Expert Sleepers Otterley, five LFOs meet in a module for drifting, musical modulations

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Expert Sleepers Otterley is a new module that brings five LFOs together, where four of them have a close, drifting, musical relation. 

Let’s stay on the topic of LFOs. The øchd from Instruo and DivKid, for example, showed that LFOs could also be fresh and exciting. It’s a very original low-frequency oscillator with unique tuning characteristics only available in this module.

Expert Sleepers, the company that enriched the Eurorack world with Disting modules, has had a growing analog range for some time. The latest addition to this is also an original LFO with fascinating features. 

Expert Sleepers Otterley

Expert Sleepers Otterley

Otterley is a new all-analog LFO module with some interesting twists. Andrew Ostler from Expert Sleepers describes its new module as a multi-LFO. 

At its core, it consists of five low-frequency oscillators. The first four LFOs offer different speeds derived from a base frequency control and spread function. They are switchable between sine and square outputs, giving you enough flexibility. 

How they work is different than traditional LFOs. They don’t have dedicated controls for each LFO but offer speed and spread control for all four. 

By turning the spread knob clockwise, you can expand the difference in speed between the channels, while turning the speed knob increases the base frequency of the LFO array. A bit like the øchd module.

Bipolar (±5V) and unipolar (10V positive or negative) options for the four LFOs are also available. You can also reset them to the start of the cycle with the reset input.

Both the speed and spread controls can be independently controlled with CV. Two knobs sound like little, but you can achieve a wide range of modulation with them.

Especially modulation curves that are musically related to one another. You can also use them for polyrhythmic complex LFO structures.

Further, you have a fifth LFO with a sine with independent speed control for traditional modulations. It doesn’t affect or have a relation to the other four LFOs.

First Impression

The feature set of Otterley reminds me of the Instruo DivKid øchd, where you have several LFOs that wave together musically. The option to reset them is convenient here. This could be an interesting module if you search for modulations to create drifting movement and texture that is musical.

Expert Sleepers Otterley is available now for $199, £189, or 220€. 

More information here: Expert Sleepers

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  1. My problem with a lot of these new modules is we are getting design and innovation that is market driven. ‘Lets just make/copy a new module with improvements’ rather than work on the original concept’s that eurorack was engineered to give. I mean for the last few years everything was just mind blowing that came out can’t we just have further iterations like a mk2 or mk3.

  2. While this is obviously a take on Ochd (seems Tesseract has one too), it definitely adds some bells & whistles to the party. We must not let ourselves become too puritanical, all innovation sits on the shoulders of those who (or whose works) came before. I also like the new Cicely module.

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