Let's have a look at the Alesis NanoCompressor, a cute little hardware compressor from the 1990s. Sound on Sound reviewed it back in March 1997, but the manual is copyright (c) Alesis 1996, so who can you trust?
Who can you trust. The front panel is vintage 1990s, just as the MicroGate and
MicroVerb look like the 1980s. Look at the cheatline running through the Micro
effects' logotypes. It's supposed to look like chrome, but without the chrome.
You know what makes me sad? My memories of graphic design in the 1990s are of
David Carson and The Designer's Republic, because I was alive then and I knew
what was hip.
But if you Google "1990s font design" the internet's examples are all purple
and yellow, like Miami Vice, and the fonts resemble the logotype from
Moonlighting, which finished in 1989. The 1980s bled into the 1990s,
but by the middle of the decade Miami Vice was dead as a dodo, a big
joke. The hip new thing was Se7en, which came out in 1995. Remember the
title sequence, with the jumpy text and the deep blacks? That was
my 1990s, not pastel colours. The internet is a bald-faced liar.
More of the 1990s.
The NanoCompressor was sold alongside the NanoVerb, which was a reverb unit,
and the NanoPiano, NanoBass, and NanoSynth, which were all sample-based
synth modules. They used the same case design, one-third of a 19"
rack. As of 2022 they're all available on the used market for peanuts,
because there's not much demand for them, so they make for a fun collector's
project.
Historically they replaced the Micro- effects, and they were in
turn replaced by a small range of Pico- effects, although as far as
I can tell the only Pico effect was the PicoVerb, which came out in 2003
for the low, low price of £70. By that time Alesis was trying to recover
from bankruptcy, and the market wanted plugins, so as far as I can tell
Alesis gave up on effects in the mid-2000s to concentrate on drums and the
Ion/Micron instead.
I bought the NanoCompressor on a whim. I've never owned a hardware
compressor, and I wanted to see what it was like to use one. I was
secretly hoping that it would be rubbish but characterful, like a Holga
camera or a toy piano. Noisy, distorted, sick, but awesome. On the other
hand the NanoCompressor is a simple analogue VCA unit, a type known for
its transparent sound; unlike the contemporary Alesis 3630 it isn't
infamous for its noisy pump, in fact there isn't much about it on the
internet at all.
My experience with Alesis' earlier Micro effects is that they're surprisingly okay. I
was expecting masses of hiss and distortion, but apart from a little bit
of low-level aliasing and some scratchy pots the MicroVerb II sounds like
a decent software plugin. Compared to my Strymon BigSky it sounds thinner,
because the reverb isn't modulated, and it's less glassy-smooth, but a
couple of the presets are really good. SMALL 1 thickens up the sound
unobtrusively and LARGE 4 is epic. The MicroGate is similarly transparent
- it gates things, there's not much to go wrong - and having used the
NanoCompressor on a couple of songs I can say that, yes, it's just as
"surprisingly okay" as the others.
Which is slightly disappointing. I was hoping for grungy sound but instead
the NanoCompressor is a low-key volume leveller stroke attack-adder-er.
Even set to maximum pump it's surprisingly restrained.
It's a stereo unit, although the panel gives the impression that it's
mono. The controls operate on both channels at the same time. It can do
peak compression - which acts quickly on transient signals such as bass
and drums - and RMS compression, which is gentler and frequently used on
the final mix in order to keep the level nice and steady. Here's an
example of the difference between the two, plus a little bit of pumping:
What is compression? It's one of those things. On the surface it's
simple, just a form of automated volume control, but compressors
are among the most sought-after, most legendary pieces
of audio equipment. A modern reissue of the 1960s Teletronix LA-2A sells
for almost £4,000, and people are prepared to pay even more for the
originals. It's a mysterious world of vari-mu and "all-button mode".
On the surface compression is simple. A compressor listens to an incoming
audio signal, and if the signal goes above a certain level the compressor turns
the sound down. Not instantly - there's a little bit of a delay so that it
feels natural. Ultra-rapid compression is generally called limiting, and
to complicate matters there are levelling amplifiers that also
boost quiet sounds so that everything is the same volume, and software
plugins called volume maximisers that look ahead a few
microseconds, so that the signal is as loud as it can be without clipping, or without clipping too much.
Compressors were developed in the before times, primarily for the radio
industry, although they filtered through to recording studios. They were
particularly useful in radio studios, where a programme might have had a
mixture of studio interviews, live music, outside broadcasts, pre-recorded
music played from shellac discs, all kinds of different sounds recorded at
different levels.
All of those things had to be broadcast as loudly as possible in order to
cut through the static and hiss, but not too loud otherwise the signal would distort. In theory the producer could move the volume slider up and down
while the programme was playing back, but a compressor could do it
automatically, without having to listen to the whole programme in advance,
and it could do so quicker.
This is essentially what RMS compression is like. It smoothly keeps the
music from getting out of hand. But paradoxically compression can be used
to increase the overall volume of a piece of music. Contemplate the
following four waveforms:
I downloaded a book a while back. Stockhausen Serves Imperialism, it
was called. I was expecting a nice big dose of imperialism, but
instead it was a bunch of moaning about conceptual music.
The first waveform is a little bit of music without any compression. It
sounds fine, although you have to strain a bit to hear the quiet bits.
Classical music is often recorded like this, with minimal or no
compression, because classical producers want to capture the original
performance without colouring the sound.
With the second waveform I've applied a really harsh compression
algorithm. The loud bits are now the same volume as the quiet bits. With the third waveform I've raised the overall volume so that the signal is as
loud as possible without distorting. It sounds punchier, more in-your-face
than the first waveform. Perhaps too punchy, because the compression was
really hard.
It could be worse, though. With the fourth waveform I've turned the volume
up until it distorts, and then I've turned the volume up even more, until
it sounds obviously distorted. This is a technique that became popular in
the 1990s. How better to make a record stand out on the radio than by
making it really, really loud?
The fourth waveform would probably sound great coming out of the speakers
in McDonalds, where no-one cares about sonic fidelity. It's torture to
listen to with headphones though, or at least it's torture to listen to
for very long.
And that is RMS compression. A tool for good. A tool for evil. Like
pliers. A tool. The NanoCompressor is perfectly anonymous in RMS mode. The
attack and decay controls are disabled, so you only have control over the threshold at which compression occurs and the ratio of compressed to non-compressed signal. What does RMS stand for? Root mean square. What does that mean?
"It's the rough average". I don't know, I'm not a mathematician.
There's another kind of compression called peak compression, which is
often used on individual instruments, commonly the bass and the drum. Those two instruments are key components of modern beat music. The
NanoCompressor's peak compression mode has attack and decay controls,
which add an envelope to the compression.
If you're used to synthesiser ADSR envelopes peak compression is a little bit paradoxical, because a slow attack actually makes the sound more aggressive. Think of a compressor's attack and decay controls as an inverted ADSR envelope, because they add quietness.
Contemplate the following two waveforms, which are a bass note put through
the NanoCompressor:
At the top the NanoCompressor has a fast attack. It instantly clamps down
on the bass note and keeps it quiet. At the bottom I've slowed down the attack, which has the effect of slowing
down the onset of compression. Notice how there's a little peak at the
beginning of the note. That's the original signal, before the
NanoCompressor clamped down on the volume. The result sounds punchy,
aggressive, with a little POP at the beginning of the note. If it's
confusing, just train yourself that slow attack = punchy sound and not the
other way around.
Compressors can do a third thing. Look:
That's an example of side chain compression. If you put a signal through the
NanoCompressor's side chain input, it uses that signal as a trigger for the onset
of compression. In this case I've fed a simple pop-pop-pop bass drum into
the side chain input. Notice how the bassline seems to go
ooowop-ooowop-ooowop, as if the bass drum was punching holes into it.
When used subtly the side chain input is handy for mixing the bass and the drum. They occupy the lower frequency range, and if you've not careful it's
easy to have the bassline overlap the kick drum. The end result just sounds
muddy and indistinct. Side chaining the kick drum to the bass separates the two so that the bass quietens down when the kick drum sounds, so that you still hear the
pop-pop-pop of the kick drum.
Side chain compression can be used unsubtly, as in the video above.
Dance music producers of the late 1990s latched on to it, but the example I'm going to post is much more modern. This is Low, from their 2018 album
Double Negative:
The whole album is masterclass in the creative use of compression. Notice how the crunchy not-quite-bass-drum seems to punch holes in the rest of the music, and then it takes a split-second for the background music to recover? That's side chain compression.
As mentioned up the page I found the NanoCompressor slightly disappointing,
because it's neither good nor bad. It doesn't have much character, and it's
less flexible than a software plugin. There's nothing wrong with
it, but what's the point? Nonetheless I decided to make a whole track with
it:
I played each part with a modular synthesiser fed through the NanoCompressor in
peak mode, with the modular plugged directly into the NanoCompressor, which
in turn was plugged into the audio interface. I didn't use it as a send
effect. This setup bakes the compression effect into the recorded
audio, but this just meant that I had an incentive to get it right first
time and stick by my decision.
I added delay and reverb with Logic, and in the video I'm running the entire
mix through the compressor in RMS mode. I didn't use the sidechain input,
and all of the voices were recorded onto individual tracks. From what I
remember the knob settings pictured in the video are more or less what I used throughout when it
was in peak mode.
I haven't mentioned the controls, have I? From left to right the NanoCompressor has
THRESHOLD, which determines the level at which compression begins; RATIO, which determines
the strength of the compression; a tiny HARD/SOFT button that determines the
steepness of the volume slope, although I could barely detect a difference; a PEAK/RMS button; ATTACK and DECAY knobs; a button that
determines whether the level meter shows the input or the output level, and
finally a bypass button that turns off the compression. And a volume knob.
As you can hear, when used subtly the result is mostly transparent, although
there's a noticeable punch to the bass, a kind of aggressive thwap sound.
Musically I was inspired by Manuel Göttsching's E2-E4, which is a
forty-minute-long synthesiser jam from the early 1980s that was apparently a
favourite of top New York DJ Larry Levan, because he could play it while
going to the toilet.
And that's the NanoCompressor. Is it better than Logic's built-in compressor
plugins? No. It doesn't even save much CPU load, because compression plugins
aren't particularly CPU-heavy.
Is it sonically characterful? No. It's a technically competent, transparent
compressor. You might appreciate it more if you're playing live without a
computer, or if you're a guitarist and you want it as part of your
pedalboard, assuming you can get it to fit. Perhaps you want to make a big chain of analogue effects. On the positive side of things
it does nothing wrong, and it's cute, so there is that.
