• J.L. Cooper PPS100
  • J.L. Cooper PPS100
  • J.L. Cooper PPS100

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J.L. Cooper PPS100

MIDI-SMPTE Synchroniser

David Mellor, reviewer of the original J.L Cooper PPS1 'Poor Person's SMPTE' unit, looks at the new rackmount PPS100 - the Professional Person's SMPTE unit.



J.L Cooper's PPS1 MIDI sync unit was labelled the 'Poor Person's SMPTE' because it was relatively cheap and used a code which did much the same job as SMPTE - but without being the real thing. SMPTE/EBU timecode is now an established standard in the arena of tape/MIDI synchronisation and other types of lock-up are falling by the wayside. Fortunately, the price of SMPTE/EBU equipment is falling too, down to affordable levels. So now the choice is between basic sync capability at a low price, or full MIDI/timecode facilities for not too much more.

The PPS100 is rather bigger than the Jaffa-sized PPS1, being a full 19 inches in width including the rack mounting ears. This must be one of the shallowest rack-mounting units I have seen, with a depth of a mere 4¾ inches. There can't be very much inside can there?

But simplicity is a worthwhile end in its own right. Simplicity of design, and hopefully simplicity of operation. There are a number of important - and unavoidable - parameters which must be dealt with by the user to achieve the desired result. The way in which these parameters are programmed into the MIDI/timecode unit varies from model to model. Sometimes it is as straightforward as can be; at other times it is better to have a large jar of aspirin handy. To be fair, the more complicated MIDI/timecode units usually do more. But I would still contend that manufacturers are not all trying their utmost to make their equipment easy to operate.

The J.L Cooper PPS100 is not just a MIDI/timecode synchroniser, it is an event generator too. The word 'event' can cover a multitude of possibilities which I shall go into later. Professional users in particular like to see a measure of event control because - would you believe it? - not all pro gear has MIDI sockets on the back yet. That's because, outside of recording studios, most sound engineers would run a mile rather than get involved with equipment that had 'nasty' musical connotations! Leave that to the people with the official MU cards. I am currently compiling a 'wants list' because I am convinced that MIDI functions could usefully be included in equipment as yet untouched by the five-pin DIN.

HEADS AND TAILS



The obverse (that's the posh word for 'front') of the PPS100 has an LCD display and five buttons, plus a power switch. A red LED indicates when the unit is generating or receiving timecode, or running under its own steam.

The rear of the unit is more revealing. It has four MIDI connectors. The normal In and Out connections: Out sends song position and MIDI clock to the sequencer, In is used to merge MIDI information - notes, etc - into the data stream. The other socket pair is used for System Exclusive input and output. System Exclusive is not only used for dumping sync data, it is also there to allow (optional) communication with a Macintosh or Atari ST computer to make programming easier.

As well as the MIDI connectors (and a further connector for old Roland-style DIN sync), there are six quarter-inch jacks. Sync In and Sync Out are, obviously, for sending and receiving timecode from tape. Contact 1 and Contact 2 are wired to relay contacts. Putting it simply, anything you can do with a common-or-garden footswitch, you can do with the two Contact sockets - and automate it against timecode. It's easy to think of good uses for this feature. Automated drop-in and drop-out, for example. Or perhaps your multitrack has a footswitch socket that can locate the tape to a particular point (my E16 has). You could therefore programme the PPS100 to return the tape back to the head of the song at the end of the sequence.

The pro user will also be thinking about triggering effects from cartridge machines or CDs. Or perhaps starting a stereo tape recorder from a timecode cue. Very handy stuff.

More adventurous synchronists will enthuse about the two Pulse outputs. These work in a similar way to the contact closures, ie. you can fire off a five volt pulse whenever a particular timecode value is passed. The PPS100 manual suggests this may be used for controlling a lighting dimmer, or even a motor, but stops short of suggesting that you fire off your pyrotechnics automatically via timecode - synchronised Thunderflashes anybody?

Pulse Output 1 can also provide a clock output (24, 48 or 96 pulses per quarter note). Pulse Output 2 can alternatively be an audio click.

MIDI SYNC



PPS100: SUMMARY OF FEATURES

INPUT:
  • SMPTE/EBU timecode

OUTPUT:
  • SMPTE/EBU timecode MIDI clock
  • MIDI song position pointer MTC (MIDI Time Code)
  • DTL (Direct Time Lock)
  • DIN sync
  • Pulse (5V one-shot, or 24, 48 or 96 ppqn)
  • Contact closure

MIDI:
  • In 1
  • Out 1 (MTC or MIDI clock merged with incoming MIDI)
  • In 2 (System Exclusive)
  • Out 2 (System Exclusive)

SYNCHRONISATION:
  • Start time
  • Meter
  • Tempo
  • Timecode offset
  • Tempo map
  • Bpm or frames per beat
  • Event programming (contact closure, pulse, MIDI)
  • Real-time event recording
  • Fast/slow song position pointer

Synchronising MIDI to SMPTE or EBU timecode is the most basic function of the PPS100, and the timecode can, of course, be any of the four standard types. The type of incoming code is automatically recognised. The PPS100 handles all the expected MIDI sync parameters:

- Start Time: The timecode value at which the sequence is to commence.

- Tempo: The tempo of the sequence, governed by the MIDI clock rate (SMPTE/EBU code does not, of course, have any tempo-related component).

- Meter: The number of beats in the bar. It is necessary to have this facility on the synchroniser so that the bar numbers keep in step with those in the sequencer.

- Offset: Sometimes omitted, this function is used to add or subtract a timecode value to the incoming code. For example, the incoming timecode may actually start at 19:05:21:12 and you would prefer to start at 00:00:00:00. The offending hours, minutes, seconds and frames could easily be subtracted by using a negative offset. More importantly, offset can be used for sliding the sync forwards or backwards in time to a very fine resolution, syncing up notes or effects very precisely.

You set up these parameters, and the event parameters too, using a hierarchical menu system on the small but adequate display (pity there is no adjustment for viewing angle). At the top of the hierarchy is 'J.L Cooper PPS100', and you can't get higher than that, can you?

From this top menu, you are asked a sequence of concise questions to which you must answer 'Yes' or 'No'. ('Don't know' is not allowed.) But you don't have to answer 'No' to Mr J.L Cooper. Pressing 'No', 'Yes', 'Enter' or 'Clear' will do. The next degree of menus has some more tasty items:

Set cue?
Set offset?
Stripe tape?
Set up?
Real-time record?
Tempo map entry?
Remove cue?
Remove tempo map entry?

Answering 'Yes' to any of these leads to another degree of questioning, the third degree in fact. It seems a little heavy on rejecting what you don't want rather than getting straight to the point, but it gets the job done.

Let's look at the sequence of events for a real synchronising job, assuming you had been through the set-up memory and tailored the PPS100's basic functions to your system.

The most important parameter is the start time - the timecode value at which the track will kick into life. This is accessed from the 'Set Cue?' menu. Answering 'No' to the next four questions gets you to a time display like this: 00:00:00:00. This 'zero' start time can be quickly altered to any desired value. When this is done, the time signature then the tempo pages pop up. You can enter a stop time as well but it is not usually necessary.

Setting the basic parameters is very easy, once you have the knack. What puzzles me is that although more and more gear uses this style of data entry, it never seems to get any easier to learn. When you get a new piece of equipment, you inevitably have to deal with a new procedure for negotiating your way around the 'small display/few buttons'. One day...

TEMPO MAP



I once heard the word 'syncopated' used to describe a person in a rather drunken state. Looking the word up in the dictionary I found: '...an unsteady wandering from bar to bar...'. Fortunately, we no longer live in the era when sequencers and sync units could only cope with one time signature and one tempo per song. Now we can speed up and slow down, and change from meter to meter, to our heart's content. The Tempo Map feature of the PPS100 is where it all happens. You access it from the main menu by pressing 'No', 'No', 'No', 'No', 'No', 'No', 'Yes'. The Tempo Map allows variation from 1/1 to 16/16 (any numerator; denominator 1, 2, 4, 8, or 16) in meter and from 24 to 250 beats per minute (bpm). A tempo of 000 bpm may be entered, and this acts as a stop command. It's rather surprising that the unit allows you to change meter halfway through a bar but the manual recommends not to do it to avoid confusion. I agree with the manual.

Unlike more expensive MIDI/timecode synchronisers like the FriendChip SRC/AT [SOS March '89], the PPS100 cannot learn a tempo map, either from MIDI clocks or from an audio input. At the price, it can't be considered a drawback and all ordinary sequencing can get along reasonably happily without it.

For extra accurate tempo setting, the PPS100 features a Frames Per Beat mode, where the tempo is displayed in terms of how many frames (and parts of frames) of timecode fall in between each beat. The resolution in this mode extends to 1/80th of a timecode frame per beat.

EVENT GENERATOR



This is the feature of the PPS100 that raises it above the level of 'good but ordinary'. It's also the feature that requires the most input from the user. Contact closures and five volt pulses don't sound exciting in themselves, but there must be an awful lot of possible uses. I have outlined a few already, but how about switching green and red cue lights for a voice over artist, or perhaps to cue a lighting or a stage effect? What about automating an effects unit, so that it gives you echo on the vocal, but - hoary old cliche - only on the last word of each line?

Contact closures and five volt pulses can be programmed to any timecode value. I found it very simple to set up an automatic drop-in on my multitrack recorder by programming the in/out times in a similar manner to setting the start time. An alternative to entering digits is to use the 'Real Time Record' feature. While the timecode is running, the 'No' button is used to programme Contact 1; the 'Yes' button programmes Contact 2. 'Enter' causes Pulse 1 to go to five volts, and 'Clear' causes Pulse 2 to go to five volts.

MIDI events can be programmed in too, or 'Real Time Recorded'. Once again, what you do with them is your business - or rather, up to your creative abilities. Think of the MIDI event programming as a sort of rudimentary sequencer: it doesn't record like a normal sequencer would, but it logs each MIDI input against a timecode value, and then repeats it whenever the timecode runs again. This is not good for recording melodic passages, as the manual warns. The Note-On messages will be quantised to 1/25ths of a second (assuming 25 fps timecode) regardless of how these fit in with your bars and beats. System Exclusive messages may be recorded in the same way. All events can be reviewed, and removed if necessary. I wouldn't say that this is particularly easy, given the smallness of the display, but help is at hand...

SOFTWARE TO THE RESCUE



PPS100Q is a software add-on to the PPS100 and runs on a Macintosh or Atari ST computer. I used it with my ST and certainly found it a great help in all aspects of programming the PPS100. Considering the price of the software, and the low price of the basic Atari 520ST, you almost can't afford not to have it. PPS100Q has three basic screens which expand all the information in the PPS100 up to a readable size.

Figure 1. Set-up screen.


The first is the Set Up screen display (Figure 1), which covers all the fundamental parameters - the ones you don't need to change often. It also has Start Time and Offset displays. Data entered here can easily be transferred to the PPS100 by clicking on 'Download' with the mouse, which sends all those System Exclusive bytes rushing off down the MIDI cable. I would have preferred some form of confirmation that they had been correctly received, but the operation is over in about half a British Standard Tick, and it never let me down. Of course, data already programmed into the unit can be transferred just as easily in the other direction.

Figure 2. Tempo screen.


The other two screens handle the Tempo Map (Figure 2) and Cue List (Figure 3). I have included some sample data in the screen dumps to demonstrate some of the possibilities. Inputting and editing data using the computer is much easier than doing it on the PPS100's LCD (even though I have to quibble that you don't get an instant update on what you have done, you have to click for it), and you get to save it all on floppy disk.

Figure 3. Cue screen.


I have been saving the best feature, or at least what I see as the best, until last. Not only will PPS100Q operate as a normal software application on your computer, it will also work as a desk accessory that can be made to pop up over another program. This means that if you are running a software sequencer, control over tempo and meter is integrated and not hidden away in the equipment rack. This doesn't quite go all the way, because you still have to press the Run button to start the sequence, if you haven't got to the tape stage yet, but it is a step forward, and almost as good as having an integrated SMPTE box, as supplied with sequencers from C-Lab, Hybrid Arts and Steinberg.

The PPS100 manual warns against automatically assuming that your sequencer, or other software, will be happy with PPS100Q running as a desk accessory. I experienced no problems, but if I were depending on this feature then I would definitely check before buying.

CHOICES, CHOICES...



If you are looking for an event controller, then the PPS100 has to be a contender. OK, it only has two contact closures and two pulse outputs, but that might just be enough. Take it away and see what you can do with it. If it's a MIDI/timecode synchroniser that you are after, then this one will do the job with all the basic functions. It isn't 'intelligent' enough to learn from MIDI clocks or from audio like other more expensive units, but if you don't need those facilities then why pay the extra? The PPS100 could be just the ticket.

FURTHER INFORMATION

PPS100 £565 inc VAT.
PPS100-Q (Mac/Atari) cue list software £25 inc VAT.

Sound Technology plc, (Contact Details).



Previous Article in this issue

Shape of Things to Come

Next article in this issue

49 Hot Signal Processing Tips


Sound On Sound - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.

 

Sound On Sound - Jun 1989

Donated by: Rob Hodder

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Gear in this article:

Synchroniser > JL Cooper > PPS100

Review by David Mellor

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