Little Labs: LL2A Compressor Limiter

I’m always excited to see a new product from Little Labs. I’ve been collecting Jonathan Little’s [Tape Op #75] ultra-handy studio devices for over 15 years, starting with the ground-breaking IBP Phase Alignment Tool [#33]. I’ve purchased a number of his various boxes over the years, and I use his plug-ins – made in collaboration with Universal Audio for the UAD format – on almost every mix. However, even as a fan of the company, it took me a minute to wrap my brain around the LL2A. It’s like hearing one of your favorite bands branch out into a new sound, and maybe it takes a few listens to decide whether you enjoy the new direction or not.

The first item to contend with is that, despite the name, the LL2A is NOT a Universal Audio LA-2A [Tape Op #26] clone. Jonathan makes it clear in the manual that the name is merely meant to evoke the spirit of the classic compressor, not to imply a lineage. Instead of using tubes, or an opto circuit, the LL2A employs a “single linear analog multiplier to control the attenuation (not the amplification) of an audio signal,” a concept Jonathan obtained from renowned gear designer Dave Amels (Bomb Factory, AnaMod) [#31]. Jonathan also reports this to be a completely new take on compressor design, and since it involves a bunch of analog circuitry math operations that I can’t pretend to understand, I’m gonna take his word on that.

The one technical thing I do understand is that the LL2A is fully differential throughout its signal path. This means that the balanced audio you put into it stays balanced throughout the whole process, running through only two active audio stages, which makes for some very clean – not to be confused with sterile – sonics. Any character the unit has (and I found it to have quite a bit) comes from the compression artifacts, and not from harmonic distortion. This fully differential design also means that although the LL2A is, on the surface, a mono compressor, you can run it in unbalanced stereo mode by using insert-style cabling to access the Tip and Ring of the TRS jacks, or pins 2 and 3 of the XLR jacks.

The faceplate of the LL2A is simple and elegant in its symmetry. There are two knobs on the front panel: Threshold and Output. They are similar in function to the knobs on an LA-2A; that is, one determines the amount of compression applied, and the other controls the amount of makeup gain to add after the compression occurs. The Bypass switch disables the Output control as well as the compression circuit, making level-matching a cinch. The Meter switch allows the beautiful orange Nixie tube (an old-school neon meter design) to represent either gain reduction or output level, with VU-type ballistics. You can stereo link two units together with the Link switch, but there is also a “secret” feature that is explicitly called out in the manual: When there’s not a plug in the Link jack, the switch drastically slows down the time constants, as described below.

I/O is all on the back of the not-quite-half-rack, not-quite-single space rack unit. You can buy a rack kit for mounting either one or two LL2As. The unit provided for review was the desktop version and comes in a cool retro-looking cream-colored housing. A screw-on barrel connector securely attaches the included 16.5V power supply. Parallel XLR and TRS inputs and outputs are there for convenience, and the parallel output is particularly handy for one task that I’ll talk about in a few sentences. There’s the 1/4-inch TS Link jack, which allows you to run two LL2As in fully balanced stereo, and finally, a jack labeled Side Chain Insert TRS. This is also where the parallel output comes in quite handy, because if you take the output of the unit and run it through an external (balanced) EQ, and back into the sidechain input, you have an extremely powerful sidechain modification tool, allowing you to “tell” the compressor which frequencies to ignore or pay attention to the most. This is in lieu of a simple sidechain filter, which many modern compressors possess. You can also use this input for “ducking,” or what the kids call “sidechaining” these days – allowing one instrument’s amplitude to trigger the gain reduction of another, such as making the kick drum duck a bass synth.

I will say, like many of my favorite other compressors, there is some amount of fine-tuning involved in finding the sweet spot of gain reduction on the LL2A. If you hit it too hard, it goes into some easily noticeable over-compressed territory pretty quickly. However, after spending a little time with the unit, and figuring out where its sweet spots lie for each instrument type, I truly ended up loving the LL2A on everything I used it on. Especially on lead vocal, I was able to find the magic space where I couldn’t hear any negative compression artifacts; just a sweetening, lifting effect that leveled out the dynamics of the performance, but also tilted the vocal just enough forward in the mix to where I didn’t have to make it overly loud to be heard clearly. On a rare single-mic’d drum track, the LL2A balanced out the various elements of the kit, helping it poke through without being too edgy. Likewise, for other drum mics, bass, guitar, keys, horns, (mono) program material – everything sounded a bit better going through the LL2A. Even though the set attack time is a very fast 400 microseconds, I rarely felt like pressing the Link button to engage the slower attack time (2.4 milliseconds), especially sitting in the first few dB of gain reduction. If you do feel it’s getting too “grabby,” or producing undesirable artifacts, the slower attack time is available, but it also slows your release waaaaaay down, from 0.9 to 4.9 seconds, which felt too slow for most sources. The ratio of the LL2A has a soft knee, so it gets steeper the more it goes into gain reduction. At the high end of that range, it remarkably approaches the sound of a vintage broadcast limiter.

The minor issues I have with the LL2A are with the functionality of the box, not its sound. First off, the detents on the pots don’t match the markings on the knobs, which makes for slightly confusing recallability. Second, there isn’t a switch to engage the sidechain input, so if you leave a cable dangling from that jack without plugging in the other end, it interrupts the internal sidechain and therefore ceases all compression – this caused me confusion a couple of times while testing. Of course, with standard patchbay normalling, you can half-normal the LL2A’s output to the sidechain input.

As Little Labs’ first foray into the crowded market of mid-priced hardware compressors, the LL2A is overall a big win. It’s reasonably priced for the build quality, passes impeccable audio with loads of headroom, and has a distinct personality that achieves super interesting and useful results with a minimal control set.