Upsampling USB DAC with AES/EBU output?
Feb 12, 2009 at 7:52 PM Post #3 of 55
What you're looking for is a resampler with AES/EBU output, Patrick. Once you actually perform the Digital to Analog conversion (DAC), you don't need digital outputs any longer.
 
Feb 12, 2009 at 8:09 PM Post #4 of 55
Quote:

Originally Posted by Sherwood /img/forum/go_quote.gif
What you're looking for is a resampler with AES/EBU output, Patrick. Once you actually perform the Digital to Analog conversion (DAC), you don't need digital outputs any longer.


I have owned a dCS upsampler but I sold it because it only had 96kHz output from single channel AES/EBU. It didn't have USB either so I can't plug my laptop to it.

I have owned a Cary 303/300 192kHz CD transport and it was perfect with AES/EBU to Benchmark DAC1.

I need to feed my DAC1 with 192kHz AES/EBU, it sounds silky smooth!
 
Feb 12, 2009 at 8:15 PM Post #5 of 55
The dCS was a reclocker, and the Cary was a transport. Neither was a proper DAC, like your Benchmark is.

What kind of an input do you want? USB? Firewire? Are you going to be using it to play files off your computer?
 
Feb 12, 2009 at 8:18 PM Post #6 of 55
Quote:

Originally Posted by Sherwood /img/forum/go_quote.gif
The dCS was a reclocker, and the Cary was a transport. Neither was a proper DAC, like your Benchmark is.

What kind of an input do you want? USB? Firewire? Are you going to be using it to play files off your computer?



My laptop only has USB output so I need the upsampler to have USB input.

I will use it to play files off my laptop. I will later upgrade to a smaller laptop.
 
Feb 12, 2009 at 9:19 PM Post #8 of 55
Quote:

Originally Posted by Sherwood /img/forum/go_quote.gif
Firewire would give you a few more options, so if your laptop can handle it you might consider getting a firewire PCMCIA card.

If you do that, take a look at the MOTU Traveller Mk. 3 and the Weiss Vesta



I have had bad experience with Firewire. I experimented with dCS Verdi Encore 2.822MHz with Firewire cable to dCS Elgar Plus DAC. It sounded noisy and bright like the wire was on fire! I tried everything, I tweaked, I wrapped with ERS Paper, I could not fix the problem.

AES/EBU 192kHz from Cary to DAC1 sounded smoother because there was no noise added to the signal. I tried dCS Purcell upsampler but it could only send 192kHz through two AES/EBU cables. I sold the dCS (two AES plugs could not fit into single hole DAC1!). I need 192kHz through a single AES/EBU cable!
 
Feb 12, 2009 at 10:31 PM Post #9 of 55
what about that Space Audio Tech thing that does 26-bit? I'm not actually trying to make a joke here, I just forget what it was actually called

it resamples to like 26-bit/22.5mhz (yes, mhz) and then drives analog out (so no AES afaik, but its putting the data to a level the DAC1 couldn't use)

as far as 192khz over a single AES cable, can the DAC1 even support that kind of data rate? (I'm curious)
 
Feb 13, 2009 at 4:20 PM Post #10 of 55
Quote:

Originally Posted by obobskivich /img/forum/go_quote.gif
what about that Space Audio Tech thing that does 26-bit? I'm not actually trying to make a joke here, I just forget what it was actually called

it resamples to like 26-bit/22.5mhz (yes, mhz) and then drives analog out (so no AES afaik, but its putting the data to a level the DAC1 couldn't use)



I can't find it, where did you hear about it?


Quote:

Originally Posted by obobskivich /img/forum/go_quote.gif
as far as 192khz over a single AES cable, can the DAC1 even support that kind of data rate? (I'm curious)


It worked when I tried it, I compared 96kHz and 192kHz, there was a huge difference.
 
Feb 14, 2009 at 7:14 AM Post #11 of 55
I am still a bit unclear what it i you are trying to do.

You have a PC with USB output. You have a DAC with AES/EBU input that you want to drive at 24/192. So far so so good.

What type of source material do you want to play and where do you want to do the upsampling? In the PC or with an external device?

For a USB connected audio device that supports 24/129 AES/EBU output have a look here. This would allow you to do any sample rate conversion in software in the PC

For an external sample rate converter you could have a look here but then the algorithm would be fixed to whatever this device provides. In this case you can use any USB->digital output adapter since this device also does format conversion to AES/EBU.

I hope I got this right.

Cheers

Thomas
 
Feb 14, 2009 at 6:10 PM Post #12 of 55
"It worked when I tried it, I compared 96kHz and 192kHz, there was a huge difference. "

Then there is a serious problem with your playback chain!!

Why on earth do you think that upsampling to 96kFs/s or 192, presumably from a CD can possibly improve anything? You think that maybe the potential artefacts caused by 16bit/44.1kFs/s are going to be magically removed by upsampling?

I'm not trying to be insulting, I am genuinely interested in why you feel you will get a better result by upsampling or using a larger bit depth.

Also, why AES/EBU, rather than optical or SPDIF?

Cheers, G
 
Feb 14, 2009 at 6:37 PM Post #13 of 55
Often running a DAC at 192Khz will increase the noise and distortions so you might actually be able to detect a difference.

However, one should not confuse that with better sound ....

Cheers

Thomas
 
Feb 14, 2009 at 7:03 PM Post #14 of 55
Quote:

Originally Posted by gregorio /img/forum/go_quote.gif
"It worked when I tried it, I compared 96kHz and 192kHz, there was a huge difference. "

Then there is a serious problem with your playback chain!!



Yes, there are many problems in my system which I'm trying to fix. Upgrading to $31 000 sources didn't fix the problem. In a way it made it worse because of higher wattage which added more edginess and noise into my system. It was like throwing money into a garbage can. I only got back 1/10th of the money when I sold them.

Luckily for me I get better sound with a $200 source and $39 amp because of lower wattage. They are very bright because of short-signal path (less veil) and sensitivity to external interferences (vibration, AC noise and RFI make it sound brighter which masks low-level detail). But they can be fixed with tweaks... I use multiple Genesis power cables daisy chained together, 11 RGC-24 Ground Conditioners, Magix levitation feet and ERS Paper. I have removed the interconnect wiring and just soldered the connectors together. It clearly beats my old dCS setup in every way except for silkiness. I hope the 192kHz upsampling will cure that.


Quote:

Originally Posted by gregorio /img/forum/go_quote.gif
"

Why on earth do you think that upsampling to 96kFs/s or 192, presumably from a CD can possibly improve anything? You think that maybe the potential artefacts caused by 16bit/44.1kFs/s are going to be magically removed by upsampling?

I'm not trying to be insulting, I am genuinely interested in why you feel you will get a better result by upsampling or using a larger bit depth.



If I didn't hear a difference I wouldn't need 192kHz and would save a lot of money, I like to save money because I'm so poor. I have made a blind test:
http://www.head-fi.org/forums/f7/car...6/#post2189319

Unfortunately I heard a difference, now I need to pay for it.

Quote:

Originally Posted by gregorio /img/forum/go_quote.gif
Also, why AES/EBU, rather than optical or SPDIF?

Cheers, G



Toslink at 96kHz had audio drop outs, different Toslink cables gave different results at 96kHz. At 44.1 kHz all cables worked but it sounded edgy with lack of low-level detail. It sounded empty because the attack and decay cut off early, however, it gave an illusion of a blacker background.

XLR plug sounds smoother than RCA plug because the ground signal has a dedicated pin/conductor. RCA should sound edgier/faster with less low-level detail.
 
Feb 14, 2009 at 8:36 PM Post #15 of 55
Sadly Patrick much of what you assert cannot be possible in this universe.

What goes through an SPDIF or lightpipe is identical. SPDIF and AES/EBU are for all practical puposes identical too. It's all 0s and 1s, the quality of those 0s and 1s is utterly irrelevant to audio quality. If you can hear a difference there must be a fault with the cables or your system. This isn't an opinion, it's simple fact.

BTW, "XLR plug sounds smoother than RCA plug because the ground signal has a dedicated pin/conductor." - Err, they both have a dedicated gound connector. I'm not sure where you are getting all your information but none of what you are saying bares any resemblance to the facts. XLR has 3 connectors, 1 ground, 2 & 3 carring the same digital signal but one of them out of phase, purely for common mode rejection. RCA (SPDIF) has two connectors, a ground and the digital signal. BTW, daisy chaining cables is never a good idea as the connections can only degrade the signal.

Upsampling to 192kFs/s cannot make a difference. Anything lost during the creation of a 44.1kFs/s product cannot be restored by resampling at a higher rate. It's gone, forever, it isn't there anymore and it can't be put back. This really is basic audio theory, taught to every first year audio student everywhere in the world. This theory has been tried, tested, proven and implimented for more than 25 years.

If you are hearing a positive difference when upsampling there must be a fault with your system or your ears, or you must be living in a universe with a different set of physical laws!!

Of course, it is entirely possible to hear a negative effect of upsampling, two or four times the data rate to transfer and process is likely to cause considerably more errors.

I know you are going to fight against what I've written here because it is a bitter pill to swallow when you've been a victim of marketing hype. Let me put it this way, I've worked in Abbey Road Studios, Air Lyndhurst, The Hit Factory and several other highly specified (and respected/famous) recording studios around the world. None of them spend more than a few bucks per meter for cabling. Go look up the cost of fully screened Klotz or Van Damme cable. I'm afraid if you're spending more than this you have been done. Unless of course you feel that spending 1000 times too much on cabling has actually made your bedroom sound better than Abbey Road Studios?

I'm not having a go at you personally, I'm just really annoyed that companies are allowed to mis-lead the consumer so much and that it's not against the law. Sure the specs look better but it doesn't make any difference. What's better, a Ford Modeo with a 900bhp engine or one with an 901bhp engine? Sure the 901bhp spec is a bit better but it's going to be completely irrelevant in a Ford Mondeo! However as I can prove that it produces more power I'm justified in charging a few extra grand and laughing all the way to the bank (or to my share holders). Unfortunately, this master plan won't work because most car buyers know a bit about power output and will realise the stupidity of putting an 900bhp engine in a Ford Mondeo in the first place. Audio equipment manufacturers are in the enviable position of being able to market ridiclous specifications just like the Mondeo example because very few consumers know even the basics so are easy to hoodwink. Capitalism is not all good!

G
 

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