Glasgow Synth Guild Oct Tone

Eurorack 8-step Sequencer Module
By Robin Vincent

On a passing glance, you’d be forgiven for thinking this is a module from Glasgow‑based Instruo Modular. However, Oct Tone is the first module from a new endeavour. The Glasgow Synth Guild emerged from the remarkable growth of Instruo over the last couple of years, and while the cross‑modulations run deep, they are their own thing. The Guild is a collective of Instruo builders and specialist designers who will be producing modules for other companies, as well as themselves.

The Oct Tone is the reimagining of the Octone, originally designed by Instruo’s Jason Lim for Qu‑Bit Electronix back in 2016, and it’s an eight‑step sequencer.

The interface is circular. It starts with a Rate knob sitting proudly in the centre. Surrounding that are eight knobs setting the pitch or CV level for each step. Shooting off from the eight knobs are eight light‑infused pulse‑activation buttons, and finally, eight gate output sockets complete the cascade. These four elements control the hypnotic dance of lights in our circle of sequencing.

Each knob sets the voltage for the step in the range of 0‑5 V. This can be unquantised or you can engage one of the six scale modes to ensure some musical behaviour. The modes are switchable from a button at the bottom left and reflected in some illuminated hieroglyphs that form an arc around the left side of the Rate knob.

The pulse buttons enable the sending of a pulse to the pulse output for the corresponding step. It doesn’t affect the sounding of the step, just whether a pulse is sent at the same time. This enables you to set up some rhythmic triggering of an envelope to a VCA or filter. The fact that they exist in a circle somehow gives it a different feel than a straight‑line sequencer with gate switches. With an enabled pulse you also get a gate from the step’s individual output. This is something I found I had to work hard at in order to make it useful. So, once per cycle I get to trigger an event of some kind, or up to eight different events in a series as the steps go around. It does give you an alternative trigger to the main pulse output, and you just have to think creatively about ways to use it.

You can run a sequence either clockwise, randomly or with a ping‑pong action. A separate knob controls the number of steps in the sequence, and it always starts with the step in the 10 o’clock position. A Retrig CV input and button lets you restart from step 1, and a clock input lets you sync to an external clock source, rendering the Rate knob superfluous. It would have been nice if the Rate knob could have offered a clock division or multiply function when clocked.

There are three modes of sequencing. Classic Mode is what we expect an eight‑step sequencer to be, Tune Mode halts the cycle and lets you play the steps from the buttons like it’s a keyboard, and Pulse Mode is the only time things can get a bit ham‑fisted.

In Pulse Mode, you can set up note repeats for each step. To do this, you have to first of all be in Tune Mode; then you select a step, hold the Retrig button and turn the Steps button to illuminate the circle of pulse buttons up to as many as you want the step to repeat (got that?). You can then double‑tap a step to enable it for pulsed repeats or no‑pulse repeats, which means the note is held for the same length without retriggering the pulse output. When you double‑tap a button, the Scale button responds by flashing very quickly for enable, and just a fraction longer for disable. Once you’ve added the repeats, you switch back to Pulse Mode, and the sequence runs with the repeats in play. It’s just a tiny bit too difficult to get right every time. The double‑tap is tricky to do, and you end up flicking back and forth, which can kill an otherwise suavely spontaneous sequencing experience. However, it is a useful feature, and it’s really nice to be able to swap between Classic and Pulse Modes on the fly for throwing in some natty pulse repeat variations.

If you have some spare room, you can cosy up another Oct Tone to give you 16‑steps. The steps run from one to another in a sort of misshapen circular motion. The combination also brings some additional functionality in the shape of transposition and the saving of sequences.

I enjoy a good eight‑step sequencer. There’s something about having eight notes in a cycle that hooks into the rhythms of our souls — well, mine anyway. The best ones tend to be easy, obvious, front‑panel‑led, playable and performable. The Oct Tone ticks all those boxes and has a visual flair that makes for a very happy sequencing experience. Despite the compact size and closeness of the knobs and buttons, I’ve found it a breeze to play with during a performance. It’s the most fun and fluid eight‑step sequencer I’ve encountered to date, and the possibility of 16 steps definitely tempts me.

£260

www.glasgowsynthguild.com

Published September 2024