[MatsudaMan]

I just downloaded a 24bit flac file from HDtracks. Thing is I don't know if my v-dac is capable of playing true 24bit files. I'm using Foobar player and connecting my computer to v-dac using highspeed 2.0 usb cable. My laptop doesn't have spidif out so....Is that the only way to get true 24bit?

I have to say that the 24bit sounds a lot better than my cd quality wav files. Maybe just recording quality? Is it the V-dac just downsampling it to 16bit?

 

[nick_charles]

Quote:

Originally Posted by MatsudaMan /img/forum/go_quote.gif I just downloaded a 24bit flac file from HDtracks. Thing is I don't know if my v-dac is capable of playing true 24bit files. I'm using Foobar player and connecting my computer to v-dac using highspeed 2.0 usb cable. My laptop doesn't have spidif out so....Is that the only way to get true 24bit? I have to say that the 24bit sounds a lot better than my cd quality wav files. Maybe just recording quality? Is it the V-dac just downsampling it to 16bit?

It is difficult to know exact;ly what formats the V-DAC accepts as the manual

http://www.musicalfidelity.com/manua...c_manual_1.pdf

just says it upsamples to 24 bit 192kHZ (sic) and does not (helpfully) mention the receiver chip. My own DAC accepts 24 bit signals but is a 20 bit DAC so alters the signal internally.

 

[Taikero]

That's the biggest problem with buying DACs. You have to look up the DAC chip before you know what's actually happening to your digital signal, or even what signals you can rightly send.

 

[dmashta]

well you can almost be sure that if a dac supports 24/96 usb, it'll be prominently advertised as such. if you don't see it, chances are that they don't. very few currently available dacs support 24/96 usb. and i'm almost positive that the v-dac isn't one of the.

 

[Vic Trola]

Folks:

Here is how I understand resolution, word length and frequency.

Think of bits as pixels in a camera. HD tracks encodes with more bits and therefore gives you more resolution into your music. Most of the codecs (DAC Chips) from AD or BB can handle the 24 bit wide sample (music bit).

Per the USB 1.0 / 1.1 / 2.0 spec, the transmission bus is 16 bits wide. But, it can transmit 24 bits of music information. Literally think of it as a bus. In a 24 bit resolution, it just has to make more trips for the same sample.

Now here is the problem. Most DACs use the BB PC2700 series of codecs. These are 16 bit wide codecs and are not capable of using the whole 24 bits, just the 16. So if your DAC uses this chip to convert, you are right - you are missing some resolution. This is not "down sampling" as it is not in the frequency domain.

Smart USB DACs use the PCM 2700 series as the USB receiver, but pass the bits using the I2S bus to the 24 bit resolving DAC. If it does this, then all is well and you will receive the whole 24 bits from HD tracks.

But, there are other issues with USB, that I will not get into here and me thinks that if you use USB with HD tracks, you are doing yourself a disservice.

I use Burrrn to burn a CD and play it back through a CD player. Go figure.

I hope that I was not too simplistic and I know that I may have twisted some technical paradigms to keep things simple.

 

[jsplice]

If you have a DVD player with a digital out, you can use lplex to burn your high res files to DVD-video. DVD-video allows for PCM audio formats of 24/48 and 24/96, so your audio files must be saved as such. I simply used lplex to burn 24/96 files to a DVD, then play them in my DVD player, using the digital coax out into my DacMagic. I know it is successfully receiving 24/96 because there are LEDs on the front that indicate the incoming sampling rate.

 

[BradJudy]

Quote:

Originally Posted by Vic Trola /img/forum/go_quote.gif Smart USB DACs use the PCM 2700 series as the USB receiver, but pass the bits using the I2S bus to the 24 bit resolving DAC. If it does this, then all is well and you will receive the whole 24 bits from HD tracks.

No, the PCM 270x cannot do 24 bits via USB regardless if the DAC is internal or external via i2s. This (and most other) USB chips are limited to 16/44(48) regardless of how they are implemented.

 

[jsplice]

Quote:

Originally Posted by BradJudy /img/forum/go_quote.gif No, the PCM 270x cannot do 24 bits via USB regardless if the DAC is internal or external via i2s. This (and most other) USB chips are limited to 16/44(48) regardless of how they are implemented.

That is my understanding as well. I think the Benchmark DAC is one of the few USB dacs that can accept higher than 16/48 via USB. I'm not sure which other ones can.

 

[BradJudy]

Quote:

Originally Posted by jsplice /img/forum/go_quote.gif That is my understanding as well. I think the Benchmark DAC is one of the few USB dacs that can accept higher than 16/48 via USB. I'm not sure which other ones can.

There's a difference between handling more than 16/48 via USB using native OS drivers and using custom drivers. Plenty of pro-audio USB soundcards can do 24/96 using custom drivers. Only a few products can do 24/96 via USB using native drivers like the Benchmark and the Empirical Audio DACs.