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Posted

yeah, heard about it but some believe that this would add to another component in the chain and likeliness that it will add something good or bad to the signal is pretty high......

CMIIW, XLR and RCA is it an entirely different topology of cables that need additional processing? Sorry for my ignorance.......

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Posted

I wouldnt worry about issues with usb-spdif if I were you. The DAC is much, much more important than that, dont compromise what you get just so it has USB.

Posted
What's the difference between adding a shitty USB converter vs using a shitty USB implementation that's already built in? Too bad you don't have a desktop.

That would mean 2 x shitty. CMIIW

I wouldnt worry about issues with usb-spdif if I were you. The DAC is much, much more important than that, dont compromise what you get just so it has USB.

Indirectly you telling me to widen my options to a non-usb DAC ? And use usb - spdif converter ? Again, CMIIW.......

@tkam - Sir, is the neko you're selling comes in worldwide voltage ? Thanks

Posted

He is basically saying that most USB implementations built into DACs are not very good, and actually fairly similar to external USB-SPDIF converters. This is actually pretty true, and some of the modern SPDIF receivers probably have sufficiently good internal PLLs to actually provide lower jitter from USB-SPDIF than you would get from the I2S output of most USB receivers.

Yeah, basically. Plenty of very good SPDIF only DACs out there, just get whatever appeals and a USB-SPDIF converter.

Posted
That would mean 2 x shitty.

Well, you just have to choose one. I'm saying you can go either way; both are OK. You can even add a reclocker or whatever in between the USB converter and the DAC if you're paranoid about jitter.

Posted
Well, you just have to choose one. I'm saying you can go either way; both are OK. You can even add a reclocker or whatever in between the USB converter and the DAC if you're paranoid about jitter.

Thanks Athotex......Will try looking for an alternatives, maybe I can present it here for further advise? Hope you guys dont mind in guiding me on making a right choice.......Thanks again

Posted

For what it's worth, in general I have more confidence in a USB -> S/PDIF converter going into an S/PDIF receiver + circuit than I do in a USB -> I2S conversion feeding a DAC chip directly. Because an S/PDIF input will often be re-clocked and re-buffered. I've yet to hear of anyone doing the same with a USB -> I2S circuit. Maybe someone does?

In other words, a bad USB -> S/PDIF conversion feeding a good DAC won't matter while a bad USB -> I2S conversion inside a good DAC will matter.

Still, it's pretty important to have a decent phone. For things like calling 911 and stuff.

"When I get a little money I buy audio gear; and if any is left I buy food and clothes." - Audiopherius Erasmus

Posted

Im about to made up my decision on usb-spdif converter. So far only found Teralink and this http://www.audiophileproducts.com/usbtospdif or this http://www.audiophileproducts.com/fireye2 which sounds very intriguing but can only do toslink but on the other hand, $97 and DAC as well......?? Wayyy too intriguing.

Can anyone enlighten me which is supposedly better? I'm totally blind......

While searching for the converter and researching on USB implementation on audio, I bumped into Wavelength Audio Proton DAC. Anyone heard or maybe owned this ?

Thanks

Posted
i2s sends the timing data to the clock so that it doesn't need to reclock, right?

that's my understanding.

Its very possible to have high jitter i2s, and what you get out of the PCM270x is quite high. Forget the measurements I have seen, but somewhere around 1ns IIRC. Also distortion goes out through the roof every 1ms as it resyncs or something. A good PLL/reclocking solution should significantly improve this. Of course, if you are async, then you can just take the masterclock signal that is feeding the USB chip and use that to directly reclock, and get the best of both worlds. Too bad that is so rare.

Posted

Honestly, this whole DAC "upgrade" thing seems a bit useless to me. You already have a Pico... do you really need to go balanced with a middling budget? Especially with that laptop.

If I absolutely had to have an uber DAC via laptop, I'd probably be using Squeezebox as transport. Used ones are only in the mid-$100s these days. I haven't seen too many jitter figures for USB->SPDIF things, but the jitter figures I've seen for Squeezeboxes are pretty good. I'm gonna talk entirely from my ass and guess that Squeezebox should be better than a USB converter.

Posted
Its very possible to have high jitter i2s, and what you get out of the PCM270x is quite high.

Do you know if SPDIF better from these chips, or is it just I2S that is a bit dodgy?

Posted

The problem with I2S is that it's still transmitting the clock (as opposed to async, where you'll see [or infer, in the case of a 2-way protocol such as USB or firewire] a clock input on the transport), so if that clock is still jittery, then the signal will still be jittery. At least, that's my understanding. Colin or anyone else, please feel free to step in and correct me.

Posted

The SPDIF is probably worse, but a good SPDIF receiver should help clean it up. Also, its much easier to get galvonic isolation of the SPDIF signal, which, especially sourced from a computer, is a good thing in my book. Dusty is right though, both the SPDIF and I2S outputs from the PCM270x are recovered clocks, and the internal PLL of the receiver isnt all that good at cleaning them. Async is really the best way to do it from a jitter standpoint, though a good PLL and reclocking would go a long way. I know some of the Tent secondary PLLs, for example, claim single digit ps range jitter figures, which is just superb.

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