Dac, Mac, and itunes.

bbqjoe

Void where prohibited
Ok, maybe I'm missing something here.
As I understand it, a Dac takes brazillions and megagobs of 1's and 0's and deciphers them into an analog signal.

My mac has all these happy binary strings stored within it.
Normally, itunes will read these binary codes, and using the internal dac on the computer, decipher them, and run those analog signals through the speakers, or headphone jack.

Ok, now I hook my modi up to the USB connection on the computer, and run RCA's to my preamp.
I select the Dac output on the computer, and tada, now the dac is feeding the preamp.
All is good!

But if I'm truly using the DAC to convert digital to analog, how is it itunes can still continue to EQ the sound, and control the volume?
Is itunes just using the DAC as an output just like anything else, or is the DAC actually doing what it was designed to do?
Am I missing a setting between itunes and the DAC so that the Mac is only sending binary signals to it?

Thanks gang.
 
how is it itunes can still continue to EQ the sound, and control the volume?

iTunes is fiddling with those megabobs of bits before it sends them to the DAC.

It's performing digital signal processing to do EQ and volume control. All done in the digital domain.
 
cpt_paranoia said:
iTunes is fiddling with those megabobs of bits before it sends them to the DAC.

It's performing digital signal processing to do EQ and volume control. All done in the digital domain.
Yes, but should it be when using the DAC?
 
If you want iTunes to do EQ and volme control, then yes, it should.

It's always using a DAC, be it internal to the Mac, or external.

If you want to send a bit-true, unfiddled stream to the DAC, I'm sure there's a setting in iTunes to bypass all the fiddling, and stream direct. "It just works", remember...

Looks like a simple on/off switch in the equaliser:

https://support.apple.com/en-gb/guide/itunes/adjust-the-sound-quality-itns2991/mac
 
If you want iTunes to do EQ and volme control, then yes, it should.

It's always using a DAC, be it internal to the Mac, or external.

If you want to send a bit-true, unfiddled stream to the DAC, I'm sure there's a setting in iTunes to bypass all the fiddling, and stream direct. "It just works", remember...

Looks like a simple on/off switch in the equaliser:

https://support.apple.com/en-gb/guide/itunes/adjust-the-sound-quality-itns2991/mac
I get that.
I realize I can turn it off, I was more or less asking if i'm sending the purest form of jiggawhosits to my dac, or if maybe I should be using a different player/organizer so I can be a true audio freakazoid. ;)
 
I was more or less asking if i'm sending the purest form of jiggawhosits to my dac, or if maybe I should be using a different player/organizer so I can be a true audio freakazoid.
If the content was downloaded from iTunes, you are listening to skinnied-down jiggawhosits that a formula thought you wouldn't hear anyway so it threw them out the window. :)
 
If the content was downloaded from iTunes, you are listening to skinnied-down jiggawhosits that a formula thought you wouldn't hear anyway so it threw them out the window. :)
Most of my content is either Ripped from CD or is flac all converted to ALAC.
I just use itunes because it's there, and there isn't a real good alternative to some of the better windows based players.
I ran Swinsian for awhile, but they aren't planning on a mobile version, and I really didn't want to have multiple libraries with differing copies of files playing and stored on multiple players.

I can't think of any reason to purchase an ituna'd song.
 
I get that.
I realize I can turn it off, I was more or less asking if i'm sending the purest form of jiggawhosits to my dac, or if maybe I should be using a different player/organizer so I can be a true audio freakazoid. ;)

No - iTunes should feed the DAC via either coaxial or optical. DAC output goes to a preamp, then to an AMP.
Control the volume with the preamp (only) for best quality. It you vary the volume in iTunes you can degrade the output quality.

I use an app on my phone to remotely control my MacPro - select song, playlist, whatever.
Files are from FLAC downloads or CDs (mostly) ripped to Apple Lossless format.
The output from the mac pro to the DAC, to the preamp, to the Amp.
My preamp has a remote level control I control the preamp volume with.
 
I was more or less asking if i'm sending the purest form of jiggawhosits to my dac

Well, it's not going to be bit-true to the ripped CD if you use the Mac for volume control or EQ. Which won't be the purest form of jiggawotsits, no...

Only you can decide if that's a problem or not. Do some listening tests, and see which you prefer.
 
It you vary the volume in iTunes you can degrade the output quality

'Can' being the important word there.

If the source is 16 bit, and the DAC is, say, 24 bits, you have 8 bits of potential volume control; 256 levels, or 48dB before you lose the original source resolution. Beyond that, you're into looking at the noise and distortion budgets within the preamp and DAC to optimise the signal in noise & distortion (SINAD) ratio.

Generally, though, the bigger the signal you send from the DAC to the amp, the higher the signal to noise ratio.

Harmonic distortion will depend on how linear the DAC output buffer and preamp input are in the presence of large signals
 
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Maybe I'm not being clear here.
My question is not so much about volume or EQ.
It's a question of whether I'm sending itunes processed signals to the DAC, or if I should be sending the DAC a different form of info somehow.
 
Any iTunes processing is done in software and prior to the built in DAC, or any external DAC. IF you skip EQ or turn volume fully up then no processing is done and file is sent as original. Hope that answers your original question.
 
Any iTunes processing is done in software and prior to the built in DAC, or any external DAC. IF you skip EQ or turn volume fully up then no processing is done and file is sent as original. Hope that answers your original question.
Thank you.
 
Actually in iTunes under Edit - Song Info - Options - the "volume adjust" and "equalizer" should both be set to "None" for the best sound quality.
Also the volume slider in the upper left of the iTunes window should be set at maximum.
 
Last try.
Is itunes feeding my DAC an analog signal through usb, or is it digital?
It would seem redundant to feed a signal to a dac that has already been previously decoded.
 
A DAC requires a digital signal to convert/decode to analog, full stop. So your computer is feeding your DAC a digital signal. If you are outputting an analog signal from the computer (to headphones or a non-digital input), you are using the DAC in the computer to do so.
 
A DAC requires a digital signal to convert/decode to analog, full stop. So your computer is feeding your DAC a digital signal. If you are outputting an analog signal from the computer (to headphones or a non-digital input), you are using the DAC in the computer to do so.
10-4.
 
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