Airplay Sound Quality-does a wireless transport make any difference if you are not using a dac?

[shafesk]

I have never heard differences in sound quality between cd players when used as transports. There only seemed to be less skips during damaged cds. I think a good streamer might theoretically do the same, reduce the need for error correction and may bring out the consequent benefits associated with it. However, I haven't had a chance to compare a high quality streamer with my atv.

Interestingly it has been said that digital cables don't make a difference, well I use a usb b type cable with my hrt music streamer and when I use a crappy cable I cannot even get the thing to turn on as it has no separate power supply. What I believe is happening is that the cable isn't giving the streamer enough voltage to power up and convert digital to analogue at the same time. When I charge my ipad, it takes a lot longer if I use a cheap third party cable. Although I've heard differences in spdif cables, a poorly implemented cable could in similar ways make things a lot worse (I know spdif cables don't carry power like usb cables but I MEANT IN SIMILAR WAYS!).

Now someone is bound to come along with a counter argument, but thats about it for my knowledge so I'm waving the white flag before hand.

 

[Andrew Everard]

It's a classic example of digital cable foo, which has already been discussed ad-nauseum, hence my remark that whilst it was relevant, there's no mileage in discussing it further.

So why bring it up?

The analogue converter, which is that part of a complete 'DAC' (in a hifi equipment sense), is the only part you can 'hear'. It's what produces the 'analogue', - you can't 'hear' digits, and perceive music.

Ah, I didn't realise that a digital-to-analogue converter had one part converting digital signals to analogue, and another converting the analogue into analogue so we could hear it. You learn something new every day, eh?

Possibly, but put your faith in 'a ray of light' emerging

I have not faith in Madonna whatsoever.

 

[jcbrum]

It's a classic example of digital cable foo, which has already been discussed ad-nauseum, hence my remark that whilst it was relevant, there's no mileage in discussing it further.

So why bring it up?

Because it's a relevant example of a common misconception concerning digital cables.

The analogue converter, which is that part of a complete 'DAC' (in a hifi equipment sense), is the only part you can 'hear'. It's what produces the 'analogue', - you can't 'hear' digits, and perceive music.

Ah, I didn't realise that a digital-to-analogue converter had one part converting digital signals to analogue, and another converting the analogue into analogue so we could hear it. You learn something new every day, eh?

Most hifi enthusiasts will think of a 'DAC' as a box full of electronic circuits with input and output connectors on the outside. Inside that box will be printed circuit boards populated with electronic components, - 'chips'.

The actual integrated circuit chips also referred to as 'Audio DACs' usually have at least four important internal components, the signal input stage, the voltage reference stage, the clock, and the converter, which feed the output buffer stage.

Take as a 'high-end' example the Wolfson WM8741 DAC. Wolfson say this . . .

The WM8741 includes fine resolution volume and soft mute control, digital de-emphasis and a range of advanced digital filter responses, followed by a digital interpolation filter, multi-bit sigma delta modulator and stereo DAC. Wolfson’s patented architecture optimises the linearity of the DAC and provides maximum insensitivity to clock jitter.

The emboldened bit (by me) means the converter. You can see that there is much more inside a 'DAC' chip than just the converter.

JC

 

[Andrew Everard]

Thank you for that clarification. Now you've put the important bit in bold type, I understand the point you're trying to make.