USB to digital using XMOS chip - cheap options

[SiW]

Currrently have a HiFiMe Sabre for going from my iPhone via usb to optical output.

It uses the SA9023 chip I believe but understand that the XMOS U208 is a better chip for USB to digital conversion.

Which cheap options are there to give me usb to digital optical or coax using the XMOS chip?

If it doesn’t really matter happy to keep the Sabre.

Simon

 

[andreasmaaan]

Currrently have a HiFiMe Sabre for going from my iPhone via usb to optical output.

It uses the SA9023 chip I believe but understand that the XMOS U208 is a better chip for USB to digital conversion.

Which cheap options are there to give me usb to digital optical or coax using the XMOS chip?

If it doesn’t really matter happy to keep the Sabre.

Simon

Not wanting to hijack your question (which I'm sorry I don't know the answer to), but most models of iPhone have excellent inbuilt DACs, much better than any Hifime DAC that I've seen measurements of. What particular reason are you using the external DAC for?

 

[SiW]

Good question

I have a iPhone 6s but the internal DAC is limited to 48kHz output from memory.

I use the Onkyo Player app on the iPhone which allows full output sampling rate dependant on the spec of the DAC connected Need the USB camera connection cable but have that already.

It will be feeding a MiniDSP NanoDIGI which takes digital optical and coax input but not usb input.

Simon

 

[andreasmaaan]

Good question

I have a iPhone 6s but the internal DAC is limited to 48kHz output from memory.

I use Onkyo Player which allows full output sampling rate dependant on the spec of the DAC connected Need the USB camera connection cable but have that already.

It will be feeding a MiniDSP NanoDIGI which takes digital optical and coax input but not usb input.

Simon

Ok, sorry I couldn't help.

One thing I will add is that a 48KHz sample rate exceeds the limits of human hearing. Any higher sample rate than that will not provide any audible benefit.

Meanwhile, other aspects of a DAC's chip and implementation will have audible effects.

Best sound quality in your circumstances is most likely to be achieved by using the iPhone's inbuilt DAC.

 

[SiW]

Sorry meant to say it’s the Onkyo player app on the iPhone

 

[andreasmaaan]

Sorry meant to say it’s the Onkyo player app on the iPhone

Yeh I realised that after re-reading your post actually and corrected mine.

My advice still stands though re: sample rates and DAC quality

 

[andreasmaaan]

To flesh out what I mean here, @amirm measured the Hifime Sabre 9018 DAC here and found that it produced slightly more than 0.01% THD+N under typical use conditions. This is low enough to be probably, but not definitely, inaudible.

Ken Rockwell measured the iPhone 6S's inbuilt DAC here and found that it produced slightly more than 0.001% THD+N under typical use conditions. This is a distortion factor an order of magnitude lower than the Hifime Sabre, and will 100% certainly be inaudible.

Both have flat frequency up to 20KHz, which is higher than you'll be able to hear if you're an adult.

PS. for clarification, increasing the sample rate raises the maximum frequency the DAC can reproduce, but does not have any effect whatsoever within the frequency range below that. In other words, a 48KHz sample rate and a 96KHz or 192KHz sample rate will - all else being equal - produce identical results below 20KHz.

EDIT: I misread the measurements! I'm sorry. The Hifime Sabre 9018 actually does perform almost as well as the iPhone's inbuilt DAC. My apologies. There's probably no audible advantage in using the iPhone's DAC. Both should sound exactly the same.

I'm not sure about your Hifime Sabre 9023, however. Other Hifime products have measured much worse than their Sabre 9018, so it's hard to say.

 

[andreasmaaan]

What can be said with a huge amount of confidence however is that the iPhone 6S is as good a DAC as you'll need (i.e. no audible distortion), so long as it has enough power for the headphones or amp it is driving. There is almost no chance the Hifime product is superior.

 

[Krunok]

While I agree with @andreasmaaan, here's a cheap option you asked for if you choose to go that way:

https://www.ebay.co.uk/itm/XMOS-XU2...op64-F-HIFI-/163110533974?hash=item25fa253b56

 

[SiW]

Thanks guys - I have the base model Sabre and according to the site it’s full model name is: HiFimeDIY UAE23 USB DAC (ESS Sabre ES9023+Savitech SA9023).

Sounds like it will do what I need it to do

Simon