Optimum settings for recording LPs with further editing (sample rate and bit depth)

[Dan McDonald]

Hi Craig -
Yes, it was relatively easy to deal with it by putting some impulse filters in a multifilter, and then follow that with the VPA. That way I could hear the final product while adjusting the impulse filters. When I was getting distortion, I clicke the VPA on bypass, and then opened up each impulse filter individually, so that I could hear what it was doing. In about half an hour, I had a pretty good multi-filter setup for a starting point (based on a 1970s jazz record - Roland Kirk). Then I tried it on a rock album (the famous Youngbloods) and adjusted it a little bit. I haven't had time to listen to it all yet, but the spot-checks sound very nice.

Dan

[Craig Maier]

Hi Dan,

Just curious what Impulse filter that you used in your multifilter line-up -

Craig

[Marc Hildebrant]

Dan,

My first question would be : Are the impulse setting different before/after the VPA ?

Second : Do you have an improvement with this method ?

Marc

[Dan McDonald]

I ended up with 1 EZclean (set with scratch at 35 and crackle at 35), then 3 EZ-impulse, set with scratch off, crackle and narrow crackle set with different values, ranging from 25 to about 50. That's a lot more aggressive than I'd be with 44.1, but I haven't found any distortion yet, and the recording sounds very clean. Both LPs were ones I had owned since the early 70s, so they were in good shape. Even in college I tried to keep them as clean as possible (not always possible with roommates).

This is probably not an ideal situation, but it's a good starting point; I feel lke I should be doing this with the expert filters, but that introduces more complexity I don't have time to investigate right now.

Marc - I'm not sure that it gives better results than doing it after the VPA. I just thought I'd see if it would/could work. I would have to run it again to see if what I come up with after the VPA would be any different. I may be able to do that next week.

I am convinced that the higher sampling rates allow for more aggressive filtering without introducing distortion. That's especially true for the narrow crackle filter.

[Marc Hildebrant]

Dan,

That's a whole lot of "crackling" going on there..... Is that the main problem you are finding with LP's ?

Marc

[Craig Maier]

Dan,

Maybe you could post your Multifilter lineup as a preset for other to try out on the presets shareing area of the forum - just lable it clearly so that folks know what it is designed to do.

Craig

[Dan McDonald]

Hey Craig -
Yes, the crackle was almost the only issue with the LPs. They are otherwise clean. I might try re-recording them after that run-through, since that cleaned out the grooves, and see if that lessens the problem.
As soon as I'm happy with it, I'll post the preset.

[Craig Maier]

Hi,

If anyone wants to try Dan's method but you do not own a flat preamplifier, one can try reversing the RIAA curve comming from a standard RIAA preamp first. To do that, go to the Virtual Phono Preamplifier and run the preset called:

RIAA Preamp Hardware playing Acoustical Records

This method is probably not as good as the use of a flat preamp, but the price is right.

Craig


ps - The Paragraphic EQ also has an RIAA Reversal Preset (not as accurate as the VPA). It is called:

Reverse RIAA Phono Equalization Curve

[Craig Maier]

Hi Again,

Real low-level stereo LP crackle (really more like surface noise) can be attenuated by the CNF. I only apply that step after applying the Impulse Noise filters first.

Craig

[Dan McDonald]

Yes, I did a CNF at the end of the chain. Will get to it again this week and experiment a little more.

[Craig Maier]

My recommendation regarding the CNF is to use it lightly. Rarely (in Normal CNF Mode) do I adjust the attenuator higher than 10. In Artifact Suppression Mode, I use it with the attenuator set for around 40-45.

Craig

[Dan McDonald]

I had it up at about 45 for this one (in artificat suppression mode), with artifacts set about 350.

[Craig Maier]

Hi,

For LPs, that sounds about right in artifact suppression mode. Attenutation values that high in non-Artifact Suppression mode are usually way too high, however.

Craig

[Dan McDonald]

I ended up with excellent results in a multifilter with the following settings: Recorded at 88.2kHz sampling rate,
graphic eq set at about -10dB, but flat (just to lower the levels), EZ-impulse with scratch at 9.1, crackle at 23.4 and narrow crackle at 39.4, solo/brass checked, then an impulse filter threshold 1, size 16, tracking 36, vinyl lp, solo/brass, and the vpa with mids and treble increased, but volume down 5.4 dB.

This produced an excellent sound, no distortion with a lot of sax, flute, various horns, piano, harmonica, etc. I posted it in the preset section in case anyone wanted to try it. The +/- dB would all depend on the level of the original, of course. Since I switched to my little recorder, it records a lot 'hotter' than a soundcard. So I'm getting true 88.2 sampling resolution, but I have to be very cautious about the levels. My soundcard had the opposite problem where everything was very low level.

I think I was being to aggressive with the first settings I tried because I was listening to it before the VPA and trying to get all the pops out. When you convert with the VPA, you can't hear the tiny clicks, so you can be less aggressive. Still kind of aggressive with the narrow crackle, but it doesn't seem to hurt anything and cleans it up enough that the CNF takes care of the remainder.

Dan

[Craig Maier]

Dan,

Thanks for sharing your experience with us using your method (de-clicking with a flat response on an LP transfer). Hopefully, it will be useful information to others here on the forum.

Dan's preset can be found at the following link:

http://www.diamondcut.com/vforum/sho...mpulse-CNF-VPA

Craig