Make Noise Echophon
Pitch-shifting echo with spiraling harmonic feedback
20 HP Eurorack module
The Echophon is a digital pitch-shifting echo module designed by Tom Erbe of Soundhack for Make Noise. It combines a variable-time delay with a pitch-shifting engine inspired by the Springer Tempophon, enabling spiraling harmonic echoes, vibrato, harmonizing, and comb filtering. Its bipolar feedback architecture and freeze function make it especially powerful for experimental, melodic, and textural sound design.
Features
- Digital pitch-shifting echo inspired by the Springer Tempophon
- Variable echo time from 7ms to 1.7 seconds
- External Tempo Input for clock sync with division and multiplication
- Echo Clock Output: 4ms wide, 0V-5Vpp pulse at echo rate
- Bipolar Feedback Panel Control with two independent feedback loops
- Loop 1 feeds back through pitch shifter for spiraling harmonic echoes
- Loop 2 feeds back around echo section for traditional repeats
- External feedback loop via Feedback Output and Feedback Input jacks
- Freeze function via button toggle or Gate input
- Pitch parameter remains active during Freeze
- Pitch 1 CV with bipolar attenuverter for vibrato and LFO modulation
- Pitch 2 CV input optimized for sequencer and keyboard CV
Controls & Jacks (31)
- Signal Input — AC coupled audio input. Expects standard signal level of 10Vpp signal.
- Mix CV Input — Unipolar control input for Mix. Range 0V to +5V.
- Mix Combo Pot — Blends between dry input signal and wet delayed/pitch-shifted signal. Fully CCW is dry only; fully CW is wet only.
- Mix Output — AC coupled audio output. 10Vpp output (depending upon Level setting and source material).
- Feedback Input — AC coupled return for external feedback loop. Expects standard signal level of 10Vpp.
- Input Level — Sets the input gain level before the delay engine. Adjust to match source signal amplitude and avoid clipping.
- Feedback Output — AC coupled send for external feedback loop. 10Vpp output.
- Pitch Trim — Fine-tuning trimmer for pitch shift calibration. Adjusts tracking accuracy of the pitch shifter.
- Pitch — Sets the pitch shift amount applied to echoes, calibrated in semitones. Center position is unity (no shift). Turn CW for upward shift, CCW f
- Echo Time — Controls the delay time from short comb-filter ranges to long spacious echoes. Can be synced via the Tempo Input.
- Echo Clock Output — Outputs the Echo Time as 4ms wide clock pulse. 0V-5Vpp.
- Depth — Controls the feedback amount and character. CCW of center: pitch-shifting feedback (echoes spiral in pitch). CW of center: traditional echo
- Feedback — Bipolar CV input for external modulation of the Depth/Feedback parameter. Range +/-8V.
- Echo Time CV Atten — Unipolar attenuator for Echo Time CV Input.
- Pitch CV Attenuverter — Bipolar attenuator for Pitch 1 CV Input.
- Depth CV Atten — Unipolar attenuator for Depth CV Input.
- Feedback CV Attenuverter — Bipolar attenuverter for the Feedback CV Input. Center is zero; CW is positive, CCW is inverted.
- Echo Time CV Input — Unipolar control signal input for echo time. Range 0V to +8V.
- Freeze Gate Input — Freezes on Gate High. Requires 1.5V trigger signal to operate.
- Depth CV Input — Unipolar control signal input for depth. Range 0V to +5V.
- Pitch 1 CV Input — Bipolar control signal input for pitch. Range +/-4V.
- Pitch 2 CV Input — Bipolar control signal input for pitch. Range +/-2V for total of 4 octave range.
- Feedback CV In — Bipolar CV input for external modulation of the Depth/Feedback parameter. Range +/-8V.
- Freeze — Indicates status of the Echo chamber. Lights when Freeze is activated.
- Tempo Input — Allows synchronization of Echoes to multiple or division of an external Clock. Requires Clock/Gate signal amplitude of at least 1.5V and wid
- Signal — Indicates input signal presence and level. Lights when audio is present at the Signal Input.
- Clock — Displays the echo clock rate, blinking in time with the current delay time or external tempo.
- Temphonic LEDs — Indicates mechanics of the pitch-shifting machine.
- Up — Indicates upward pitch shift is active (Pitch knob above center position).
- Mix Auto — Indicates the Mix control is being modulated by the Mix CV Input.
- Tempo — Displays the rate of the external Tempo Input clock signal.
How-To Guides
- Basic Wet Echo Setup
- Vibrato with LFO
- Sequenced Harmonizing
- Freeze and Play Melodically
- Comb Filter Drone
- DigiCello - Bowed String Synthesis
- Stutterphon - Rhythmic Stutter Effects
- Bipolar Feedback LFO Crossfade
- External Ring Mod Feedback Loop
- Pillars of Hercules - Percussive Pitch Modulation
Explore the interactive Echophon panel on BleepDex — tap any control to learn what it does.
