Maybe it's my love for all things LFOs, maybe it's just that the number nine is my lucky number, or maybe it's just because Otterley is the ninth and newest module in Expert Sleepers superb all-analogue series of modules, the titles of which come from the wonderful Cocteau Twins album, Treasure.
I know the common modular refrain, "you can never have enough VCAs," is true, but I feel that way about EGs, VCFs, and, well…attenuators, too. Can't have enough of those. But I definitely feel that way about LFOs, and Otterley has five of them in one compact 8HP space.
Otterley is pretty straightforward; it's got three inputs (Speed CV, Spread CV, and Reset), and those five LFO outputs. The first four LFO outputs have a range of 150 seconds/cycle to 75Hz and share controls for Speed, Speed CV amount, and Spread. There's a three-position +/-5V toggle for range selection (all-negative, bipolar, or all-positive voltage), a three-position Sine/Square toggle (middle position off) for LFO shape selection, and a Speed control for the fifth LFO, which is independent of the first four and is a fixed sine wave with a range of 50 seconds/cycle to 50Hz. All the output jacks have Expert Sleepers' signature light up jacks for distinguishing between positive (red) and negative voltages (blue), and if the Shape toggle is in the middle position (off) there is no illumination, a nice visual indicator. I love that you can effectively mute the LFOs. It's a brilliant feature that I'd love to see on more modulation modules.
Right away, I'm digging the Spread function. I mean, having four synced modulators is cool, but not always called for, and conversely, having four random LFOs also has a place, but…Spread takes care of that conundrum, providing the best of both worlds, and literally everything in between. You can adjust (and CV control) the amount of timing between each of the LFOs from one another, and this is valuable and interesting in so many different ways, with phase exploration being the most interesting to me. The speed—the frequency—increases with each successive LFO so that they aren't identical shifting LFOs, with LFO1 being slower than LFO2, LFO2 being slower than LFO3, etc., which is really helpful for creating quick, interesting modulation in any patch.
At its most basic, by patching up those first four outputs into whatever parameters (filter cutoff, 1V/Oct on a VCO, filter resonance, distortion/saturation amount…) and increasing/decreasing the Spread amount you can hear the relationship the changes caused by the as time goes on, giving your patch a nice, organic quality.
Due to it being analogue and the fact that the frequencies of each oscillator aren't calibrated (it's a random module, after all!), out of the box Otterley's four top LFOs were not the same frequency, and even with Spread fully off and no Spread CV, there was always a slight separation from each other. I thought it could be interesting to have those four LFOs perfectly synced until the Spread was activated so that you could hear the full evolution of the spreading effect, from zero to wild nirvana, and well, lo-and-behold, a quick peruse of the manual and it details exactly how to do this via trim pots on the back of the module. Nice! Also on the back of the module are other trimpots to change the shape of the sine waves for each LFO into a near-triangle, if you want to do that sort of thing. I wouldn't mind this to be on the front of the panel, or with jumpers on the back to make it a bit easier, as the trimpots are tiny, but either way, it's great to have these options.
You can also sync the four top LFOs by patching into the Reset, and then have them drift from each other, by a little or a lot—depending on the Spread setting and length of time before Reset is triggered again. This sort of musicality reminds me of musicians playing together in different time signatures where they meet up briefly, where the universe aligns and the math makes sense, before slinking away into their own distinct corners of the galaxy again.
Doing exactly this, and patching into percussion modules to create a rhythm track, with the LFOs set to square wave for triggering drum hits, was pretty great. You could feel the anti-rhythm taking hold more and more right until the moment that the clock I'd patched into the Reset brought it all back together, stacking everything on top of each other into one sound, only to drift away again and start to become a sorta-rhythm. It's pretty interesting to make a random, ever-changing loose-grooving patch, something I almost never do, as everything is usually synced to a T in my patches. This is a great module to help break away from that rigidity of time structuring, and with the Spread up high and the LFOs inserted all around a dense patch, you have the ability to add plenty of unpredictability into an otherwise predictable patch. Oh, that balance of consistency and unpredictability…the key to life, right? Maybe. Even if that's not your cup of tea, Otterley can heap loads of spice into a needy patch.
Patching into four different VCOs pitched similarly, where Otterley was modulating the 1V/Oct inputs, was a good time, as was when I used the same configuration to modulate the cutoff of four different VCFs, using the same input signal for each before stereo mixing them for some weird comb-filtering effects. It was so often beautiful and mesmerizing—especially with a slower overall pace for the LFOs, and adjusting the Spread really highlighted the various frequencies that were poking through in mind-altering ways. This generative way of creating movement brought a lot of dynamic change and worked really well in creating dense backgrounds on which to build off of—blankets of mutating sound.Patching into four different VCOs pitched similarly, where Otterley was modulating the 1V/Oct inputs, was a good time, as was when I used the same configuration to modulate the cutoff of four different VCFs , using the same input signal for each before stereo mixing them for some weird comb-filtering effects. It was so often beautiful and mesmerizing—especially with a slower overall pace for the LFOs, and adjusting the Spread really highlighted the various frequencies that were poking through in mind-altering ways. This generative way of creating movement brought a lot of dynamic change and worked really well in creating dense backgrounds on which to build off of—blankets of mutating sound.
Otterley's fifth independent LFO allows for some pretty neat self patching—whether of the Spread or the Speed—to modulate the other four LFOs, and it's pretty cool to have this—what I'd call extra or bonus—LFO onboard with which to do so. You can also do the same with any of the other LFOs—this self patching bit—for similar effect. You can get a lot of weird stutters and irregular modulation, and with a little time spent lining things up just right (especially if using the fifth LFO), you can control more of the randomness than you'd think, for semi-controlled quasi-pseudo-random-changiness.
If you're looking for more than square or sine waves and are into construction, you just need to go a little old school and cook that up yourself by mixing the LFOs together. With the differences of the separate times and shapes—if you use the first four as square waves; the fifth is always a sine—you can create your own complex, random LFOs for even more randomness. Plugging this through the trusty Mordax DATA to see the mix progress, it was interesting to patch/unpatch the LFOs and study the effects one wave—at a different rate and intensity (due to the location of its cycle)—would have on the entire mix.
Otterley is maybe my favorite blend of attributes on a module; simple to operate, but offering up a lot of complexity, mostly user-created. Five plug and play random LFOs are always appreciated, and it was really interesting to explore in various ways the interconnectivity that the Speed and Spread controls had on the various LFOs. It's just one of the unique features and interesting possibilities that Otterley offers up here, and is another win for Expert Sleepers.

Price: $199

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