USB Audio

c1.4 Feature

The Deluge can act as a USB audio interface. When it’s connected to a computer over its USB type-B port, it shows up as a class-compliant audio device alongside its existing USB MIDI ports, so no driver is needed. You can:

• play audio from your computer through the Deluge’s outputs
• record the Deluge’s output into your computer
• record and monitor audio from your computer in an audio clip, just like the line input

Format

	From computer to Deluge	From Deluge to computer
Channels	2 (stereo)	2 (stereo)
Sample rate	44.1 kHz	44.1 kHz
Bit depth	24-bit	24-bit

The Deluge’s own sample clock sets the rate for audio going to the computer. For audio coming from the computer, the Deluge offers two modes, and the computer picks whichever it supports:

• Following the Deluge’s clock. Computers that support this (such as macOS) send audio at exactly the Deluge’s rate, so it’s passed straight through.
• Following the computer’s clock. Computers that can’t follow the Deluge’s clock, such as Windows, send at their own rate instead. The Deluge occasionally drops or repeats a single sample to stay in step, which isn’t normally audible.

Caution

Windows support hasn’t been confirmed yet.

Setting up

1. Connect the Deluge to your computer with a USB cable.
2. Choose the Deluge as an audio input and/or output device in your computer’s sound settings or your DAW. On macOS it’s listed in Audio MIDI Setup.

The Deluge’s USB MIDI ports keep working as before.

Settings

USB audio’s settings are in SETTINGS > USB AUDIO (USBA on 7SEG):

Setting	7SEG	Options
ENABLED	ON	On (default), off
INPUT	IN	On (default), off - see below
OUTPUT	OUT	MAIN MIX (default, MIX), LINE IN (LINE) - see below

Turning USB audio off

USB audio is on by default. To turn it off, set SETTINGS > USB AUDIO > ENABLED to off. The Deluge then connects to your computer as a USB MIDI device only, exactly as it did before USB audio was added.

The setting takes effect the next time the Deluge is turned on, since your computer only finds out what kind of device the Deluge is when it first connects.

Note

If you’ve used the Deluge over USB MIDI before, your computer may treat it as a new device the first time you connect it with this firmware, since it now describes itself differently. Unplugging and reconnecting it should sort out any problems with it not appearing.

Playing audio from your computer

Audio from the computer is mixed straight into the Deluge’s main outputs and headphones, after the song’s master volume and effects. This is on by default, and can be turned off with SETTINGS > USB AUDIO > INPUT. When it’s off, you’ll only hear the computer’s audio through an audio clip that’s monitoring it, or while sampling it.

This audio is not sent back to the computer as part of the Deluge’s output, so you won’t get an echo. To put the computer’s audio through the Deluge’s effects, monitor it with an audio clip instead (see below).

When an audio clip is monitoring the USB input (see below), the computer’s audio is heard through that track instead, with its volume and effects. The Deluge stops mixing it straight to the outputs while that’s happening, so you never hear it twice. Mixing straight to the outputs comes back by itself once nothing’s monitoring the USB input, for example when a sampler clip has finished recording.

Recording the Deluge into your computer

SETTINGS > USB AUDIO > OUTPUT sets what the computer receives:

• MAIN MIX (the default) is the Deluge’s final stereo output: the same audio that goes to the main outputs, including any monitored inputs, but not the computer’s own audio when it’s mixed straight to the outputs.
• LINE IN is the Deluge’s line input (or mic) as it arrives, before any of the Deluge’s processing. This turns the Deluge into a simple audio interface for whatever’s plugged into it. The internal mic only has one channel, so it’s sent to both sides.

Recording audio from your computer in an audio clip

USB can be chosen as the source for an audio clip, like the line input or another track:

1. In an audio clip, open the Audio Clip Sound Menu (Shift + Select).
2. Go to AUDIO SOURCE and select USB INPUT (USB on 7SEG).

USB is always a stereo source. Unlike the line input, it isn’t normalized after recording, since the computer’s audio already arrives at the level it was meant to be.

Monitoring follows the audio output mode, as for any other source (see Select Audio Clip Source and Monitoring): SAMPLER and LOOPER monitor the USB input, while PLAYER doesn’t.

Caution

If an audio clip is monitoring the USB input, the computer’s audio becomes part of the Deluge’s output, which is sent back to the computer when OUTPUT is MAIN MIX. If your DAW is also playing its Deluge input back out to the Deluge, that makes a feedback loop. Turn off input monitoring in the DAW, or use the PLAYER mode on the clip.

Recording a sample from a synth or kit’s sample menu still uses the line input only.

Latency

Audio from the computer is buffered by about 6 ms (256 samples) on the Deluge before it’s played or recorded, which keeps it smooth when the Deluge is busy. Audio going to the computer is buffered by about 2 ms. Your computer adds its own buffering on top of both, which you can usually set in your DAW.