0.9z-2 Sample Rate Conversions

[PeterSt]

In this case the DAC is 24/96;
The input file is 192000.
The Output Rate is fixed to 96000 (fx button).

Since the conversion from 192000 to 96000 is not supported, the input shows red, because it is the input causing the problems.

Not allowed.

[PeterSt]

The DAC is 24/96;
The input file is 192000.
The Output Rate is not fixed this time (fx button) thus the set 2x by the slider creates an output of 2x 192000 = 384000.

The output shows red (impossible) now, because the DAC can do 96000 only.
The input also shows red, because whatever is done, there will be no way to create an output of 96000 (which the DAC needs).

[PeterSt]

The DAC is 24/96;
The input file is 88200.
The Output Rate is not fixed (fx button) thus the set 2x by the slider creates an output of 2x 88200 = 176400.

Again the output is red, because the DAC can't cope.
This time the input is normally blue, because the file can be played, if only the slider is set to 1x. See 2nd picture.

[PeterSt]

The DAC is 24/96;
The input file is 44100.
A most normal situation, in which making fx (fixed output rate) active or not does not matter.

Take notice :
When fx is active, always a virtual base sample rate of 44100 or 48000 is taken. Which if the two depends on the file's sample rate. So, for a 44100, 88200, 176400 file, the virtual base is 44100 and for 48000, 96000, 192000 the virtual base is 48000.
With fx active, the output rate is determined by the slider (1x, 2x, 4x, 8x, 16x) the virtual base rate (44100 or 48000).

Because the file's sample rate is equal to one of the virtual base rates, making fx active or not does not matter one bit.

In a situation like this (file is equal to virtual base sample rate), it is the slider which just won't go further to the right than the DAC's sample rate implies, nothing can turn red.

[PeterSt]

The DAC is 24/192;
The input file is 352800 (DXD;
fx is active, and the slider is set to 4x.

This an the exception to the general (current) rules, and important to understand;

We have an 192000 DAC, and thus normally higher rate files will not play. However, and the one and only downasmpling means built in, a conversion can take place from 352800 to 176400. And the DAC can do *that*.
This exception is there because DXD files are often master files for several studios, and at not having a DAC to play them would be a sort of waste. But keep in mind : it is the only exception that downsamples sample rates. It always uses AntiAlias filtering under the hood, hence there is no special button for it, and you can not see it happening.

Remember, this can only play when fx is active, and the slider is set to 4x (the virtual base rate, which is 44100 in the case of a 352800 file).

Also see the second picture, where the (fx active) output rate was set to 88200, which now is not allowed, because no downsampling exists for 352800 to 88200.

[PeterSt]

The DAC is 24/384;
The input file is 352800 (DXD;
fx is active, and the slider is set to 8x.

Notice the above and the difference with the before situation.
So, now the 352800 is allowed to play because the slider (fx active) implies 8 times the virtual base rate, thus 8 x 44100 = 352800.

But also see the second picture, where the only thing changed is the slider position, now to 4x;
All is still blue, which implies what we already know : we can downsample from 352800 to 176400. Thus, even when the DAC now is 384000, this is still allowed.

Lastly, compare the 3rd picture;
Two things were changed compared to the first picture :
1. fx now is inactive;
2. The slider is set to 1x.

Understand ? the base now is the input file, hence 352800, and that 1x gives 352800.

[PeterSt]

The DAC is 16/192;
The input file is 24/192000;
fx is active, and the slider is set to 4x.

This example is not related to the subject of sample rate conversion, but it shows that a 16 bit DAC can still play 24 bit files.
This counts for 88200, 96000, 176400 and 192000 files.
Without really investigating it, it must be taken that this does not count for 24/48000 and 24/44100 files.

[PeterSt]

This last one is merely a teaser. Still there is a message in it :

If you set your DAC to "Is 24/768" this just can be done. But, if you do not have a DAC being capable of this really, nothing holds you from doing this and press Play.
The result completely depends on the driver; when all is right you will receive a message that this can't be done (unsupported format and the like), but when all is not so right - it just depends. The data *will* be fed to the DAC in such a case ...

[jarek]

Peter,
looks perfectly ! I understand, that when I have fx button switched permanently on, then I have always optimum solution (max sampling allowed by the DAC). Am I correct ?

[PeterSt]

Correct Jarek. Except, the virtual base rate is respected. Thus (nit picking perhaps), if the file is e.g. 88200 but your DAC can do 192000, the output will be 176400. This is not 100% the max output rate, but I'm sure you understood that.
This could theoretically be covered for by setting "96 Khz or 192KHz only" in the DAC settings, and let AI upsample to the uneven rate when the virtual base doesn't comply to the even rate.
But I wouldn't do that, unless you like AI better than AP in the first place.

Anyway, thanks for your good input, and initiation of the subject to begin with.
Peter

[jarek]

I understad this, perfect work !

[Telstar]

This is just perfect!
Great job on the sample rate settings, Peter