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Why are USB S/PDIF interfaces so expensive?

post #1 of 14
Thread Starter 

Hi Head-fiers, I'm a long time lurker first time poster, and this time my wallet is stumped!

 

I was hoping someone could kindly educate me about USB to S/PDIF interfaces.

 

I find that the Schiit Bifrost DAC is $450+ and houses a 24/192KHz C-Media CM6631 USB interface, so why would spending upwards of $350 on a USB S/PDIF interface make sense?

 

The Audiophilleo alone costs twice as much as the Bifrost, I'm simply stumped why a USB interface (that doesn't even require dedicated power) can cost more than a top rated DAC.

 

I'm aware in most cases a USB S/PDIF interface will output in coaxial, but if it's going into a DAC with Optical, Coaxial and USB inputs, how would that make a difference? Obviously this could be useful if your DAC doesn't have USB, or the USB interface is of poor quality, but are these prices justified?

 

Thanks in advance!

post #2 of 14
Quote:
Originally Posted by josephsart View Post

Hi Head-fiers, I'm a long time lurker first time poster, and this time my wallet is stumped!

 

I was hoping someone could kindly educate me about USB to S/PDIF interfaces.

 

I find that the Schiit Bifrost DAC is $450+ and houses a 24/192KHz C-Media CM6631 USB interface, so why would spending upwards of $350 on a USB S/PDIF interface make sense?

 

The Audiophilleo alone costs twice as much as the Bifrost, I'm simply stumped why a USB interface (that doesn't even require dedicated power) can cost more than a top rated DAC.

 

I'm aware in most cases a USB S/PDIF interface will output in coaxial, but if it's going into a DAC with Optical, Coaxial and USB inputs, how would that make a difference? Obviously this could be useful if your DAC doesn't have USB, or the USB interface is of poor quality, but are these prices justified?

 

Thanks in advance!

My two cents.

I'm guessing the price is high because the demand is limited to the few audiophiles who are willing to spend large amounts of cash for their audio hobby.

If there was a higher demand for the USB to S/PDIF converter, more companies would get into making these devices and competition would drive down the price.

post #3 of 14

2 points:

 

#1  It's a relatively new phenomenon to break out the USB-to-SPDIF out of the system

 

Integrated units were long common before the days of specialization in circuits.  The advent of separate pre-/power amplification was relatively new in terms of hi-fi (30 years ago?  35 maybe?  Too lazy to verify).  Even newer, you can point to CD transports and DACs broken out into separate chassis.  The theorized benefits would include:

* modular and upgradeable design for replacement of parts, rather than replacing a whole system;

* allows the use of premium parts, design and shielding within each chassis to suit the specific purpose regardless of component size since there is minimal competition for space;

* allows the use of dedicated power supplies for each chassis, again to replace any competition between subsystems.  Dedicated transformers and large capacitance networks tend to mean a more consistent power supply for each device and a corresponding better sound quality.

 

Of course, there are drawbacks to separate housing as well.

 

 

#2  in a trickle down industry like audio, integration of server-storage systems is still relatively new in the higher end. This means that USB is still not integrated in to many of the expensive and cutting edge systems, where users would pay for the highest resolution inputs and circuits possible.  For example, the EMM Labs $25k XDS1 Reference digital source still does not have a USB input*

 

*(technically this is not true; EMM Labs does software updates via USB interface on the unit rear panel.  However this is only a hardware USB connection and is isolated from all audio circuits and is not usable for connecting to a digital source.  Perhaps better phrasing is that the "XDS1 still does not have USB Audio inputs").

 

 

From my personal experience, you will not hear an improved sound using a desktop or rack outboard USB-SPDIF converter on a $450 DAC.  The only reason you would need one at that price point is that your DAC completely lacks any USB input at all.  That said, since Apple has chosen a proprietary USB line out format, IPods/Pads will not interface with standard USB connectors, so using a Algorhythm or other device on an Apple product will work for high-end portable applications.  There's always an exception.

post #4 of 14
Thread Starter 
Quote:
Originally Posted by PurpleAngel View Post

If there was a higher demand for the USB to S/PDIF converter, more companies would get into making these devices and competition would drive down the price.

 

Thanks PurpleAngel, any idea how you output 24/192KHz if you are using your computer as the source?

 

I imagine an onboard soundcard or USB to S/PDIF converter provide the only methods, but what is most cost effective?

 

Quote:
Originally Posted by Smeckles View Post

From my personal experience, you will not hear an improved sound using a desktop or rack outboard USB-SPDIF converter on a $450 DAC.  The only reason you would need one at that price point is that your DAC completely lacks any USB input at all.

 

Thanks for the info Smeckles.

 

My current DAC supports 24/192KHz through Coaxial/Optical, but 24/96KHz through USB.

 

I'm looking for a solution that will allow me to sample audio from my computer at 24/192Khz. I'm not sure if there will be an audible difference to my ears, but I'm anxious to find some high quality source and compare the difference.

 

I have an iMac which has optical outputs, although the onboard sound outputs at 24/96KHz. So either way a USB device is the only solution, and currently these seemingly simple devices are outrageously expensive. I'm not certain, but I think I'll be needing to upgrade my DAC.


Edited by JosephsART - 8/20/12 at 11:29pm
post #5 of 14
Quote:
Originally Posted by josephsart View Post

 

Thanks PurpleAngel, any idea how you output 24/192KHz if you are using your computer as the source?

 

I imagine an onboard soundcard or USB to S/PDIF converter provide the only methods, but what is most cost effective?

 

 

Thanks for the info Smeckles.

 

My current DAC supports 24/192KHz through Coaxial/Optical, but 24/96KHz through USB.

 

I'm looking for a solution that will allow me to sample audio from my computer at 24/192Khz. I'm not sure if there will be an audible difference to my ears, but I'm anxious to find some high quality source and compare the difference.

 

I have an iMac which has optical outputs, although the on-board sound outputs at 24/96KHz. So either way a USB device is the only solution, and currently these seemingly simple devices are outrageously expensive. I'm not certain, but I think I'll be needing to upgrade my DAC.

I think the highest necessary for normal CD audio is 44.1Khz, so outputing 192Khz seems overkill.

First off, the DAC does not send thru the optical/coaxial, the DAC outputs an analog (wave) audio signal, optical and coaxial is a digital signal.

So when your outputing thru the optical, coaxial (& USB), the DAC (in your Mac) is being bypassed.

I'm guessing your best bet is to output optical to a quality external DAC.

post #6 of 14
Quote:

Originally Posted by josephsart View Post

 

I find that the Schiit Bifrost DAC is $450+ and houses a 24/192KHz C-Media CM6631 USB interface, so why would spending upwards of $350 on a USB S/PDIF interface make sense?

 

It does not make sense if you have a well engineered DAC. But some people believe it improves the sound, and are willing to pay the extra money, just like in the case of "high end" cables, so why not sell them ?

post #7 of 14

You might have a look at M2Tech hiFace 2 US$ 185

A converter like this allows you to play anything up to 192 kHz at its native sample rate.

You can upsample CDs to any higher rate and it might change the sound as sample rate conversion can create artifacts.

Some DACs do change their sonic signature when driven at a higher sample rate.

I prefer to play everything at its native sample rate.

post #8 of 14
Thread Starter 
Quote:
Originally Posted by Roseval View Post

Some DACs do change their sonic signature when driven at a higher sample rate.

I prefer to play everything at its native sample rate.

 

When I switch from 96KHz to 44.1KHz there is a very noticeable difference, 44.1KHz sounds narrow and linear, where upsampling to 96KHz sounds much more robust and dynamic. I think I prefer 96KHz, but I'm not sure if it's is a good or bad thing.

 

Quote:
Originally Posted by Roseval View Post

You might have a look at M2Tech hiFace 2 US$ 185

 

Thanks for the suggestion Roseval. From my searches, the M2Tech hiFace is certainly one of the few below $200.

 

I also found the Musiland Monitor 01 USD to be incredibly good value, with the latest 2012 version being an apparent 32Bit/384KHz for $70.

I keep reading about these drivers for it though, doesn't look there's much going on in the Mac department.

Not sure if they're required or not.


Edited by JosephsART - 8/21/12 at 5:36am
post #9 of 14

It is not so complicated.

There are 2 USB standards for audio, UAC1 (up to 24/96) and UAC2 (  > 96 kHz)

UAC1 is available in Win, OSX and Linux

UAC2 is available in OSX and Linux. For Win you need a third party driver.

 

A product might not use UAC at all but comes with a proprietary driver using bulk mode.

In this case, the manufacturer needs to develop a driver for each OS.

If a manufacturer doesn’t claim support for OSX and/or Linux you can be almost sure it uses a proprietary driver so it won’t work on these OS.

As far as I know, the Musiland is Win only

post #10 of 14

If all you need is analog out from the DAC, check out the ODAC. I am thoroughly enjoying mine. It's a very simple and small device, about 1/2" x 2" x 3", with only USB in and 1/8th stereo jack out. Uses UAC1 built in drivers/supports 24/96.

post #11 of 14

It is odd that the practice of adding a USB > S/PDIF clocking device prior to a DAC proper remains so popular as it makes absolutely no technical or economic sense.

 

Digital Audio is made up of 2 components. In the case of commercial CDs the first is a series of 16  bit numbers which represents a voltage which in turn is an analogue of the atmospheric pressure at the exact time of recording. The second component is the timing of these samples. Since they were made at 44.1k times a second they have to be read again at a similar rate in order to recreate the original voltage.

 

Early CD players carried out this process in 2 stages. Add the timing data back to the samples. This creates S/PDIF. Then pass that signal to the DAC chip to recreate the voltages. This is the cheapest and easiest method. Not only are the chips themselves less expensive they don't require any programming or technical skills from the designers. When the possibility to sell separate DAC boxes occurred to hi-fi grade sellers this is their preferred  solution.

 

You can see the inherent problem here? If you want a 'better' DAC than that already in your PC why still trust the internal clock to recreate the timing? So another additional market was created for a USB to S/PDIF reclocking device. 

 

On the other hand the pro audio manufacturers, who already had people on board with software skills and experience with high end digital audio via studios and musicians, took advantage of the more advanced integrated DAC chips which buffer data, detect and correct any errors automatically, add the timing data back in and recreate the voltages in a single operation. These chips are marginally more expensive and require user written or licensed software. 

 

So the moral of the story is?

 

Don't waste money on an old fashioned, obsolete, and overpriced signal chain. Buy an all in one async USB  2 audio interface right from the off.

post #12 of 14

I did not know that usb to optical S/PDIF or IEC 958 was expensive. I have a Creative Sound Blaster X-FI HD which I use to convert usb output from computer to optical and thereafter, send to  preamp's optical input at 24/96. It sounds awesome. I cannot distinguish iTunes at 256k from SACD.


Edited by sterling1 - 8/22/12 at 1:49pm
post #13 of 14
Quote:
Originally Posted by RonaldDumsfeld View Post

On the other hand the pro audio manufacturers, who already had people on board with software skills and experience with high end digital audio via studios and musicians, took advantage of the more advanced integrated DAC chips which buffer data, detect and correct any errors automatically, add the timing data back in and recreate the voltages in a single operation. These chips are marginally more expensive and require user written or licensed software. 

Care to elaborate a bit on the technology you are referring to?

post #14 of 14
Quote:
Originally Posted by Roseval View Post

Care to elaborate a bit on the technology you are referring to?

He is saying dont go USB-> SPDIF -> DAC just go with a USB DAC, like the ODAC (it use I2S internally instead of SPDIF, which is a simpler and more elegant solution.)

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