Zoë Blade's notebook

JL Cooper PPS-2

PPS-2 tech specs

The PPS-2 was a MIDI-era synchroniser by JL Cooper.

As with other synchronisers of the era, using frequency-shift keying, it can convert your MIDI sequencer's MIDI clock events into audible waveforms and back again. You can therefore use it to "stripe" a single track on a multitrack recorder with the song's tempo. When playing the recording back, your MIDI sequencer can stay perfectly in sync with the recorded material.

Unlike earlier synchronisers, the PPS-2 doesn't record a simple (somewhat standardised) tape sync signal. In addition to noting when each clock pulse occurs, it also notes which pulse it is, counting them at regular intervals. Alas, as there's no standard for such a signal, it has to be written in a proprietary "Smart FSK" signal,[1] so don't expect anything else to read it directly.

However, it's a useful tradeoff: when playing back the signal, the PPS-2 uses this extra information to send a single song position pointer event and continue event before relaying the subsequent clock pulses. This tells your MIDI sequencer exactly where in the song you're starting playback from. This is a real timesaver compared to recording every part for the full duration of the song, even if it only comes in for the outro.

As with other synchronisers, this lets you continue evolving your song even after you've started tentatively recording a few tracks, something we take for granted with modern DAWs. Synchronising a multitrack recorder and MIDI sequencer was very much the precursor to the modern integrated studio.

The PPS-2 can also record a SMPTE timecode signal (at 30 FPS only) by itself, then read it back and convert it to MIDI time code. This allows you to change the song's tempo later on, as SMPTE timecode is tempo-independent.

Lastly, it can also convert its SMPTE timecode signal into Mark of the Unicorn's proprietary Direct Time Lock timecode.

Tips

The MIDI out port seems to act like a MIDI through port as well. To avoid a MIDI feedback loop, only plug in the MIDI in cable when first striping a tape, not while playing the recorded clock signal back.

References

  1. "PPS-2 manual" JL Cooper, Aug 1997

Downloads

Documentation

Synchronisers: JL Cooper PPS-2