[BILL TWEAKS ANDROMEDA'S FILTERS]

BILL HOLLAND: Welcome back to Gearwire.Com. My name is Bill Holland, and today I'm looking at the filters and modulation controls on the Alesis Andromeda.

[BILL TWEAKS FILTERS]

You have two filters here. The first one is a two-pole filter based off the Oberheim Xpander module from the 70s. The second is a four-pole filter based off the Moog Modulars of the 60s. So, analog circuits modeled very carefully after super old-school analog synth circuits. The patching on here is equivalent of a large modular patch bay except you have small casing to maintain it and keep it in. Let's go in and take a look at some of the programming involving the filters and modulation.

[BILL TWEAKS PRE-FILTER MIX]

You'll notice going to your filters here, we have the pre-filter mix which then goes to the filters and not to post filters. Pre-filter mix, we have oscillator 1, sub oscillator 1 -- notice modulation controls for all of these -- ring modulator, noise, and external audio, so you can either do white noise, pink noise, or what I believe red noise, and there's audio external in so you can feed in vocals like guitar, whatever you want, and throw into your mix in the same place you would the noise, very similar to a Moog, works in that same sort of way, but again a lot of power afforded to you via the digital programming and the fact that you can send the modulation differently than you would otherwise. So let's here real quick; I'll turn everything else off. We have oscillator 1 which comes in [BILL PLAYS SOUND FROM OSCILLATOR 1] so I can feed that to my filters over here [BILL PLAYS AROUND WITH FILTERS]. Okay, listen. We have both filters checking in. These can again be set to mixed, notch [BILL TESTS NOTCH FILTER], or band pass [BILL TESTS BAND PASS] given to that in a second here. You'll notice I can send oscillator 2 with oscillator 1 to kind of balance them out [BILL SENDS OSCILLATOR 2 SIGNAL WITH OSCILLATOR 1]. Let's pick a different patch real quick [BILL SWITCHES PATCH], a ring modulator [BILL TESTS PATCH WITH RING MODULATOR], hit it to mod [BILL TESTS PATCH WITH RING MODULATOR]. Notice we also have sub-oscillators for each of these so [BILL ADJUSTS SUB-OSCILLATORS] we'll send those to modulation as well [BILL TESTS PATCH], and again white noise, pink noise, red noise or audio in [BILL MODIFIES PATCH WITH NOISE].

So now, moving over to the filters, you'll see we have filter 1. This is based off of the Oberheim Xpander unit from the 70s to two-pole filter. This is a four-pole filter that was in the Moog Modulars; very similar circuitry: this one being 12 dB, this one being 24. So, when you use them as low-pass filters, keep in mind that this one's going to have a wider sweep [BILL TWEAKS FILTER 2] than this one [BILL TWEAKS FILTER 1].

Okay, let's switch patches again real quick [BILL SWITCHES PATCH AND PLAYS AROUND WITH FILTERS]. You can see, when I adjust the envelope, how far that one goes. Now let's open that up, the frequency up all the way, and then take this one down [BILL PERFORMS FILTER ADJUSTMENTS], change up my keyboard tracking. So, this is much a narrower margin for filtering; this is sort of like your big, fat, you know [BILL PLAYS A NOTE].

Let's get like a house bass or something here. [BILL PLAYS AROUND WITH HOUSE BASS PATCH AND ADJUSTS FILTERS]

So again, we have mixed, notch, and band pass. Let's see how band pass can work with the two of these. [BILL PLAYS AROUND WITH FILTERS]