Rackears IconRackears.io
Teisco SX-240 - Image 1

Teisco SX-240

KeyboardAnalogPolyphonic

Back in 1984, this synth arrived as Teisco's top-of-the-line 8-voice polyphonic powerhouse, right before Kawai fully rebranded it—capturing that late analog era magic just as digital was knocking on the door.

Each of its 8 voices packs two DCOs plus a sub-oscillator, delivering saw, sine, and pulse waveforms with pulse width and PWM control, all feeding into SSM 2044 24dB/oct lowpass filters boasting resonance, cutoff, envelope amount, and a dedicated ADSR. A single LFO with saw, square, or triangle waves offers speed, delay, reverse, and depth tweaks to modulate DCO, VCF, or VCA, while dedicated ADSR envelopes shape the VCA and a high-pass filter adds bite. Hands-on editing shines via a big data wheel, four scroll buttons for parameter selection, LED indicators for every control, pitch bend wheel, dual volume sliders, and a bright electroluminescent display for naming and storing up to 48 tones—plus a 1,500-note sequencer with 8 song memories. The 61-key keyboard supports poly-8, poly-4, dual, split, and mono modes (stacking all 24 oscillators for massive leads), with chorus, portamento, glissando, hold, and early MIDI In/Out/Thru (omni receive).

Owners cherish its wide, warm analog tone—brighter and fatter than some DCO peers—often praising the filter growl and sequencer for hands-free inspiration, though the single-LFO limits complex modulation and basic MIDI feels dated today. It's a hidden gem for vintage poly chasers seeking Juno-era vibes without the hype.

Released

1984

Status

Discontinued

Synthesizer
Format
Keyboard
Type
Subtractive
Internal Battery
-
Voice
A/D
Analog
Polyphony
Polyphonic
Oscillators
2
Oscillator Type
DCO (Digitally Controlled)
Voices
8
Filter
Lowpass, 24dB/oct (4-pole)
Envelopes
2
LFO
1
Effects
Chorus, Hold, Portamento and Glissando
Expression
Aftertouch
No
Velocity
-
MPE
No
Additional
-
Software
-
I/O
Audio In
-
Audio Out
-
Headphone
phones out
MIDI
In, Out, Thru
MIDI Type
DIN (5-pin)
Ports
-
Wi-Fi
No
Workflow
Arpeggiator
-
Sequencer
Yes
Mod Matrix
-
Memory
48 Tone memories. Sequencer has 8 memories.
Measurements
Dimensions
-
Weight
-
Last updated Mar 24, 2026