Endorphin.es Autopilot (E-AP / Rev.3) – Dual Eurorack Auto-Tuner (4HP)

If you run analog VCOs, the Autopilot is one of those “why didn’t I buy this sooner” utilities. It sits between your pitch CV (1V/Oct) and your oscillator, listens to the oscillator’s waveform, and automatically corrects tuning so your system locks to pitch fast—great for studios, live rigs, and any setup where drift or imperfect tracking is costing you time.

Condition:

Good overall cosmetic condition with normal rack/handling wear. You can see light marks around some jack hardware and general signs of use, but nothing that looks like structural damage on the PCB (pins look straight/clean and the board looks intact).

What it’s good for?

• Instantly tuning analog oscillators before recording or a live set (no hunting with a tuner app).
• Fixing 1V/Oct tracking so sequences and chords land properly across multiple octaves.
• Calibrating two VCOs (or two voices) since this module has two independent tuner channels.
• Quick “A reference” tuning from a keyboard/sequencer so everything in the rack agrees on pitch.

Key features / specs:

• Dual auto-tuner (two identical channels)
• Patch points per channel:
• • Key In (1V/Oct): from sequencer/keyboard
  • Tune In: from your VCO waveform output (audio)
  • Drop Out: corrected 1V/Oct back to your VCO pitch input
• One-tap tuning: press the button to tune the oscillator to the closest A reference
• Improved tuning algorithm (noted for better performance in lower registers)
• Reference pitch options: supports 440 Hz and 432 Hz reference modes (mode can be saved on power-up depending on firmware)
• Size: 4HP
• Depth: ~13mm
• Power draw: ~25 mA (+12V) / 15 mA (-12V)

FAQs:

Is this a tuner for guitars/bass?
No—this is for Eurorack modular synth oscillators (VCOs), specifically to correct pitch CV tracking.

Do I need a specific type of oscillator?
It’s intended for analog VCOs that accept 1V/Oct pitch CV. (Most Eurorack VCOs do.)

How do I patch it?
Typical flow: Sequencer CV → Key In, VCO waveform out → Tune In, Drop Out → VCO 1V/Oct input. Then press the button to tune.

Does it tune a whole song/key?
It’s mainly an auto-calibration tool to get oscillators accurately tuned and tracking. It references an “A” pitch standard and aligns the oscillator accordingly.

Why two channels?
So you can tune two oscillators/voices (or a two-VCO voice) without swapping cables constantly.