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Roland EF-303




Roland EF-303 goove effects

infoCountry: Japan
Weight: 1,9 Kg
Dimensions: 303 (w) x 235 (h) x 92,5 (d) mm
audio demo trend price : 200€
manual demo video comments

Roland EF-303
Groove Effects (1999)


Dj-oriented machine with step value modulations inspired from analog sequencer.

The EF303 also includes a VA digital drum machine and a TB -303 emulation.

Roland EF-303 logo
steps effects

info EFFECT MODULE Main panel features a segments display, 16 sliders, 7 knobs and 30 buttons.

Rear panel terminal connectors:
- Midi interface
- RCA stereo outputs
- headphones
- microphone input
- line RCA input switch between line / phono with ground terminal for turntables.

ac Power supply
is a 9V external DC PSU negative polarity -)+




edit VOICE internal DSP resolution works at 20 bits / 44 kHz sampling rate.

The EF-303 groovebox is a fully digital unit which manages 3 main sound sections:
- a modulator effect processor
- a virtual analog TB303 bassline emulator
- a virtual analog drum machine


edit MODULATOR the 16-steps modulator is especially designed for real-time visual performance.
The principle is quite simple: the step modulator cyclically changes the effect settings to a specified values and creates moving textures or rich rhythmic patterns.

steps modulators ef303

modulator motion can be played in 5 modes:

- forward -->
- backward <--
- forward / backward .--><--.
- pendulum --><--
- random -?-

TIP: It is also possible to set the number of steps for a sequence, up to 16 at 480 ticks per note resolution.

the machine features 16 algorithm effects:

algorithm pot filter : classic cutoff filter with resonance and a digital LFO
pot isolator: boosts or cuts specific frequency ranges on 3 bands low / med / high
pot flanger: classic short delay metallic effect with LFO modulation
pot pan delay: echo with panning ping-pong effect
pot reverb : adds classic reverberation
pot pitch/delay: shift the pitch and adds a time delay
pot slicer/pan: tremolo effects with stereo panning variation
pot comp: adds compression
pot LO-FI: reduces sound quality lowering the sampled BIT depth (bit crusher)
pot ring mod: iss a digital ring modulator
pot phaser: phase shifting effect with own LFO
pot voice: formant pitch shifter as voice changer, ROBOT for synthetic voice
pot vo Mod: tracks the incoming signal and triggers the internal synbass synthesizer.

DRUM MACHINE is based on modelling virtual analog.
Internal DSP generates 5 electronic percussions with no possible edit.

drum machine

Drum Patterns are recorded using the step modulator. Each step slider is split into 5 equal zones and each of them corresponds to a specific percussion between:

- mute (no sound)
- open hihat
- closed hihat
- snare drum
- bass drum.

demo internal VA d rum machine HEAR

TB303 is also virtual analog and emulates the iconinc TB303 bassliner: notes are entered using the step modulator sliders from bottom position for lower octave to higher, in addtion the bassliner has some sonic controls including filter cutoff, resonance and slide emulation (but no accent "twang").

tb303 vs ef303 demo internal VA TB303 HEAR

internal frequency range is from 40 to 240 BPM or defined by TAP button.
Tempo can be slaved to to an external Midi clock or engage the AUTO-DETECT function that digitally counts the BPM from external signal and automatically syncs the patterns.

midi clock The sync function provides 12 tempo dividers: 16th, 16th dotted, 8th, 8th dotted, quarter, half note, whole, two whole notes, four whole notes, 16th triplet, 8th triplet and quarter note triplet.


MIDI synth and drum can be triggered by Midi and EF-303 knobs do transmit Midi CC#.

edit MEMORY:

- 16 setups that can be data dumped to Midi sysex.
- 21 tuning scales : chromatic, diatonic, minor, dominant, whole, pentatonic and more.

ef303 motherboard



demoVST PLUGIN no official roland EF VST PLUGIN, however some alternatives:

  name price
BigSeq2 Audio damage

-AdrenaLinn Sync Software Plug-in

-BigSeq2 Audio damage

Commercial VST





demo Synched loop with stepped filter
demo Synched loop with stepped filter 2
demo high speed phasing sequence
demo filtered pad
demo pattern II

demo Tb-303 emulation
demo flanger
demo flanger 2
demo texture
demo drum machine VA modeling



Roland EF-303 Roland EF-303 Roland EF-303
video1 video2 video3

Company: Roland
Model: EF-303
Class: effect module
Dates: 1999
Technology: digital effect
Synthesis: Virtual Analog
Resolution: 20 bits
Sampling rate: 44 kHz
Algorithms: 16 models
Sequencer: 16 steps
Tempo: 40 to 240 BPM
Sync: Midi clock
Memory: 16 slots

Tuning scale: 21 models
Demo: 10





EF303 Factory Reset procedure

hold shift, turn on, press WRITE, CONFIRM


-more demos



ef303 gadget
edit editMug o'Ef303




Roland EF-303 FOR SALE
tb303 vs ef303









motherboard roland assy japanese

original IDEA

Ugly 303 emulation


"EF303 is original and fun! why tit is only limited to a bunch of standard Roland effects? as an analog CV sequencer it would have been great! The Tb 303 emulations is simply awful."

manual manual
-idea - RCA cinch
-step sequencer
-drums and tb are below average
-synthesis functions -no CV sequencer options


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Roland EF303 Roland EF303
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