USB DAC With No Volume Control on Mac? Add a Software Slider

Short answer: When a USB DAC has no volume control of its own, the Mac's volume slider and keys can't change its level. SoundDial adds a " volume" slider for that device and still gives every app its own slider.

You plug in a USB DAC or audio interface, choose it as your output, and the volume keys stop doing anything. The volume slider in the menu bar won't move, or shows as unavailable. Music plays at full level, and the only way to make it quieter is a knob on the device, or, if there's no knob, lowering the volume inside every app one by one.

Why the Mac's volume control stops working

macOS can only change a device's volume if the device gives it a volume control to adjust. Many USB DACs and interfaces don't. That's often deliberate: the designers expect you to send a full-level signal and control loudness on the device itself, or on the amplifier or powered speakers after it. When there's nothing to adjust, the Mac's slider and volume keys have nothing to act on.

That's reasonable if your DAC has a knob within reach. It's frustrating when:

• the DAC has no knob at all,
• the knob is behind a monitor or on an amp across the room,
• or you want to turn things down quickly without reaching for hardware.

What macOS offers instead

Audio MIDI Setup (in Applications > Utilities) shows each device's format and lets you choose its sample rate. For some devices it also shows channel volume controls, but when the device doesn't provide any, there's nothing to adjust there either.

You can lower the volume inside each app, but that means changing Spotify, the browser and every other app separately, and some apps don't have a volume control at all.

How to get a volume control back with SoundDial

SoundDial is a menu-bar app that gives each app that plays sound its own volume slider. Version 2.0 adds a software volume for output devices that have no volume control of their own.

1. Connect your DAC. You can make it your output from the device menu on SoundDial's output card, or in System Settings > Sound.
2. Open the SoundDial popover from the menu bar or with Control-Option-S.
3. For a device without its own volume control, SoundDial shows a " volume" slider, named after your DAC. The app explains it: "This device has no volume control of its own, so SoundDial sets the level for every app."
4. Set the level you want.

SoundDial applies this level as software gain to every app it controls, and remembers it per device, so the next time you plug in the same DAC it comes back at the level you left it at. For devices that do have hardware volume, nothing changes: you get SoundDial's normal output volume.

Check the sample rate while you're there

The output card also shows the device's format as a label, for example "48 kHz · 32-bit". When the device offers more than one sample rate, there's a sample-rate menu with the rates it supports, from 44.1 up to 384 kHz. If only one rate is available, there's no menu. It's the same setting you'd otherwise change in Audio MIDI Setup's Format menu; see Change Mac Sample Rate Without Audio MIDI Setup.

Two layers of volume

The device slider sets the level for everything SoundDial controls on that DAC. On top of that, every app keeps its own slider from 0% to 200%:

Control	What it changes
" volume"	Software level for that device, across every app SoundDial controls
Per-app slider (0% to 200%)	One app, relative to the others
Per-app mute	Silences one app
Control-Option-M	Mutes or unmutes all apps shown in the main list

So you can set the DAC to a comfortable room level once, then make a browser video quieter than your music, or boost a quiet podcast above 100%. When an app is above 100%, a soft limiter rounds off peaks instead of clipping them hard.

Practical setups

DAC without a knob into powered speakers. Set the speakers to a sensible fixed level, then use the DAC's software volume in SoundDial as your everyday volume control.

Desk DAC for music, headset for calls. Keep the headset as the main output and send Spotify to the DAC with ⋯ > Play Through. Several apps can play on different devices at the same time. See Send Only Spotify to Your USB DAC on Mac.

Quiet evenings. Lower the DAC's software volume, then give Spotify the Late Night preset via ⋯ > Equalizer & Balance…. Each app has its own EQ, so your browser and call apps stay as they are. Save the mix with Save current mix as a profile to switch back and forth with one click.

Keyboard and links. Control-Option-S shows or hides SoundDial, and Control-Option-M mutes or unmutes all apps. sounddial://output-volume?value=40 sets the output volume and sounddial://sample-rate?value=48000 sets the sample rate, from any launcher or script that can open a URL, or with open in Terminal.

Limits worth knowing

• The device slider appears only for devices without their own volume control. If your device has working hardware volume, you get the normal output volume instead.
• SoundDial is stereo only; it's not a surround or multichannel tool.
• Profiles save each app's volume, mute, EQ and balance, but not the output device.

Common questions

Why don't my Mac's volume keys work with my USB DAC?

Usually because the DAC doesn't give macOS a volume control to adjust. SoundDial adds a software volume slider for devices like this.

Is the level remembered when I unplug the DAC?

Yes. The software volume is remembered per device.

Can I still control apps individually on the DAC?

Yes. Every app keeps its own slider, mute, EQ and balance, whichever device it plays on.

Does SoundDial go online or need an account?

No. SoundDial is sandboxed, has no network entitlement and no account, and it does not read or record microphone audio. It needs macOS's System Audio Recording Only permission, under Privacy & Security > Screen & System Audio Recording.

Which macOS do I need?

macOS 14.2 or later.

SoundDial, a per-app volume mixer for Mac needs macOS 14.2 or later and costs €14.99 one-time purchase on the Mac App Store, no subscription.

Get SoundDial on the Mac App Store.