No. No. No.
but dont take my word for it. Take Paul Frindle(DSP Expert, digital audio mastermind, one of the powers behind the Sony Oxford Console, among other things)
**POSTED WITH MR FRINDLES PERMISSION*
Paul is a digital audio expert and DSP mastermind. I often ask him for advice/information.
His Bio is here.
http://www.proaudiodsp.com/
Paul Frindle - Product Design
Paul Frindle has 35 years' experience in the pro audio and music industries. He has worked as a studio engineer in Oxford and Paris, and was a design engineer at SSL with responsibilities for E and G-series analogue consoles, emerging assignable consoles and nascent digital audio products. As one of the original team that became Sony Oxford, he is responsible for many revolutionary aspects of the Sony OXF-R3 mixing console. More recently he was responsible for product design and quality assurance at Oxford Plugins. On leaving Sony Oxford, he co-founded Pro Audio DSP in order to make novel sound-processing applications to fulfill many issues he had identified in the audio production chain over his career.
___There are only 2 things a DAC responds to; 1) the data we feed to it ,
2) the timing information it gets.____
For the data; data is data - there is no possibility that identical
data sets could ever produce a different sound, regardless of their
origins. In short, numbers are numbers - and if they are the same,
they are the same - period.
For timing it's a slightly different matter, because it is essentially
and analogue signal - it's properties (i.e. rate) are analogue in
concept.
So there is a slight possibility that interference on the clock signal
can affect the DACs performance, if the timing is modulated in some
way, by slightly changing the rate of plyout with time.
Of course a good DAC system will circumvent this possibility by using
it's own internal clock and some buffering of the data - so that the
DAC's timing follows the filtered average rate of the input timing -
such that short term timing rate variations (due to interference) do
not make it through. I.e. it will synchronise to the input clock,
rather than simply passing the input clock straight into the DAC.. You
can almost think of it as stacking up the data as it ccomes in and
playing it out using it's OWN high quality clock set to the same rate.
However - as you can imagine, price competition tends to rule out
anything that might increase the cost of the product - and so you will
have to spend extra money on your DAC system to get this..
So where does the timing modulation of the clock rate come from
(sometimes called jitter)?
First on the list are wires and connections. Line frequency hum, RF
and interference getting into clock cables will modulate the timing at
the recieving end. If you DAC doesn't reject them (as above)
performance may suffer.
Next on the list is bad design. For instance, in consumer players
where the DAC is within the player box, power supply modulation from
bad design may cause internal circuits to interfere with each other.
For instance if the motor servo is being varied by slightly eccentric
discs and/or wobbly ones that stress the focus servo, the cyclic
changes to current draw my affect the clock oscillator if the power
supply is badly desogned etc.. So although the data is correctly read,
the DAC itself may perform less well than it might, due to internal
design flaws.. And of course this is true of any electronic system...
So there you go - it's a simple as that - no PHD required
In summary:
Data itself coming from different systems cannot cause a change in
sound - if the data values are both identical.
But hardware may perform slightly differently if the timing integrity
is compromised.
Having an external DAC does not avoid the issue - unless it's a very
good one with internal timing re-clocking. In which case it will be
effectively immune from timing errors and will sound the same whatever
way it gets connected, providing the data is correct.
So instead of worrying about data coming from Macs or PCs and/or a
whole load of hot air from HiFi zealots filling pages with 'waffle' -
**get yourself a high quality DAC and say bye-bye to the whole
discussion**
I hope this helps..
Paul
