Back in the late 1990s, not long before I left Australia, I had a co-worker from Hong Kong who was always bringing back interesting things from HK. VideoCD players (and loads of great HK movies), my first DVD player – region free, of course – a NES clone with a bunch of those yellow Chinese clone multicarts, and many other cool items and software. One of the last things I acquired through him was a MiniDisc player – I certainly don’t recall the model at this point in time – and I remember really enjoying the futuristic nature of this music format.
Fast forward to 2020 and something or other reminded me of the existence of MD and encouraged me to get back into it. So I bought an MZ-E60 player, an MZ-NE410 NetMD recorder, and an MZ-R500 recorder (more about this later), and about 45 discs, and have been enjoying their capabilities. This post is a random set of notes about “things to know” if you’re new to the format or returning to it after a long absence. You should also go register at the Sony Insider Forums, as (among other things) you’ll find the old Sony NetMD software there, as well as service manuals for a few of the models. Information on the site skews heavily towards the portable Walkman models; very little is written about the hifi component models and the in-car models.
Recordable discs are available in 60, 74 and 80 minute nominal capacities (actual recording time depends on recording mode and can be up to 320 minutes), with 74 minutes being by far the most common capacity you’ll find from US sources.
As of September 2020, Tascam and Onkyo are both still manufacturing, or at least selling, new professional-grade MD recorders, but these are very expensive. Sony (and nobody else, as far as I can determine) is still manufacturing blank 80 minute MD (not HiMD) media for the Japan market only, at about $3.50 each – I have not found a way to order them for shipment to the United States, but with that said – there’s huge amounts of unopened NOS here and if you shop around you can find affordable prices; a few places such as Retro Style Media (UK) also sell them from a retail web presence.
Data retention was quoted by Sony at 30 years, and write life at 1M erase/write cycles, so even assuming a worst case, NOS disks probably have a decade or more of life left in them. I say “worst case” because there is a certain amount of literature about the materials used in the disc being quite delicate and subject to chemical degradation; if true, this means that it is inevitable that all the media now in existence will eventually become unusable regardless of whether they’re being rewritten or not. Certainly there are discs in my collection that are in the region of 20 years old and still have low BLER, so their impending demise is still unproven. As they are magneto-optical, MD media are believed to be considerably more stable than CD/DVD-R(W) discs that rely on chemical dyes. You can think of an MD as sort of like a piece of magnetic tape that is read back by a laser using the Kerr effect, rather than a writable CD/DVD which consists of a reflective layer with a writable dye layer in front of it to simulate the pits and lands of a pressed non-writable disc.
There are a few different recording modes, player/recorder types, and random considerations you may want to have in mind when selecting hardware.
- The three standard recording modes are SP, LP2 and LP4, corresponding to 1x, 2x and 4x time recordings (e.g. a 74 minute disc will store 296 minutes of LP4 audio). Older decks only support SP – do not bother buying one of those unless you have some specific collectible interest in it. My MZ-E60 purchase was not smart, and I regret it. LP2 sounds very good for music, and LP4 is perfectly adequate for the spoken word (audiobooks, radio plays and the like). Significant artifacting including loss of stereo is evident when using LP4 for music.
- Moving the laser carriage and accelerating the disc are the most power-consuming activity in the player. Most portables have a power saving mode where the sled and disc are accelerated gently, to reduce current drain from the battery at the expense of extended seek time. Because there is less head motion and disc velocity change per unit playback time in the LP2 and even more so LP4 modes, these modes have significantly longer battery life; it’s not quite x2 and x4 but it’s typically close to x1.5 and x3. Minidisc.org has a wealth of information like this for a wide variety of MD models.
- HiMD is a twice-orphaned subformat and not worth further investigation at this point in time, IMHO. If you have HiMD discs that you believe to contain something of massive import, you probably already have the hardware and certainly already the knowledge and motivation to get your data off those discs.
- There are various, excitingly confusingly versioned flavors of the ATRAC codec and DSP versions used in the recorders over time. This is mainly of interest when recording audio on the MD where you are reliant on the DSP’s realtime encoding performance (as opposed to loading it over USB, where the encoding is being done by the PC software). In summary: The newer the recorder, the better the results will be if you’re connecting it to a mic, line-in or TOSLINK audio source to record audio.
- The best way to get audio onto MiniDisc is, arguably, from a PC over USB. This requires a “NetMD” recorder. There are two pieces of Sony software, or a positively brilliant modern hack, that can be used for this purpose, but they all have downsides. The brilliant hack is Web Minidisc (requires Chrome or similar) and it will work from anything, including a phone. The downside to Web Minidisc is that, as a webapp, if/when it disappears off the web, you will have no way to use it any more. The other two options are both from Sony, and are now only available from the Sony Insider forums: SonicStage (allows you to transfer files in SP, LP2 and LP4 modes, but copy-protects them, see below), and MD Simple Burner (allows you to transfer in LP2 and LP4 modes only, but doesn’t have any of the copy protection issues). Both of these pieces of software can be coerced to run in Windows 10, but a) given that Windows 10 is constantly evolving, this might break at any time, and b) it’s an annoying hack requiring the installation of unsigned driver software. Much easier, IMHO, to install an older Windows version in a VM (XP is ideal) and run the software in there. Everything works perfectly with VirtualBox.
- Yes, I know about linux-minidisc. The status and functionality of this project are not obvious to me, and I haven’t yet tinkered with it; I don’t currently believe it will do anything for me that MD Simple Burner won’t.
- Copy-protected files from SonicStage are a real bear because they have an elaborate checkin/checkout mechanism, and the tracks are marked as “protected” on the disc itself. The only way of removing those tracks from your disc is to check the track back in using the same NetMD recorder and computer that you used to check it out. You can neither delete these tracks, nor even erase the entire disc, on most MD recorders – so SonicStage can easily create discs that are very difficult to reuse. Workarounds for this include having access to an old MD recorder that doesn’t honor the protection bits and lets you erase the disc anyway, or having a junker MD recorder on which you have disconnected the magnetic head. If you have one of these, you simply put the disc to be erased in it, record a short length of audio, and hit stop – the laser in write mode erases the TOC, but since the magnetic head is MIA, it can’t be rewritten and hence the TOC gets corrupted. This will allow an unmodified recorder to see the damaged TOC, build a new TOC and hence effectively erase the disc.
- There is no way, on a standard unmodified player, to extract digital data directly over USB (except on the very last HiMD player Sony ever released, the MZ-RH1, and even then there were copy protection rules). You can obtain a “perfect” recording by using a MiniDisc player with optical output and recording it in realtime, but there aren’t many decks with that feature. Given that you’re not actually extracting the original ATRAC bitstream anyway, but rather a decoded PCM bitstream, making a copy using line-out is probably almost as good.
- There are a confusing array of different inputs and outputs available on MD recorders, especially since oftentimes a single connector is used to perform double duty. Inputs may include: optical in (always TOSLINK Mini, buried inside a 3.5mm jack, on portables), line-in, mic in, and/or USB. Outputs may include: optical out (rare on portables), line out and headphone out. In some cases you may need to navigate menus to set the desired input or output mode. Consider your use cases carefully and choose a player/recorder with appropriate ports.
- There are data versions of MD and HiMD that can be used as computer drives, but they’re expensive, finicky and hard to come by both drives and media. And no, you cannot directly extract music data using one of these drives; it’s not like ripping a CD.
- The NetMD manuals talk about a “dedicated USB cable”. Don’t worry about it, it’s just a standard MiniUSB (not MicroUSB) connector.
- While there are many fine pieces of non-Sony equipment, most of the “hacker” information you will find, and community support, revolves around Sony models.
- Portable MD players and recorders have a few power options; roughly from oldest to newest: proprietary NiMH/Li-Ion battery packs, 1xAA cell, “gumstick” NiMH battery, internal non-removable LiPo cell. Many of the units that take an internal rechargeable cell also have a fitting for a battery case that screws onto the side of the player and generally allows you to use a single AA cell. The “gumstick” cells appear to still be in production, but obviously an unusual form factor like this is unlikely to have the forward-looking longevity of a standard LR6 AA. I recommend focusing on players and recorders that take the 1xAA option internally. This will preclude you from buying most of the ultra sleek Japanese players in particular, but it is the most future-proof choice IMHO. The screw-on battery cases are an annoying excrescence that makes the device less portable and enjoyable in the pocket.
- If you do buy a unit with an internal LiPo, especially of the nonswappable type, you should remove it as soon as possible to avoid it swelling and bursting the unit. Yes, it’s possible to rework these units with an off-the-shelf LiPo; videos exist on YouTube. Since these MD recorders are likely the sort of thing you’ll be putting away and only using infrequently, this possibility doesn’t change my advice to stick to 1xAA recorders and players.
- Many portable MD players and recorders have a remote control inline with the headphones. There are often features (such as editing track titles) that require this remote. Of course, the remotes are frequently lost :(.
- Speaking of cables and such – the slimmer NetMD recorders don’t have integral USB ports – they are designed to sit on a proprietary desk dock. If you don’t have that dock, you won’t be able to load music from your computer. As far as I can tell, all the 1xAA NetMD recorders do have an integral USB port, so if you follow my advice above when selecting models, it won’t be an issue.
My MZ-NE410 had malfunctioning buttons, which is a very common failure mode. Only the PLAY/PAUSE/Enter button worked – and this is because that button is connected directly to an interrupt line on the microcontroller, whereas the other buttons connect through a resistor ladder to an ADC on the micro. Oxide formation on the FFC connector made these resistance values wrong, and interfered with the key scan process. Unplugging the connector (upper right of picture below) and cleaning the FFC contacts with a Q-tip soaked in ispropyl alcohol fixed the issue.
MD has two modes of operation; magneto-optical (for recordable discs) and pure optical (for pre-mastered discs). If you are doing any significant maintenance on MD recorders/players, you will need to run calibration activities that require both a recordable disc and a “CD-ROM” pre-mastered disc, since the read paths are different for each type of media. Unfortunately, pre-mastered discs are rare, highly collectible, and hence ridiculously expensive – doubly so for the US, since the format never really took off here (and in Japan, where it was more popular, it was used almost exclusively in recordable mode). Thus, most of what you’ll see in the way of pre-mastered discs on eBay will be European imports at astounding price points.
The above maintenance activities are built-in to the device firmware and can be accessed using secret button press codes that you will find at Minidisc.org in the relevant Sony service manuals archived there. Interestingly, some players can be EEPROM-hacked using this service mode to enable functionality that was normally only available on higher-end models in the same family.
It’s possible to get lucky when looking for a calibration disc. In 1994, Rolling Stone magazine ran some kind of contest that involved distributing copies of a MiniDisc sampler album packed with mostly obscure tracks, and titled Turn It Up! – I managed to score a copy of this off eBay for $3 and it is my calibration target. I’ll look for a few more copies of it, or similar inexpensive demo/promo discs, for the same purpose. Nobody is making pre-mastered MD any more; there is a SMALL amount of niche software still being released on this format (very nicely produced, too), but it’s being made on recordable discs. You can see this very easily because “CD-ROM” discs don’t need to allow the magnetic write head access to the media. They therefore only have a door on the bottom; the label occupies the entire top surface of the disc. Recordable media have holes on both top and bottom, and a door that opens up both sides of the disc housing.