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A few days ago, an acquaintance sent me a message and a video of the Denon DR-M2 cassette deck, asking if I was interested in buying it. Within 5 minutes, I replied to him not to sell it to anyone else.

This model is part of the 1983 series, which consisted of models DR-M1, 2, 3, and 4. So, according to the model numbers, the M2 was only the second out of four offered. Interestingly, at a time when most manufacturers had multiple models in their catalogs, only one or at most two were three-headed. I’m not talking about Nakamichi, but about mainstream Japanese brands like Technics, Aiwa, Pioneer, Sony, Yamaha, etc.

With Denon, it was the opposite: out of the four DR-M models, three were three-headed, and only one was two-headed (DR-M1). Among the three-headed models, the M2 was the most modest. However, on the contrary, its price was not modest nor to be underestimated: it was around 500 EUR or 1,000 former German marks.

For that money, you got a nice silver deck (there was also a black version, if I’m not mistaken), and for an additional fee, optional wooden side panels and a wired remote control.

The device itself doesn’t have anything particularly special in terms of options… or almost nothing, at least not visibly. However, it is well-made and honest, although it’s clear that cost-saving measures were taken, but not in crucial areas.

The specificity of the Denon DR-M2 (as well as the entire series) is the membrane keypad for basic functions. It’s a designer’s play to make the deck look flatter from the front and a bit more futuristic. The keypad itself isn’t exactly a true membrane like on early home computers (who remembers Sinclair ZX80 and 81), but behind it hide standard micro switches, which is a great and long-lasting solution, instead of having a conductive layer on the foil itself that deteriorates over time and needs to be renewed.

The rest of the deck is classic: sliding potentiometers, Dolby, mechanical tape/source selector switch…

Although you would never guess, the entire front panel has not a sliver of metal but is entirely plastic, and when dismantled, it is extremely light, so it lacks any anti-vibration properties. The same applies to the door cover – about 4 mm thick plastic in one piece, of good quality but again just plastic. The cassette holder is a mixture of metal and (how many times should I mention) plastic and is sturdy, which can be important.

The display is nice, quite large, fluorescent type, with dual-color pixels but without peak hold – really a shame, I miss this function.

I also miss the ability for the user to adjust bias – it’s so simple to implement, but Denon just didn’t want to. The DR-M3 model, next in line, has automatic calibration, and logically, they should have included at least manual bias adjustment here, like in the later DR-M33 and others. But they didn’t. Besides peak hold, variable bias is what I miss, and perhaps, a memory for the counter.

Speaking of the counter, let me say that it’s also executed via a fluorescent tube, quite deep behind the window, and the values can be read easily only at small angles relative to the central axis. It has 4 digits, and one side of a C60 cassette counts around 3,200 value changes. Additionally, the counter processor can display remaining time – for this, a specific function must be selected and the cassette length chosen, and then let the processor do a bit of “thinking,” which takes a few seconds. It’s quite precise, I’ll admit, but the remaining time changes in minutes, not seconds, up to 6 minutes before the end. Also, the value doesn’t change during fast forward or rewind; it’s recalculated only upon playback or recording start. Although somewhat primitive, the remaining time function isn’t as bad and unusable as it may seem from my description.

Internals

The electronics are neatly arranged but with plenty of connectors, as was customary during the eighties. The mechanics of the DR-M2 are a fairly valuable part of this device: three motors, the main one being DD. I don’t know who made it for Denon, maybe they did it themselves. Anyway, it has been used in several generations of better decks from this manufacturer; I think the last of them was the DR-M800, but with a belt drive and a regular DC motor instead of the direct drive, which is a real shame. I’ve never tried installing a DD motor from a DR-M2/3/4 series onto the DR-M800; perhaps it would work without excessive modifications.

Speaking of transports, in the DR-M 1-4 series, the best solution is, of course, the DR-M4 because it uses two flywheels in a closed loop, which unfortunately makes maintenance more complex. The DR-M3 and 2 have identical mechanics, with a specifically designed tape tensioner. Denon calls it the Tension Servo Sensor; I believe it’s version 2 on the DR-M2, but I’m not familiar with the differences between versions of the system itself. Honestly, the mechanics of the DR-M2/3 are fully ready for the installation of an additional flywheel with bearings, roller holder with roller, and a belt. However, they avoided doing that. I believe the difference in manufacturing costs was very small, but they somehow had to distinguish the DR-M4 from the DR-M3, not just by adding some cosmetic option. Overall, the development of this series of devices reminds me of the top-down method used by Sony for the ES line of components: first, they developed the flagship model, then simplified in terms of options and technical solutions, thus arriving at the cheapest model. I would say Denon used the same methodological approach, which I find brilliant.

Returning to the Tension Servo Sensor: at first glance, it bears a striking resemblance to the lever used in old inexpensive Walkmans and cassette mechanisms for basic autostop systems. In those mechanisms, the lever is located between the erase head (if present) and the recording head. In such an autostop system, when the cassette reaches the end, the tape tightens and lifts the lever, which mechanically influences another lever. Due to the change in position, a tooth on one of the mechanism’s wheels catches the second lever and moves the next lever—the one for locking the play or record button—unlocking it and releasing it. It’s a simple and quite effective solution, but it doesn’t work when it comes to fast-forwarding or rewinding.

As far as I understand, the Tension Servo Sensor is a assembly of a movable erase head (similar to decks that use a felt tensioner) and a movable lever. The entire system is finely constructed so that it dynamically adjusts the optimal tension of the tape over the recording and playback heads by dynamically moving the lever depending on the tension of the tape and controlling a system composed of a lever and an erase head. Additionally, the lever over which the tape slides further stabilizes the movement of the tape.

Let me delve a bit deeper into the story without boring you, dear followers of my site:

Namely, the way the tape moves over the recording and playback heads is one of the crucial parameters for achieving quality sound. Here, we have factors like the shape of the head, as well as the mechanics of the cassette, which significantly affect this. As a compact cassette is essentially an ultra-simple and rudimentary solution that was never intended to venture into HiFi waters, its mechanical properties reflect that. Over time, they have improved a lot: materials, precision of manufacturing, etc., but the cushion in the cassette (tape pad) is still there. And… it presses the tape against the head, while on the other hand, the force of the tension changes (due to mechanical friction, layers of tape stacked on each other, etc.), and the tape itself is not stable along at least one axis. It can even “wobble” when approaching the head because the guides are nowhere near as precise as, for example, those in video recorders or DATs that have rotating heads and guide rollers. All of this causes various effects, which boil down to the tape’s non-uniform passage over the head; effectively, it’s not on a stable path, and these changes can be very small and fast.

That’s why manufacturers have tried to introduce various solutions to:

A) Ensure a constant and optimal level of tape tension, without large fluctuations, ideally completely without fluctuations.

B) Isolate the part of the tape that passes over the heads from the rest of the system, such as:

• The tape take-up reel, which is fortunately already isolated with the main audio shaft and roller.
• The reel that supplies the head with tape, where the main problem lies.

The Closed Loop Dual Capstan system very nicely addresses these problems but requires considerable precision in manufacturing to maintain optimal tape tension, avoid unwanted component resonances, etc. It is more sensitive in the long run because it is more complex. That’s why manufacturers have tried other solutions, like Denon with the mentioned Tension Servo Sensor.

Many would say: Why would I need that? In reality, the human ear is a very sensitive but also terribly imperfect instrument at the same time. However, when you connect a deck with a good system with two flywheels in a closed loop and another one that has only one flywheel and a simply resolved tape tension (by the way, even systems with two flywheels in a loop have tape tensioners on the reel itself, but let’s not delve into the topic…), you immediately see how unstable the tape is over the heads in those with a single flywheel. Fluctuations in signal strength are clearly visible, especially on the left channel, which is always critical. Mind you, I’m talking about serviced decks, with new rollers, idlers, cleaned, lubricated.

The human ear hardly registers this directly, and my modest opinion is that this is what manufacturers of mechanics used when making the latest generations of transports. Subjectively, the biggest difference is noticed in the high tones, which lose their crystal-clear representation and appear a bit muffled because they lose their edges, but not constantly because the tape becomes a bit stable, then wanders a bit. Even when switching off and on playback, different signal values from the test tape are obtained, which can be up to 0.3 dB or similar. And this is a standard phenomenon that I encounter… and it’s a matter of design.

And here comes Denon: their solution really works, and the level fluctuations in the channels are about 3 times less than in other decks with a single flywheel that I have tested and do not apply similar solutions, so the level fluctuations in playback go to about 0.05-0.10 dB, which is very good. Let me mention that my favorite Sansui D550M with its anti-scrapping filter based on two flywheels, the first of which is a simple audio shaft without a roller, works great. But Denon is great too, I admit.

Returning to the mechanism: of the three motors, the second is intended for rewinding, and the third for servicing the mechanics in terms of lifting and lowering the heads, releasing brakes, etc. Standard and one of the best solutions.

This mechanism is solid, not in the Revox category, but it causes few problems and is generally long-lasting. When changing modes, it is not as quiet as the Nakamichi transport of the II generation or the Pioneer Reference mechanism, but it is quiet enough because it does not contain any actuators or classic electromagnets for brakes and head lifting. Furthermore, it is very fast, and switching from one mode to another is smooth and almost instantaneous.

Regarding electronics, Denon evolved its series rather than revolutionizing them, so the electronics resemble those installed later in the DR-M22/33/44. Irrelevant to the story, even the internal plastic casing is identical. One of the differences is that the DR-M2 uses a mechanical instead of an electronic switch, and it is sensitive to dirt and dust. However, when properly cleaned, it can degrade sound less than the later popular 4066 IC.

Also, the DR-M2 does not have mute transistors at the output whose function is to disable the output when the deck is not in playback or recording mode. These transistors were standard at the time (and later), but Denon uses a small, quiet relay. In my opinion, this is a better solution.

Service

This little Denon DR-M2 is full of surprises. First, the deck practically didn’t work at all; it had been sitting on a shelf or who knows where… for forty-something years. Imagine…

Dust had entered it through the cooling slots, which I cleaned out. The owner was not a smoker or at least did not indulge in nicotine addiction near his equipment. So there was no need to wash the electronics and mechanics, which looked like they just came from the store.

What fascinated me was that both the roller and the idler still worked, even though they were so old. Replacing the roller is not difficult, replacing the idler is not exactly pleasant, but everything can be fixed… yet I decided not to replace them; I felt sorry because they were in such good condition and would work for some time longer.

Also, the output relay still worked – yes, it is hermetically sealed, but even those fail.

The recording and output level potentiometers, as well as the monitor button, were more interrupting than conducting, due to being stagnant, and the potentiometers had a lot of dust, so I cleaned and lubricated them several times until they worked like new. I rarely see something like this.

The clip of the door damper for opening the door was broken and malfunctioned due to age, and it gave me a bit of trouble, but I had spare parts, patched up the hole with epoxy resin, and replaced the clip. And everything worked well enough.

The biggest trouble was caused by the counter – the display didn’t work. I replaced resistors, capacitors, looked for cold solder joints, and in the end, it turned out that they actually existed, on the pins of the display that lead to the heater.

It’s simply incredible what standing does to a device.

Adjusting the DR-M2 was easy because it had only minor deviations, except for the bias. The mentioned deviations could have arisen due to aging components or because the deck was incompletely tuned at the factory. On the other hand, bias is adjusted, according to the service manual, using a Denon DX7 cassette of 50 minutes. It’s a chrome tape, but I didn’t have it in my collection, so instead, I used a Maxell XLII and adjusted the recording level and bias.

I was surprised that the frequency response was very linear, not quite like the wonderful little Grundig CF4 or Fisher CR-9070, but still great. I didn’t measure the range for each type of tape myself, but the DR-M2 showed me that it can reach up to about 20-21 kHz using a Maxell XLII cassette at -20 dB input signal and with a threshold value of -3 dB.

It is important to note that the foil on the front panel, which covers the buttons of the basic transport commands, showed no signs of aging, which is excellent. Procuring such foil is practically an impossible task, and it should be protected from extreme temperatures, as well as direct sunlight. Handling, however resistant it may be, should not be rough – gentle pressure is sufficient.

The sound

The Denon DR-M2 sounds very, very good, even with a no-name normal cassette that I inserted. Unexpectedly dynamic sound and very good harmony across the entire range provide an excellent overall result. Compared to the source, I got a slightly darker character, but that’s quite normal for decks that don’t have user-adjustable bias and are used with cassettes they are not calibrated for. However, the essence of quality remained: brilliant, stable notes flowed from it. Interestingly, it persistently made me enjoy the music instead of paying attention to the technical characteristics of the sound. Excellent!

With the TDK D, the situation changed, and the sound became brighter, but it still remained soft, with a lovely, powerful bass. I noticed that the DR-M2 has that nice, soft bass that is so pleasing to the ears. It’s not “round,” “boxy”; it’s just right – soft, defined, powerful, with a large body. Delightful. This applies to its recordings as well as to others.

Switching to the optimal cassette – Maxell XLII, with which, as I mentioned, I performed the internal calibration of the recording amplifier gain and deck bias – naturally yielded even better results. It was quite difficult to distinguish the recording from the original, whether using the tape/source switch or comparing the 1:1 recording in my system. Let me return to the description – subjectively, the dynamics were not better, but the edges of the notes were better defined, as were the high tones. The sound, overall, was highly recommendable.

All the positive elements of playback of my own recordings that I noticed using an unknown normal tape remained here as well.

Playback of tapes recorded on other decks (some of which were Grundig CF4, TEAC V-770 and V6030S, Fisher CR9070, Yamaha KX-1200) was excellent. Why am I writing this? Well, because a considerable number of deck enthusiasts have an old cassette collection and want to play them on the device they buy, so it must be at least roughly compatible with the standard (provided that the original cassettes were recorded according to the IEC standard).

As a conclusion regarding the sound, I could say that the Denon DR-M2 is one of the most musical decks I’ve had the opportunity to hear. Its bass is excellent, and the details of the high tones are truly unexpected for this category of device, along with a soft and nicely presented midrange.

As a drawback, I would mention the struggle with sibilance, which is a common problem with a large number of cassette decks. This drawback doesn’t always manifest, but it occurs frequently enough for me to mention it as a con.

Conclusion

Plastic on the front and inside, foliaceous, modest in options, decently engineered, with very good mechanics relatively easy to maintain, with solid peak meters and… great sound both in playback and recording. An underrated and unknown machine with which, despite all its limitations, I could live. What more? If you can find a piece in good condition, and you need something like this, definitely consider it – it’s excellent for playing old cassettes, as well as for recording. For enthusiasts who love to adjust every detail during recording, there are certainly better decks available, but the Denon DR-M2 itself is fantastic. Recommendation.

I should mention that our house cat seemed to know when I was recording with the Denon, and despite standing together with other devices for weeks, it was precisely then that he jumped on it and started rubbing against the edges. A little model, wanting to be photographed.

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