[hsg120]

I have owned several 'hi-fi' DDCs (e.g. Denafrips Gaia, Topping U90, Singxer Su6, etc) and often wondered why they almost invariably have a USB input, but never a corresponding USB output.

S/PDIF is fabulous, if you're exclusively doing 24bit/192kHz or less.

And if the proposed advantage of I2S is fewer digital conversion steps, then the argument is sort of moot if the source is USB in the first place xD

But USB--love it or hate it, undeniably offers the best support for all of the 'latest' digital audio formats.

So then, why do most DDCs go from a USB input, to all sorts of other arguably inferior digital outputs? For example, what if I wanted a DDC that just ensured that my DAC is getting a good USB input signal irrespective of the quality of the source? It doesn't seem as though there are 'hi-fi' DDCs that offer this(?).

I assume there's a reason why, but would be so grateful if someone would please fill me in.

 

[kumar402]

I have owned several 'hi-fi' DDCs (e.g. Denafrips Gaia, Topping U90, Singxer Su6, etc) and often wondered why they almost invariably have a USB input, but never a corresponding USB output.

S/PDIF is fabulous, if you're exclusively doing 24bit/192kHz or less.

And if the proposed advantage of I2S is fewer digital conversion steps, then the argument is sort of moot if the source is USB in the first place xD

But USB--love it or hate it, undeniably offers the best support for all of the 'latest' digital audio formats.

So then, why do most DDCs go from a USB input, to all sorts of other arguably inferior digital outputs? For example, what if I wanted a DDC that just ensured that my DAC is getting a good USB input signal irrespective of the quality of the source? It doesn't seem as though there are 'hi-fi' DDCs that offer this(?).

I assume there's a reason why, but would be so grateful if someone would please fill me in.

I guess apart from providing galvanic isolation between Desktop and DAC, a DDC also uses good quality clock to re-clock the signal in SPDIF and I2S format and DAC with these input method can use the clock information.
USB output kind of defeats the purpose of better or high quality clock inside the DDC. This might be one of the reason.

 

[b0bb]

It doesn't seem as though there are 'hi-fi' DDCs that offer this(?).

Intona makes them, with galvanic isolation, minus non usb outputs.
The 7055-C even has an "ultralow noise" output
https://intona.eu/en/products/buy/7055/7055-c

 

[technobear]

Also see iFi Audio: iPurifier 2/3, iUSB3.0, iGalvanic

 

[msing539]

Maybe just me but I don't think of galvanic isolators as ddcs.

 

[technobear]

Maybe just me but I don't think of galvanic isolators as ddcs.

Your re-education begins here: https://ifi-audio.com/products/nano-igalvanic3-0/

 

[msing539]

Your re-education begins here: https://ifi-audio.com/products/nano-igalvanic3-0/

If it was a DDC, iFi would have named it iDDC.

 

[dougms3]

Your re-education begins here: https://ifi-audio.com/products/nano-igalvanic3-0/

Your initial? education begins here.

https://www.ti.com/video/6138482962001

DDC and a galvanic isolator are two completely different things.

And there are levels of galvanic isolation.

 

[technobear]

Your initial? education begins here.

https://www.ti.com/video/6138482962001

DDC and a galvanic isolator are two completely different things.

And there are levels of galvanic isolation.

Can no-one around here be bothered with reading any more?

The iGalvanic re-generates, re-clocks and re-balances the USB signal. If that isn't a DDC...

 

[dougms3]

I have owned several 'hi-fi' DDCs (e.g. Denafrips Gaia, Topping U90, Singxer Su6, etc) and often wondered why they almost invariably have a USB input, but never a corresponding USB output.

S/PDIF is fabulous, if you're exclusively doing 24bit/192kHz or less.

And if the proposed advantage of I2S is fewer digital conversion steps, then the argument is sort of moot if the source is USB in the first place xD

But USB--love it or hate it, undeniably offers the best support for all of the 'latest' digital audio formats.

So then, why do most DDCs go from a USB input, to all sorts of other arguably inferior digital outputs? For example, what if I wanted a DDC that just ensured that my DAC is getting a good USB input signal irrespective of the quality of the source? It doesn't seem as though there are 'hi-fi' DDCs that offer this(?).

I assume there's a reason why, but would be so grateful if someone would please fill me in.

The reason why theres no usb output is because usb is a really bad method of transport for audio.

Its definitely one of the most widely available and convenient methods of transfer but its not desirable because its very noisy, carries alot of interference vs other mediums.

For example, I have the ifi zen dac. I use an odin knockoff usb for it, very thick cable with solid core sterling silver conductors. Its so efficient that I don't even have to plug in the 5v power to the dac. It draws enough to power the dac from the usb cable itself. Mixing the 5v power and data signal in the same line is not desirable as it causes degradation in the signal.

If the ifi zen dac were galvanically isolated, it would not be able to be powered by the usb cable.

spdif, i2s, optical are all superior forms of data transfer than usb.

Unfortunately, while convenient and more accesible, the drawback is inferior sound quality.

 

[dougms3]

Can no-one around here be bothered with reading any more?

The iGalvanic re-generates, re-clocks and re-balances the USB signal. If that isn't a DDC...

Obviously not, thats why I send you a video.

Thats what they named of the device because one of the things it does is galvanic isolation.

And no the igalvanic is not a DDC. A DDC, as it implies in the name, DIGITAL TO DIGITAL CONVERTER, converts a digital source (from USB) to a different type of digital format thats capable of being carried by SPDIF, I2S, AES, etc.

 

[technobear]

Obviously not, thats why I send you a video.

Thats what they named of the device because one of the things it does is galvanic isolation.

And no the igalvanic is not a DDC. A DDC, as it implies in the name, DIGITAL TO DIGITAL CONVERTER, converts a digital source (from USB) to a different type of digital format thats capable of being carried by SPDIF, I2S, AES, etc.

Yes, but the OP wanted USB in and USB out!

 

[kumar402]

Yes, but the OP wanted USB in and USB out!

There are devices like Uptone ISO Regen etc and obviously Intona makes great device for galvanic Isoaltion.

 

[dougms3]

There are devices like Uptone ISO Regen etc and obviously Intona makes great device for galvanic Isoaltion.

I'd be careful with some of those devices and not just blindly buying because of the reputable brand name. I don't know much about those devices as I haven't researched them but I know the uptone etherregen is not good.

As in the case with the ifi igalvanic, I had one and it degraded the sound quality on my system quite severely. It did reduce noise but the consequence in the way it was doing it was that it compressed the sound, flattened the bass and killed the liveliness in the music.

Ifi makes some great products but the igalvanic was not one of them, theres a reason why they discontinued it.

 

[kumar402]

I'd be careful with some of those devices and not just blindly buying because of the reputable brand name. I don't know much about those devices as I haven't researched them but I know the uptone etherregen is not good.

As in the case with the ifi igalvanic, I had one and it degraded the sound quality on my system quite severely. It did reduce noise but the consequence in the way it was doing it was that it compressed the sound, flattened the bass and killed the liveliness in the music.

Ifi makes some great products but the igalvanic was not one of them, theres a reason why they discontinued it.

I have not used them myself except Intona is known brand for galvanic isolation. I only suggested as OG poster wanted to use USB in to USB out. So for galvanic isolation Intona is best out there.
There is no point to have fancy clock for USB in to USB out device.