from this thread
http://www.oade.com/cgi-bin/miva?Forum/technology/showmsg.mv+message=6166"The line stage mod simply changes the equalization to provide a
warmer sound with cetain mics."
The line stage rebuild actually improves detail dramatically by
improving the detail in the analog signal presented to the A/D chip.
This is not EQ or any other form of coloration, it is simply an
audible improvement in signal clarity. The SBM-1's AD converter
does sound warm and natural, like most Sony studio gear. The bit
mapping done by the Sony 45 bit DSP chips does not color the
signal, it reduces low level distortion with SBM dither and this
allows 16 bit data to resolve nearly as much detail as 20 bit data.
Sorry, I am so slammed with work, I do not have time to go in to
more detail, Studio Geek's post along with this one , I hope, will
clear things up...peace...>Doug
this is studio_geek's post referenced by Doug:
http://www.oade.com/cgi-bin/miva?Forum/technology/showmsg.mv+message=6142 Most DAT decks only record 16 bits, but a lot of 16 bit AD
converters are 24 bit capable. The SBM-1 uses a 24 bit AD chip to
provide data for the 24 bit DSP chip. This DSP chip applies SBM to
the 24 bit data, then outputs 16 bit data that sounds like 20 to 24
bit recordings. Some tapers call Doug's SBM-1 upgrade a 24 bit mod,
but the SBM can only output 16 bit data, maybe it's near 24 bit
sound is why. I asked Doug about making the SBM-1 output 24 bit
data and he said he did not do that, I doubt any 24 bit output
SBM-1's exist. The line stage rebuild disable the stock mic preamps,
due to power restrictions, but you can run the modified SBM-1's
internal mic preamps, if you also have the mic preamp mod done.