But there is something to be said about 1-bit conversion from analog. The dcs converters that were 
used at Polygram's Edison NJ studio for the Mercury transfers involved what Philips called 
"bitstream" conversion back then, which was a 1-bit system. Inside the dcs box, the 1-bit stream was 
converted to 24-bit/44.1kHz PCM, which was then fed to a dither-down converter designed by Weiss but 
sold under another name, something like Harmonia Mundia. That digital buss then fed 44.1/16 PCM to 
the two Sony 1630 master recorders plus two reference DAT recorders. Philips soon afterward adopted 
a similar system for their own transfer chain in Holland. They started using the Bitstream logo on 
their reissues because Philips owned the brand for the technology. I am not 100% sure of this, but I 
think DSD was an outgrowth of Philips' Bitstream technology. I'm not sure who aside from dcs was 
making 1-bit A-D converters circa 1990.

What Don Cox was touching on was something I've read and heard from several different engineers in 
different countries -- that even if you're already reducing the digital resolution before you get to 
a storage medium, it's good to grab the analog in maximum resolution possible and let the math work 
from known values rather than filling in blanks. I know this is gross oversimplification, but that's 
the best and English/political science major can do today!

-- Tom Fine

----- Original Message ----- 
From: "Gray, Mike" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, November 29, 2012 9:10 AM
Subject: Re: [ARSCLIST] Interesting history of DGG-Polydor-Polygram-Berliner Studios-SACD-etc

> DSD was originally intended as an archival preservation format - it never caught on with archives, 
> which now favor
> 24/96 as their PCM preservation standard. As an interesting side note, the late David Smith from 
> Sony once did a shoot-off between DSD and PCM at 192, and found that the PCM was just a little bit 
> better. Not to mention that PCM formats are much easier to process in a DAW environment.
> Mike