Download RexSync files

The longest title of a post so far, but it describes exactly what this post is about. Syncing those vintage instruments with a modern sequencer without any additional hardware. The only thing needed is a sound card with more than two outputs.

How the vintage stuff works

In this tutorial I’ll be using three different instruments. They all have different kind of functions that deal with time. The LinnDrum is a drum machine and therefore has a built in sequencer which you can set at a certain BPM. The Roland Juno-6 has an arpeggiator with a simple slider – you never know the exact BPM it plays back on. The Roland JX-3P has a very basic 16 step sequencer which also has a simple slider and therefore unknown BPM.

For the instruments to know when to hit the next note or drum sound they have a built in clock. The clock generates pulses, and a pulse is simply 5V for a couple of milliseconds.

All the instruments each have one input jack at the back allowing us to feed them with our own pulses instead of the ones from the built in clock.

The Rolands are the most simple ones. Each time you feed the Juno-6 with a pulse in the “arpeggio clock in” input, it plays the next note in the arpeggiator.  The JX-3P works in a similar way, feed the “seq trigger in”  with a pulse and it plays the next note in the programmed sequence. This means that if you want your sequence or arpeggio to run play 16th notes, you just feed it 16 pulses each measure.

The LinnDrum works in a similar way, but it expects 192 pulses each measure to its “sync in” input jack. This might sound like a lot – and it is. If you listen to the sync signal sent to the LinnDrum it’ll sound like a very loud, annoying buzzing sound, whereas you in a 16th pulse signal would hear each pulse as a “tick”.

In addition to the sync in jack, the LinnDrum also a sync out jack. Back in the day, when recording a song with a synced LinnDrum, you’d do like this:

1. Connect the sync out from the LinnDrum to your mixing desk, preferably to the last track, eg 24. The reason for putting it at 24 is that the signal is very strong, and could “leak” to the neighboring track (23). Track 23 might have to be unused of this reason.
2. Run the LinnDrum for a little longer than the song duration and record the sync signal to that track.
3. Connect the output of channel 24 to the sync in on the LinnDrum which would make LinnDrum sync to the recorded track.

To sum it up: External syncing of these old instruments work in a very simple way – you override the pulses from the built in clock with  your own external pulses.

How my convenient solution to this works

So, from where do you get the pulses? There are hardware solutions like the Doepfer MSY-2 available, and software solutions like AU/VST sync generator plugin.

My solution is very simple and convenient. I’ve sampled a clock pulse from my LinnDrum and created a couple of Recycle files that each are one measure long. These Recycle files has pulses from 1/4 note up to 1/192 note. As you probably know, Recycle files are like Apple Loops, they automatically adjust to the tempo of the sequencer by using a “slicing” method.

How to use (in Logic)

1. Create a new mono audio track.
2. Set no input and choose the output to eg output 3 of your sound card.
3. In your sound cards mixer application, make sure that output 3 isn’t patched to your stereo output. You don’t want to listen to the sync signal, it’s quite annoying.
4. From the output 3 jack of your sound card, connect a cable to the sync in on your instrument.
5. Drag and drop one of the Recycle files to the track. You’ll get an error message, here it’s important that you choose Don’t fix, otherwise Logic’s “fix” will make it go out of sync.
6. Press play in Logic and hopefully the instrument will start to sync!

Roland Juno-6 instructions

1. Insert the cable with the sync signal in “Arpeggio clock in”
2. Turn on the arpeggiator
3. Try to play on the Juno-6 (nothing should happen)
4. Run your sequencer
5. Try playing again, arpeggiator should now sync to the sync signal

Korg Polysix  instructions

1. Insert the cable with the sync signal in “Arpeggio trig in”
2. Turn on the arpeggiator
3. Try to play on the Polysix (nothing should happen)
4. Run your sequencer
5. Try playing again, arpeggiator should now sync to the sync signal

Troubleshooting

Q: Nothing happens!
A: Make sure that the sound card’s output really outputs the sync signal.

Q: I can’t stand the noise!
A: You have to configure your sound card not to include the audio output that’s used for the sync signal in the master stereo mix. On my sound card, the RME Fireface 800, this is done in the Fireface Matrix.

Q: Sync is not synced!
A: The output level of the sync signal is important. A level that’s too low can make the instrument miss certain pulses.