Auto-Sampler

Automatically record hardware synths or VSTs via MIDI

Overview

This was the feature I most wanted. Sampling a synth manually is tedious: play a note, record it, trim it, play the next note, repeat 8 times. The Auto-Sampler does all of that automatically.

Point it at a hardware synth or VST, tell it what notes to sample and it sends MIDI, records audio and trims everything for you. A complete multisample in minutes instead of hours. It relies on audio and MIDI routing on your computer, so it’s a desktop feature and isn’t on the mobile app.

Setup requirements

Before using the Auto-Sampler, you need to set up two connections:

1. audio loopback (required)

Audio loopback lets you capture audio output from your DAW or software synth as an input source.

macOS: BlackHole

• Download and install BlackHole (free virtual audio driver)
• Open Audio MIDI Setup (in /Applications/Utilities)
• Click the + button and create a “Multi-Output Device”
• Check both your speakers/headphones AND BlackHole in the Multi-Output Device
• Set your Mac’s sound output to the Multi-Output Device (so you can hear audio while recording)
• In Auto-Sampler, select “BlackHole” as Audio Input

Windows: VB-Cable

• Download and install VB-Cable
• Set VB-Cable as your system audio output
• In Auto-Sampler, select “VB-Cable” as Audio Input

2. virtual MIDI (required)

Virtual MIDI routes MIDI messages from EP-PatchStudio to your DAW or VST.

macOS: IAC Driver (Built-in)

• Open Audio MIDI Setup
• Go to Window → Show MIDI Studio
• Double-click “IAC Driver”
• Check “Device is online”
• A bus named “IAC Bus 1” should appear
• In your DAW, create a MIDI track and set input to “IAC Bus 1”
• In Auto-Sampler, select “IAC Bus 1” as MIDI Output

Windows: loopMIDI

• Download and install loopMIDI
• Create a virtual MIDI port
• In your DAW, set MIDI input to the loopMIDI port
• In Auto-Sampler, select the loopMIDI port as MIDI Output

Verifying your setup

If the Auto-Sampler can’t find a loopback device or a MIDI output, it says so under the device menus. The “Setup Guide” accordion at the top has step-by-step instructions for your platform.

Auto-Sampling process

The Auto-Sampler is laid out in four steps:

1. Input Setup

   • Audio Input Device: BlackHole or VB-Cable for a VST, or your audio interface for a hardware synth
   • MIDI Output Device: IAC Bus or a loopMIDI port, or your MIDI interface
   • MIDI Channel: match your DAW track or synth (usually channel 1)
   • Input Gain: watch the live level meter and aim for strong levels without clipping
   • Test Note: sends a single note so you can check you hear it and see the meter move

2. Recording Config

   • Lowest Note and Highest Note: the range to sample (C3 to A4 by default)
   • Interval: record every N semitones. The default of 3 records minor thirds, which gives 8 samples from C3 to A4. A run records between 2 and 8 samples, the most the EP-40 takes in one multisample.
   • Velocity: MIDI note velocity, 1 to 127
   • Sustain Time: how long each note is held (2 seconds by default)
   • Pre-Roll Time: how much it records before each note starts
   • Post-Note Time: how much it records after each note ends, to catch the release tail

3. Audio Processing

   • Normalise: on by default, bringing each sample’s peak up to the level you set
   • Trim Silence: on by default, with the threshold at -60 dBFS. If you hear a short gap before each note (common with VSTs going through loopback), raise it towards -40 dBFS.
   • Sample Rate and Channels: the format of the recorded samples

4. Start Recording

   Click “Start Recording” and the app will:

   • Work out the notes from your range and interval
   • Send each MIDI note in turn and record it
   • Trim and normalise each sample
   • Show progress as it goes

Using the samples

When the run finishes you have two options:

• “Open in Sample Editor” switches the Sample Editor to Multisample mode and loads every take, each with its root note already set to the note it recorded. Check the mapping, then send it to your EP-40.
• “Export ZIP” saves the takes as WAV files named by note (C4.wav and so on). If you import them later, switch the Sample Editor to Multisample mode first, then add them all at once. The filenames set the root notes.

Sampling hardware synths

To sample a hardware synthesiser:

1. Connect your hardware synth’s audio output to your computer’s audio interface
2. Connect MIDI out from your computer to the synth’s MIDI in
3. In Auto-Sampler, select your audio interface as the Audio Input Device
4. Select your MIDI interface as the MIDI Output Device
5. Set the MIDI channel to match your synth’s receive channel
6. Set the note range, interval and timing
7. Click “Start Recording”

Sampling VSTs & software synths

To sample a VST instrument in your DAW:

1. Open your DAW and load the VST you want to sample
2. Create a MIDI track with the VST as the instrument
3. Set the MIDI track’s input to your virtual MIDI port (IAC Bus or loopMIDI)
4. Arm the track for recording (if required by your DAW)
5. Set your DAW’s audio output to BlackHole or VB-Cable
6. In Auto-Sampler, select BlackHole/VB-Cable as Audio Input
7. Select the virtual MIDI port as MIDI Output
8. Click “Start Recording”

DAW Configuration

Some DAWs require “MIDI Thru” or “Input Echo” to be enabled for the MIDI track to respond to external MIDI. Check your DAW’s documentation.

Tips & best practices

• Use a longer Sustain Time for pads: sustained sounds need time to develop their full character
• Keep it short for percussive sounds: 0.5-1 second is usually enough for plucks and leads
• Leave enough Post-Note Time: the release tail needs to finish before the next note, especially with reverb
• Test first: use “Test Note” to check everything works before a full run
• Monitor levels: watch the input meter to make sure audio isn’t clipping
• Disable DAW effects: turn off master bus effects like limiters and reverb for clean samples
• Sample evenly: spread samples across 2-3 octaves for the best pitch tracking

Troubleshooting

No audio being recorded

• Verify audio loopback is set as system output
• Check the input level meter in Auto-Sampler
• Make sure your DAW or synth is actually playing sound

MIDI notes not triggering synth

• Verify the virtual MIDI port is connected in your DAW
• Check the MIDI channel matches
• Enable “MIDI Thru” or “Input Echo” on the track
• Arm the track for recording if required

A short gap before each note

• Raise the Trim Silence threshold towards -40 dBFS, so the quiet lead-in before the note is trimmed

Samples have clicks or pops

• If the start of the note is cut off, lower the Trim Silence threshold (towards -80 dBFS) so it keeps more of the attack
• If the tail is cut off, increase the Post-Note Time
• Smooth the start and end with the attack and release in the Sample Editor

Samples are too quiet

• Check Normalise is on
• Increase output volume on your synth/DAW
• Check that no limiters are reducing gain