Software Based RIAA Equalization For Audiophile Quality Vinyl Archival?

[NuMystic]

I'm about to begin archiving my collection of 3000+ records into 24 bit / 96kHz files for preservation, digital playback (on VERY serious pro soundsystems), and sample material.

I've come across one or two references to sidestepping the phono stage EQ and doing the RIAA equaliztion on the computer to achieve a more transparent recording.

This is a software package designed expressly for that purpose:

Pure Vinyl

And this is a second company that sells software as well as phono preamps without RIAA conversion for this purpose:

The New Way For Vinyl Recording

A few quotes I've found relating to the idea and methodology...

The RIAA playback equalization curve functions much like an integrator with a 75 microsecond time constant. This is also known as a pulse stretcher, and you will notice that your click waveforms have tails on them.

You might try plugging your turntable directly into the iMic to record a track, and then do your declicking right away. Then you can feed the declicked file to the Griffin software for RIAA equalization. This will avoid the phenomon of pulse-stretching of clicks by the RIAA playback curve.

Doing the RIAA equalization in the Griffin software will have the effect of amplifying the quantization noise and distortion increasingly below 500 Hz. But the human ear has decreasing sensitivity to low-level sound with decreasing frequency, so this may not be a problem. I do not own an iMic nor use the Griffin software, so you might try a transfer both ways, and see which you prefer. The RIAA curve can be done more accurately in the digital domain, in most cases, compared to the analog domain.

Right off the bat I'm very dubious about the above person's advice as the Griffin iMic and software is FAR from professional quality. (the iMic is a cheap A/D converter for macs that plugs into the mic input)

But then I found one other person talking about the same thing:

Software RIAA equalization can take a bit more effort (at this time) than a "conventional" phono pre setup (more work on the hook-up side), but there are many advantages to doing it this way. For instance, a balanced input mic pre and low output moving coil cart will provide zero audible hum (if the TT is wired correctly, that is). No capacitors in the signal chain (at least not the ones required in a phono preamp); just clean, straight-wire gain. Perfect channel phase and RIAA amplitude match (no analog component tolerances to deal with). I've noticed some information going around that suggests that using software RIAA EQ throws away resolution from your audio interface, but this isn't a factor in a real-world situation, if the EQ is done properly.

Problem is the two people above are the ONLY ones I've ever heard making mention of this and I've spent days trolling audiophile forums and haven't turned up any other references to this process.

So my question is, with all else being equal (Audiophile turntable, tonearm, stylus, proper isolation, interconnects, top notch A/D converter) would going this route truly provide the absolute best quality encodings?

There's no doubt that many audiophile phono stages are prized as much for their unique "coloring" of the sound as they are for their low noise floor. Since I am looking for the most transparent archiving possible taking one piece of hardware out of the signal chain makes sense to me (at least in theory).

Many thanks in advance for any light you can shed on this subject. I'm an absolute newcomer to the high end digital domain and while the theories put forth on the websites above are compelling, I don't have enough real world experience to separate the hype from the facts. (they are after all selling software/hardware)

This is going to involve literally hundreds of hours of effort and I would prefer to do it only once.

[DSD_Mastering]

I have done about a 1/3rd of my archiving of my albums. I've gone down this route also and the best results I've gotten have been through outboard converters and pre's.
I'm archiving everything to DSD with an SME 20/2, Lyra Titan cart., Asthetix or Manley Steelhead pre and my EMM Labs converters into my Pyramix rig. I know this is beyond the budget of most people, but like you said, I only want to do this ONCE!
Also, I clean my albums with a vacuum system and play them wet!

Regards,
Bruce

[networkresearch]

Play them wet? How? Why? Can this be done just for listening? Any harm to the stylus? I just bought a turntable and vacuum and love them! What I am looking for is a phono preamp that has xlr outs so I can plug directly into my PMC TB2+ and give that a listen.

Jonathan

[NuMystic]

Originally Posted by DSD_Mastering

I have done about a 1/3rd of my archiving of my albums. I've gone down this route also and the best results I've gotten have been through outboard converters and pre's.
I'm archiving everything to DSD with an SME 20/2, Lyra Titan cart., Asthetix or Manley Steelhead pre and my EMM Labs converters into my Pyramix rig. I know this is beyond the budget of most people, but like you said, I only want to do this ONCE!
Also, I clean my albums with a vacuum system and play them wet!

Regards,
Bruce

What's your address Bruce... I'm on my way over!

So just to be completely clear, are you saying you've done an A/B comparison between the Asthetix and/or Manley pre vs. software based RIAA correction? (or any other A/B comparison really so long as all else in the system is the same)

I have no doubt your recordings are stellar but it is this specific area of the signal chain I'm needing first hand experiences with.

[DSD_Mastering]

Originally Posted by NuMystic

What's your address Bruce... I'm on my way over!

So just to be completely clear, are you saying you've done an A/B comparison between the Asthetix and/or Manley pre vs. software based RIAA correction? (or any other A/B comparison really so long as all else in the system is the same)

I have no doubt your recordings are stellar but it is this specific area of the signal chain I'm needing first hand experiences with.

Yes, I've done A/B of many hardware pre's and software based RIAA curves. I even tried to do it on my own!
But seriously, it's almost like the CD/Vinyl realization. You won't be able to tell the difference on low-end budget equipment. It's also more noticeable on wide freq acoustical instruments like trio's and quartets.
Yes, you can play them wet. I use something like Discwasher. It cuts down on the surface noise greatly. No, don't do it for every play, just once or twice and don't forget to clean your stylus between every side!

Regards,
Bruce

[NuMystic]

Originally Posted by DSD_Mastering

Yes, I've done A/B of many hardware pre's and software based RIAA curves. I even tried to do it on my own!
But seriously, it's almost like the CD/Vinyl realization. You won't be able to tell the difference on low-end budget equipment. It's also more noticeable on wide freq acoustical instruments like trio's and quartets.
Yes, you can play them wet. I use something like Discwasher. It cuts down on the surface noise greatly. No, don't do it for every play, just once or twice and don't forget to clean your stylus between every side!

Regards,
Bruce

Thanks so much for your feedback Bruce.

You're the very first person that has been able to share first hand experience comparing the two methods. Though someone did just get back to me saying that DSP based RIAA correction still has a long way to go which entirely supports your impression of it.

One more thing I can chalk up to marketing hyperbole. (the second quote above was someone basically quoting the software developers marketing info so I was dubious to say the least)

Did you by any chance use Pure Vinyl or Diamond Cut's RIAA correction in your exploring that option?

As for wet playing... care to share a bit more on that. How much fluid for example? Any other considerations when doing it?

[DSD_Mastering]

Originally Posted by NuMystic

Did you by any chance use Pure Vinyl or Diamond Cut's RIAA correction in your exploring that option?

As for wet playing... care to share a bit more on that. How much fluid for example? Any other considerations when doing it?

Actually I used Pure Vinyl, Diamond Cut and Audacity. I even have a couple of Microsoft friends that do DSP based algorithms and they couldn't do much either. There is a hardware based pre that does RIAA curves via DSP software but I haven't tried it yet. HERE

As for wet playing, just spray the record so it's all wet. Don't have any standing puddles though. Make sure the record is as clean as you can get it though. I go through a ritual of spray, vacuum, anti-static gun and then another spray.

Regards,
Bruce

[NuMystic]

Thanks again Bruce. Someone with your exact experience is just what I was hoping for when I posted the question.

Now of course I need to research a decent phono stage within my budget and tack that on to my summer shopping list.