Topic: Gain difference with iPad Pro vs MacBook Air?????

When I plug in USB-C cable to connect iPad Pro to (the USB port of) ADI-2 DAC FS, I have to set the volume level to -30db for the same music (Amazon Music) and same headphones (HD800S), as I use with MacBook Air at -20db, via the same cable.

What accounts for this?
On the surface it seems that digital output from iPad/MacBook should not be carrying gain markers, but ....

Obviously not an electronics expert, so please be gentle. smile

2 (edited by Jeff 2024-02-08 20:28:01)

Re: Gain difference with iPad Pro vs MacBook Air?????

Check options on the Amazon Music preferences.

  • Ultra HD quality

  • Loudness Normalization

  • Spatial Audio

One source is set differently than the other.

Regards,
Jeff Petersen
Synthax Inc.

Re: Gain difference with iPad Pro vs MacBook Air?????

Checked that first. Same settings on both devices for Amazon Music. Hence puzzled.
smile

Re: Gain difference with iPad Pro vs MacBook Air?????

And the Audio output volumen on iPad and MacBookAir are both set to maximum 0dB ?
The keyboard keys for volumen F9 and F10 on the MacBookAir and the buttons on the side at the iPad, may be one of the devices remembered a lower volumen level for the connected interface...

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue

Re: Gain difference with iPad Pro vs MacBook Air?????

The volume on iPad has no effect on the sound level through ADI-2. I tested that as well. Mystery remains?

6 (edited by waedi 2024-02-09 01:08:56)

Re: Gain difference with iPad Pro vs MacBook Air?????

And the volumen on the MacBookAir ? Check Audio-Midi-Setup

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue

Re: Gain difference with iPad Pro vs MacBook Air?????

I can check that too, but the fact that the iPad is at its max volume and yet requires much less amplification for its signal, tells me that it is not an issue with the MacBook volume.

Furthermore, I am perplexed why a volume setting used for the amplification of an analogue signal from a source would affect the digital signal the source is passing to ADI-2 for conversion to analogue and amplification.

8 (edited by waedi 2024-02-09 02:36:56)

Re: Gain difference with iPad Pro vs MacBook Air?????

you have a difference in volumen outcome when using the two devices.
Obvious there must be e volumen stage different. There are many.
The volumen in the Audio-Midi-Setup in the MacOS is one.
Let's check one after one until you find it.
( May be, disconnect the ADI-2 from MacBook, max the volumen with the keyboard keys, reconnect ADI-2)

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue

Re: Gain difference with iPad Pro vs MacBook Air?????

Checked, and there are no active volume controls on MacBook Air when the Sound output is set ADI-2 DAC. I now have also checked what happens when I replace iPad with an iPhone. The levels stay the same as they were for iPad (and so still require much less gain on ADI-2 than the signal fed from the MacBook). Perhaps this has something to do with how ADI-2 talks to Mac OS vs iOS. I am still curious about whether/how the gain info is passed to ADI-2 in the digital signal from the source.

10 (edited by waedi 2024-02-10 17:05:11)

Re: Gain difference with iPad Pro vs MacBook Air?????

I mean this one volumen control, it is always there regardless what interface is in use...?
In MacOS system preferences


https://i.ibb.co/NFm8m32/gain.jpg

M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue

Re: Gain difference with iPad Pro vs MacBook Air?????

Yes, that control is at max and is disabled when ADI-2 is connected. One cannot slide it.