Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

SDAVE

macrumors 68040
Original poster
Jun 16, 2007
3,578
601
Nowhere
Hi all I have a speaker that has optical and no usb and would like to connect it to my Mac Pro 2019

Since macos doesn’t allow volume control on optical/digital without software, is there some kind of usb DAC available to control the volume with the mac keyboard? So I can connect the speaker via optical to the DAC then control the volume that way.

I don’t want to control the audio on the speakers themselves. Just need it on the keyboard
 
What is the make and model of the speaker?

LS50WII

I had the LS50W (First gen) before this and it had USB in with the dac thats built in. They removed USB and replaced it with HDMI. They did keep optical though and added AirPlay 2, but I don't want to use wireless, there's always a lag.
 
Why not use a DisplayPort-to-HDMI cable? (Or will the HDMI port only do eARC?)
I think its eARC on this speaker. I have a 6900XT in a MP7,1, even if I connect it directly to the HDMI out I cant control the digital signal volume.

Im in a pickle and really looking for a solution
 
Digital audio devices are kind of hit and miss when it comes to compatibility with the built-in volume controls of any computer OS. My Presonus doesn't have that but I have a cheap USB headset that does.

This USB to optical/coaxial, according to reviews, works in that manner:


I'm sure there are others but I don't know of a source that lists them.
 
As an Amazon Associate we earn from qualifying purchases.
  • Like
Reactions: sshamim
If you only use a limited number of applications, one workaround could be to simply change the applications volume instead of the systems.
As an example, here's an Applescript I bound to a key with BetterTouchTool to increase iTunes' volume:
AppleScript:
tell application "iTunes"
    set vol to sound volume
    set vol to vol + 10
    if vol is greater than 100 then
        set vol to 100
    end if
    set the sound volume to vol
end tell
You could modify it so only the frontmost application is controlled or all currently opened.
Maybe not every program has an Applescript interface but I suspect for most there is a key combination you could simulate.
If iTunes was running in the background and its volume could only be increased by pressing "cmd+up", I'd start like this:
(> get name of currently activated application > activate iTunes > change volume > re-activate the application from step 1)
AppleScript:
tell application "System Events" to set frontMostApp to name of first process whose frontmost is true
tell application "iTunes" to activate
tell application "System Events" to key code 126 using command down #this means cmd+up
tell application frontMostApp to activate
 
Last edited:
Digital audio devices are kind of hit and miss when it comes to compatibility with the built-in volume controls of any computer OS. My Presonus doesn't have that but I have a cheap USB headset that does.

This USB to optical/coaxial, according to reviews, works in that manner:


I'm sure there are others but I don't know of a source that lists them.

Definitely and it seems that if you are controlling the volume of a digital source you're actually losing quality. I will order this and try. You would think that there are USB DACs out there that let you control the volume of optical, hopefully this is it. Seems like a decent chipset too.

If you only use a limited number of applications, one workaround could be to simply change the applications volume instead of the systems.
As an example, here's an Applescript I bound to a key with BetterTouchTool to increase iTunes' volume:
AppleScript:
tell application "iTunes"
    set vol to sound volume
    set vol to vol + 10
    if vol is greater than 100 then
        set vol to 100
    end if
    set the sound volume to vol
end tell
You could modify it so only the frontmost application is controlled or all currently opened.
Maybe not every program has an Applescript interface but I suspect for most there is a key combination you could simulate.
If iTunes was running in the background and its volume could only be increased by pressing "cmd+up", I'd start like this:
(> get name of currently activated application > activate iTunes > change volume > re-activate the application from step 1)
AppleScript:
tell application "System Events" to set frontMostApp to name of first process whose frontmost is true
tell application "iTunes" to activate
tell application "System Events" to key code 126 using command down #this means cmd+up
tell application frontMostApp to activate

Thanks! Ill give this a shot too. My main concern is to control the overall system volume. I do a lot of Zoom calls and constantly lower/raise volume and switch to music all the time with these desktop speakers.
 
As an Amazon Associate we earn from qualifying purchases.
Digital audio devices are kind of hit and miss when it comes to compatibility with the built-in volume controls of any computer OS. My Presonus doesn't have that but I have a cheap USB headset that does.

This USB to optical/coaxial, according to reviews, works in that manner:


I'm sure there are others but I don't know of a source that lists them.

Just tried this little adapter and it worked. Wow.

Thank you you solved a major headache for me

One note it seems that its not the greatest DAC (obviously for this price, should it be?) I wonder if there's anything higher end that can work this way (with volume control).
 
Last edited:
As an Amazon Associate we earn from qualifying purchases.
Digital audio devices are kind of hit and miss when it comes to compatibility with the built-in volume controls of any computer OS. My Presonus doesn't have that but I have a cheap USB headset that does.

This USB to optical/coaxial, according to reviews, works in that manner:


I'm sure there are others but I don't know of a source that lists them.
Thanks. This worked perfectly on my 2020 iMac 27 and I can control volume using MacOS when connected to Bose 300 Smart Soundbar.
 
As an Amazon Associate we earn from qualifying purchases.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.