RPI IQAudio DAC+ Re-Sampling

[The Black Adder]

Hi all.

Just wondering. Does anyone use 32Bit 384khz re-sampling with their pi/iqaudio dac+ ?

I've been looking around and it seems that there is a mismatch to what it can 'actually' do. That is it can resample up to 32Bit 384khz but it outputs 24Bit 192khz?

I've just been looking at the audio info regarding this whilst playing a track it seems to be correct. So, why is the higher options available to choose from? What's the point in re-sampling higher to then output lower?

Also, has anyone found that using the Pi3 to be any better whilst using re-sampling or do we generally set it the resampling to disabled or 16Bit 44.4khz?

Any more info would be great.

Thanks.

PS... Does anyone find that the DSP Programming options beneficial with certain rates?

[struth]

Ive been using that setting Josie. I,m using an audiophonics board.

[The Black Adder]

Ah.. thanks, Grant. Interesting.

Could you check with your Audio information in Moode and paste it in? I'd like to see what it says in regards to output.

Thanks :)

[The Black Adder]

Ah... :doh: ok. I missed this in the info panel.

Architecture: Sigma/Delta Advanced Segment 24 bit 192 kHz

Makes sense in one way now. But the Pi does allow itself to use the 32bit 384KHZ option as it does do the extra processing so... (I'm probably answering my own question but I'll go along with it just in case any boffins know otherwise) is there a benefit of the higher option with this dac or is it just using heat?

[struth]

Will do next time its on.


Which wont be long lol

[struth]

Similar here


http://uploads.tapatalk-cdn.com/20160907/58a0bf51b1a46dd46db26e71600ebc9b.jpg

[The Black Adder]

Thanks Grant.

Ah... it must be whatever the original input sample rate is... Makes sense. I'm now getting below. So basically the processor is working doubly hard as it's 24bit hardware hence a higher temp.

Audio information Input Processing

Source:
USB/Music Drive 1TB/Rock/Queen/Queen - A Kind of Magic/01 One Vision.flac


Encoded at:
16 bit, 44.1 kHz, Stereo


Decoded to:
16 bit, 44.1 kHz, Stereo


Rate:
762 kbps


DSP Operations

Resampling:
32 bit, 384 kHz, Stereo (soxr very high)


Chip options:
FIR interpolation with de-emphasis, aVol=0 dB, aPbb=.8 dB


Volume:



Output Stream

Format:
32 bit, 192 kHz, Stereo


Rate:
12.288 mbps


Audio Device

Device:
IQaudIO Pi-DAC+


Chip:
Burr Brown PCM5122


Architecture:
Sigma/Delta Advanced Segment 24 bit 192 kHz


Interface:
I2S




CPU: armv7l, 900 MHz, 16%, 45°

[The Black Adder]

So I'm guessing the Pi3 would find this process easier as there is a little stutter at the start of each track.

[struth]

So seeing as it only goes to 32/ 192, ive set mine to that.

http://uploads.tapatalk-cdn.com/20160907/daf735aa3922088daa0ec1265006c89a.jpg

[The Black Adder]

Same here, Grant. It makes sense to keep processing down.

Are you running a Pi3?

Just wondering if the higher output rate would become available due to the faster CPU?

[struth]

No just pi 2+ ...i used to run it at 32 192 and only recently upped it. Actually thought i liked it better so if im not as happy it will go back up. Wether it makes sense or not ;)

[The Black Adder]

Sure, same... lol

[WAD62]

I use piCorePlayer on my 2 pi2 DACs, IQ and Audiophonics boards...

I did try upsampling on the IQ version (via SOX), to the highest available rate, at the highest upsampling quality (I have the piCorePlayer parameter string for this somewhere should anyone want it).

As you guys have pointed out 192khz was the highest I could see...

I've subsequently turned upsampling off, I felt it left things a little 'flat' to my ears anyway...I prefer the original red book FLAC :eyebrows:

P.S. I had no stuttering or any such issues from the Pi2 when upsampling, perhaps piCorePlayer itself has a smaller footprint, and leaves enough capacity for the upsampling process...