Buying A Used Tape Machine

The sound of analogue tape is still revered, but acquiring and maintaining your own machine presents a unique set of challenges.

At least a generation has grown up without hearing high‑quality analogue tape recordings, and with no experience of using reel‑to‑reel machines, but as more people move to digital recording, the old technology is becoming more affordable, and there's a resurgence of interest in tape. There are plenty of reasons to want to use it ('Analogue Warmth' in February's SOS explores them in detail), but buying and maintaining a tape machine can be a minefield for the unwary...

Look Before You Leap!

Let's start with a reality check. If you want good results, a tape machine can be expensive to run and is likely to become more so over time: there are lots of moving parts in even the simplest machines, and they spend their time slowly wearing themselves out. No big manufacturer has built new machines for years, so some spare parts are becoming scarce and expensive. Motor bearings, tape guides and rollers, pinch wheels, brakes and tape heads are all essentially consumable parts. The electronics also need regular alignment, so recording and replay remain within appropriate tolerances. Most settings need adjusting as heads wear or if tape type is changed, and ideally should be optimised for each new batch of tape. If everything isn't aligned and properly maintained, quality suffers quickly and obviously.

Routine maintenance includes cleaning the tape path, heads and pinch roller of the oxide and other deposits that gather as tape runs through. Running a magnetised tape over ferrous objects in the tape path will also induce some magnetism in them, so you should also consider degaussing (demagnetising) the machine: how often depends on the machine's design and the amount of tape run through it, but could vary from weekly to annually. Decent degaussing tools aren't expensive, but they need to be used with care: it's easy to end up magnetising the machine quite strongly if you're unsure what you're doing, which could damage any tapes you play on it.

Electronic alignment comes down to physical head alignment, replay gain and EQ, record gain, EQ and bias. To align the heads and replay circuitry you need a decent test and alignment tape, which will also wear out eventually.  To set up the record electronics, an audio signal generator will be required too. It's not hard to align a tape machine's electronics if you have the equipment and knowledge, but if you don't the machine will need to go to a specialist.

Mechanical alignment of the transport is often quite straightforward on more modern three‑motor servo‑controlled machines: little is needed other than lubrication with the correct oils or greases in the appropriate places. Older machines, though, often relied on friction brakes to control tape tension and arrest fast winds, can be fiddly to set up, and may require specialist spring gauges and other tools. The medium itself (tape) isn't especially cheap, either!

The oldest machines tend to have valve electronics, which can add an extra sonic dimension, but they also tend to have wide replay head gaps, which limits top‑end response dramatically, and they're mostly mono rather than stereo. The heads can be replaced with modern, narrow‑gap alternatives (they may have to be replaced, due to wear and tear). More modern machines tend to have better specifications, including more headroom, making them better able to cope with modern high‑output tape formulations. Better machines also have sophisticated servo‑controlled motors, providing much gentler tape‑handling and better wow‑and‑flutter figures.

Recording Formats

Paul White's Tascam 32 half‑track tape machine.

The narrowest common open‑reel tape format is quarter‑inch, generally available on five‑, seven‑ or 10.5‑inch spools, the first two with 'cine' centre sprockets and the latter usually with NAB centres (which usually require cine‑NAB adapter hubs). Domestic tape recorders generally record two tracks (or stereo) in one direction, and another two tracks in the other direction. This is usually called a 'quarter‑track' format, and the track width is the narrowest in common use. Narrow tracks mean fewer magnetic particles to record the signal on to, and hence a poor signal‑to-noise ratio: they tend to be hissy. This is made worse because such machines run at low speed, typically 3.75 or 7.5 inches per second (ips): the slower the speed, the fewer magnetic particles pass the heads. It's impossible to be precise, but machines of this type would usually have perhaps a 55dB signal‑to‑noise ratio, with high frequencies rolling off increasingly above 14kHz.

Next up is the 'half‑track' format on quarter‑inch tape. The tape runs in a single direction, capturing two tracks (or stereo) along its length. The doubling of the track width brings a reduction in tape noise, and most half‑track machines can also be run faster (typically 7.5 or 15ips), bringing a further quality improvement. Pro and semi‑pro stereo machines usually employ this format, and well set‑up half‑track machines running at 15ips pretty much defined 'broadcast‑quality sound' for half a century: a signal‑to‑noise ratio of 65dB and a bandwidth close to 20kHz is perfectly achievable.

The primo format is half‑track, half‑inch at 15 or 30 ips. These are popular high‑end mastering formats, and provide well over 20kHz bandwidth and a 75dB signal‑noise ratio. Machines are relatively rare and expensive, the Ampex ATR100 being among the most favoured for this role.

The quarter‑inch, quarter‑track format was also used for semi‑pro four‑channel multitrack recorders, with the tape only running in one direction, usually at 7.5ips or faster. Scaling this format up, half‑inch tape allowed eight channels with the same track widths and speeds, and one‑inch tape gave 16 tracks. In each case, the relatively poor signal‑to‑noise ratio was a problem when mixing four, eight or 16 tracks together, so various double‑ended noise‑reduction systems were employed. Dbx systems were very common on semi‑pro and project‑studio machines, while some later machines adopted Dolby C or Dolby S.

Professional multitrack machines tended to extrapolate from the professional two‑track formats: half‑inch tape generally supported four tracks, one‑inch carried eight, and two‑inch had 16 or 24 tracks. Sixteen tracks on two‑inch tape provides broadly the same quality as half‑track quarter‑inch and is a highly regarded format — but 24 tracks offered versatility, and in the '70s, 24‑track became the de facto standard. Again, noise‑reduction systems were commonly used (Dolby A and latterly Dolby SR being the favoured choices), and were absolutely necessary with the two‑inch, 24‑track format.

Which Machine?

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The cheapest available machines these days will be simple, two‑head, low‑speed, quarter‑track machines using quarter‑inch tape. These have an erase head and a combined record/replay head, much like most cassette recorders. They're a nightmare to align, and best avoided for serious work. On the next rung are several reliable three‑head domestic machines, the Akai 4000D, DS (Mk I and MII) and DB. The Sony TC377 or TC399 recorders were particularly popular, but there were many more from the likes of Tandberg, Philips, Ferrograph, Dokorder, Technics and others. Three‑head machines use an erase head, and physically separate record and play heads (making off‑tape monitoring possible), and are usually much easier to use and maintain. Most can't accommodate spools larger than seven inches (diameter) and use the quarter‑track format, but they're fine machines for messing around with tape loops and learning basic tape-editing skills, or for providing lo‑fi tape saturation. They're unsuitable for high‑quality recording or mastering.

Moving up a notch brings us into the realm of the mighty Revox, the domesticated half of the Studer‑Revox group, which shared much of its professional sibling's DNA. There's massive support available for virtually the entire Studer‑Revox lineage, from valve machines like the G36, through the A77 and A700 and onto the B77 and PR99s. Quarter‑track, slow‑speed Revox variants do exist, but the majority on the market tend to be high‑speed (7.5/15ips) half‑track machines, and all accept 10.5‑inch reels of quarter‑inch tape. It's possible to convert low‑speed quarter‑track machines to high‑speed half‑tracks, but it's not a cheap option.

With the broadcasting industry's wholesale move to digital recording, countless Studer (and other) machines flooded onto the market and are now easily found: models ranging from the elderly B67s, through the A810s and A80s to the A807 are all quite common. You may also find the A80's broadcast‑studio rival, the Telefunken M15, both huge flat‑bed machines ideal for fast tape editing. There are plenty of other equally high-quality machines from Sony, Ampex, Ferrograph and others, and Nagra should get an honourable mention too: the Nagra T is a stunningly good studio machine, and for transportable applications you can't beat a Nagra IV‑S, but the Nagra name inevitably attracts a high price. Other professional options include machines from Otari (MX5050 and its siblings), and the unusual but impressive Technics RS1500, with its unique 'closed loop' transport.

Perhaps the most dominant name after Studer‑Revox is TEAC‑Tascam, who produced a wide range of two‑track and multitrack machines over a long period. They're reliable workhorses, and their four‑track 3340 and 3440 introduced affordable multitrack recording into the project studio market.

I've focused largely on stereo machines because that's where it's easiest to get quality on a budget, but the same names crop up in the multitrack market. The high end was dominated by the Studer A800 and Otari MTR90 (and their forebears and derivatives), followed by various Tascam models, with a wide variety of Fostex machines popular in the home market. The Fostex machines tended to use narrower tape formats (eight tracks on quarter‑inch tape, 16 tracks on half‑inch) and slower speeds, so the quality isn't up to that of the large‑format high‑speed recorders, but they generally included Dolby C or Dolby S noise reduction, and are perfectly adequate for most semi‑pro purposes.

Other Considerations

One thing you shouldn't forget is that the recording medium's characteristics have an impact on other aspects of the recording process. Recording to tape will inherently impose a certain sonic character (however subtle), which will change the way you work compared with DAW recordings and mixes: you might prefer to use a rich‑sounding valve mic, or a mic pre with generous transformers when recording to a DAW (to impart musical character), but when working with tape you may prefer something that sounds a little 'cleaner' or 'sharper' as a source. Similarly, you may find that when working with all‑digital audio, you choose plug‑ins to smooth the sound, but with tape you work to add air and sparkle. There's nothing wrong with either approach, but they are different, and you have to take that into account. Blending the best of both worlds can be a great option, whether that means tracking with a DAW to capture a pristine, accurate source, and selectively bouncing tracks to tape and back to introduce tape saturation or character, or recording to multitrack tape and transferring to your DAW for editing and processing — or working completely in your DAW but bouncing the mix down to a tape master.