never mind. Winding times are respectable, though the flimsiness of the mechanism is evident when the tape tape is fully wound in either direction – the mechanism coming to a swift halt with a grind and a clunk. If you don’t have the perfect size of capstan belt fitted, the mechanism will throw the belt from the flywheel at this point. It’s also a good test of whether you cleaned any belt residue from the belt path successfully, as if the reel drive belt sticks it too will lead to another belt throwing incident.

Aiwa Ad Wx727 Front Turned On

How to sum this up. Would I buy one? No, not at all. There are countless better tape decks for similar money. Guide price for one of these is about £50 refurbished, £30 not serviced but claimed working, and £5 broken. Equivalent models from Sony, Pioneer, JVC and others will give you better performance, reliability and quality for similar money. But if you have one already, or you can pick up a broken one for nothing or close to, it can give you reasonable sound despite its shortcomings in build quality. But proceed with caution, free is about £5 too much.

By Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2


  1. Great job Ashley! Somebody has to do it (if only to tell others what they might be in for..) 🙂

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