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Gear / Technical Help => Recording Gear => Topic started by: JasonSobel on February 12, 2006, 02:16:58 PM

Title: pre-emphasis question, Sony R500 dat deck
Post by: JasonSobel on February 12, 2006, 02:16:58 PM

Hey folks, I'm transferring a couple of old DAT tapes (uncirculated sources for Phish.  this one happens to be a FOB AKG source for 11/25/95).
anyway, I'm going Sony PCM-R500 > Microtrack.
on the Sony screen, it says "emphasis", which I haven't encountered before.
from the R500 manual, it says

Quote

If "EMPHASIS" appears in the display
The deck is playing an audio signal recorded with emphasis (in the higher frequencies).  The deck, however, plays the signal while automatically deemphasizing it.

So, I think analog playback out of the R500 is as it should be, but I think the S/PDIF output is identical to what is actually on the DAT.  if that's the case, then I should remove the pre-emphasis on my computer before I seed the show.  but I'm not sure how to do that.  (if someone can give WaveLab specific details, that would be great.  but I could also use Cool Edit 2000 or I guess I could install Audacity, because that's free.  also, out of curiousity, what exactly is pre-emphasis, why would it be advantageous to use it, and why isn't it used anymore?

any help is greatly appreciated :)

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: Roving Sign on February 12, 2006, 02:23:54 PM

Is the R500 "removing" emaphais by decoding it?

Do subsequent copies off the R500 read as "emphapsis"

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: JasonSobel on February 12, 2006, 02:46:42 PM

well, this is my understanding.  although the S/PDIF signal has a bit marking whether pre-emphasis is on or off, the .WAV file format has no place for such information.  I'm not making DAT clones, I'm transferring the files to WAV via the M-Audio MicroTrack.

I think the R500 is "removing" emphasis for the analog outputs, but I think the S/PDIF output from the R500 still has emphasis.
Is there any way to verify this on my computer with the WAV file?  and assuming the WAV file still has emphasis, how to go about removing it?


oh, and although Brian moved it from "Ask the tapers" to "Recording gear", I think the question sort of falls somewhere between "recording gear" and "computer recording", which is why I put it in the more general "ask the tapers" section.  not that it really matters...

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: JasonSobel on February 12, 2006, 03:09:42 PM

ok, so the DAT finished transferring, and I did a quick test.  I played the original DAT back in the R500, and then went S/PDIF into my D8, and cloned about a minute onto a new DAT tape.  I then played the new DAT back in the R500, and the "emphasis" light was on.  So, now I have verified that the S/PDIF signal from the R500 still contains a signal with pre-emphasis.

The WAV files that I have transferred have pre-emphasis.  how do I de-emphasize these files on my computer?

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: drewloo on February 20, 2006, 11:27:16 AM

Looks like Waves' Q10 plug-in for ProTools will do it.  Maybe someone here who has it can help you out.

"Included presets cover pseudo-stereo, band-limiting, harmonic comb filter, pre/de-emphasis, crossover, notch, multimedia and other EQ application categories."

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: udovdh on February 20, 2006, 02:11:21 PM

I could do that for you.

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: JasonSobel on February 20, 2006, 04:10:52 PM

thanks guys, PM sent.  +T to you both :)

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: tim in jersey on February 20, 2006, 04:26:54 PM

Looks like you found a solution, but I figured I'd point you here: http://www.oade.com/cgi-bin/miva?Forum/technology/viewthread.mv+thread=1114&message=1114 in the event you want to read up a little more on emphasis...

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: JasonSobel on February 20, 2006, 04:31:38 PM

Quote from: tim in jersey on February 20, 2006, 04:26:54 PM

Looks like you found a solution, but I figured I'd point you here: http://www.oade.com/cgi-bin/miva?Forum/technology/viewthread.mv+thread=1114&message=1114 in the event you want to read up a little more on emphasis...

thanks.  actually, I've already searched all of the old teach archive threads at oade.com, and I had read through that whole thread.  and while I realize that it's possible to set the pre-emphasis bit to "on" when burning a CD so that your CD player will de-emphasize on playback, I figure most people don't know how to do that or wouldn't bother.   which is why I'd prefer to just de-emphasize the recordings before seeding them :)

it is kind of interesting.  while I've found a lot and read a lot about what pre-emphasis is, I haven't found too much info on why it was used on some early DAT decks and CD players.  that side of it is more for my own curiousity, though...

Title: Re: pre-emphasis question, Sony R500 dat deck
Post by: tim in jersey on February 20, 2006, 04:34:04 PM

Quote from: JasonSobel on February 20, 2006, 04:31:38 PM

it is kind of interesting.  while I've found a lot and read a lot about what pre-emphasis is, I haven't found too much info on why it was used on some early DAT decks and CD players.  that side of it is more for my own curiousity, though...

I'm quite curious as to the why myself.