It shouldn't add any if the connection is asynchronous and there is a decent buffer of some sort.
There is no better altenative to connect a computer. Maybe ethernet, but not much is available yet. usb->i2s receivers instead reached an excellent level nowadays.
Hmmh. Then you need to get an USB-SPDIF interface that's feeding your SPDIF-DAC or reclocker.
Too complicated.
You just move your problem to another device.
What you need is an USB interface DONE RIGHT.
Perhaps combining the WAVE-IO XMOS with the FIFO reclocker could be it.
The WAVE-IO supplies fully isolated I2S at quite a good quality.
And the FIFO squeezes the last bit out of it. The noise we left on the WAVE-IO and the last bit of jitter we left at the FIFO.
Of course you'd need a DAC ( or preferably a full digital amp
) with I2S input.
Too complicated.
You just move your problem to another device.
What you need is an USB interface DONE RIGHT.
Perhaps combining the WAVE-IO XMOS with the FIFO reclocker could be it.
The WAVE-IO supplies fully isolated I2S at quite a good quality.
And the FIFO squeezes the last bit out of it. The noise we left on the WAVE-IO and the last bit of jitter we left at the FIFO.
Of course you'd need a DAC ( or preferably a full digital amp
) with I2S input.
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Async USB audio connection relies on interpolating/fake samples. Otherwise there is a need for a hefty buffer memory. The USB audio chips don't have that luxury. A decent buffer is in a FIFO device with some MB of memory.
The whole point of isolating USB is to not do it at the i2s side which adds 100ps+ jitter. The FIFO can absorb some, but well it's just an expensive patch IMO.
There is serious audio gear doing it this way (Berkeley, Ayre), and i tend to believe them more than... hmm... others.
Of course you'd need a DAC ( or preferably a full digital amp
Ofc I have. but not the buffalo.
I am using this device, SuperSpeed USB 3.0 Over Fiber Optic Expansion System made by Adnaco, a Canadian company.
I am sure that it satisfies all the requirements given by soundcheck.
You need neither soldering nor special connectors.
One big problem is a cost, approximately 400 USD.
I think the isolation has brought me a certain level of improvement on SQ and I am satisfied with the result.
The system provide you a galvanic isolation of electrical grounds between external USB Audio devices and PC by achieving a digital data transfer over a pair of optical fibers of computer data communication grade.
Its primary intended use might be for factory automation or medical electronics where a long bus extension or a complete galvanic isolation is required.
The system consists three major parts.
1. Extension card for PCI Express bus in PC
2. Multi-mode optical fiber
3. Two port USB 3.0 interface unit with an external power adapter
As the two USB ports support USB 3.0, a data transfer on USB 2.0 High speed (480Mbps) is achieved without any problem and that makes me explore DSD512 or PCM 352.8 kHz/24bit stereo plays.
This system does not expand any USB 3.0 signals on PC but expands PCI Express bus signals based on their proprietary technology in a hardware domain. Therefore, no special driver software is required for the PCI Express bus card side.
Only a driver for USB 3.0 compatible USB interface chip, TI chip, built in the interface unit hooked at the end of optical fibers needs to be installed. The driver software is provided by TI.
The expansion system is completely transparent to any audio application level traffics. In other words, any software applications for audio play do not know that a pair of optical fibers are inserted in the middle of the data pass.
One big limitation is that this system is not directly applicable to PCs of no PCI Express bus.
An audiophile grade power supply can be connected to the USB 3.0 interface unit. The actual draw is 0.5 A for +5.0 V DC.
Another merit is that you can locate your PC long away from your audio system because a long optical fiber cable for industrial use can be available.
You can stop using a USB cable if you don't like it.
The price of the system is almost or slightly over 400 USD including tax and shipping charge. Some people may think it's too expensive while some crazy audiophiles may think it's worth paying.
I am not sure the price is within the range of initial expectation of soundcheck.
In my case, I thought it was a good product to buy.
Hi folks.
FYI.
I switched back to Toslink. Got myself away from USB.
I really love the low complexity of that solution.
I slightly tweaked the TL transmitter and the receiver PS/decoupling.
What you need is a good reclocker/data revovery chip on the receiving end.
All those active USB isolation elements come with their own challenges/drawbacks.
Cheers
FYI.
I switched back to Toslink. Got myself away from USB.
I really love the low complexity of that solution.
I slightly tweaked the TL transmitter and the receiver PS/decoupling.
What you need is a good reclocker/data revovery chip on the receiving end.
All those active USB isolation elements come with their own challenges/drawbacks.
Cheers
As for me, I am mostly interested in playing DSD256 and DSD512. Neither Toslink for S/PDIF nor USB Full Speed meets my requirements.
Oh, they say it supports USB 2.0 High-speed 480 Mbps. That's good!
Your information is very valuable for me. Thank you very much!
Though they say nothing on their isolation method, I guess USB signal lines must be isolated. I think we do not have to stick to jitters on USB lines.
Does anyone know its price?
I don't think the Ifi does data isolation - only power. And you get low noise from old chips like LM723 = 2.5uV noise.
I'm also concerned that their site uses a lot of pseudo technical language with capitalisation - so it's not a real technical term but their own Brand Of Bu"sh"t.
I think the easiest way to do this hi-speed USB isolation, is to isolate the I2S output with an adum6400c. I've ordered a couple of samples and I'll give it a try.
cheers
I'm also concerned that their site uses a lot of pseudo technical language with capitalisation - so it's not a real technical term but their own Brand Of Bu"sh"t.
I think the easiest way to do this hi-speed USB isolation, is to isolate the I2S output with an adum6400c. I've ordered a couple of samples and I'll give it a try.
cheers
I notice the distro or manufacturer posted in that thread a massive long post designed to baffle, complete with subterfuge about competitors using splice cables with batteries and saying they are not low noise by quoting that same decade old website of noisy 9v batteries under high load, like anyone uses a 9v non rechargeable battery to supply power to these things, like they use a 9v anything to power these 3.3-5v things. most are using LiFePO4 which are totally just idling with this sort of current
Guys, do yourself a favor and try this one for less than USD50, with a good, low noise regulated supply:
USB Interfaces « Circuits@Home
USB 2.0.
I don't know of newer products.
M.
USB Interfaces « Circuits@Home
USB 2.0.
I don't know of newer products.
M.
$50 is very expensive for something that doesnt do the job =) as mentioned above it does not do USB2 high speed, so its not really usb 2.0 at all. I have some, at least the version I have comes on a DIY PCB and the regulators are of pretty average quality, cheap LDOs
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