How do the volume controls work on iM and MB as controlled by the keyboard keys marked with the speaker icon?

Is this some sort of digitally controlled amplifier, or is there bit reduction going on?

Thanks

Hi,

That volume control is implemented by maths inside the OS, which internally performs calculations with bit-depth sufficient such that turning the volume down shoudn't throw away detail.

That said, if you're using a proper audio interface, you'll normally find this volume control is disabled. If you're using the built-in analog output, you'll find it's more than sufficiently crap such that you don't need to worry about such subtleties.

Thanks again, Chris.
Yes, with an interface is irrelevant.
But I did want to know what's happening.
BTW, this stuff really should be known, but I've not seen it anywhere. Can I ask where you find this stuff-or perhaps your work brings you contact with such information?

Hi
I would tend to agree with Korff…
Of course it’s harder to play an acoustic guitar(we’ve been there…),but once you can play it,it’s easier to play ‘any’ guitar,with a 'little adaptation’…
Also,it compensates in the practice way,because you can play it everywhere(yes,even around that camping fire…)
We guitarists know that ‘electric’ and ‘acoustic’ are different planets(yet,complementary),but if you learn how to play an acoustic,it will be much easier to go from there to anything else 'string related’(I’ll pass here about the ‘dynamics’ involved in playing acoustic guitar…)…
ANW,hope he’s motivated enough,guitar is great but can be a very 'un-grateful' instrument,and yes,at the begging,it will hurt,no matter what he chooses…But that’s just IMO.

ps:I see guitar as a rowing boat,going against the current(?),if you stop practising,you go ‘backwards’,to the place where you came from in the first place…Still rowing...

Sorry guys,wrong place...

You can gleam some info from the Coreaudio-api list.

When you say 'digitally controlled amplifier' I guess you mean digitally controlled analog amplifier, which AIUI is the sort of thing you get in £1000 DA convertors. Whereas the built-in audio circuitry in most Macs sounds so bad it probably cost less than £1. So you can be pretty confident the volume control operates in the digital domain.

Quote Jeraldo:

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How do the volume controls work on iM and MB as controlled by the keyboard keys marked with the speaker icon?

Is this some sort of digitally controlled amplifier, or is there bit reduction going on?

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Interesting to consider whether it would make any difference. How many bits does it take to fill a given dynamic range?

About 8 bits, considering the quality of most Macs' built-in audio...

However, the makers of high-end DACs do see fit to use such circuitry.