I just bought a Mod Rex to compliment my Super Pulsar – the idea to have two stereo channels of harmonised modulation.

I got up and running fairly quickly as I had been studying the manual that I had downloaded but soon found that something was wrong as the modulation was not synchronised.

My Super Pulsar is triggered by a Time Bandit and I play into a Zoom R24 which has its own tempo and provides a drum track.

In order to match the beat of the drums at 120bpm, I set the Mod Rex to 30 (a quarter of 120) but that was too fast. I then halved it to 15 and that was close but was still not right.

All the clocks are pretty much in synch, the LEDs of the Zoom R24, Time Bandit the Super Pulsar are all flashing at the same rate but the Mod Rex is not.

I tapped the tempo of the Mod Rex LED when it was set to 15 on the Zoom R24 and it came out at 101.6bpm and then I checked by opening the clock on my iPhone and counted the LED flashes from the Mod Rex set at 15 for one minute and it was 102 – pretty much exactly what the I found using the tap tempo on the R24.

I would have expected that if the Mod Rex LED flashed on quarter notes, it would flash in synch with a 120bpm beat when set to 30.

I did a factory reset thinking I might have made some accidental adjustment and tried again but it is just the same.

It is brand new and I would like to know if this is a fault before I send it back if somebody could advise me please.

I should also add that when I took it out of its packaging, it felt like there was something loose inside. It wasn’t rattling exactly, just moving. I took the back off but there was nothing obvious and after putting the back on again, I could still hear it. I don’t know what moving parts it might have, if any, which could explain this.