The LFO – Low Frequency Oscillator – is one of the most fundamental of electronic music elements. Creating a signal that modulates the sound of something else, the LFO has a history that’s roughly as old as sound-making electronic circuits themselves.

And yet, there’s still more that can be done with them. Two new LFOs blur the lines between analog and digital, hardware and software, and pack clever features into their interface and function.

A Handheld LFO for Analog Gear

Justus Kandzi’s Brute LFO puts hardware modulation in the palm of your hand. Brute LFO runs on any iPhone, iPad, or iPod touch with iOS 6 or later. But it’s not a self-contained app: it comes alive when you connect your phone or tablet to external analog hardware. Route the audio from the headphone jack on one of those devices into a control voltage input – which now includes a growing range of inexpensive gear – and you can use your iThing as a modular signal source. It can shape pitch, the filter, or any other parameter with CV input.

You actually get three LFOs, controllable separately. Justus explains the controls:

It consists of three separate LFOs. LFO 1 and 2 can be controlled using the control elements in the top half of the screen. The big knob in he middle sets the rate of both the LFOs. Additionally you can change the waveforms of the LFOs, detune LFO 2 and change its phase. The amount knob in the top half also sets the overall amount of the modulation.

The elements on the bottom half (LFO 3) can be used to modulate the frequency of LFO 1 and 2.
And the brute switch destroys everything!

See the video for this in action:

As seen on Synthtopia

A Unique LFO for Ableton

If Ableton Live is your preferred tool, there have been a variety of LFOs from which to choose – most recently, even one from Ableton themselves. Sadly, Ableton has never offered an integrated LFO source in the software, but Max for Live provides most of the features you’d want. Your only challenge was picking which one.

Maestro Robert Henke, the absurdly-prolific musician and engineer who helped found Ableton, has created an LFO that might make that choice a lot easier.


LFO 2.0 will work with your software. You can directly integrate it with Live’s engine – there’s no modulation control, but that keeps everything fast. Or you can set it to graphical control via the on-screen knobs.

You can also use LFO 2.0 with analog hardware. Ideally, you’ll want an audio interface like MOTU’s excellent offerings that include a DC coupling. (MOTU, themselves, offered a similar product in Volta.) Robert says he’s using his with Arturia’s MicroBrute (cough, ahem, CDM review coming very soon on that), and the MOTU UltraLite, which remains one of my favorite interfaces for its bang-to-buck ratio, usability, and sound.

Of course, you could also use the audio mode for resampling and synthesis. (The same would be true of Brute LFO.)

Because it’s a Max for Live device, you can map Robert’s LFO in the same way as the new Live 9 LFO. Press Map, then click on a target parameter – done. (This feature alone is enough to warrant ponying up cash for Live 9 Suite with Max for Live.)

What makes LFO 2.0 appealing is the broad approach to features – it gives you more or less exactly what most people will want:

  • Waveforms: Sine, Ramp Up, Ramp Down, Square, Stepped Random, Smooth Random, and Binary Random.
  • Large frequency range, “from extremely slow (several minutes for a cycle) to audio rate.” (Whoa. Yes, that’s different than what you usually get.)
  • Restart in beat intervals, but via a Phase control. (Generic beat-synced modulation actually is kind of overkill once you’re in software like Live – and I agree with Robert that it’s a bit boring.)
  • Modulation for the LFO output: Quant adds steps, Sample & Hold samples in regular intervals, Sync uses beat time intervals, Smooth and Curve create symmetrical and asymmetrical modulation, respectively.

In other words, what looks on the surface like Just Another LFO in fact has some Robert Henke Twists (TM) that can produce some unique results – once you get creative with those knobs.

Price: free.

But Robert does describe this as emailware: “If you find it useful, I would appreciate an email with some feedback or a link to your music.” (Hey, let’s bring back Postcardware. Anyone remember that, or have I just been online for too many years?)

And you can add this to your library o’ Robert Henke Max for Live plug-ins.

It’s a fascinating relationship to have with artists. Whereas once you might get lessons with a composer, or study scores, now you can study plug-ins. And just like the lessons and scores, you can take what you learn and bend it to your own unique desires and personality.

So, while you’re telling Robert what you’re making, do tell us, too.

Working with Hardware from Software

Modular patching with Expert Sleepers Silent Way and ES-3 from Andrew Ostler on Vimeo.

If you start to get addicted to computer modulation of gear, you will absolutely want to look at using an audio interface suited for the job – and you may find yourself feeding your addiction with other software.

UK developer Expert Sleepers has you covered on both counts.

First, they have a brain-bogglingly-huge collection of plug-ins for OS X and Windows. (They even still make the PowerPC version, meaning you can take that old iMac out of the closet and put it to work in your studio, saving landfills and givving you a warm, fuzzy feeling.)

The collection: ” Silent Way AC Encoder, Silent Way CV Input, Silent Way CV To MIDI, Silent Way CV To OSC , Silent Way DC, Silent Way ES-4 Controller, Silent Way ES-5 Controller, Silent Way ESX-4CV Combiner, Silent Way Follower, Silent Way Learner, Silent Way LFO, Silent Way Quantizer, Silent Way SMUX, Silent Way Soundplane, Silent Way Step LFO, Silent Way Sync , Silent Way Trigger and Silent Way Voice Controller.”

Now, combining that with Robert’s LFO I think makes some sense. The Silent Way stuff works perfectly in Ableton. LFO 2.0 then becomes an easy-to-access LFO that’s simpler than the Expert Way one that can swap between internal and external control.

You can get a demo to test your gear before you spend the (paltry) US$59 to buy the software.


Silent Way

Just as importantly, they’ve made a nice list and compatibility guide to which audio interfaces provide DC coupling, and how to work with AC-coupled interfaces – just as applicable to LFO 2.0 (Expert Sleepers makes requisite hardware, too):

Have fun out there, folks.

  • Matt

    Check out the following list to determine whether your interface has dc-coupled outputs:

  • ▓▒░ TORLEY ░▒▓

    Peter, that “It’s a fascinating relationship…” paragraph is brilliant and inspiring! I thrive on positive communication with toolmakers. I LOVE to call out the tools I enjoy. The makers tend to work in relative social isolation and not hear the fruits of their labors, as bequeathed by the adoptive parents that are musicians. One thing I hear so often from sound designers and plugin creators is that they don’t get enough specific feedback!

    I’ve wrote Robert before on previous topics, and may have to send another note on this one… :)

  • jonah

    i asked the brute LFO dev and they said that MIDI control of the app is being worked on. :)

    for me, that’s totally awesome! i have enough CV generators, but being able to plug my (portable, battery powered) iOS device into something and have it operate via wifi MIDI? the future.

    now if we could just get an app to read CV in… :)

    • Jos Smolders

      this has been discussed at already. I tested it and couldn’t get any module to be nutched by this. Someone wrote there that the output voltage of the iphone isn’t nearly enough to use the device as a real lfo. So it’s just a bunch of oscillators oscillating, but that’s about it.

  • Zangief

    no native LFO in Ableton Live, a continued embarrassment or some kind of carrot (or is it stick) motivator to get you wallet open for a M4L license ?

    whatever the reason, it the M4L solutions are absolute cpu pigs. unacceptable really for a simple control signal. to add insult to injury he codes this for live 9 only …as per the usual I suppose (‘backward compatibility’, even for content that has no reason not to be, is obviously a dirty word in accounts department of Abelton HQ)

    • Aaron Zilch

      Well, technically Live has had a native LFO ever since Clip Modulation Envelopes were introduced. More powerful ( draw your own complex shapes ), but not as intuitive or quick as a standard LFO. Robert himself actually wrote a very well thought out and informative post on the reason Live has no native LFO years ago on the forums. Had a lot to do with how that modulation would be integrated into the current system without compromising other modulation/automation elements or becoming super confusing.

      As far as control signals being “simple”, well thats really not the case when you think about it. We are mostly talking about non-linear data here, which sounds way better than linear but is much more intensive to compute. It’s a big reason why digital virtual analogs have only recently ( with more CPU ) been able to touch on the “musical” ( aka non linear ) quality of analog. A big part of what gives individual analog synths their special sound ( especially when taking in terms of “snappy” or “punchy” ) has to do with the non linear qualities (exponential curves) of their LFOs and Envelopes. The “perfect imperfections”. Quality ain’t cheap, just one of the hard truths of the world.

      So an investment in 9 Suite not only gives you access to M4L but also Sampler and it’s great selectable curve envelopes ( amazing for drum layering ). Or learn how to use modulation envelopes. Build a library of useful shapes and timings and keep them in your starter template for cut n paste action.

    • Zangief

      “technically Live has had a native LFO ever since Clip Modulation Envelopes were introduced.” …. wow, that’s one 14 carrot pile of apologist bullshit right there. Only bettered by the absolute waffle that followed. throw in a couple buzzwords you don’t seem to fully comprehend in the context of a friggin LFO device and hey presto… you’ve got yourself one stomach churning crap omelet. you should be banned from the internet.

    • Aaron Zilch

      Rather than just attacking my statement with a potty mouth, why don’t you actually try a well though out counterfactual argument. Seriously. An unlinked clip modulation envelope can have a more complex shape than an LFO. Granted you can’t change the speed in realtime, but you have realtime depth control if you set up your macro’s right. Two words: Dummy Clips. One of the most powerful modulation techniques I can think of.

      As far as backwards compatibility goes, wouldn’t you rather have issues there than some sort of horrible iLok situation? Ableton is pirated like crazy and their strategy to combat that is to reward those that stay up to date with new content, rather than punishing those that actually pay with annoying dongles and what not. Live 9 addressed nearly every complaint and feature wish of the user base. Yeah, certain things maybe should have been there a lot earlier ( Session Clip automation, curve tools for automation and modulation envelopes, dual monitor, a more intuitive browser sand library layout ) but we get them.

    • Aaron Zilch

      Here is Henke’s Post on why theres no native LFO from ’08:

      …this is a long story. I try to make it short.

      First of all, we (Ableton) would want to have modulation devices like LFOs in Live too. So, why the are we not doing it ????

      The reason is a technical reason that leads to a conceptual problem, and we need to
      solve the conceptual problem, which is very tricky, first. Then we can address the
      technical problem, which is a huge effort. It’s basically rewriting an important part of the engine.

      So, you want to ask what is the problem? The problem is the ambiguity between
      automation data, which is e.g. the parameter changes you can record in the arranger, and modulation data, which is the clip envelopes.

      In the current internal data structure, each parameter can be controlled by exactly
      one automation and one modulation. The automation is always directly the
      movement of a ‘knob’ in the pannel, and this movement can be created by a
      moving a knob with the mouse, or by an automation curve in the arranger, or by a
      midi mapping, or by a macro control. The modulation which currently only can be
      provided by a clip envelope belongs to that parameter and is independent from the
      automation. The point where these things come together is the parameter itself.

      When we invented the clip envelopes for Live 3 this structure seemed to be a good
      concept, since the user does not need to do anything but drawing a clip envelope,
      and he/she still can change the parameter that is modulated and there is no further understanding needed.

      A better system from a todays perspective would allow any parameter to be
      controlled in a relative or absolute fashion by many sources, and therefore allow for things like:

      -automation of parameters within a clip, and not just modulation.
      ( -> automation recording not just of MIDI CCs but all parameters from within a clip )
      -more then one modulation source per parameter ( -> LFOs !!! )
      -control of a single parameter from various sources with variable curves. ( e.g. macro controls )

      This sounds all very exciting, and would improve Live dramatically. However, it
      would be the one single most complex re-design of the software since version 1.0.

      It would change not only the way the engine handles automation data, but would
      also require new interface strategies. It raises questions like: Is there automation
      in the clip or in the arrangement or both? If so, which one wins if you move/delete
      things? How to visualize multiple modulations? Can an LFO be modulated by itself?
      What happens at overdub, … and many more little things that can drive you nuts
      if you sit in front of a whiteboard and try to solve them…

      We planned to address the automation story for Live 7 but we had to realize that it
      would be too risky at that time, and there were too many open questions. We are
      still continue thinking about it, because it is obviously very very desirable.
      However, it might turn out that the changes would be so drastic that it would be
      impossible to open older documents in that new version and things like that.
      Things we simply cannot do anymore, too many users rely on us.*

      We could find a it-somehow-works solution for the LFO idea. But it would be a
      dirty hack, and would make it even harder to finally come up with a better solution
      for all the above mentioned wishes.

      So, at the current state of affairs, it is not too likely that the LFOs will come soon.

      Now you can hang the messenger,
      Cheers, Robert.

      *as a side note, this happens to a lot of companies: Mac OS 9 had to die because
      there was no way to maintain and improve it anymore. Protools has this huge
      legacy of the TDM hardware, that makes it hard to re-write the audio engine
      without making customers who payed a gozillion for their old systems totally

    • lala

      yes it is a carrot

      but robert is robert and not ableton
      he is obviously using 9 so why should he care about boring compatibility with yesteryears version?

  • Austrian Apparel

    extensive use of monolake’s LFO zero 1.0 controling sylenth on this track

  • Mike Gintz

    Has anybody had any difficulty using LFO 2.0 in that it doesn’t preserve mappings when reloading a saved Set? It’s retaining all parameters correctly for me, but it’s no longer mapped to the correct parameter, so it just sits there LFOing nothing. I can remap it and everything works fine, but this happens every time I reload the saved set. Am I the only one having this problem?

  • dmyra

    i think you can use autopan as an LFO if you set the phase to 360.