Archived from groups: rec.audio.tech (
More info?)
"Arny Krueger" <arnyk@hotpop.com> wrote in message
news:k9-dndAoq8gLIoTeRVn-tw@comcast.com...
> "Stewart Pinkerton" <patent3@dircon.co.uk> wrote in message
> news:6h3jh1hqke67a2lg3qekbg4e0bi480fnqj@4ax.com
>> On Sat, 3 Sep 2005 07:22:41 -0400, "Arny Krueger"
>> <arnyk@hotpop.com> wrote:
>>
>>> "Stewart Pinkerton" <patent3@dircon.co.uk> wrote in
>>> message news:15jih11lsjgk25c7euvbsb43sb99ha206l@4ax.com
>>>> On Fri, 02 Sep 2005 22:34:42 -0700, hoarse with no name
>>>> <no@2spam.com> wrote:
>>>>
>>>>> Marketing material for audio equipment often boasts
>>>>> that the equipment contains either BB or C DACs. Are
>>>>> these chips really that good? Is there any objective
>>>>> way of deciding?
>>>>
>>>> It's called a specification sheet, and Wolfson DACs
>>>> appear to be the current state of the art. Of course,
>>>> they would be - they were developed in Scotland! :-)
>>>
>>> Here's a collection of Woflson DAC specs:
>>>
>>>
http://www.wolfson.co.uk/products/digital_audio/dacs/?f...
>>>
>>> The best has 112 dB dynamic range.
>>>
>>> Both Crystal and AKM have DACs with 120 dB dynamic range.
>>
>> Lost your specs, Arny? The one favoured by Arcam is the
>> WM8740, which even my ancient eyes perceive to be
>> specified at a SNR of 117dB for each half of the dual
>> DAC, when used as a single-ended pair.
>
> OK, but Wolfson's 117 < Crystal and AKM at120.
>
>> I commend you also to this link:
>
>>
http://www.arcam.co.uk/downloads/upsampling%20multidac....
>
>> where you can see how Arcam use the WM8740 in parallel
>> differential pair mode to achieve 120dB dynamic range in
>> their upsampling 'MultiDAC', with SOTA linearity.
>
> How about keeping this comparison a matter of apples and apples? IOW
> let's compare stereo chips to stereo chips. *ANY* chip can be used in
> groups to improve dynamic range if the individual chip noise contributions
> are uncorreleated.
>
>> Admittedly, this is compromised somewhat by the rest of
>> the gear to achieve a system SNR for the whole player of
>> a mere 113dB, but that ain't too shabby for a Redbook
>> player.
>
> Forgetting briefly that no 16 bit system can have more than about 96 dB
> dynamic range.
And ignoring the fact that you could play very few practical sound systems
loud enough (or would want to) to actually hear wideband noise at -96dB.
Furthermore, with the production values used to manufacture many commercial
music CDs, they could put all their useful information in 10 bits with no
loss of data (a provocative statement, but not flame-bait).