By adrian
Sat Feb 26, 2005 5:35 am
I was going through a stack of old Keyboard magazines and I found some articles that are informative. I'll post others later next week.
In ancient times, patch cords connected synthesis modules together to create sounds.
But many people didn’t like patch cord clutter, nor various reliability issues (oxidized jacks, loose solder connections, etc.).
To eliminate these problems, the EMS VCS3 synthesizer (made in the late ’60s) employed a mechanical patch bay consisting of a small, square matrix of tiny pin jacks. Each audio or modulation source (output) fed a row of these jacks, while each column fed an audio or modulation destination (input). Inserting pins at the junction of rows and columns physically connected ins and outs. ARP used a similar concept, but with a slider instead of pins.
Mechanical matrix crosspoint patching systems are long gone, but they’ve been reincarnated as software. Today’s patch cords still connect outs to ins, but they do so virtually, via matrix modulation.
Before continuing, though, let’s consider modulation’s importance. Synthesized sounds are naturally static. Modulation sources (envelopes, LFOs, aftertouch, velocity, expression pedals, MIDI controller messages, mod wheels, etc.) can add variation and interest. If you’re not using modulation options in a patch, it’s not sounding as animated and interesting as it could.
JACK INTO THE MATRIX
Software-based matrix modulation typically includes a list of modulation sources, a list of modulation destinations, and a certain number of “slots” (i.e., a software patch cord). Each slot specifies a modulation source and destination. The more available destination parameters, the better; if you want to be able to modulate a parameter, hopefully it will be available.
Software improves on its hardware ancestors by usually including two controls between the mod source and destination (a third control may shape the controller’s curve, e.g., linear or exponential response):
• Level. Adjusts the strength of the modulation source reaching the destination.
• Offset. Sets an initial, fixed modulation value.
For example, to apply an envelope to filter cutoff, select the envelope as the source and filter cutoff as the destination. Set the offset to the desired initial filter setting, then use the level control (which will usually offer positive and negative levels to add to, or subtract from, the offset value) to add the desired amount of envelope modulation.
FUN WITH MATRIX MODULATION
Some modulation options have become common: envelope to filter, LFO to oscillator for vibrato, velocity to envelope amplitude, etc. Here are some other possibilities.
• Expression pedal. This is a highly useful realtime control device. For example, use it with hard sync to sweep the oscillator being synced, thus changing the sound’s harmonic structure. Sure, you can use an envelope, but “human tweaking” of the sound can add expressiveness to lead lines. A pedal is also ideal for wah effects.
Also try using pedal to vary the amplitude envelope’s attack or decay time. With string patches, varying attack allows fading in a pad over a variable amount of time, whereas varying decay is perfect for making a bass line more or less staccato, as the music requires.
• Aftertouch. With plucked and struck patches, route aftertouch to oscillator pitch with very little level so hitting the keys really hard momentarily sharpens the pitch. You don’t want to keep pressing down on the keys; just grab that fraction of a second when your fingers smash down the keys and generate some aftertouch.
A more traditional application is to use aftertouch modulation instead of the pitch or mod wheel so that you can keep both hands on the keyboard. Or, increase the filter cutoff a bit as you press down, to add emphasis. This can help brass patches “swell,” especially if aftertouch also increases the overall level a bit.
• Modulating effects parameters. If your synth has overdrive or distortion, varying the drive amount with pedal or aftertouch can make a sound smash through. When the singer is singing, back off on the distortion. But when the big drum/synth bass fill kicks in, increase the overdrive and stand back. Yow! A bit of distortion can also make your electric piano solo (or any other sound, for that matter) stand out.
If there’s a chorus or similar effect, try modulating the modulation rate with another source, preferably a random one (e.g., random LFO waveform or sample and hold). This eliminates the rigidity that can occur with tempo sync, or any situation where the periodic whoosh-whoosh-whoosh of an LFO gets annoying.
In any event, modulation is the key to expressiveness, and matrix modulation is your key chain. When you need to spice up a patch, jack into the matrix.
Keyboard magazine 2003
In ancient times, patch cords connected synthesis modules together to create sounds.
But many people didn’t like patch cord clutter, nor various reliability issues (oxidized jacks, loose solder connections, etc.).
To eliminate these problems, the EMS VCS3 synthesizer (made in the late ’60s) employed a mechanical patch bay consisting of a small, square matrix of tiny pin jacks. Each audio or modulation source (output) fed a row of these jacks, while each column fed an audio or modulation destination (input). Inserting pins at the junction of rows and columns physically connected ins and outs. ARP used a similar concept, but with a slider instead of pins.
Mechanical matrix crosspoint patching systems are long gone, but they’ve been reincarnated as software. Today’s patch cords still connect outs to ins, but they do so virtually, via matrix modulation.
Before continuing, though, let’s consider modulation’s importance. Synthesized sounds are naturally static. Modulation sources (envelopes, LFOs, aftertouch, velocity, expression pedals, MIDI controller messages, mod wheels, etc.) can add variation and interest. If you’re not using modulation options in a patch, it’s not sounding as animated and interesting as it could.
JACK INTO THE MATRIX
Software-based matrix modulation typically includes a list of modulation sources, a list of modulation destinations, and a certain number of “slots” (i.e., a software patch cord). Each slot specifies a modulation source and destination. The more available destination parameters, the better; if you want to be able to modulate a parameter, hopefully it will be available.
Software improves on its hardware ancestors by usually including two controls between the mod source and destination (a third control may shape the controller’s curve, e.g., linear or exponential response):
• Level. Adjusts the strength of the modulation source reaching the destination.
• Offset. Sets an initial, fixed modulation value.
For example, to apply an envelope to filter cutoff, select the envelope as the source and filter cutoff as the destination. Set the offset to the desired initial filter setting, then use the level control (which will usually offer positive and negative levels to add to, or subtract from, the offset value) to add the desired amount of envelope modulation.
FUN WITH MATRIX MODULATION
Some modulation options have become common: envelope to filter, LFO to oscillator for vibrato, velocity to envelope amplitude, etc. Here are some other possibilities.
• Expression pedal. This is a highly useful realtime control device. For example, use it with hard sync to sweep the oscillator being synced, thus changing the sound’s harmonic structure. Sure, you can use an envelope, but “human tweaking” of the sound can add expressiveness to lead lines. A pedal is also ideal for wah effects.
Also try using pedal to vary the amplitude envelope’s attack or decay time. With string patches, varying attack allows fading in a pad over a variable amount of time, whereas varying decay is perfect for making a bass line more or less staccato, as the music requires.
• Aftertouch. With plucked and struck patches, route aftertouch to oscillator pitch with very little level so hitting the keys really hard momentarily sharpens the pitch. You don’t want to keep pressing down on the keys; just grab that fraction of a second when your fingers smash down the keys and generate some aftertouch.
A more traditional application is to use aftertouch modulation instead of the pitch or mod wheel so that you can keep both hands on the keyboard. Or, increase the filter cutoff a bit as you press down, to add emphasis. This can help brass patches “swell,” especially if aftertouch also increases the overall level a bit.
• Modulating effects parameters. If your synth has overdrive or distortion, varying the drive amount with pedal or aftertouch can make a sound smash through. When the singer is singing, back off on the distortion. But when the big drum/synth bass fill kicks in, increase the overdrive and stand back. Yow! A bit of distortion can also make your electric piano solo (or any other sound, for that matter) stand out.
If there’s a chorus or similar effect, try modulating the modulation rate with another source, preferably a random one (e.g., random LFO waveform or sample and hold). This eliminates the rigidity that can occur with tempo sync, or any situation where the periodic whoosh-whoosh-whoosh of an LFO gets annoying.
In any event, modulation is the key to expressiveness, and matrix modulation is your key chain. When you need to spice up a patch, jack into the matrix.
Keyboard magazine 2003
... and some nice numbers for all the chaos ...
