Synthesizer Expander Module (SEM)
Key Features
- Monophonic Oberheim SEM-inspired synth voice with a compact vintage-style workflow
- Dual oscillator design for classic saw and pulse basses, leads, and percussion patches
- 12 dB/oct state-variable filter with lowpass, bandpass, highpass, and notch character
- Massive unison mode for thicker mono lines and stacked analog-style tones
- Phasor effect modeled after the early Oberheim pedal sound
- Tempo-sync echo, 100 factory presets, MIDI learn, and DAW automation
- Resizable interface with focus zoom for detailed editing on modern displays
Description
Synthesizer Expander Module is Cherry Audio's mono virtual instrument based on the classic Oberheim SEM voice. It focuses on the direct SEM formula: two oscillators, a 12 dB/oct state-variable filter, fast envelopes, and a compact panel built for basses, leads, percussion, and vintage electronic tones.
The filter is the center of the instrument, with lowpass, bandpass, highpass, and notch modes giving it a more open and flexible tone than a typical ladder-filter monosynth. Cherry Audio also adds a unison mode, 100 presets, MIDI learn, DAW automation, zoom options, and a tempo-sync echo so the workflow feels modern without turning the synth into a broad modular environment.
For sound design, the built-in Phasor effect is a useful bonus because it echoes the early Oberheim pedal character and gives simple patches extra movement. The tradeoff is intentional simplicity: it is monophonic and does not include a built-in arpeggiator or step sequencer, so complex patterns need to come from your DAW or an external MIDI tool.
Use it when you want a focused Oberheim-style voice for expressive bass lines, biting leads, Berlin-school sequences, synthwave hooks, or layered analog texture. It is also a practical way to learn the SEM sound before moving to larger paid Eight Voice or OB-style instruments.
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Frequently Asked Questions
Is Synthesizer Expander Module polyphonic?
No. It is designed as a monophonic SEM-style instrument, so it is best for basses, leads, percussion, and single-note sequences. For chords and multi-voice SEM textures, Cherry Audio points users toward Eight Voice.
Does it include a built-in sequencer or arpeggiator?
No built-in arpeggiator or step sequencer is listed on the developer page, and external reviews call that the main missing workflow feature. You can still sequence it from your DAW, MIDI hardware, or a dedicated MIDI sequencing plugin.
What makes the filter important?
The SEM sound is built around a 12 dB/oct state-variable filter rather than a typical four-pole ladder filter. Its lowpass, bandpass, highpass, and notch modes make it useful for bright leads, hollow sweeps, and animated midrange tones.
Does it require a Cherry Audio account?
Cherry Audio says the software prompts for account login when first opened, and the download page also references Cherry Audio Sync for managing installs. The SSA download button points to Cherry Audio's own download page so the current account and installer flow stays under the developer's control.
