Chapter 2 – Copying the Original: 78 RPM Records

Last updated: 25 November 2008


First, some general copying guidelines:


1. CRT monitors are terrible noise sources. LCD monitors are much quieter. If you are using a CRT monitor it’s important to keep your turntable, reel-to-reel tape deck or audio cassette deck at least four feet from the monitor.


2. Operating your monitor (especially if it’s the CRT type) on a line-isolation transformer may help to reduce the noise. Also reversing the monitor’s mains cord plug and/or the turntable or tape deck plug may help. (I’ve seen a plug reversal make a 6 dB noise level difference so it pays to experiment.)


3. Power your computer and monitor on a different electrical circuit from the one powering your audio playback equipment. Have an electrician put in a new circuit if this is needed.


4. Copy the original source to a WAV file format: at least 16-bit stereo and 44,100 samples per second. This is the “Red Book” standard for CDs. You can copy at a higher resolution and a faster sample rate and then use your audio editing software to convert to the Red Book standard but it’s doubtful that any of your source material will benefit from the extra time and hard drive space needed to do this.



78 RPM Records


You will need a good quality turntable with speed control from 70 to 80RPM [1], a preamplifier with selectable equalizations [2], a computer with a good quality sound card [3], a program to copy the sound card output to your hard drive [4], and (VERY IMPORTANT) good quality cables to connect the preamp output to the sound card’s line-in connectors [5]. 78s are mono but I prefer to copy them in stereo because I have found it easier to do the “clean up” – that is, removing the clicks, crackle, pops and noise.


Most modern turntables include a stroboscope for setting the speed built into the outer edge of the turntable for setting 33-/1/3, 45 or 78 RPM (depending on which speeds the turntable has). However, if you need one please see reference [6] -- they are very inexpensive. 78 RPM was not really a standard, just a sort of average, as some labels were intentionally recorded either slow or fast for one reason or another. (Maybe the recording engineer’s breakfast didn’t agree with him that morning.) The following may help but, in practice, I’ve found it doesn’t make much difference. I have listened to the same “78" record at speeds from 75 to 82 RPM and frankly I can’t tell what speed was used for recording. Of course, I don’t have perfect pitch so some folks may be offended by a slightly off key performance.

 

Berliner, Zonaphone, early Victor                  71.29 RPM

Victor acoustic (through the mid ‘20s)          76.59

The supposed “standard”                                78.26

Acoustic, Columbia, Edison, Pathe,

   Emerson, Brunswick and Okeh                    80 RPM


As a starting point, set the equalization according to the record label (and year if you know when it was recorded and it’s in the table). With the sound card line-in volume control set to about 90% start your computer recording program (16-bit stereo, 44.1 kHz sample rate) and play the record through once without saving the recording file to set the volume level using the preamp’s volume control. The program will have a bar graph or other indicator to display the peak amplitude. Adjust the preamp volume control so the maximum peak is 2 or 3 dB below the maximum input. Then play the record through again and save the recording file to your hard drive. I like to use a simple, descriptive name when saving the file, such as, side1.wav for the front or “A” side and side2.wav for the back or “B” side. (Different sound card brands have different maximum input levels. If you can’t set the max peak as high as 2 or 3 dB below the max input, you will either have to live with what you can get or get a preamp with a higher max gain.)


The following chart provides the equalization curves for the (maybe) accurate reporduction of early LPs and all electrical 78s. Starting in 1955, all LPs use the standard RIAA curve, which is built into all new preamps. Acoustic 78s were made without any equalization.


“Turnover” is the frequency below which the record manufacturer diminished the bass when mastering the disc. So these frequencies need a corresponding boost during playback.


“Rolloff” is often defined as the amount of treble cut (diminishment) at 10 kHz needed during playback to compensate for the boost added during recording. However, it’s easier (in my opinion) to look at this as the corner frequency of a lowpass filter that produces the needed amount of cut at 10 kHz. Hence rolloff is also a frequency in this chart. A corner frequency of 1600 Hz provides about 16 dB of cut at 10 kHz, 2122 Hz provides 13.7 dB cut, 2700 Hz provides 12 dB cut, 5500 Hz provides 7 dB cut and 6360 Hz provides 5 dB of cut.


78 RPM equalizations were not standardized and were sometimes left to the preference (whim?) of the recording engineer so there may be considerable variation from one disc to another or one year to another even for the same brand name. You can make adjustments using another equalization curve: decrease the turnover frequency if the bass sounds too thin, or increase the rolloff frequency if the treble is too strong.


The numbers in parentheses are the closest setable frequencies in the TDL® models 407 and 408 preamps.



           Equalization Chart for Pre-1955 LP Records

 

 

Turnover

Rolloff

Angel

500 Hz

2700 Hz

Audio Fidelity

500 Hz

1600 Hz

Bach Guild (501 - 529)

500 Hz

1600 Hz

Bartok 301-304, 309,

 

 

     906-920

629 Hz (500)

1600 Hz

Boston

500 Hz*

1600 Hz

Caedmon 1001-1022

629 Hz (500)

1600 Hz

Capitol

400 Hz

2700 Hz

Capitol-Cetra

400 Hz

2700 Hz

Cetra-Soria

500 Hz*

1600 Hz

     or

400 Hz

2700 Hz

Colosseum

400 Hz

2700 Hz

     or

500 Hz*

1600 Hz

Columbia

500 Hz*

1600 Hz

Concert Hall

400 Hz

2700 Hz

     or

500 Hz*

1600 Hz

     or (until 1954)

500 Hz**

5500 Hz (-8.5 dB)

Decca

400 Hz

2700 Hz

Decca (until 11/1955)

500 Hz*

1600 Hz

Decca FFRR (1951)

300 Hz (200 or 400)

2122 Hz (RIAA)

Decca FFRR (1953)

450 Hz (500)

2700 Hz

Ducretet-Thomson

450 Hz (500)

2700 Hz

EMS

375 Hz (400)

2700 Hz

Epic (until 1954)

500 Hz*

1600 Hz

Esoteric

400 Hz

2700 Hz

Folkways

500 Hz*

1600 Hz

Haydn Society

500 Hz*

1600 Hz

HMV

500 Hz*

1600 Hz

London (up to LL-846)

450 Hz (500)

2700 Hz

London International

450 Hz (500)

2700 Hz

Lyrichord

500 Hz*

1600 Hz

     or

400 Hz

1600 Hz

Mercury (until 10/1954)

400 Hz

2700 Hz

MGM

500 Hz

2700 Hz

Oceanic

500 Hz*

1600 Hz

Oiseau-Lyre (until 1954)

500 Hz*

5500 Hz (-8.5 dB)

Overtone

500 Hz

1600 Hz

Polymusic

500 Hz

1600 Hz

RCA Victor (until 8/1952)

500 Hz

2700 Hz

Remington

500 Hz

1600 Hz

Urania (most)

500 Hz*

1600 Hz

Urania (some)

400 Hz

2700 Hz

Vanguard (411-22, 6000-18)

500 Hz*

1600 Hz

Vox (until 1954)

500 Hz*

1600 Hz

Westminster (before 1956)

500 Hz

1600 Hz

     or

400 Hz

2700 Hz

 

 

 

RIAA (standard after 1955)

500 Hz

2122 Hz




             Equalization Chart for 78 rpm Records


 

Turnover

Rolloff

Acoustics

Flat

Flat

Blumlein

250 Hz (200)

Flat

Brunswick

500 Hz

Flat

BSI 78

353 Hz (400)

3180 Hz (2700)

Capitol (1942)

400 Hz

2700 Hz

Columbia (1925)

200 Hz

5500 Hz

Columbia (1938)

300 Hz (400)

1600 Hz

Columbia (England)

250 Hz (200)

Flat

Decca (early 1930s)

150 Hz

5800 Hz (5500)

Decca (1934)

400 Hz

2700 Hz

Decca FFRR (1949)

250 Hz (200)

6360 Hz

Early 78s (mid 1930s)

500 Hz

Flat

EMI (1931)

250 Hz (200)

Flat

HMV (1931)

250 Hz (200)

Flat

London FFRR (1949)

250 Hz (200)

6360 Hz

Mercury

400 Hz

2700 Hz

MGM

500 Hz

2700 Hz

Musicraft #

200 Hz

Flat

Parlophone

500 Hz

Flat

US (mid 1930s)

400 Hz

Flat

Victor (1925)

200 to 500 Hz

5500 Hz

Victor (1938-47)

500 Hz

5500 Hz

Victor (1947-52)

500 Hz

2700 Hz



* modified from NAB: less bass below 150 Hz, requiring about 3dB boost with bass tone control or multi-band equalization..


** "Very close" to 500 Hz


# Based on listening tests, that is, trying various equalizations and choosing the one with the best sound.


This table is based on information from the following web sites which cite still more references:

http://sound.westhost.com/project91.htm

http://www.rfwilmut.clara.net/repro78/repro.html

http://www.swazoo.com


Also, please take a look at the extensive equalization table in the Model 4010 (The Restoration Preamp TM) User Guide. Click here to download a copy of the User4010.zip file.


I just found this web site (November 2008). The page is titled “How to EQ Old Records” and it contains much interesting and useful info:

http://www.geocities.com/midimagic@sbcglobal.net/mixphono.htm


1. We like the direct drive Stanton model STR8-80 (http://www.stantondj.com). We have several interchangeable head shells with pickup cartridges using wide groove styli with diameters between 2.5 and 3 mils. These include a Stanton 520SK cartridge with a 2.7 mil stylus and a Shure M78S with a 2.5 mil stylus: (http://www.shure.com). For more information on selecting a turntable, please see our Audio Help page: Where can I buy audio equipment in different price ranges?

I've been criticized by a couple of readers for recommending a turntable with a straight pickup arm for 78 RPM restoration. I'll explain my reason and give you an alternative -- then you can take your choice. A "bent" or offset pickup arm does have a lower tracking error than a straight arm, but at a price. The offset arm tends to pull towards the center of the disc. 78's are often worn or warped so the inward pull tends to make the pickup arm jump out of the groove, especially when using a low tracking force. So we have two opposing needs: track with minimum distortion and keep the pickup stylus in the groove. I suggested the straight arm because it maximizes your chance of playing worn and warped records. If your 78's are all in good to excellent condition, then go with a turntable with an offset arm. You can find additional information on this subject in our Audio Help section: “How do I listen to 78 RPM records?” and “How do I copy a 78 RPM record to CD?”


There are 35 useful articles on tracking and several other topics that have been reprinted in a 160-page paperback book titled: "The LP is Back." It is available from the Audio Amateur Press, Peterborough, NH, (http://www.audioXpress.com). I have a copy and I recommend it to those who

are serious about playing and restoring music from 78's and LP's.


2. We especially developed our models 407 and 408 stereo preamps to restore 78's. To download a data sheets or User Guide click here to go to our Preamp Products page.


3. Some restoration advisors suggest using a preamp with a flat frequency response and then correcting the file with a software equalizer. THIS IS A BAD IDEA. The phase response is totally wrong because of the phase shift at each band edge in the equalizer. An equalizer is dangerous to use because the phase distortion (time delay distortion) can sound terrible -- I can demonstrate this. I plan to write an article on this subject, when I get around to it!


4. Sound cards are not created equal. For a fairly comprehensive comparison go to (http://www.pcavtech.com/soundcards/compare/index.htm). The site operator, Mr. Arnold Krueger, tests the cards and posts his findings. We like the Turtle Beach Santa Cruz card (it has a score of 7 with 5 being the best) and the Waveterminal 192X (it’s not rated but it does up to 24-bit sampling at up to 192 kHz). Also check out the cards at (http://www.tracertek.com).


5. There are many programs which you can use to copy the sound card output to your hard drive. Among other, we use the following: CoolEdit Pro (in May 2003 Adobe bought the Syntrillim software and Cool Edit Pro became Adobe Audition), Dart XP Pro (DARTech, Inc., 7400 Metro Blvd #350, Edina, MN 55439. 800-799-1692. (http://www.dartpro.com) and Sony Sound Forge 8, (http://www.sony.com/mediasoftware).


6. Buy the best quality cables you can afford! Cheap cables have insufficient shielding to keep noise and power line hum out of your audio. If you have gotten this far, you have already spent quite a few dollars getting set up for restoration so get good cables. Primarily, we use Dayton Audio Cables from Parts Express (http://www.partsexpress.com). Radio Shack Goldline Cables are pretty good too. (http://www.radioshack.com)


7. A stroboscope for 78 and 80 RPM is available from Hawthorns Antique Audio, (http://www.thoseoldrecords.com) for $4.00 postpaid (as of Oct ‘05). A 12-speed model covering 16, 33, 45 and 68.5 to 90 RPM costs $9.60 postpaid (as of Oct '05) from Esoteric Sound Products, (http://www.esotericsound.com).



Click here to download this chapter in Adobe Acrobat (pdf) format.




TDL® Technology, Inc.

Las Cruces, New Mexico USA