You want to sync your sequencer to tape but the budget's tight and you don't know if FSK code's smart enough or SMPTE code's cheap enough - let Vic Lennard introduce a budget synchroniser that handles both.
The combination of tape recording and MIDI sequencing is now the basis of bedroom studios and professional studios alike. At the heart of the system is a synchroniser - perhaps Syncman.
AS ANY STUDIO engineer will tell you, if you're going to make music by building up layers of sequences, you have to ensure that each take will be in perfect sync with the previous ones - if you are to remain in control and the music is to sound anything like you intended it to.
With older synchronisation systems there is also the problem of having to start the song from the beginning every time - a minor irritation, you might think, but after the 20th take, it's sometimes hard to tell which is wearing out faster, your nerves or the tape. Not only that but you inevitably end up asking yourself "Will it still be in sync by the 53rd bar?".
Of course, over the past two years or so, tape sync devices have appeared which 'chase" the song and lock in at any position. Generally speaking, these have been split into two categories - SMPTE and 'intelligent' FSK. We'll discuss the differences later, but for now let me introduce you to the latest addition to the latter group - the Syncman, from Musicsoft in the good ol' US of A.
AT LAST - A piece of gear which isn't in a black box. Instead, Syncman takes the form of a small grey box (well that must have really brightened up your day - Features Ed) with In/Out sockets for MIDI and Tape (each with its own red LED indicator), a Write button and a block with six DIP switches for various applications. A quick peek inside revealed Syncman to be constructed to the same high quality as its sister (brother?) unit, MIDIMan (reviewed last month), and like its stable mate, it too is powered via an external 9V supply.
IN SIMPLE TERMS, Syncman takes the MIDI timing and position data provided by a sequencer or drum machine, and encodes it onto tape. Standard FSK (Frequency Shift Keying) code takes MIDI timing clocks and creates a two-tone signal which can be regenerated on playback. Syncman, however, goes one step further and encodes MIDI Song Position Pointer (SPP) into this signal. The signal is sent out every 16th note and keeps track of how many semiquavers have passed since the start of the song. Consequently, when the tape code is replayed from any position, the SPP directs the sequencer to the next 16th note and playback then commences with MIDI timing clocks (every 96th note), keeping the machines permanently in sync.
Setting up is quite straightforward; in fact, the connections of MIDI Out from the sequencer to MIDI In on Syncman and Tape in/out to the recorder can be left permanently connected. DIP switch 3 (Song Pointer) has to be set to On and generally, it is best to avoid passing the code through a mixing desk. But, of course, this will depend on the level showing on the recorder when directly connected; some attenuation of the signal may well be necessary (though it is unlikely to need boosting). On a Fostex E16, the meter registered 0dB, which is fine, but if there is a problem you could try using a simple potentiometer to cut down the signal level.
To record, first check that the sequencer is set to output MIDI clock and SPP. Then, set the tape recorder to Record, hit the Write button (which turns on the Tape LED), start the sequencer, and check that the MIDI LED flashes to indicate that Syncman is receiving timing information. If possible, turn off all tracks with MIDI note and performance data to ensure that there are no delays in the sending out of MIDI clocks.
To sync up on playback, simply set the tape to Play, the Tape LED lights up and the MIDI Led starts to flash, at which point the sequencer locks up - locks in sync that is, not locks up like a computer going into an electronic sulk.
ONE PROBLEM OF working with MIDI clocks is their inherent inaccuracy during tempo changes. Let's say that the piece you are recording is at 120 beats per minute and decreasing in tempo. A MIDI clock occurs each 5.2 milliseconds at 12Obpm; as the piece slows, the gap between pulses increases leaving the sync unit waiting to be told what to do. This situation can give rise to audible fluctuations in tempo. And the slower the tempi involved in a tempo change, the more noticeable the problem. On the other hand, SMPTE is an absolute timing reference which has no dependence on Tempo or the relative position in a song. Each SMPTE timing "Frame" is unique.
You could, of course, try recording MIDI information directly to tape but as MIDI operates at a rate of 31,250 bits per second, the necessary audio bandwidth is outside that obtainable from analogue tape. So what is the solution?
Well, without delving too far into the theory, MIDI Time Code (MTC) is a non-tempo based timing protocol which can be merged with other MIDI information (which SMPTE cannot). Syncman can record SMPTE to tape in any of the four main formats (these are set using DIP switches 1 and 2), and will then convert this to MTC. Additionally, DIP switch 4 allows for SMPTE to be converted to Direct Time Lock (DTL) which is used by the Performer sequencer package on the Apple Macintosh. The problem I had was in locating a device that will read MTC - there are currently very few around - so unfortunately I did not get the opportunity to check this out.
"Nothing untoward occurred with the review unit, so I can only assume that the 'Jam' sync facility works well - or I've stumbled across a batch of perfect 1/2" magnetic tape."
SYNCMAN'S LOCK-UP TIME is less than one second but depends on the speed of the piece of music (because the next 16th note is that much further away at slower tempos). Syncman is very flexible in terms of recording level on tape - anything upwards of -20dB seems quite satisfactory and while too high a level will often cause code distortion, I found I could run it beyond the range of a Fostex E16 which is +8dB.
It would take a major tape flaw to make the Tape LED flicker, and Musicsoft claim to have included an automatic "jam" sync facility where Syncman will continue to run even if small dropouts occur. In the course of three days recording and usage, nothing untoward occurred with the review unit, so I can only assume that the "jam" sync facility works well - either that or I've stumbled across a batch of perfect 1/2" magnetic tape.
Throughout the review, Dolby C on the E16 was left switched in. Care has to be taken with some FSK generators, as the higher of the sync tones can be above 1kHz - the area in which Dolby B and C act (SMPTE does not usually venture anywhere near this frequency). Syncman, however, appears to be flexible enough to cope with this, and I encountered none of the traditional problems associated with time code and noise reduction systems.
If a MIDI keyboard is connected to the MIDI In on Syncman and DIP switch 6 (Merge) is turned on, you can continue to record onto the sequencer while still locked up to tape - incoming MIDI data is added to the MIDI clocks being created and then sent to the sequencer. As the sequencer will have to output MIDI clock and then be set to receive it, it is conceivable that a loop could occur, with MIDI clocks from the sequencer being merged with those being generated within Syncman. With the merge switch turned off, however, this situation cannot arise.
Concluding our tour of Syncman's DIP switches, DIP switch 5 is for duplicating a SMPTE or Tape Sync code either from one machine to another or from one track to another on the same recorder.
PROVIDED THAT CARE is taken with the time code track, there should be little to choose between either FSK and SMPTE code in terms of reliability. The main difference lies in the treatment of tempo changes. As SMPTE is completely independent of tempo, any changes have to be input in the form of a table. Cheap units generally cater for few changes typically less than 20 - but these can be input without re-recording the time code. FSK records MIDI clocks, with tempo changes being indicated in the gaps between them. This means that any number of changes can be accommodated, but that once recorded, any subsequent alterations will involve re-recording of the entire time code track. You pays your money...
Incidentally, it's usually a good idea to leave an unrecorded track between the track carrying the sync code and the next recorded track. Some engineers even advise recording two sync tracks simultaneously, but the number of tape tracks you have available is obviously going to be a determining factor here.
ON THE SMPTE front, the only unit that comes close to Syncman in terms of price (£180) is XRI's XRO3, retailing at £189.95. FSK converters include Tascam's MTS30, which has no merge facility, takes three to four seconds to lock up and costs £150, and the Kabanda TS9 which retails at a mere £195 but is difficult to obtain.
The obvious competition for Syncman comes from the JL Cooper PPS1 which is similar to Syncman (if a touch more expensive at £199) but features an automatic merge facility so that all incoming data is mixed with the MIDI clocks being created. However, in the case of a MIDI loop occurring with the PPS1, the MIDI In lead has to be disconnected - not as convenient as the option of turning off Syncman's merge facility. Also, the PPS1 does not have the ability to regenerate a tape code and can only function with 30 frame SMPTE code when being used to output MIDI Time Code. On the other hand, it does have two MIDI outputs and can place a small waiting period between the SPP and the MIDI clock for those machines which are unhappy without this. By the way, Syncman will read the PPS1 code quite happily, but the opposite does not appear to be true. Perhaps Syncman is a little more forgiving in the range of frequencies it's prepared to accept.
There are also software alternatives - C-Lab's Unitor and Steinberg's Timelock, for example - but these are not SPP converters. They inject SMPTE into the programming code and so are likely to be more accurate, but can only be used in conjunction with the related software.
A TAPE SYNC box is an important addition to any recording setup and Syncman appears to function flawlessly. Quick to chase and easy to use, I can think of no particular reason not to buy one.
The problem for Musicsolt lies in the fact that the PPS1 has had chance to become well established over the past two years and it has certainly shown itself to be reliable. Against this, Syncman is cheaper, offers more functions, and does its job with the minimum of fuss. If you are in the market for a tape sync box, you've got to check it out.
Review by Vic Lennard
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