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struts
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My first needle drop - lessons learnt

Okay, so I finally did it, I transcribed an LP to digital (aka a 'needle drop'). It was a slightly frustrating, although ultimately rewarding experience which I thought I would share with you here. I trawled around a little on this forum beforehand to see if I could find any useful tips but gave up pretty quickly. The advice on offer seemed to mostly fall into two camps: "buy XYZ USB turntable/phono stage" or "don't bother/buy the CD" and I had no intention of doing either. Here is a short description of what I did do and a couple of lessons learnt along the way.

The Aim
My aim was to produce as high a quality digital transcription as possible, given my existing equipment, of one of my father's cherished LPs - Beethoven's Violin Concerto played by Alfredo Campoli with the RPO under John Pritchard, (HMV Concert Classic, SXLP 20043). I was prepared to invest a fair amount of time in achieving a good result as I saw this as a learning exercise. I only mention this to make the point that my approach and lessons may not be relevant to anyone whose goal is quantity (i.e. digitizing a given size of LP collection to mp3 in the shortest possible time) rather than quality.

Equipment
Part of the impetus for embarking on this project was the sudden realization that I had all the necessary equipment on-hand and there were simply no excuses for not doing it. No 'necessary investments' either , oh well. In fact the biggest problem I had was that the audio equipment and the PC equipment were in different rooms! Whether to take Mohammed to the mountain or vice versa? For convenience I decided to move the record deck and preamp into my study which probably was the wrong call, see later.

The specific equipment I used was:

  • VPI HW-16.5 record cleaning machine, MoFi 'Super Deep Cleaner' and VPI Record Cleaning Fluid
  • Nordic Concept Artist/Breuer 8c/Dynavector XV-1s (deck/arm/cartridge)
  • Boulder 1012 (phono/pre)
  • Dell XPS tower PC (2006 vintage) running Windows 7
  • Lynx L22 sound card, Windows Driver 2.0 Build 017 Release Candidate 3e
  • Rudistor RPX-33 and Sennheiser HD800 for monitoring
  • Audacity 1.2.6 and later 1.3.9 (beta) for recording and editing (FREE!)

Probably the only point I would like to make here is that the only equipment I deem absolutely necessary to make a good quality digital transcription of an LP is:

  • A record cleaner
  • A record deck and phono stage
  • A PC/Mac with sound card

There is absolutely no need to get a USB-equipped record player or phono stage - your existing record player and phono stage will do the job just fine! Also, the advantage of using your existing equipment (both analog and digital) is that the resulting transfer should almost by definition be of the sound quality you are used to hearing. Almost all PCs have a built-in sound card and the Line Out of your phono stage (or Record Out of your preamp) can be connected to the Line In of the sound card (NOT the microphone input) with a simple RCA-to-3.5mm jack adapter cable.

IMHO, buying something new for this project (e.g. a USB-equipped phono stage) just introduces a big new sound-quality variable and risks disappointment. However if you insist on 'investing' I would suggest that you are likely to get better bang-for-the-buck SQ-wise spending money on a decent sound card (internal or external) than a USB-equipped phono stage. Let the flames begin!

Procedure
I hooked up the Record Out of the Boulder to the Analog In of the L22 (luckily both run balanced so no special cables needed). The first challenge was to figure out how to configure the Lynx card to record from Analog Ins 1+2 while simultaneously monitoring on Analog Outs 1+2 (which drive the Rudi). That took a surprising amount of futzing, especially since the UI of the Lynx Mixer did not correspond to the instructions in the manual which appeared to be referring to an earlier software version. Finally I found the magic combination of buttons to enable 'hardware pass-through' so I didn't have to use Audacity's 'software pass-through' which consumes precious CPU resources.

Next I set both the Lynx card and Audacity to work at 24-bit 88.2 kHz and tried to set the recording level. This is where I encountered my first big problem. The level was very low - despite the fact that the 'Input Level' slider in Audacity was at maximum. What gives? The Boulder was undoubtely outputting a line level signal which is what the Lynx was expecting, so why so quiet? Checked in the Windows volume mixer, same there - set to maximum - yet when I played the LP the average level was down around -25dB/-30dB and none of the peaks exceeded -12dB which meant that the files really had to be cranked up on playback. Finally I realized what the problem was (long after I was finished, meaning I ended up doing everything twice). The Lynx has two different 'Trim' settings for the Analog Inputs and Outputs (set in the 'Adapter' pane of the Lynx Mixer): +4dBu ('professional balanced') and -10dBV ('consumer balanced and unbalanced'). I had never really noticed these before but they were set to +4dBu, presumably by default. Switching to -10dBV did the trick* and brought the maximum level to the point where the recording only clipped in about 3 places. Two of those were on clicks that I removed anyway and the third was a very marginal clip that wasn't really audible. Nevertheless, if I had infinite time I would have recorded everything a third time taking the level down by 3dB-or-so but it was 1 am by this time and bed was beckoning! Oh well, next time.

* Incidentally, the 'Trim' setting has an equivalent effect on the Analog Out meaning I now need to dial in a fair bit less volume on the Rudi to get the equivalent volume level in the cans.

I saved the Audacity 'project' and listened to the resulting recording. Not bad, pretty damn good in fact! There was some minor vinyl roar and crackle at the start of each side, and of course some master tape hiss from the 1962 recording, but the audio was beautifully clear and clean right across the frequency band and with subjectively excellent micro- and macro-dynamics. In fact, the resolution was so good that I could clearly hear a very low level of mains hum I had never noticed before - from the original recording!!

Next job was to remove the clicks. I had run the record through the VPI twice before starting, following Stephen's recommended 'two-fluid regime' (see his blog - sorry I couldn't find the link, the 'Search' function doesn't seem to cover the blogs - weird!) and the result was very little surface noise indeed - some very minor crackles in a couple of places and only about four 'proper' i.e. scratch-type clicks in total. Kudos to the old man for taking good care of his vinyl - this record is older than I am! Anyway, Audacity has a Click Removal tool for this very purpose, however just like the old 'Unsharp Mask' in Photoshop it takes some practice to get the very best results. After much experimentation I found the default settings of 90 (threshold) and 20 (width) to be well chosen, eventually finding that I only needed to increase the width for the few really large clicks and decrease the threshold for some really small ones. Generally this tool rendered the clicks completely inaudible (nice job Craig DeForest!), however in a few cases there were audible artifacts (at or below the level of the programme, so pretty unobtrusive) that I was unable to banish, seemingly regardless how much I futzed with the parameters. If I start doing this more I may try a more advanced noise removal tool like Golden Wave or Sound Soap, but I suspect there is more mileage to be had from 'Click Removal', if I can only figure out how to extract it.

The result was a pretty clean file, clearly identifiable as an analog recording (I made no attempt to remove the master-tape hiss) and even as an LP transcription - but the latter only really in a few places. I did notice that there was a very slightly higher level of vinyl roar than I am used to, but I initially dismissed this as a subjective effect of monitoring through headphones (I almost always listen to vinyl through the speakers on the bigrig). However when I was done I did some checking and realized that the noise floor was indeed noticeably higher with the record deck on the desk in my study than on its usual rack in the living room. I will not claim to have eliminated all the variables here but as far as I have been able to ascertain the difference is down to the support. Compared to my Grand Prix Audio Monaco four-shelf stand (with Apex footers) the noise floor was about 3-6dB higher when I moved the turntable to my IKEA study desk - despite the fact it was standing on its dedicated Base Technology constrained layer isolation plinth. I was quite astonished at the magnitude of the difference - quite an endorsement of the Grand Prix Audio rack!

After trimming the lead-in and lead-out grooves (but not too much - they establish an important aural 'context'), adding a short fade in and fade out, and splitting side 2 into two tracks (using Audicity's neat 'Label' feature) I tried to export the resulting project to FLAC. This is where I encountered my second problem: the export just gave a useless error message, something like "Exporting to FLAC failed". Great, thanks! I looked in the help and searched for the error message on the Audacity Wiki. Nothing. Damn! After much frustration and poking around I chanced upon the solution in the release notes of the still-in-beta Audacity 1.3.9 (up to that point I had been using the 'latest stable version' 1.2.6). Bingo! There it was in the release notes: "Export to FLAC - now working in Version 1.3.3". Jeez! After upgrading Audacity and opening the project in 1.3.9 the export worked fine (once I'd figured out how to set the parameters correctly - I ended up with a 24/44.1 file first time I tried it).

Eventually I ended up with three 24/88.2 FLAC files with the correct metadata (Audacity fires up a metadata editor on Export - again, pretty handy) however for some reason they wouldn't play in foobar, giving some unhelpful error message about not being able to set an endpoint. By this stage I was beginning to feel the same way! In order to see if foobar was the problem I resampled the files to 16/44.1 using dBpoweramp Music Converter. The conversion worked fine and the resulting files played both in foobar and on the Sonos indicating that the problem might be related to the high sample rate. I initially suspected a bug in the hi-rez FLAC export routine of the still-in-beta Audacity but this turned out not to be the case as the problem disappeared when I upgraded the Lynx device driver from Build 017 RC3 to RC3e. Turns out foobar was just having a problem opening a 24/88.2 stream to the soundcard, well why the heck didn't it just say so!

Conclusions
All-in-all I am very happy with the results I obtained here. I feel I have achieved what I set out to and learnt a great deal in the process - although I wouldn't say I have any more scars on my mighty audiophile derri

jazzfan
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Re: My first needle drop - lessons learnt

Struts,

Great write up - a very informative and fun filled read. Hopefully by revealing your somewhat painful learning curve others will be able to avoid suffering many of the same headaches.

Out in cyberspace there seems to be a growing movement of people doing both high resolution (24/88.2 or 24/96) and CD resolution (16/44.1) "needle drops" and uploading the audio files to various file sharing services, such as Rapidfile. The interesting thing is that many of these needle drops are being made from the vinyl versions of recent CD releases, even those of fully digital recordings. The reason being that many people feel that the masters used for vinyl releases DO NOT suffer, or suffer much less, from the dreaded affects of the "Loudness Wars", in other words the vinyl has better dynamic range. But that's a discussion better left for another thread.

Thanks again for very entertaining and informative post.

struts
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Re: My first needle drop - lessons learnt

My pleasure jazzfan, glad you enjoyed. Happy holidays!

mrlowry
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Re: My first needle drop - lessons learnt

Struts-

That's a very interesting write up. Especially the part about the recording having a higher noise floor and the theory that it was because the turntable wasn't on a proper stand.

Wouldn't you have to have three passes to properly record an album? One to set levels, one for the recording process, and one for any noise reduction that was necessary.

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Re: My first needle drop - lessons learnt


Quote:
Struts-

That's a very interesting write up. Especially the part about the recording having a higher noise floor and the theory that it was because the turntable wasn't on a proper stand.

Wouldn't you have to have three passes to properly record an album? One to set levels, one for the recording process, and one for any noise reduction that was necessary.

with 24 bit recording there is no reason whatsoever to set levels above say -10(at peak).. you could have peaks at -22 and still surpass the range of any redbook cd.. so that being said, in my DAW, i play the loudest track, and set levels according to that. I would never "ride fader" or pencil in automation curves... the dynamic range is already on the record as the conductor intended it, so as long as I set my levels right(and by that I mean set them ONCE so that the loudest track does not go into clipping), the dynamic range will be preserved..... for the noise reduction... .with vinyl the noise is pretty consistent, so what I do is have my denoise algorithm sample a "fingerprint" of a selected passage and apply it across the whole recording..of course clips, ticks, etc, spikes...have to be manually penciled out, but as I said, the noise pattern with a lot of vinyl is spread across the whole record.. denoising and editing can be overdone very easily, so I try to leave it be if I can get away with it.

maybe with tape you would require multiple passes, but not digital.!

mrlowry
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Re: My first needle drop - lessons learnt

ncdrawl-

I think you have misinterpreted what I was saying because you've pointed out the same steps.

1. Setting a proper level
2. Recording
3. Noise reduction

That's three passes through the music.

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Re: My first needle drop - lessons learnt

Yes, my mistake. I got the impression that you were implying "passes" to be a bad thing, IE each pass causing a degradation .. (of course with digital, it doesn't matter how many times you go through...whether 1 or 1,000, youd still get bit perfect results) I am an analogue tape head, so here, "pass" means the act of actually capturing the data, committing it to tape.. at any rate, yes, I guess it would take 3 times going through the music(though I would never go through the whole thing just to set levels..I would use one track for that and roll with it)

struts
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Re: My first needle drop - lessons learnt


Quote:
ncdrawl-

I think you have misinterpreted what I was saying because you've pointed out the same steps.

1. Setting a proper level
2. Recording
3. Noise reduction

That's three passes through the music.

Sam,

Yes, I guess in theory you would need three full passes although in practice I used ncdrawl's approach of just setting the level based on an arbitrarily chosen subjectively loud passage. Unfortunately the one I chose didn't quite represent the highest peak.

I found a function in Audacity, 'Find Clipping' which shows that my transcription clips in two places (I'd missed one earlier), however examining the waveforms these are very marginal clips where it looks like the peak would have only gone a fraction of a dB over. I have replayed both again and again and try as I might I can't hear them.

However the point remains that for a 'perfect' result I would have to record the whole thing again a few dB down, effectively ending up at your three passes. Mea culpa.

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Re: My first needle drop - lessons learnt


Quote:
I had run the record through the VPI twice before starting, following Stephen's recommended 'two-fluid regime' (see his blog - sorry I couldn't find the link, the 'Search' function doesn't seem to cover the blogs - weird!) ...

Great account, Struts. Just wanted to address this point: for historical reasons, the blogs and forums run on a different server using a different content management system to the news and archives. The website's Search engine only looks for keywords on the latter server, unfortunately. One day, we shall consolidate the different systems, I hope.

BTW, A/D converters tend to produce higher levels of distortion as they approacch 0dBFS, so it is best to under-record a little, not peaking above -3dBFS. Afer you have done all the noise reduction and clip removal, you can then normalize, though I recommend doing so to -0.1dBFS rather than 0dBFS, to leave just a little breathing room for when you downconvert to Red Book (if that's your final goal).

John Atkinson
Editor, Stereophile

struts
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Re: My first needle drop - lessons learnt

Thanks John.

When I started playing with the spectrum plot I noticed that there is a whole bunch of content between about 42-44 kHz (but nothing at all between 21-42 kHz). I am pretty sure this didn't come from the record so I presume it is some kind of artifact from ADC.

1. Can anybody explain?
2. I assume since it isn't program it would be wise to filter it out, right?
3. Given that if I do this the program only extends to 21 kHz is there any benefit to be had ripping vinyl at 88.2 kHz rather than 44.1 kHz?

Thanks in advance for any clues for the clueless.

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Re: My first needle drop - lessons learnt


Quote:

When I started playing with the spectrum plot I noticed that there is a whole bunch of content between about 42-44 kHz (but nothing at all between 21-42 kHz). I am pretty sure this didn't come from the record so I presume it is some kind of artifact from ADC.

The most likely cause is that it is the tip-mass/groove-wall compliance resonance of your phono cartridge.


Quote:
I assume since it isn't program it would be wise to filter it out, right?

If you can do so without affecting the baseband. But if you are going to convert to Red Book, it will be filtered by definition.


Quote:
. Given that if I do this the program only extends to 21 kHz is there any benefit to be had ripping vinyl at 88.2 kHz rather than 44.1 kHz?

You will get better coding of clicks, which can have significant HF content, meaning they can be eliminated more cleanly. You are also captruing the tip-mass resonance without it aliasing down into the audioband, again making it easier to eliminate later.

John Atkinson
Editor, Stereophile

Editor
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Re: My first needle drop - lessons learnt


Quote:

Quote:
Given that if I do this the program only extends to 21 kHz is there any benefit to be had ripping vinyl at 88.2 kHz rather than 44.1 kHz?

You will get better coding of clicks, which can have significant HF content, meaning they can be eliminated more cleanly. You are also [capturing] the tip-mass resonance without it aliasing down into the audioband, again making it easier to eliminate later.

Just to expand on this point: because of their transient energy, LP clicks and scratches will all give rise to ringing from the A/D converter's anti-aliasing filter at the Nyquist frequency. This ringing will persist even if the offending noise is itself removed in post-processing. With a sample rate of 88.2kHz, this ringing will occur at 44.1kHz, so if you capture the audio at 88.2kHz and do all the processing at this sample rate, when you downsample to 44.1kHz, you will eliminate the spuriae.

Similarly, if you use any aggressive filtering, such as a deep, narrow notch at 60Hz or 120Hz to eliminate hum, these filters will also ring on transients. Best to do do these operations at a higher sample rate.

You should also do all the signal processing with 24-bit or 32-bit data, which will ensure that any mathematical artefacts of the processing will be eliminated when you decimate the data to to 16 bits. Downsampling and decimation should therefore always be the last operations you perform on your needle drops.

So, the work flow for a needle drop should be:

1) Capture the audio data at 88.2kHz with 24-bit word length. (I recommend 88.2kHz rather than 96kHz, because not all sample-rate converters perform well with 96-44.1kHz conversions.) Keep the maximum level no higher than -3dBFS.

2) Perform all the click removal and other processing of the data with the maximum bit depth supported by your program, most probably 32 bits.

3) Normalize the data to -0.1dBFS peak (not RMS)

4) Make a copy of the master file for archival purposes.

5) Downsample the data to 44.1kHz, using your program's SRC at its highest quality level.

6) Decimate the word length to 16 bts, making sure you have the dither and noise-shaping options set optimally.

7) Enjoy the music.

John Atkinson
Editor, Stereophile

struts
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Re: My first needle drop - lessons learnt

Very helpful, thanks John!

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More Needle Drop Notes

Note: on request by struts, this text is copied from another thread to this one which is more relevant.

I just read the excellent posting by struts about figuring out needle drops. It's been a few months now since I started doing this myself and I just got to a point where I start to be quite satisfied with the results. I thought I might share a few things with you guys.

The System:

Thorens TD145 MKII + Shure V15 Type V + Pickering XSV3000
ProJect Phono Preamp
Primare I30 Integrated Amplifier
EMU 0202 Audio Interface
Imac 24" + lots of drive space

Audacity freeware software for audio recording and editing
ClickRepair + DeNoise to make things quiet

The Action:

The first difficulty has been figuring out that the EMU 0202 has no input attenuators, you can only increase the input gain from its fixed base input level. This is inconvenient because the ProJect preamp (a really nice piece of gear, despite its low price) has a fixed (40dB) gain too.

Reducing the gain via software on the "Audio Midi Setup" panel won't work either because it will only reduce the gain of the digital subsection of the audio interface, the input amplifiers will saturate anyway. Dumb.

My vintage (perfect conditions) Pickering XSV3000 won't do with this setup: its output is just about loud enough to saturate the audio interface inputs in the loudest transients. I Would have to use some -3dB RCA attenuators out of the preamp to use this cartridge.

Fortunately my other vintage cartridge (the stellar Shure V15 Type V) is some 3dB less loud than the pickering and using it I have yet to find an album that overdrives the audio interface. I also slightly prefer the sound of the Shure over that of the Pickering

zeb
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Re: More Needle Drop Notes

Thanks for the thread - very interesting, specially that I am thinking to attempt this for the first time this weekend.

I've got an Macbook Pro and use an Apogee Duet as a sound source. In the Duet disc, they show you how to digitise LPs using the Output of the phono stage or Tape out into the Duet, and using Garageband (which comes for free with Macs) as the recording software.

Would Garageband be good enough or would I be much better off with something like Audacity, which is also available in Mac version? Any info on the pros and cons of each would be great.

Thanks

alrmad
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Re: My first needle drop - lessons learnt

Thanks for some great accounts of archiving vinyl, a theme mainstream mags seem to have slightly overlooked in my humble opinion.
When I set out to digitize my vinyl-collection (around 200 lps), I first looked at sound-cards, lap-tops and the like. Having read Michael Fremer preferred the Alesis Masterlink solution, I began to look at dedicated digital recorders instead. In my settings, not having to set up a computer, even a lap-top near my stereo-equipment is an obvious advantage, and you can always import files into your favourite wave-editor afterwards.

I ended up buying a Korg DSD-recorder to do the job. Just like major record-labels, if you archive your stuff in DSD, any PCM-resolution will be available subsequently. I found the recordings astonishingly indistiguishable to the vinyl rig. My route is:

Rega P9 w/Lyra Argo i
Holfi Battriaa
Korg MR-recorder (w. balanced inputs)

I can perform basic native DSD-editing using Korg's Audiogate-software (divide songs, normalize, dither, fade and transcribe to PCM), and the resulting files can be burned directly from AudioGate as a DSD-disc which can be played back by the Sony XA SCD-5400ES player, Kalman Rubinson has been raving about recently (Stereophile Class A+).

The only real down-side for me is I can' get rid of surface-noise in native DSD, but this has never been much of an issue for me anyway.

I would love to hear other readers' experiences with digital recorders for this purpose.

fricc
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Re: My first needle drop - lessons learnt

Audacity is free too and is way more flexible than GarageBand for LP recording.

The thing is that it is hard to just do a straight recording from an LP, you always need to tweak stuff (clicks, pops, etc.) Audacity will give you all the tools you'll ever need for that. Try it out, see if you like it...

- Fabio

struts
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Re: More Needle Drop Notes

Hey Fabio,

I've been taking a look at ClickRepair and DeNoise. You stated in your post that you decided to keep everything at 24/96 when you realized what wide bandwidth your LPs had, however as far as I can tell (the documentation appears to be non-existent) both tools only work on 16/44 AIF or WAV files.

Please could you elaborate a little on the workflow you used between Audacity and ClickRepair/DeNoise and how you maintained the 24/96 resolution? I would also be interested in any non-default parameters you found to work particularly well.

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