After working on my microKORG ADK for the last couple of weeks I am keen to get back to tuned sounds so this week I am going to concentrate on a bass sound to accompany the drums. My favourite synth bass sound ever probably comes from the Moog Taurus bass pedals, which bellows out the most fantastically rich bass sound. I have used a sampled Taurus sound (from a Future Music cover disc I think) in a lot of my tracks over the years and am keen to squeeze something like that out of the microKORG. I was also inspired with the sound of a bass guitar, where you can't get infinite sustain.
Starting with the initialized patch, I changed the voice assign to monophonic and the trigger to single (so the envelope doesn't reset on each successive note, like sliding the fingers up and down the bass guitar). I also added a little portamento to simulate the change in pitch as you work up and down the frets.
I experimented with the oscillator types (twin saw or saw / square) and settled on twin saws, with the second detuned slightly. To beef up the sound further I modulated the pitch of waveform of Osc 1 using LFO1 by altering Control 2, fattened things up further by dropping Osc 2 and octave and added distortion (reducing the levels in the mixer so it wasn't too overdriven). For a bit more oomph I turned unison on, with a small detune amount. Filter-wise I closed the 24dB LPF filter a bit (with very little resonance) and added a little bit of envelope modulation.
For the amp envelope I increased the decay time but dropped the release time. I wanted the sound to decay when held but drop away quickly if released (like a bass guitar). I started with a sustain of zero but increased this slightly as I thought it sounded more natural. I made sure the patch was velocity sensitive but unfortunately couldn't work out, even on single trigger mode, how to ensure that the amp level was dictated by the initial note on velocity (any suggestions??). To combat this, I only increased the modulation amount to 20, any higher than that and the change in level sounded off unless you sequenced it or played very skillfully. [Try it yourself, increase the sensitivity and then strike the initial key softly and subsequent keys hard, it sounds dreadful.]
I finally added a flanger and can't really describe the effect it has except to say it seems to add definition to the lower notes, which, for a bass instrument, has to be a good thing! And apart from some minor EQ tweaks that was it. Unfortunately I haven't done a sound comparison with a Taurus bass yet so can't tell how close it sounds, but I like it. Probably more for slow, brooding lines, rather than rapid bass runs but it works for both.
Here are the settings (starting from init, shift+3):
Voice: SYT, SGL, UNI, SGL, 2
Pitch: 0, 0, 0, 2, 10
Osc 1: SAW, 0, 10, ---, ---
Osc 2: SAW, OFF, -12, 5, ---
Mixer: 76, 103, 0, ---, ---
Filter: 24L, 80, 3, 2, 27
Filter EG: 5, 121, 0, 69, ON
Amp: 127, CNT, ON, 0, ---
Amp EG: 5, 121, 6, 56, OFF
LFO 1: TRI, OFF, OFF, 10, --- (unchanged)
LFO 2: SIN, OFF, OFF, 70, --- (unchanged)
Patch 1: VEL, AMP, 20, ---, ---
Patch 2: LF2, PTC, 0, ---, --- (unchanged)
Patch 3: LF1, CUT, 0, ---, --- (unchanged)
Patch 4: LF2, CUT, 0, ---, --- (unchanged)
Mod FX: FLG, 15, 12, ---, ---
Delay: STR, OFF, 40, 0, --- (unchanged)
EQ: 1.00, 5, 16.0, -6, ---
Arpeg. A: 120, 1.16, 80, UP, 1 (unchanged)
Arpeg. B: OFF, 0, ON, 8, --- (unchanged)