Doepfer A-138n Narrow Mixer
Four-channel CV and audio mixer with master output
4 HP Eurorack module
The A-138 Mixer is a four-channel mixer for the Doepfer A-100 modular system, capable of handling both audio signals and control voltages. It features individual attenuators for each input plus a master output attenuator, giving it musical utility as both a sound blending tool and a CV summing node. Its two variants — linear for CV mixing and logarithmic for audio — make it a versatile utility module at the heart of any patch.
Features
- Four independent input channels each with attenuator knob
- Master output attenuator for end-of-chain level control
- Available in linear (A-138a) and logarithmic (A-138b) potentiometer variants
- Compatible with both audio signals and control voltages
- Optional DC offset function on Input 1 via internal jumper JP4 (modules from mid-2004)
- Positive or negative DC offset selectable via jumper position
- Can interface directly with external mixers, amplifiers, or mixing desks via master attenuator
Controls & Jacks (10)
- In 4 — Attenuator for input 4 level control
- In 3 — Attenuator for input 3 level control
- Input 3 — Third input jack for audio or control voltage signals
- Input 1 — First input jack for audio or control voltage signals
- In 2 — Attenuator for input 2 level control
- In 1 — Attenuator for input 1 level control
- Input 2 — Second input jack for audio or control voltage signals
- Output — Mixed signal output jack
- Input 4 — Fourth input jack for audio or control voltage signals
- Out — Output level attenuator for the mixed signal
How-To Guides
- Blend Two VCO Waveforms
- Sum ADSR and LFO for VCF Modulation
- Four-Voice Drum Bus Mix
- Keyboard CV with DC Offset Tuning
- Combine Four Modulation Sources for VCA
- Layered Drone from Multiple Oscillators
- Generative CV Soup from Random Sources
- Stereo Bus Interface to External Mixer
Explore the interactive A-138n Narrow Mixer panel on BleepDex — tap any control to learn what it does.
