Digitizing LPs -- Some Ideas

D Vautier
updated 1-12-2013


At First

I have collected LP records for a long time.  I started recording my vinyl immediately but my recording methods changed as the technology improved.  At first I used reel-to-reel recording at 7 IPS (inches per second) then as machines got better I went to 3 1/2 IPS and then even to 1 7/8 IPS.  Later I switched to eight-track, which was not too good but was car friendly before cassettes were.  I liked eight-track even though you could only fast forward or change to one of four tracks.  At first tape recorders didn't work well in cars but they did get better.  Cassette tape was initially for kids and only voice quality but when it got good enough I started doing everything on cassettes.  The cassettes lasted maybe a year then had to be replaced.

Digital

Finally digital media came to town.  What a vast improvement!  I originally did everything in wav format because players were not yet enough advanced to use compressed formats so space on a CD was limited to about one album and the documentation was what you could write on the CD itself.  Recording a vinyl record and album documentation using mp3 tag data represented a huge step forward because the documentation went with the songs.  My preference now is vinyl to wav to mp3 at a 48000 sample rate for wav and 320 BPS for mp3.  

I prefer digitizing from LPs instead of prerecorded CDs.  The quality sounds better if the record is good.  This issue can be debated forever because it is a personal thing.

I can produce good digitized copy from a good LP, and some of the pop filters do a fair job cleaning up small scratches during silent passages.  I never have had as much luck with crackle filters.  Crackle can come from playing a record on a "gorilla" record player that track at over 6 grams and permanently deform the small wiggles in a grove.  This type of record destruction is impossible to see and also impossible to electronically repair without removing some sound.  Vinyl is basically rubber and the record stylus deforms the groves slightly every time it is played.  If the deformation is gentle the wiggles immediately return to their original shape.  If the stylus weight is excessive the groves are distorted and never recover.


A few things I have learned

An important component in LP digitization is the phono cartridge and to a lesser degree the turntable itself.  These two items are often a weak link in the chain from LP to good sound digitizing.  You want to convert those little physical analogue wiggles in a record grove into digital impulses as best as possible.  Your emphasis and money should not necessarily go toward computer sound cards but may be better spent on transducer devices, those mechanical devices that get the wiggles converted to electronic signals.  A good sound card will get you there.  A great sound card could get you there a little better but maybe just a little better.

Sound quality depends on a number of things, but to my way of thinking a good stylus is still the most important ingredient in this entire process.  A stylus should track at no more that 2 grams and should be able to pick up 20 to 22,000 Hz. (cycles per second) with perhaps a 2 or 3 db drop at either end.  The pre-amps and software of today can adjust the other stuff.


 

Turntables also have to be better when digitizing because digital picks up a lot more.  This can happen with turntable rumble which may not be apparent on a regular analog playing system.  If you have any rumble, your digital mp3's will be sure to pick it up for you, and it can sound bad as I have found out.  I use a direct drive Sony PS-454 or my newer (older) Technics SL-D212, both which have practically no rumble.

Some turntables don't use heavy platters.  A good heavy aluminum platter is one of the ways that can indicate turntable quality and certainly eliminate wow-and-flutter along with rumble.  I think it's also good to get a turntable that uses a standard removable headpiece so you can fit just about any cartridge to it.

Turntables are equipped with tracking calibration and antiskating.  One of the first turntables I got in Germany in 1965, a PE LB-34, had no antiskating.  Other turntables of that time (e.g. Lab-80 and Dual 1009) were equipped with it.  Today just about all turntables have antiskating.  I think the best TTs were made in the 1980s.

I have another page that talks about some of my earlier experiences with LP records.  

 

Another consideration is your pre-amp.  I needed a pre-amp with 90+ s/n ratio because my old 60 db one was not good enough. The additional cost was not that much and my results were excellent.  Also you may want to shorten as much as possible your low voltage cables between the turntable cartridge and the pre-amp and solder the connections because this low voltage cable is quite sensitive to noise.  Use a very small well shielded wire for this connection  because the signal is weak and it gets weaker as the line gets longer.  So keep it short.  Ground the turntable wire shield to the pre-amp.  Although good turntables frames are bakelite plastic or wood they do provide a ground shield for the low voltage wires.  It is also quite necessary to get a pre-amp with an external power supply, and keep that power supply as far as possible away from the low voltage cartridge pickup wires and pre-amp electronics.

If you have older equipment like a receiver from the 1970s with pre-amp input and tons of sentimental attachments, my only suggestion is to upgrade.  90+ db S/N was absolutely unheard of in those bygone days and I think there is just too much noise in those older sets.  Even the good ones like Kenwood and Harmon Kardon don't measure up.  The newer solid-state pre-amps are great and not too expensive and have all the RIAA equalization.  

This RIAA thing is a standard that adjusted for some physical limitations in record cutting.  Low frequency grove size had to be reduced in volume otherwise it would wind up too close to the next grove.  High frequency had to be incresased or the wiggles became too small to be physically detected.  The RIAA standard does other things as well as adjust for these things conditions.  You can find lots of articles discussing RIAA.  For old Sinatra, Crosby, Jo Stafford and big band stuff originally recorded on 78 and later put on LP, you have to do your own equilization because it all sounds dull.  You have to kick up the high mid range.  

By investing in a good cartridge and turntable and a quality pre-amp, you will get great sound going into your computer and that's the part that really counts.


Some comments on digital recording

It is impossible to determine the condition of a record without listening to it.  Any unopened record could be fatally damaged.  It just takes one play be bad equipment to damage the little wiggles creating an unacceptable background noise level.  In manufacturing the production may be at the end of a stamper life and have poor quality.  

I capture an album side at a time then put markers between songs and save the files in a folder.  I use the stereo wav format at a 48,000 KHz sampling rate.  I dust records immediately before play.  I do all editing on wav format because it has the most granularity.  I use good quality earphones in editing because it is the best way to hear high frequency and background noise.  Earphones also help exclude external noise and does not disturb the rest of the family.  I remove all extra lead-in and leave about one second at the beginning.  I reduce this lead-in usually to zero sound.  Some songs fade in so I don't have to leave any lead-in.  I trim the end to just at where the background noise starts to be audible.  I have noticed that the automatic software that tries to separate songs doesn't do anything like what I want it to do.

Once the material is captured as separate files big pops that are visible can be manually removed.  Amplification can be done to bring songs up to a uniform volume.  Some albums are not on LPs so I capture from CD or cassette.  Songs ripped from pre-recorded CDs to wav always need editing.  The lead-ins are often way too small.  The trailers sometimes have 10 seconds or more of silence.  The volumes can be way too low or high.  Cassettes have to be brightened up bringing the high end up enough to create more head room.           

When I'm satisfied with the edit I go go to mp3 at VBR 320 kbps.  I like the LAME converter.  Using an mp3 tag editor I then add tag information immediately with album in hand.  Otherwise the documentation gets lost and the record gets put away and I have to get the kids.  I have lots of songs laying around where I forgot to do this and I don't know what they are.  I sometime scan jackets to get extra information into the comments.

Pops and Crackles

I have had good success with some pop filters but they can be slow.  I usually keep my pop time around 1 millisecond and pop threshold at 20% but this all depends on how much Hi freq may be lost and how bad the pops are.  The crackle is another matter and can occur in just one channel, sometimes the inside one.  I have never been successful at removing crackle without compromising sound so I choose to keep the sound and put up with the crackle or drop the somg. 

Cassettes

The only real difference recording from cassettes is that it goes directly into the computer and no preamp is needed.  This kind of recording definitely requires equalization depending on the type of cassette player used.  I usually boost my 2k, 5k, 10k ranges about 5 dbs.  Cassettes can have different attenuations.  Newer ones have stronger signals which reduces background and bleedthrough.  But in general the cassettes sound dull and never have the sparkle that vinyl has.

78s

When I converted a bunch of old 78 rpm records I did use some scratch filters and developed some information on this subject.  All 78s require equalization and filtering and a lot of love.