Solving MIDI clock problems

Where to start

Firstly, ensure that the Kenton product is actually receiving MIDI clock. This is not as silly as it sounds – there are a number of reasons why it may not be receiving MIDI clock messages in the first place. Many Kenton products have a MIDI analyser function built-in to help you identify MIDI problems. Refer to your Kenton product manual for how to use this (*2) . Check that both MIDI clock and Start information is being received. If both clock AND start commands are being received, go to section 3 , otherwise go to section 1 or 2 . For more general information see section 4.

The Kenton device is receiving MIDI clock but no start command

The MIDI spec requires that a MIDI start command be sent at the start of a sequence (i.e. when you press the start button), however not all sequencers do this. Instead they send a Song Position Pointer Zero followed by a MIDI continue command. Kenton products produced since around 2004 will automatically treat this as a start anyway. For older products there is a setting called “continue = start”. Set this to ON (and save settings). This will let sync start even when a start command is not received. It may be necessary to use this setting even on recent products if your sequencer uses a Song Position Pointer reference other than zero before the continue message. If in doubt, enable it.

The Kenton product is NOT receiving either MIDI Clock or Start commands

Possible problem sources:

Many sequencers have MIDI clock turned OFF by default – you have to go into one of the setup pages to turn it on.

If you have more than one MIDI port available, ensure that MIDI clock will go out of that port. Some sequencers will only allow MIDI clock to go out of one MIDI port. Ensure that the port you want to use has MIDI clock enabled to it, or change the port you connect the Kenton product to.

Try connecting the Kenton product directly to your sequencer or clock source. Some MIDI mergers, patch bays and other devices can actually remove MIDI clock information from the data stream. For testing purposes at least, try connecting direct. This will show where the problem lies. You may have to change a setting, enabling MIDI clock, to allow it to pass through to the MIDI port you are using.

The Kenton product is receiving both MIDI Clock and Start commands

Possible problem sources:

a) For DIN sync 24 connections –

Check that you are using a proper sync cable. Although MIDI cables look the same (5 pin DIN each end) there is no guarantee that a MIDI cable will work. A MIDI cable only needs 3 wires connected, and they are a different 3 from those needed by DIN sync. You should use a DIN audio lead with all pins connected, or buy a proper sync lead from Kenton.

Check that you are connecting to a DIN sync 24 INPUT. Some devices only have a DIN sync OUTPUT.

Check that your DIN sync port is switched to INPUT. Some devices (TR-808 for example) have a sync switch to allow a single socket to be either an input or an output. Check that it is set to input.

If a Roland device seems to be running at the wrong speed, check the pre-scale setting. To sync with MIDI clock you need to have pre-scale set to 3. See our FAQ section for further information about this. Click here for the FAQ.

b) For Jack Lead connections – Avoid using leads with an adaptor. These are notorious for unreliability. Kenton sell proper 3.5mm to 1/4″ leads for this purpose.

If you haven’t used the clock input on your device for some time, it is possible that the jack input socket has become tarnished. This can often be remedied by repeatedly plugging the jack in and out (perhaps 20 times). In extreme cases it may require the attention of a service engineer.

When using the clock output jack socket of a Kenton product to connect to a drum machine, you will usually have to press the Start button on the drum machine first to make it ready to receive sync, it will then wait until you start your sequencer before actually starting.

If a device seems to be running at the wrong speed, you may have to change the divide ratio on the Kenton product. See the manual for how to do this (*2) . MIDI clock pulses are sent at 24 Clocks per Quarter Note (cpqn). There are many different clock requirements for devices. 12 cpqn is common (e.g. CR-78, SH-101), but others are used.

Further information about MIDI Clock

MIDI clock is not on any MIDI channel. It is on its own “sync channel”.

MIDI clock is not the same as MIDI timecode – they are entirely different and pretty much unrelated.

Sync polarity. While DIN sync 24 is a defined standard and is always the same, the same cannot be said for jack inputs used for sync. Nearly all devices trigger on the positive going edge of the clock signal (the transition from zero volts to a positive voltage), however some devices require the opposite. All Kenton products (*1) can be set to invert the clock signal to drive these devices properly. If this setting is wrong, the devices will be very slightly out of sync.

The DIN sync ports on Kenton products can drive more than one sync device. We sell DIN sync splitter cables to allow you to connect 2 devices and we have heard of people driving up to 4 units – although we do not guarantee this.

Similarly the clock output jack sockets can often be split to drive more than one device. Again we do not guarantee this, you will have to experiment.

Clock IN will not usually affect the LFO. Some synths use the LFO to clock the arpeggiator.
This doesn’t mean that the clock input signal will clock the LFO! (e.g. SH-101)

Connection information for DIN sync 24 cables:

Plug type is a 5 pin 180 degree DIN connector.
Looking at the solder terminals of a plug – held so that the pins form an arc above the centreline, numbering clockwise, the pins are numbered as follows:
1 – 4 – 2 – 5 – 3
Pin 1 – Stop = 0 volts Start = +5 volts
Pin 3 – 5 volt pulses; 24 clocks (pulses) per quarter note, the same as MIDI
Pin 2 – Ground (zero volts)
Pins 4 & 5 are not used.
(MIDI uses these pins 4 & 5 and pin 2 – which is why not all MIDI cables will work for sync)


*1) Except for the Pro-2 (discontinued 1997).

*2) If you have lost your manual, you can download one from this website. Download a manual here.