45 rpm record distortion

[sirshambling]

I'm trying to clean up some old 45s from the 60s and having trouble with distortion which seems to come from 2 sources - the recording being made "hot" with the sound generally too loud, being made worse by the deterioration of the vinyl which is causing unwanted "tearing" of the music, particularly at loud sections.

Having used the de-clipper successfully I'm left with the need to restore the desired sound from the distortion.

I'm sure I'm not the first person to run into this one. Can somebody help me with some suggested filter(s) and settings which might help me?

TIA. John.

[Craig Maier]

Re: \"Distorted\" 45s

I have had some success with the de-esser in the dynamics processor. You might also want to try to use the CNF in spectral subtraction mode. First, sample a bit of the distortion (not the noise). Using the spectral subtraction mode, adjust the attenuation control to minimize the distortion.

[sirshambling]

Re: \"Distorted\" 45s

Thanks very much for the quick and helpful response Craig.

I'll give those two a try and report back in due course.

I'm grateful. John.

[kent]

Re: \"Distorted\" 45s

I work with 45's all the time and the distortion used to be one of my biggest problems until I started using a mono cartridge which came with a 1 mil stylus. As I mentioned in an earlier post, I don't know whether the improvement was because of the larger stylus tip or the mono cartridge or the combination of the two, but the resulting sound is much, much better. I use the Grado Prestige ME+ cartridge for all of my older 45's.

[Craig Maier]

Re: \"Distorted\" 45s

I do not know if there would be a difference here, but you can sum a stereo cartridge signal to mono with the file converter. I do not know if that is 100 percent equivelent to using a monophonic cartridge, although I suspect that it is. However, the 1 mil stylus could make a more significant difference in performance. Most LP/45 cartridges are 0.7 mils, so using a 1 mil stylus might yield the signal above the wear pattern on the record.

[BigAl]

Re: \"Distorted\" 45s

I'm with Craig here. I've found that recording in stereo, then converting to mono using the file conversions filter (using r-channel only) works well for 45s and mono-LPs.

[DougMac]

Something else to try

John,
One other trick you might try, which might be especially effective on "hot" 45's, is to record at fractional speed. Some of the distortion may be coming from mistracking.

DC5 has some nifty tools to help accomplish this. Record the single at 33 1/3. Apply reverse RIAA filtering if you can't record flat. Change speed using the default 33-45 setting. Then apply the RIAA equalization.

I've tried this on some 78's that would play fine until a loud spot. I recorded at 45 rpm with no eq. Before I changed speed, I did some runs through the impulse filter. I then changed speeds and did a little more impulse work. Then I applied the appropriate rollover. Passages that were distorted at 78 came out much better. I've also found recording at 24/96 allows me to be more aggresive with filtration.

Good luck,

Doug
PS - I tried to clean up the guitar distortion on some 60's Jimi Hendrix 45's with little success. [img]/ubbthreads/images/graemlins/confused.gif[/img] [img]/ubbthreads/images/graemlins/wink.gif[/img]

[Craig Maier]

Re: Something else to try

Doug Mac,

I love Jimi Hendrix, but "guitar distortion" would be an oxymoron in that context! Jimi Hendrix was the king of controlled distortion on the electric. Remember, he used to put the neck of the guitar on the tube amp, turn the gain all the way up so that it would go "rail to rail", and then manipulate the sustained oscillations. Great sound, but clearly (pun not intended) 100 percent THD!

[img]/ubbthreads/images/graemlins/cool.gif[/img]

[DougMac]

Precisely

[ QUOTE ]
Doug Mac,

I love Jimi Hendrix, but "guitar distortion" would Great sound, but clearly (pun not intended) 100 percent THD!

[img]/ubbthreads/images/graemlins/cool.gif[/img]

[/ QUOTE ]

That's why I used Jimi for my little joke.

BTW, the only time I saw him live was at the 2nd Annual Atlanta Pop Festival the evening of July 4/5. I worked on the film crew and my job that night was crab dolly grip for the camera that occupied the dolly platform immediately in front of the stage and five feet down. Even earplugs didn't help much. My understanding is he was very uneven as a performer, and that night wasn't one of his better nights. Still, it was a bit of rock history viewed from closer than front row center and just a few months later he was dead.

Doug

[Dan McDonald]

Re: Precisely

Well, you know what they say, Doug. If you can remember the 60s, then you probably weren't there.
[img]/ubbthreads/images/graemlins/laugh.gif[/img]
Dan

[Craig Maier]

Re: Precisely

Well, I don't hardly remember nothing from those days and I don't know if I did not remember it or not that way or that it may have been the other way around. Somebody, please decipher my correct or incorrect recollection of those events; please, either way, one way or the other advise me one way or do not do so. Either way is fine by me!

Thanks,

Craig

ps: Please do not shoot me - - - that was my feeble attempt at humour - - - i is an enginear, not a linguist, yet I am a child of the 60's, or so I am told. [img]/ubbthreads/images/graemlins/smile.gif[/img]

[sirshambling]

Re: \"Distorted\" 45s

The de-esser was helpful. Need to play around with the settings a bit though. Couldn't seem to get the CNF in spectral subtraction mode to work at all well. Must be doing something wrong!

I'll try again.

Thanks for all your help. John.

[sirshambling]

Re: \"Distorted\" 45s

Can you tell me what settings you use on the Converter please. Do you use the convert to mono "above" or "below" a certain threshold?

I'd like to try this as I can't change my cartrdige as Kent has done to a momo one as I've just shelled out a fortune on hi-grade stereo equipment!

TIA. John.

[sirshambling]

Re: Something else to try

Thanks for your help Dougmac.

I've changed to 24/96 recording which has helped a bit.

I'll certainly try the "speed" suggestions you've made. A sound engineer friend of mine has also said that he uses that one quite a lot where vinyl mistracks. I hadn't thought of using it for my 45s though as I hadn't spotted the speed convertor settings - I have now thanks to you!

I'm grateful. John.

[Malcolm]

Re: \"Distorted\" 45s

I need a little help here with Spectral Subtraction. I tried it once a long time ago as an experiment and it didn't seem too bad, but I have forgotten step by step how I did it!
I have come across one of my 1959 45rpm discs (fortunately only one), rarely played that had to be a bad pressing since it totally filled with heavy crackle and densely packed clicks, at a level almost surpassing the recording level.
Page 111 of the manual wasn't too clear to me, but here's what I did:
I took a "normal" CNF noiseprint of the full wave file, pulled down the box menu to Spectral Subtraction and the blue dots went away. I ran the filter. saved the result as the destination (I did not raise the level of the blue dot line). Played the file and it was awful. Very tinny; sounded as though the pressing was an aluminium platter.
I re-did the process adjusting the FFT overlap to smaller percentages, sample size 4096. I did a preview increasing the baseline blue dots after noiseprinting the wavefile, but the results were very hollow and tinny even prior to going to the SS mode. The SS resultant file was even worse.
This procedure doesn't seem familar to what I did before -- am I missing something, and if so could someone please step me through the process?
Thanks
m