[eclein]

The other day I was posting how great Steely Dan "Gaucho" 24/96 sounded and how blown away I was only to have a member here (a great source for info and tweaks) remind me gently that my SB DUET did not natively playback 24/96 files so knowing that my Grant Fidelity Tube DAC-09 supports files with that resolution I was trying to find a way to actually hear my new awesome music.
 Long story short I remember I haven't ever tried the USB input on the DAC because of a bad experience with a totally different model, so I dug up a USB cable and stretched it along with everything else to make it fit and low and behold I had 24/96 for real and was totally blown away just like my avatar. As I'm typing I'm listening to Jan Garbarek Concert in Dresden and a piano solo just powered its way through my brain clear, smooth as glass, not harsh at all and with tremendous dynamics and thats with a USB cable from an Oxygen 8 midi keyboard and no great shakes so I got in touch with Alex at WyWires and he made me up a cable due to arrive tomorrow or the next day or so...this sounds better to me than the COAX digital input on my DAC and with probably what you guys would consider a stock run of the mill USB cable...its just a touch clearer and more dynamic than the COAX input probably because I'm actually hearing the 24/96 file as it should be heard. I love finding new stuff, especially when it's been sitting in front of me for months now

[firedog]

But the SBS software (SOX) only downsamples the file to 24/48 for the Duet, so it should be VERY hard  or impossible for you to tell the difference from the original in a blind test. But if your USB implementation is inherently superior (quite possible), then enjoy it.

[srb]

Although the USB input on the Maverick D1 DAC will accept a 24/96 input, it is apparently downsampled to 16/48 by the USB receiving chip before being internally sent to the DAC chip.  I thought the Grant Fidelity DAC-09 was pretty much the same circuit, but maybe its USB chip is different?
 
Steve

[eclein]

Below are the tech specs and I highlighted what I think is the pertinent line, so according to this am I getting true 24 bit?
I don't know for sure thats why I'm asking but it looks like it to me...
 
Specs from Grants website:

Features:

(5) sets of selectable inputs to allow you plenty of choices - including 2 sets RCA, 1 coaxial, 1 optical and 1 USB 
(2) sets of RCA Outputs tailored to your taste - one with transistor and one with single 6N3 (5670) vacuum tube.
Built-in headphone amp to allow you enjoy music in privacy (standard 6.5mm jack). Transistor output.
Key parts are of audiophile quality from Germany
High efficiency low noise R-shape transformer which is usually used on high end audio only.
Separate power supply rectification to analog and digital circuits
Gold coated signal connectors throughout
Supports 16 bit, 20 bit and 24 bit audio source through coaxial and optical inputs.
USB chip is used to transfer data only, decoding is at 24 bit.
Supports sampling frequency of 32k, 44k, 48k, 88k and 96kHz (automatic - not manually selectable)
High quality processing chips used throughout  - Cirrus Logic for main D/A converter and National Semiconductor LF353N for op-amp (Please understand that in order to deter unlawful design copy, manufacturer chooses not to disclose the exact model number for the main D/A converter chip and we respect their decision. The chips inside the unit have been erased off model number during production.)

[eclein]

So guys tell me whats the verdict am I hearing my 24/96 files in all their glory or do I need new equipment to make that happen???

[srb]

This was the conclusion from the 150+ page Maverick D1 topic at Head-Fi.  The Grant Fidelity DAC-09, although based on the same general circuit, perhaps has some differences in the USB input circuitry.
 
I do know that not all "manufacturers" understand their USB input capabilities and how downsampling might be performed in the OS, driver, music player or DAC hardware.  Emotiva claimed (and still does) that the XDA-1 DAC's USB input has 24/192 capability but I found that to not be true.  On that DAC, when using a true known native file output chain (Foobar > WASAPI) I was unable to play greater than 16/48 through the USB input.
 
Steve

[eclein]

Steve..so its like with alot of these DACs and such- a "maybe" they play 24 bit....It sounds excellent so thats kind of all that matters but it would be nice to know....but how would one be able to test for that...you'd have to be able to-using the analog outs- analyze the signal some way to find out and that seems to me to be impossible.
 Thanks!!

[Wayne1]

Ed,

What program are you using to playback your files into your DAC from your computer?

If you are using Foobar, it should say what the bit rate of the files are.

[Vincent Kars]

Emotiva claimed (and still does) that the XDA-1 DAC's USB input has 24/192 capability but I found that to not be true.  On that DAC, when using a true known native file output chain (Foobar > WASAPI) I was unable to play greater than 16/48 through the USB input.

I'm afraid specs often need some close reading
http://emotiva.com/xda1.shtm says that the DAC is 24/192.
This is probably true for the DAC (the chip set)
They don't say anything about the inputs.
My rule of the thumb: if nothing is stated explicitly about the USB assuming it is 16/48 max is a save bet

[eclein]

Media Monkey GOLD and I have it set to display Bitrate and Sample Rate and they go like this- Steely Dan-"Gaucho"

                                 Bitrate    Sample
1)Babylon Sisters           2951      96000
2)Hey Nineteen              2941      96000
3)Glamour Profession       3034      96000
4)Gaucho                      3085      96000
5) ...and on..
So I'm playing back the 24/96 files in at least 24/96 so is the DAC playing that 24/96? or changing it to something lower??

[srb]

Again, just heresay from the Head-Fi group, but they came to this conclusion on the Maverick D1:  http://www.head-fi.org/forum/thread/470639/maverick-audio-tubemagic-d1-dac-amp-condensed-faq-and-info-thread
 
"There was information in this thread to get 24-Bit / 96kHz supposedly bit-perfect working with the USB on the D1. It has since been discovered that even though the rate can be changed, there's some kind of hardware issue (either design or chip limitation) and only 16-Bit / 48kHz is being sent to the DAC itself. Because of this, any other format that's sent through USB is resampled to that. Depending on the format you send, it may noticeably degrade audio quality. However, it should be bit-perfect if you send 16-Bit / 48kHz but there's no real way of knowing."
 
Like they say, if it is being downsampled internally there's no real way of knowing, and like you say, if it sounds better to you then that's all that really matters.
 
With the Emotiva XDA-1 DAC, it did not downsample internally, and the misconception that the USB input could do more than 16/48 was based on the lack of understanding how downsampling might be performed in a particular OS, driver or music player software.
 
Steve

[Wayne1]

Then I guess the only way to know for sure is to ask Grant Fidelity to ask the manufacturer.

Ed,

If you want to give it a go, I could send you my M2TECH USB/SPDIF interface to try. That most certainly will playback 24/96 and even higher resolutions. Then you might be able to compare it with your USB input.

[eclein]

At least I know that everything up to that USB port is at least 24/96 on those particular files so the signal is there...
 by the way Steve, the Jan Garbarek Group- Dresden In Concert files from HD tracks are incredible music, I think you'd like the perfomance and music alot.
 Thanks

Wayne-Thanks anyway but I'm not going to worry about it, the gear I have is the gear I'll have for awhile and I'm enjoying the sound immensely--so I'm good, but thanks!!

[srb]

I'm afraid specs often need some close reading
http://emotiva.com/xda1.shtm says that the DAC is 24/192.
This is probably true for the DAC (the chip set)
They don't say anything about the inputs.
My rule of the thumb: if nothing is stated explicitly about the USB assuming it is 16/48 max is a save bet

I read the specs very closely and and determined they were ambiguous.  That is why I called them on the telephone and asked them about the USB input specifically and was told it was also 24/192 capable.  When I returned it for that reason (among a few others), they agreed to pay return shipping which tells me that they conceded that fact.  They don't pay for return shipping if you just don't like the product.
 

At least I know that everything up to that USB port is at least 24/96 on those particular files so the signal is there...

What you know is that the output from the music player software is at that resolution.  On the Windows platform, if you don't specifically enable a driver that bypasses the Windows Kernel Mixer such as WASAPI or ASIO (not possible on iTunes), the operating system will resample the file at 16/48 and that will be the resolution coming out of the USB (or S/PDIF) port.
 
Steve

[eclein]

We got ASIO going...I think...LOL,,,I'll check under the hood

[srb]

We got ASIO going...I think...LOL,,,I'll check under the hood

If you can play a 24/96 file, try and play one of higher resolution (24/176 or 24/192).  Since we know the DAC can't do that resolution via USB, if you are getting bit perfect output at the USB port you should get an error that the resolution or stream is not supported.  If it plays, then you know downsampling is being applied by Windows or the music player software.
 
Steve

[cryoparts]

OK, try this, if you are on a Windows machine, go to "control panel", then "sounds", the select your device, then hit the drop down menu, if you see this, you have a 16/44.1 or 16/48 kHz device, ie., you can only select 16/44 or 16/48 output (device is some kind of cheap DAC with a PCM27XX USB receiving chip):



If you see the below, you have a 24/96 capable device, ie, you can select above 16/44 (device is an early first generation Sonicweld Diverter, with a custom 24/96 USB receiving chip):



Does that help?  Or, as usual, am I off track?

Peace,

lee

[eclein]

I'll check both things--hey Lee!!!

But first I have found a website that says it has 24/96 Radiohead album and all I get is 16/44...

[cryoparts]

I'll check both things--hey Lee!!!

But first I have found a website that says it has 24/96 Radiohead album and all I get is 16/44...

The download should come with 16/44, 24/96, and some kind of MP3 nonsense.

Kee

[srb]

OK, try this, if you are on a Windows machine, go to "control panel", then "sounds", the select your device, then hit the drop down menu, if you see this, you have a 16/44.1 or 16/48 kHz device:

Does that help?  Or, as usual, am I off track?

Lee, that should indicate if the DAC is 24/96 capable.  But it could still be receiving a downsampled stream from the computer depending on the driver and music player.
 
Steve