[78-L] Fake stereo

[Michael Biel]

From: "Milan Milovanovic" <milanpmilovanovic4 at gmail.com>
> Michael, are there consequences regarding eq while doing it
> (digitally) on flat 78rpm monaural transfers? What really we
> can expect in that matter? Cancellation of some frequencies?
> Other irregularities?  Thank you,  Milan

What was being specifically discussed in the presentation was "undoing"
the pre-emphasis curve where the goal is a transparent unnoticeable
restoration back to the original.  Since the analog pre-emphasis had
filters would do some phase bending, that phase change would also have
to be undone, which does happen in the analog domain but digital
filtering doesn't -- unless it is purposefully built into the program,
which is expensive.  The phase-sensitive Audiophools notice the change
in the soundstage.  Since we are not "undoing" any eq on most 78s --
although with the research of Nick Bergh we are finding more about what
the Victor engineers were doing with those filter settings shown on the
victor ledgers (and are being ignored by the Victor Project discograpy)
-- I am not sure whether any of us can really tell the difference
between analog and digital tone controls.  Settings do not change things
so much as to affect cancellations of frequencies.  I think.  But I
still rather do these things analog.

Mike Biel  mbiel at mbiel.com   


----- Original Message ----- 
From: "Michael Biel" <mbiel at mbiel.com>
> Let me explain something about echo/reverb vs. tone controls and comb
> filtering. There is a slight amount of phase shifting whenever tone
> controls are used. ANY tone control. In electronic terms this phase
> shift is a slight delay measured in microseconds. (This includes
> inherent equalization like RIAA, and is why RIAA playback
> re-equalization must be done in the analog domain, NOT in the digital
> domain. We had a tutorial about this at ARSC a couple of years ago.
> You cannot feed a flat LP audio into your computer and expect any but
> the very expensive programs to put in the RIAA equalization.) It is
> also why the Vinylphools do not have variable tone controls in their
> systems. Changing the tone can affect the "soundstage" of 2 or 3-mic
> stereo like Mercury Living Presence, Decca/London blue-backs, or RCA
> Living Stereo which depends on phase relationships. Overdub or
> multitrack stereo are not affected as much, but these guys hate that
> stuff anyway.