I decided the other day that it was necessary to upgrade my music-generating capability with the purchase of more effects processors. After a relatively small amount of research (reading the gear review issue of Bass Player Magazine and googling the Talkbass forums), I impulsively bought a set of two pedals from Chunk Systems, a small electronics company based in Sydney. They are the 'Agent 00Funk Mark II' envelope filter (pronounced 'double-oh funk' like James Bond. With a name like that, how can it not be awesome?) and the 'Brown Dog' gated fuzz effect.
Uh, I'm not an expert on analogue audio signal processing; can you explain what the hell do they actually do?
Fair enough. Let's start with the 'Brown Dog'. It's basically a distortion pedal. Imagine a plain old audible tone at a particular pitch. It looks like a sine wave. All distortion and fuzz effects work by 'chopping off' the tips of the waveform, making it look more and more like a pure square wave. This emulates the effect of an amplifier turned up way past its designed output volume. In the early days of rock, you got this effect by doing exactly that. It's the definitive rock guitar sound. These days, you use a distortion pedal to get the sound without all the bother of overheating and blowing up your amp.
An envelope filter is also known as auto-wah. An ordinary wah-wah pedal (popularised by Jimi Hendrix et al) contains a filter, either band pass or low-pass. The filter emphasises one particular frequency (or pitch), while attenuating the frequencies around that centre frequency. The location of the centre frequency (or the pitch the filter will emphasise) is controlled by pushing the pedal. Pumping the pedal results in the voice-like 'waaah' wail or 'wacka-wacka' rhythm guitar tone.
Auto-wah dispenses with the musician-controlled pedal, and modifies the filter frequency automatically based on the volume of the input. So as a note starts, the filter quickly sweeps from a low pitch up to a high one with the attack, and then slowly sweeps back down to a low frequency as the note dies off. This gives a kind of 'waahup' sound. A noteable use of auto-wah is on Stevie Wonder's keyboard in Superstition.
Ok. So what's unique about these particular effects pedals?
Firstly, Bootsy Collins uses and enthusiastically endorses them. When the guy who made auto-wah bass guitar famous is using your auto-wah pedal, you know you've done something right. Other notable users are Beck and Architecture In Helsinki.
The 'Brown Dog' is, as mentioned before, a gated pedal; it won't produce sound unless the input is above a certain volume. Turning the 'gate' control up really high makes notes start and stop extremely quickly, giving a very tight sound. The effect itself is similar to any other distortion pedal, but with a much better bass response than say, a standard Boss overdrive pedal. You can get a filthy, resonating fuzz right down in the low end.
The 'Agent 00Funk' is a very complicated unit. The controls are sensitive and you have to fiddle a bit (and consult the manual) to get some squelchy analogue goodness. It can produce quite a range of sounds. Again, as with the 'Brown Dog', it has a very good bass response compared to a standard guitar pedal.
But these effects really shine when daisy-chained together. They're designed for you to do this: as well as signal input/outputs, each pedal has an 'envelope' input which you connect together to control the envelope filter's centre frequency with an amplified but un-distorted instrument input.
You hook these two pedals together and start shredding fuzzy, squelchy analogue synth-bass like there's no tomorrow. It's insane fun. I can't wait to try it with a digital piano or organ, or even a voice or wind instrument.
I want to hear this shit! How can I find out more?
They're Australian-made products and slightly difficult to obtain even here; I got them from the excellent Bass People shop in Annandale. I revel in knowing I've added some pretty unique sounds to my repertoire.
Chunk Systems also make a programmable analogue/digital pedal called the Octavius Squeezer. It looks really cool, really complicated, expensive and I'm not likely to buy it anytime soon.