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Re: Hello and a Sony PCM D100 question

Subject: Re: Hello and a Sony PCM D100 question
From: "umashankar" umashanks
Date: Fri Jun 20, 2014 8:11 am ((PDT))
just two points

a long time ago someone pointed out pcm and dsd are mappable to each other.=
 the advantage of pcm is the ease of processing.

how do two parallel a-d convertors improve matters. two capsules in paralle=
l have noise that is random and signal that is not, and it gives an improve=
ment in noise. What do you get if you combine two non-synchronous bitstream=
s? and if they are synchronous, what noise advantage can you get?

I think this is again an old problem, thinking analog in the digital domain=


From: " [naturerecordists]" <=>
Sent: Friday, June 20, 2014 7:37 PM
Subject: [Nature Recordists] Re: Hello and a Sony PCM D100 question

> Hi David,=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0  Sony has two t=
echniques, the first is noise shaping via "Super bit mapping" - this is use=
d if the record bit depth is 16 bit - basically uses noise shaping/ditherin=
g to shove the noise above 20 Khz.


Ah, but "super bit mapping" sounds much better than "dither". I don't know,=

but my guess is that the double A to D conversions are probably out of sync=

to get a better dither and less low level "gravel". Just a guess, but if
they were doing an identical job, one would be redundant. Do they use two 2=
bit ADC's for the second 16 bit conversions?

>=C2=A0 Why is DSD better?

Theoretically, it doesn't produce harmonic artefacts in tune with the
sampling frequency. Effectively the sampling rate is random at audio
frequencies. I've never seen any proof that it is better than 24 bit and
higher sampling rates as used in studio setups. Wild sounds are essentially=

"low-fi" at source, so I have no hangups using 16 bits and economical
digital sampling rates.

>=C2=A0 3.5mm sockets I don't consider as a "toy"

I've lost recordings from the 3.5mm jack coming out and they are prone to
crackle if moved, especially with DC on them as with PIP. I use balanced
land lines up to 200 metres long and balanced and floating XLR's are the
only way over distance. They go into an SQN mixer and then to my toy Tascam=

via the 3.5 line in.

"Toy" sounds pejorative, but with care you can get high quality if not high=

reliability from toy recorders.

David Brinicombe

Posted by: 


"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.


Yahoo Groups Links

=C2=A0 =C2=A0

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