This unassuming black box provides full MIDI to tape synchronisation without tears. Paul White gets himself locked up...

JL Cooper has established a strong reputation for building very practical accessories designed to fill a specific need, usually in areas involving MIDI. The PPS2 is the latest in a line of easy-to-use, low cost, MIDI-to-tape sync units built by this company for use in studios where MIDI sequencers and tape machines are required to work in synchronism with each other. It has been possible to sync MIDI to tape almost since the first MIDI sequencer came off the drawing board, but JL Cooper recognised that existing methods were either inadequate or too complicated. At one extreme, you can generate a time code based on MIDI clock pulses. This works perfectly well — but only if you start from the beginning of the song every time you want to sync up. At the other extreme is SMPTE, a powerful real-time code developed for the film industry, which doesn't suffer from the above problem, but which is unnecessarily complicated for applications which don't involve sync'ing to picture.

JL Cooper pioneered Smart FSK, FSK standing for Frequency Shift Keying. This simply describes a system for recording time code information as a series of tone bursts at two different frequencies and need not concern the user. The Smart part of the name comes about because, unlike FSK systems working only from MIDI clock, Smart FSK utilises a part of the MIDI protocol known as MIDI Song Position Pointers, so that when you start your tape machine part way through a song, your sequencer is almost immediately told whereabouts in the song it should be and, within a second or two, both machines are running in sync. This assumes your sequencer is equipped to work with SPPs, but the vast majority in current usage are.

Though Song Position Pointers tell the sequencer where it should be, the timing information itself is still based on the MIDI clock which, in turn, is related to the tempo of whatever piece of music happens to be running in the sequencer (or drum machine) at the time. This is good news for ease of use, because any tempo changes that have been programmed into the original sequence will be reflected in the rate of the time code when it is recorded to tape. Here's how it works in the case of the PPS2.

PPS2

The PPS2 is a small, utilitarian, black brick fed from an external power adaptor almost as big as itself. It has two three-way toggle switches on the front, a couple of LEDs, and rear panel connections for Sync In and Out and MIDI In and Outs. One of the switches allows the PPS2 to work directly with MTC (MIDI Time Code) — (a MIDI equivalent of SMPTE which few sequencers support yet), DTL (a proprietary system for use only with Mark of the Unicorn sequencers) and FSK, which relates to the Smart FSK system we've been talking about. The other switch has positions for Stripe (recording the code to tape), Read (reading the code from tape) and Off (which means just what it says). A red LED indicates that the power is on, while a green LED shows that MIDI clock is being received during Striping (recording time code to tape), and that the unit is receiving time code while in Read mode.

To stripe a tape, the MIDI output from the sequencer is linked to the MIDI In of the PPS2 and the Sync output of the PPS2 fed to a spare tape track, traditionally the highest numbered track on the machine. With the PPS2 set to Stripe, the tape machine is put into record and then the song in question played through on the sequencer.

Once the code has been recorded, the tape output is fed to the Sync In of the PPS2 and the MIDI Out of the PPS2 linked to the MIDI In of the sequencer. The PPS2 is switched to Read. Once the sequencer is set to external MIDI Sync mode, it will automatically play in sync with the tape, regardless of where in the song the tape is started, and the green Lock LED will come on. It is now possible to record parts onto tape while listening to whatever is recorded onto the sequencer, and if additional sequencer parts need adding while the system is sync'ed up, plugging a MIDI keyboard into the MIDI In of the PPS2 will accommodate this, by merging the MIDI clock information with the new MIDI note information before passing it to the sequencer.

This is how most people will use the unit, but it can also function as a SMPTE generator and reader (30 frames per second format only in generate mode) if it is set to either MTC or DTL before being powered up. As a further benefit, the PPS2 can regenerate SMPTE codes; when a SMPTE code is present at the input, a regenerated version is provided at the Sync Output, which will continue intact, even if the input SMPTE code has small dropouts (up to six frames long).

Practicalities

Most users of this kind of equipment will want to use the Smart FSK mode of operation, unless they own MOTU sequencing software, in which case they'll probably use the DTL option. While the SMPTE facilities offered by the machine could be useful, this is not designed to be a full-function SMPTE sync unit — but the ability to regenerate SMPTE code is a welcome bonus.

The only critical thing about using the machine is making sure that roughly the right signal level goes onto tape; if it's too high, the code could bleed through to an adjacent track, while if it is too low, it could become unreliable. As it comes, the PPS2 works fine plugged directly into most home recording machines which use the -10dBv operating level, though it gets a bit near the knuckle with pro machines, where some degree of gain control would be welcome. Since it is a definite advantage to route the PPS2 directly to the tape machine, rather than going via the mixer, with a risk of possible crosstalk, this refinement would be particularly useful.

"For the musician working at home with a multitrack and sequencer, who hasn't already got a sync facility, Smart FSK gets my vote."

On tape machines with dbx noise reduction, the dbx should be turned off on the sync track, or the code may not read reliably, but Dolby systems don't seem to cause a problem — though with virtually all sync units, if there is a choice of turning off the noise reduction on the sync track, then it's best to do it, regardless of what type of noise reduction is being used. Similarly, on tape machines with no dedicated sync input, ensure the EQ settings are flat on the sync channel.

Summary

Of all the possible sync systems, Smart FSK is arguably the easiest to use, the only consideration being that you have to record at least part of your sequence with all the relevant tempo information before you can stripe the tape. If you subsequently decide to change the tempo or arrangement, you'll need to stripe the tape again but, as this only takes as long as the song you're working on, it's not a serious limitation. With my C-Lab sequencing software, sync was achieved in a second or less which, for all intents and purposes, is instantaneous.

If you're working with video, then a SMPTE synchroniser is mandatory, as SMPTE is the de facto standard time code for film and video work. If your sequencer package has a dedicated SMPTE interface, such as C-Lab's Unitor, then you should find it as easy to use as Smart FSK, even though it costs a little more. But for the musician working at home with a multitrack and sequencer but no sync facility as yet, Smart FSK still wins my vote — SMPTE really is a sledgehammer to crack a walnut. JL Cooper's sync units are reliable, simple to use and sensibly priced, which is why they have dominated this section of the market since Smart FSK was first introduced. Once you get used to the sync way of working, you'll wonder how you ever managed before.

Further Information
JL Cooper PPS2 £185 including VAT.

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