The Pittsburgh Modular Generator is basically a compact 2-oscillator FM voice built for unstable, aggressive, non-1V/oct, wide-range sound design. From the manual:
This means the module shines when you think of it less like a “precise dual VCO” and more like a chaotic FM percussion/bass laboratory.
Because Gen 1’s Index Out is internally routed to FM Gen 2, the Index pot and Index CV input are major performance controls.
Practical result:
That is the main source of movement for: - metallic percussion - tearing bass attacks - animated drones/pads
The External input can be routed to modulate: - Gen 1 when switch is up - Gen 2 when switch is down
This allows: - Gen 2 → FM Gen 1 - another module → FM either oscillator - self-patching from one output into the FM input - pseudo-feedback patches using mixers/VCAs/filters
This is where the most extreme sounds live.
Because the waveforms of the two oscillators move in opposite directions, the Shape knob changes both: - harmonic content - FM character - how sharply the oscillators “bite” each other
Use it like a macro timbre control rather than just a waveform selector.
This is the first thing to patch for impact.
Why: - it creates a dynamic FM amount - it shapes attack brightness and aggression - it can make sounds start noisy/metallic and settle into pitch
Try: - short decay for kicks, snares, zaps - medium decay for bass growl - long attack/release for evolving pads
Patch one oscillator output into the External input and route it to the other oscillator.
Examples: - 2 → External In, route to Gen 1 - 1 or Index Out → external processor/VCA → External In, route to Gen 2
This creates: - clangorous percussion - distorted bass textures - unstable digital-sounding sidebands - “ripping zipper” tones mentioned in the manual
Even though there’s no dedicated Shape CV in the manual, you can still perform it manually or use adjacent system tools to animate the output after the module. But if you’re playing live, the Shape knob is one of the best movement controls.
Good uses: - square-heavy settings for more edge and impact - triangle-heavy settings for softer, hollow, pad-like tones - subtle movement around the center for evolving timbre
The external FM attenuverter is extremely useful.
Try both: - positive FM - negative/inverted FM
Inverted modulation often gives: - different attack behavior - asymmetrical bass motion - “inside-out” sounding timbres - more complex percussion transients
Each oscillator has: - Low - Mid - High
Interesting combinations: - Gen 1 low / Gen 2 mid = percussion, kicks, snapping bass - Gen 1 low / Gen 2 high = broken digital artifacts, neuro bass textures - Gen 1 mid / Gen 2 low = wobbling unstable sub with noisy overtone movement - Both high = metallic, alias-like, insect, scream, lead tones - Both low = chugging LFO/audio-borderline chaos, horror drones
The Generator is naturally excellent at FM percussion, especially because the internal FM depth can be hit by an envelope.
Patch: - Listen to Index Out - Set Gen 1 range = low - Set Gen 2 range = low or mid - Patch envelope → Index CV - Keep Index pot toward the side that gives strong gain (full left = max) - Tune Gen 1 lower for body - Tune Gen 2 slightly higher for attack click/knock - Use Shape toward more triangle for rounder body, more square for harder punch
What happens: - envelope opens Gen 1 VCA and increases FM into Gen 2 - attack gets brighter and more distorted - decay settles into a lower thump
For more distortion: - patch Gen 2 out → External input - route external FM to Gen 1 - raise external FM amount carefully
Result: - gabber-style kicks - industrial thumps - broken-machine toms
Patch: - Gen 1 range = low or mid - Gen 2 range = high - Envelope → Index CV - Gen 2 output → External input - Route external FM to Gen 1 - Turn FM attenuverter to a moderate positive or negative amount - Listen to 2 or Index Out
Tuning: - Gen 1 provides body - Gen 2 in high range provides noisy metallic shell
For sharper results: - use more square content with Shape - use very short envelope decay
This can produce: - electro snares - laser toms - metallic knocks - broken arcade percussion
Patch: - Both oscillators in mid or high - Patch a fast envelope to Index CV - Route Gen 2 → External input → Gen 1 - Sweep one frequency knob while triggering
Best trick: - start with low external FM, then increase until pitch starts smearing
This gives: - old-school sci-fi zaps - drum’n’bass fill hits - “Nintendo zipper” sounds the manual hints at
Patch: - Both oscillators high - Shape toward square-heavy tones - Short envelope to Index CV - Listen to 2 or Index Out - Optionally patch Gen 1 output → external VCA/filter for additional shaping
Try tuning the oscillators non-harmonically: - not octave-related - not fifth-related - awkward intervals give more noisy metallic splatter
This yields: - brittle hats - glitch ticks - harsh industrial tops
This module is not intended as a perfect tracking bass oscillator, but it is fantastic for resampled, dirty, animated bass design.
Use: - one oscillator as the low fundamental - the other as a moving FM aggressor - Index CV for timed bursts of timbral violence
Patch: - Gen 1 range = low - Gen 2 range = mid - Listen to 2 for the more FM-affected voice - Patch slow/moderate envelope or LFO → Index CV - Patch Gen 2 → External input, route to Gen 1 - Use small to medium external FM amount - Tune Gen 2 slightly detuned from a harmonic ratio
Why it works: - internal FM from Gen 1 to Gen 2 creates movement - external cross-modulation back into Gen 1 adds instability - slight tuning offsets generate animated growl
For more dubstep: - run output into a lowpass or bandpass filter with additional modulation - automate Shape by hand while recording - resample several passes
Patch: - Gen 1 low - Gen 2 high or mid - Listen to 2 - Strong envelope to Index CV - Gen 2 output → External input - Route external FM to Gen 1 - Turn attenuverter negative, then compare with positive - Set Shape near center and wiggle it manually
This creates: - vowel-like FM shifts - tearing attacks - phasey vocal overtones
To push further: - mult output to waveshaper, filter, phaser, or comb filter - automate post-processing with synced LFOs
The Generator itself supplies the raw complex motion; your downstream modules turn it into full-on neuro funk.
Patch: - Use Gen 1 as the sub-ish source - Set Gen 1 low, shape closer to triangle - Set Gen 2 mid/high - Keep internal FM moderate with Index settings - Use Envelope → Index CV for attack only - Listen to: - 1 for cleaner source - 2 for more shredded version - Index Out for dynamic aggressive contour
Best workflow: - split outputs and layer them externally: - 1 = sub/body - 2 or Index Out = growl layer
This is especially good for: - drum and bass stabs - modulated one-shot basses - fill transitions
Patch: - Sequence pitch loosely through EXP input, but don’t expect precise melodic tracking - Use short-decay envelope to Index CV - Set Gen 1 low, Gen 2 mid - Add Gen 2 → External FM → Gen 1 - Tune by ear per pattern, not by keyboard intervals
Important note: Because the manual states it does not track 1V/oct and is not temp compensated, this works best for: - short riffs - one-note bass patterns - manually tuned sequences - hostile techno/dnb phrasing
This can sound huge if clocked tightly and fed into: - VCA - envelope - lowpass filter - saturation/compression
Patch: - Build your bass tone on 2 - Moderate internal FM using Index - Put output through a filter - Modulate the filter with an LFO - At the same time, modulate Index CV with a second slower envelope/LFO
Why: - filter movement gives the expected wobble - FM-index movement adds internal animation - the result is less static than a normal subtractive wobble patch
Try: - lowpass wobble + subtle Index modulation = modern dubstep - bandpass wobble + stronger Index modulation = screaming DnB lead bass
Generator can do pads, but not in a classic “stable polysynth oscillator” way. Think: - unstable haunted organ - metallic fog - cold sci-fi choir - detuned dread ambience
The magic is slow movement and gentle FM, not maximum brutality.
Patch: - Set both oscillators to low or mid - Keep frequencies close but not identical - Use minimal internal FM at first - Listen to 1 and 2 separately, or mix externally - Set Shape toward more triangle content - Slowly increase Index until overtones begin to bloom
What to modulate: - slow LFO to Index CV - manually sweep frequency knobs a tiny amount - occasional external FM from another slow oscillator
Result: - shifting organ-like drone - eerie chorusing through non-precise tuning - unstable spectral bloom
Patch: - Gen 1 low - Gen 2 mid - Long attack/long release envelope to Index CV - Listen to Index Out and/or 2 - Keep external FM low - Shape near center or triangle-leaning
Behavior: - sound opens gradually into complexity - sidebands bloom during attack - release falls back into a hollow core tone
Best with: - reverb - delay - lowpass gate or VCA after the module
This makes beautiful: - dark ambient beds - soundtrack tension drones - haunted intro pads
Patch: - Both oscillators in mid - Tune to a dissonant interval - Use Gen 2 → External input - Route to Gen 1 - Keep both internal and external FM modest - Slowly move Shape during performance
Tip: The sweet spot is just before the sound turns fully abrasive.
This produces: - bell-like haze - rusted choir tones - frozen-air metallic ambience
Add: - shimmer reverb - granular delay - stereo filtering
Patch: - Long cycling envelope or slow LFO to Index CV - Another slow CV source to an external VCA/filter after the module - Set Gen 1 low, Gen 2 low or mid - Use 1 for a more stable component, 2 for unstable harmonics - Mix both externally
This layered approach works very well: - 1 = body - 2 = moving spectral layer - Index Out = animated transient/wash layer
Blend to taste and drown in reverb.
This is the most immediate “go crazy” patch.
Patch: - 2 → External input - Route switch up to Gen 1 - Use attenuverter to set amount/polarity
Sound: - violent cross-FM - sharp percussion - growling bass - unstable drones
A lot of the personality lives here.
Because Index Out is post-VCA and tied to internal FM behavior, it often feels more alive than the plain oscillator outputs.
Use when you want: - dynamic percussion - animated bass attacks - envelope-shaped timbre shifts
Take: - 1 = cleaner/rawer Generator 1 before index VCA - 2 = Generator 2, already influenced by internal FM - Index Out = dynamic processed Gen 1
Mixing these externally gives a much bigger sound than using only one output.
Great for: - bass layering - drone stacks - parallel distortion/filtering
The Generator rewards: - envelopes into Index CV - self-patching with External FM - non-harmonic tuning - manual performance on Shape and frequency - layering multiple outputs
It is less about precise tonal FM and more about alive, unstable, aggressive motion. For your goals:
If you want, I can also turn this into:
1. a quick-start cheat sheet,
2. a set of 10 named patches, or
3. a rack-aware patch plan if you tell me what other modules you have.