[78-L] CEDAR

Spats spats47 at ntlworld.com
Thu Oct 9 12:08:04 PDT 2008


Hi!

I do not have the black box version, I have a computer (PC) with 
nothing but the software version of CEDAR installed on it.

Unlike my normal computer (as in the Apple Mac upon which I'm typing 
right now), it IS in the same room as my gramophone, so what you say 
doesn't apply to my situation.

My current problem is that, just to get the hang of the thing, I'm 
practising by accessing a rather noisy track from a CD, trying to 
process it with CEDAR, through its three processes, but can hear very 
little difference between the before/after versions. Indeed, only one 
of the three processes seems to make any difference at all.

The CEDAR people kindly popped in once, so I know that it's wired up correctly.

Earl.

If you plan to use the CEDAR decrackler (the hardware "black box" 
version rather than the software I assume), you'll have to hook it up 
directly to the turntable preamp, or via a "lossless" digitized copy 
- Audio-CD or high-resolution (32bit/96kHz) WAV. An intermediate 
Minidisc transfer, while certainly better than a cassette, may still 
give problems because the crackle impulses as they come from the 
record are "softened" by the Minidisc compression (which is similar 
to MP3 if I'm not mistaken) and subsequent re-encoding to WAV or 
AIFF, and thus more difficult to separate from percussive musical 
sounds - you would need to crank up the CEDAR settings further to get 
a similar decrackling effect, and consequently get more artifact and 
distortion problems. A similar situation is found with other, 
software-based decracklers - they always work best with a straight, 
"flat-EQ" digitization with as few intermediate steps between 
turntable and decrackler as possible. A flat (microphone
  ) preamp will work better than an RIAA preamp followed by a 78rpm 
re-equalizer.

  From a practical point of view, working from a pre-compressed 
(Minidisc/MP3) or analogue (cassette/tape) transfer rather than 
directly from the original 78 or a 1:1 DAT/Audio-CD dub means about 
two to five times as much worktime you have to spend on each track to 
get a similar result (because more manual adjusting and editing is 
needed as the automatic correction algorithms won't work 
effectively), and often that result is still slightly lower in 
fidelity than from a direct transfer.

Any type of EQing should always *follow* rather than precede the 
decrackling/denoising process and is less critical regarding slight 
compression/signal-loss, so it would probably be fine to record the 
*output* of the CEDAR onto Minidisc, if you need that intermediary 
step because of your desktop being in a different room/house from 
your turntable, and do the remaining processing steps (EQ, fades, 
editing, etc.) software-based in the computer.

Chris Zwarg



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