[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [ARSCLIST] playing 78s
joe@xxxxxxxxxxx wrote:
IIRC the PB worked best with a stereo input to better define noise and
make the choice of switching between groove sides. Better to sum the
channels post-PB.
The PackBurn works ONLY with a stereo input, at least for the switcher
circuit. There were three sections in it, and the first was the
switcher. It listened to the two groove walls and decided which one was
the quietest at any point in the record. If it did not have a stereo
source, how could it tell???????????? And how could it give one or the
other walls separately??? The original model gave an output of either
the left or the right. The "Centennial Model" numbered 1977 and issued
in 1977 added a feature that would give the sum of the two channels when
both walls were equally quiet.
The second section was the blanker which was a mono impulse noise
eliminator, and this is pretty much what most other noise-reduction
systems in use are. If all that was available was a mono source, this
still would work. The third section was the dynamic noise filter which
we discussed yesterday. This raised and lowered the top frequency of
the low-pass filter to allow more highs when the louder musical content
would mask the surface noise, but then reduced the top frequency when
the program content was quiet and would otherwise allow the surface
noise to be heard. I HATED this filter, but as I mentioned yesterday,
Dick Burns LOVED it.
Of course any of these three sections could be switched in or out of the
audio path.
Mike Biel mbiel@xxxxxxxxx
John Eberle wrote:
Playing 78s through an RIAA preamp basically rolls off the highs and
boosts the lows dramatically altering the frequency response from
what it should be . The RIAA pre-emphasis eq curve is applied during
the disc cutting stage of 45 and LP record mastering . 78 RPM
records were not cut with RIAA pre-emphasis ; but rather were cut
mostly flat with perhaps some low end roll of to control the size of
the bass groove excursions .
A simple and cheap way to playback 78 RPM records is to connect the
turntable or tone arm audio out to the HI-Z microphone inputs available
on many preamps . This will give the flat response desired for 78s
and a little low boost will bring the lows back in to proper
perspective . Also , most cartridges in current use for playing 78s
are actually stereo and of course 78s are mono . It is totally weird
to hear a 78 RPM disc being played with stereo clicks and pops . The
cartridge can be wired in the headshell to reproduce lateral mono
modulation only . This makes the record noise a lot less and less
need for the Packburn or any other analog or digital transient noise
reduction and better over all quality . If anyone would like an mp3
of one of my commercial 78s reproduced in this manner , just contact
me off list and I will email it to you .
John Eberle : Over 27 years disc cutting experience and over 35
years in Mastering !
AMERICANA CD MASTERING 313 EAST COLLEGE STREET SUITE 3A
DICKSON , TENNESSEE 37055
615-441-4660
**************Feeling the pinch at the grocery store? Make dinner
for $10 or less.
(http://food.aol.com/frugal-feasts?ncid=emlcntusfood00000001)