Playback equalization for 78 rpm shellacs and early 33⅓ LPs

From Audacity Wiki
Jump to: navigation, search


Ultraphon.JPG

The audio on almost every phonograph record is not the same as that originally performed. For technical reasons the signal's frequencies need to be modified when cutting the disc. Playback equalization (EQ or de-emphasis) is necessary to restore the signal's original frequencies. Only thus can music lovers enjoy the original sound of the music performed long ago from their rare discs.


Contents


Usage

The most relevant EQ curves are presented as Table 1:

  • You can download some of them from the EQ Curves Library section and import them into Audacity using Effect > Equalization
  • You can generate any curve yourself with the 78 rpm EQ Curve Generator plugin
  • You can set the sliders of any digital or analog graphic equalizer manually
  • You can determine appropriate settings for any adjustable analog pre-amplifier.

Which EQ curve will be needed for a specific record label is answered:

Equalization (EQ) Curves explained

When phonograph records are made, the sound being recorded is deliberately distorted by reducing the volume of the low frequencies and increasing the volume of the high frequencies. This process, known as 'pre-emphasis', allows the low frequencies to be accommodated in the limitations of the record groove and reduces the effect of high frequency surface noise. If pre-emphasis was not carried out, the bass notes in the music would create a groove in the record that oscillated so wildly that the stylus could jump out of it on playback, and the treble notes would be drowned out by the surface noise of the stylus in the groove.

On playback, the pre-emphasis must be reversed in order to restore the original sound. This is known as 'de-emphasis' or equalization (EQ).

Modern vinyl records use a method of pre-emphasis and de-emphasis adopted by the Recording Industry Association of America (RIAA) in the 1950's, and the EQ curve used is known as the RIAA curve. However, before the RIAA curve was adopted, each record label used its own EQ curve for recording and, for these records (78rpm and early vinyl), the correct EQ curve must be used for playback.

Each EQ curve is a combination of two filter characteristics; a bass boost curve, defined by a 'Bass Turnover' (or 3dB) frequency, and a treble cut curve, defined by a '10 kHz Gain Rolloff' parameter, i.e. a defined level of treble cut at 10 kHz.

As an example, Figure 1 below shows the characteristic of the bass boost curve defined by a 500Hz Bass Turnover, and Figure 2 shows the characteristic of the treble cut curve defined by a 10 kHz Gain Rolloff of -13.7dB. These two curves, when combined, give the characteristic shown in Figure 3.


Bass Boost curve

Figure 1. Bass Boost curve: 3dB at 500 Hz


Treble Cut curve

Figure 2. Treble Cut curve: -13.7 dB at 10 kHz


Combined Bass Boost and Treble Cut curve

Figure 3. Combined Bass Boost and Treble Cut curve


The EQ curve may also include a Low Frequency Shelving filter, (although it is absent from the definition of most 78 rpm EQ curves). This addition reduces the effect of the bass boost at very low frequencies (typically 50 or 100 Hz) in order to attenuate low-frequency noise such as turntable rumble. Figure 4 shows the effect of a 50 Hz LF shelving filter being added to the curve in Figure 3. This is in fact the RIAA standard EQ curve.


Combined Bass Boost, Treble Cut and 50 Hz LF Shelving curve

Figure 4. Combined Bass Boost, Treble Cut and 50 Hz LF Shelving curve


Acoustically recorded (pre-electric) 78 rpm records have a completely different characteristic because they were cut with a different type of cutter (For more details see: Acoustic recordings). In some early EQ curves of electrically recorded shellacs, while there is a bass boost curve, there is no treble cut necessary – i.e. the 10 kHz gain rolloff is zero.

Note that in the combined EQ curve, the gains at the Bass Turnover frequency and at 10 kHz may be different from those specified by the parameters. This is not an error, but is due to fact that the gains of the bass boost and treble cut curves are simply added together.

Because 78 rpm EQ curves were non-standard and, in many cases, accurate records were not kept to show what EQ curves were used when recording 78s, there is a degree of uncertainty about what is the correct playback EQ for many record labels. The tables below have been obtained from websites which, in their turn, have compiled data from a number of sources and should prove reasonably accurate. However, the ear of the listener is the final arbiter - if it doesn't sound right, it isn't right!

According to NAB standards, the nominal speed of a 78 rpm record is precisely 78.26 rpm +/- 0.3% (for North America and other countries with an utility frequency of 60 Hz). According to British Standards Institution it is 77.92 rpm +/- 0.5% (for Britain, Europe and other countries with a mains frequency of 50 Hz).

EQ Curves

Pre-equalization of most records – especially of shellacs – was always determined by the cutter head used and often by internal regulations of the record company. Both left quite some room for the recording engineer to make changes to improve the sound. Also if Graumann uses 250 Hz in playback of an EMI disc and Copeland votes for 300 Hz this is not a contradiction. Both mean the same EQ curve but have different opinions on what sounds best. This should encourage you to try both versions and take the one which sounds right to your ears.

Please do not worry about fractions of a dB! Still in the 1960s an accuracy of a curve of +/- 2 dB was considered to be standard. In the 1950s +/- 3 dB were a very fine result and nobody will ever know if recording engineers in the 1940s or 1930s applied their curves correctly (or if they applied them at all!) So the spread in pre-equalization during recording will outnumber any bias in playback equalization by far.


Table of EQ Curves

The most relevant EQ curves are presented in table 1. All curves are described from the point of view of a playback or de-emphasis curve, where bass / low frequencies must be amplified / boosted and where treble / high frequencies must be attenuated / cut in order to achieve the original sound that had been recorded. The corresponding pre-emphasis curve used for cutting the master disk is inverse.

When comparing with lists provided by the manufacturers of equalizer preamps it should be considered that those may be misleading, as they might not quote the correct parameters of the curve but rather the next-best possible settings of these devices. For example the Conductart OWL 1 Sound Restoration Module – a renowned preamp of the 1980s – offered settings of flat/ 250/ 375/ 500/ 750/ 1000/ RIAA for turnover and flat/ 5/ 8.5/ 12/ 14/ 16/ RIAA for rolloff. Thus for the widely used standard “AES 400N-12” settings of 375 Hz and -12 dB were listed; for the “Bartok 629C-16” curve it was 750 Hz and -16 dB and for “LONDON LP 500C-10.5” it was 500 Hz and -8.5 dB. These recommendations were quoted or copied by other authors and three “new characteristics” had come to existence.


Table 1 gives the three parameters to characterize any EQ curve: the turnover frequency f1 for bass shelf, f2 for bass boost and f3 for treble cut (or alternatively the three corresponding time constants τ1, τ2 and τ3). These are the necessary conditions to compute and plot any EQ curve, determine the correct settings of a digital equalizer or to solder an electronic filter circuit.

The gain at two typical frequencies will give you a rough impression of what the curve does to the audio from the record. The frequencies are:

  • 50 Hz, where usually the bass shelf becomes effective
  • 10 kHz, because the treble curve is often indicated by rolloff at 10,000 Hz

The very descriptive “code” is a good tool to avoid misunderstanding when EQ curves come under various alias names (what they do too often).

  • The first 3-digit number indicates the turnover frequency of bass boost (f2)
  • The letter in the middle is
N … (“None”) if no bass shelving is applied, or
R … 20 dB (named R after RCA or RIAA)
B … 18 dB
A … 16 dB
C … 14 dB (named C after Columbia LP curve)
X … 12 dB
  • The last number shows the reduction or rolloff of treble at 10 kHz and is always preceded by a minus sign. Please mind that this is only a code and that the exact value – after normalization to 0 dB at 1000 Hz – might be different.

This code can be used to find the correct settings of most equalizer preamps.

(Example: “RIAA 500R-13.7” means for the RIAA curve that bass must be boosted below 500 Hz, but no more than + 20 dB and that treble must be cut at 10,000 Hz to – 13.7 dB)

The geographic region and the time period are added to allow a qualified guess for the required EQ should a record label not be listed. In general, American recording curves were more deliberate in cutting bass and boosting treble. The British and Europeans tended to apply only the necessary minimum of bass attenuation and often no treble boost at all, that means they had a “flat” treble curve. Early pre-emphasis curves were simply built and rather soft. In the late years (after 1945) curves became highly sophisticated, with the third turnover frequency f1 added to manage the bass shelving and also with gain ranging from -20 dB to + 20dB.


Table 1: Playback Equalization Curves

Region Timeperiod Curve Name, alias names Time constants Turnover frequencies Bass shelf Bass boost Treble cut Code
τ1 [μs] τ2 [μs] τ3 [μs] f1 [Hz] f2 [Hz] f3 [Hz] [dB] @ 50Hz
[dB]
@10kHz
[dB]
Normal Groove, 78 rpm
Eur., Brit. 1926 - 1946 "European 78", Old Europ.,250,EMI 78 636 250 [5] + 14,4 0 (flat) 250N-0
Eur., Brit. 1927 - 1946 "Blumlein 300" 531 300 [5] + 16 0 (flat) 300N-0
Brit., Amer. 1926 - 1950 "500-FLAT", Blumlein500, Europ.500 318 500 + 19 0 (flat) 500N-0
America 1926 - 1951 "American 78" 636 250 5900* + 14 - 6 250N-6
America 1926 - 1951 "American 78" 636 250 4400* + 14 - 8 250N-8
Amer.(CBS) 1938 - 1948 "Columbia 78" 530 100 300 1592 + 16,7 - 15,0 300N-16
Amer.(RCA) 1941 - 1947 "Old RCA" [4] 199 36,7 800 4340 + 22,2 -9,9 800N-8
Eur., Brit. 1944 - 1956 "DECCA 78", FFRR 78, London ffrr 78 531 25 300 [5] 6366 + 15,4 - 5,7 300N-5.5
Germany 1952 - 1955 "CCIR 78", Recomm. No.134 (1953) [1] 450 50 354 3183 + 17,0 - 10,5 350N-10.5
Eur., Brit. 1955 - end "IEC N78" = "B.S.1928" for N78 only 3180 450 50 50 354 3183 + 16 + 14,0 - 10,5 350A-10.5
Microgroove, 33⅓ and 45 rpm
America 1942 - 1949 NAB (broadcast transcriptions, 1942) 318 100 500 1592 + 20,5 - 15,6 500N-16
America 6/1948 - 1956 "Columbia LP", Col. M33, "LP" [3] 1590 318 100 100 500 1592 + 14,5 + 13,6 - 15,5 500C-16
America 4/1949 - 1958 "NAB", NARTB (standard 1949) [3] 3180 318 100 50 500 1592 + 20 + 17,5 - 15,6 500"B"-16
America 1/1951 - 1958 "AES" (standard 1951) 398 63,7 400 2500 + 18,1 - 12,3 400N-12.3
Amer.(RCA) 1947 - 8/1952 "RCA 45" (45 rpm) [6] 200 75 796 2122 + 22,6 - 13.7 800N-13.7
Amer.(RCA) 1947 - 8/1952 "RCA Old Orthophonic" (33⅓ LPs) [6] 318 75 500 2122 + 19,7 - 13.7 500N-13.7
Amer.(RCA) 8/1952 - pres. "RCA New Orthophonic" 3180 318 75 50,05 500,5 2122 + 19,5 + 16,9 - 13,7 500R-13.7
Amer. (all) ca.1956 - pres. = "RIAA" (US-standard since 1955)
Europe ca.1962 - pres. = IEC No.98 (1955) = B.S.1928 (1955)
Amer., Brit. 1949 - 1956 "LONDON LP" [2] 1590 318 50 100 500 3183 + 13,8 + 12,5 - 10,9 500C-10.5
Germany 1955 - 1962(?) TELDEC (as proposed 1957 for DIN) 3180 318 50 50 500 3183 + 19,3 + 16,5 - 10,9 500R-11


Table 1 is mostly based on Tab. 2a of: Heinz O. Graumann, Schallplatten-Schneidkennlinien und ihre Entzerrung, in: FUNKSCHAU 1958 / Heft 15, pp 359 ff
* computed frequencies to get 6 or 8 dB @ 10 kHz
[1] CCIR used by Deutsche Grammophon modified with 50 Hz bass shelving => IEC N78 [Brice]
[2] Used by British Decca and for London releases in US and UK, mostly M33
[3] Gary A. Galo, The Columbia LP Equalization Curve, ARSC conference March 2008; Gary A. Galo, Disc Recording Equalization Demystified, in ARSC Journal Fall 1996
[4] Old RCA is one of the original RCA curves for shellacs. It continued to be used for 33⅓ LPs by RCA-Victor, Brunswick, Concert Hall, Coral, Decca (Amer.) and Westminster. The turnover f3 and the time constants are computed values for an equalizer set at 800N-8. (This EQ was added in January 2017 in response to a Wiki user's request.)
[5] 250 Hz or 300 Hz seem to be a question of personal listening preference, as explained in Individual fine tuning
[6] Robert C. Moyer, Evolution of a Recording Curve; in: Audio Engineering, vol.37, no.7, July 1953; pp 19-22, 53-54. Rolloff is frequently listed as between 10 and 12 dB, but this “flattening off” to ca 10 dB at 10 kHz was an intentional high cut which must not be compensated for in playback. Thus a setting of 13.7 dB is correct!

78 rpm EQ Curve Generator

EQ Curves for Audacity can be generated from these Frequency and Rolloff values using the experimental Nyquist plug-in "78 RPM EQ Curve Generator". This plug-in is obtainable from the top of this Forum topic and requires Audacity 1.3.13 or later. Please give feedback on this plug-in, or ask for help if you need it, by replying to that Forum topic.

  1. Extract 78EQCurveGen.ny from the zip file downloaded from the above Forum topic.
  2. Place 78EQCurveGen.ny in the "Plug-Ins" folder inside the Audacity installation folder, then launch or restart Audacity. For more help installing the .ny file to the correct location, click here.
  3. Click Generate > 78 RPM EQ Curve. You can find help inside the plug-in by choosing one of the Help options in "Select Function or Help".
  4. Choose the curve you want from one of the lists.
  5. Enter the values for your chosen curve for
    • "Bass Turnover Frequency (Hz)"
    • "10 kHz Gain Rolloff (dB)"
    • "LF Shelving Frequency (Hz)" (if a value is given)

    in the equivalent boxes in the plug-in dialog.

  6. Click "OK" in the plug-in to save the .xml file to your chosen location.
  7. Select some audio and choose Effect > Equalization.
  8. Choose "Save/Manage Curves...".
  9. Choose "Import...", navigate to the location where you saved the .xml file from 78EQCurveGen.ny, then "Open".
  10. Click "OK".


EQ Curves Library

Here you can find some useful EQ curves for download to Audacity for use in Effect > Equalization. How to get an EQ curve from this Wiki and add it to your Audacity’s Equalization effect is explained here.

  • EQ toolbox for 78 rpm shellacs contains the following nine EQ curves which can be downloaded individually as well.

    • 500-FLAT 500N-0: used by British Columbia, EMI, His Master’s Voice, MGM and Parlophone between 1931 and 1953. Later releases have modified treble.

    • ‎American 78 – 250N-6/250N-8: Common setting for many American shellacs. This curve here is a compromise between both varieties with -7 dB rolloff.

    • BBC 2dB/octave: used by smaller British labels (Aco, Broadcast, Linguaphone, Vocalion, …) from 1926 to 1933, which had their recordings mastered by BBC with the Marconi system.

    • Blumlein300 - 300N-0: A British traditional for Gramophone Company, Decca, Columbia and EMI (1930s – 1944).

    • ‎Columbia 78 – 300N-16 is the right one for American CBS-Columbia shellacs (1938 - 1948).

    • Decca 78 – 300N-5.5: For Decca and London shellacs featuring the ffrr (full frequency range recording) system. Here in the version of Copeland/The British Library Sound Archive.

    • European 78 - 250N-0 is a common setting for European shellacs (1926 – ca. 1944), especially for Columbia and His Master’s Voice produced by EMI (UK), Cetra and Cetra-Soria.

    • Telefunken 400N-0: used by European Ultraphon, Supraphon and Turicaphon from 1929. Also used by Telefunken – after the takeover of Ultraphon – until mid 1950s.

    • Western Electric: Very early Columbia and Victor recordings (1926) used a bass turnover frequency of 250 or 300 Hz but their treble is described as “flat”. The perceived treble amplification was possibly only the result of resonant peaks of the early Western Electric condenser microphones used in recording. The above download is an experimental replay EQ curve for this microphone / pre-emphasis combination. Additional background information is given in this PDF.

  • EQ toolbox for pre-RIAA 33⅓ LPs contains the following six EQ curves which can be downloaded individually as well.

    • ‎AES – 400N-12.3: Intended by AES (Audio Engineering Society) as a replay standard for many American shellacs of the 1930s and 1940s. Also used by many record producers as a recording curve for N78 and M33 between 1951 and 1958. Also to replay Capitol and Capitol-Cetra recordings with “Capitol curve” 400N-12.7 (1951 – 1955).

    • Columbia LP – 500C-16: For Columbia and many other labels, mostly 33⅓ LPs (M33).

    • London LP – 500C-10.5: Used for British Decca and for London / Decca releases in the US featuring the ffrr (full frequency range recording) system. Mostly 33⅓ LPs (1949 – 1956). Here is the most likely of some slightly different versions which have been published.

    • NAB – 500B-16: A widely adopted standard of NAB / NARTB (National Association of Radio and Television Broadcasters) requiring ca. 6 dB more bass boost than Columbia LP.

    • RCA 45 – 800N-13.7: RCA’s curve for their 45 rpm discs (1949 – August 1952). Possibly identical with Technichord’s “Technichord curve” 800N-12 already used since 1938 for their 78s. (Updated March 2017)

    • RCA New Orthophonic – 500R-13.7, identical with RIAA: not in this library because it is already one of the standard curves of Audacity’s Equalization tool.

    • RCA Old Orthophonic – 500N-13.7: RCA’s curve for 33⅓ LPs (1950 – August 1952) and for LPs mastered by RCA for other labels. Possibly identical with “MGM curve” 500N-12 used by MGM. (Updated March 2017)

All these curves are suited for Audacity 2.1.2.

Individual fine tuning

In some cases it will be not enough to apply the correct EQ to get the desired result. According to the condition of the record and to personal listening preferences you might consider one of the following methods:

  • The 250-or-300-Hz dilemma: To use “European250” or “Blumlein300” EQ seems to be not a question of right or wrong but of personal listening preferences. In general, Continental European authors prefer 250 Hz (derived from the original Western Electric recommendation) for Decca (Brit. and Europ.), Brunswick, Cetra, Columbia (Brit.), EMI-HMV and Parlophone. Englishman Copeland favors 300 Hz (derived from the recording characteristic of the Blumlein cutter) for British EMI, His Master’s Voice and Columbia and also for Odeon. Copeland puts it like this: “[…] but when I’m not sure I use 300 Hz.” [Copeland, Manual, p 129]. Being derived from the previous 250-or-300-Hz curve the same applies to “DECCA78” which was used from 1944 for shellacs with the ffrr system. So you should also feel free to decide the 250-or-300-Hz question according to your own listening preference: 300 Hz will give an extra amplification of bass in play back (ca 1.5 dB at 50 Hz).
  • To remove low frequency noise Robinson (MidiMagic) recommends a low cut filter at 100 Hz with just 6 dB/octave. (Especially for many acoustic recordings which have only noise below 150 Hz or for the “long-playing” shellacs of RCA Victor of 1931/32). This filter will do exactly the same as the “C”-type bass shelf of Columbia LP curve.
  • Vadlyd uses a variable low cut filter for American Victor, early British Decca, EMI, His Master’s Voice and Columbia at frequencies between 40 and 70 Hz. This is very similar to the recommendation of Phonomuseum.org. In Audacity you can experiment with different settings for “Frequency” and “Rolloff” in Effect > High Pass Filter (a different word for Low Cut Filter) and listen to the result with “Preview”.
  • All bass shelf settings on analog equalizers (R-B-A-C-X) can also be used to remove low frequency noise (especially from acoustics and early shellacs). This is why the extra positions X and A were provided [MidiMagic]
  • A known trick of recording engineers was to increase bass t/o frequency on very long recordings. Thus bass attenuation was increased and bass amplitude and necessary groove width were reduced. So the given duration of the audio could be squeezed into the given space on the disc. If a disc is filled with grooves as can be a higher bass turnover frequency can be necessary to restore the original sound. Example: Colosseum [ES]
  • To improve the weak bass on some 45s (especially on EPs – Extended Play) Esoteric Sound uses a higher turnover frequency for bass in replay than in pre-equalization. For example 700 Hz instead of the “correct” 500 Hz. This will give a smooth, extra bass amplification of roughly 4 dB at 50 Hz.
  • To reduce surface noise of early American Columbia, Victor and RCA-Victor iasa recommends an additional high cut (= low pass) filter set to 5500 or 5200 Hz with 6 dB/octave. This will reduce treble by 3 dB at around 5000 Hz and by 9 dB at 10000 Hz – and hopefully most of the noise.

Remarks for Analog Purists

  • Hiss and high frequency scratch due to old worn records:

When digitizing such recordings Audacity’s Effect > Noise Reduction will do a good job to improve the sound once and for all. Those who prefer entirely analog replay with an adjustable preamplifier will have the opportunity to improve the sound every time they replay. They can cut / attenuate the frequency range most affected by the noise. A higher value for rolloff at 10 kHz than the “correct” EQ will usually give a better result than a simple treble filter – but: at the expense of the high frequencies of the audio itself.

  • Dull, lifeless sound:

If you improve poor bass on discs of any speed by choosing a higher bass turnover frequency than the “correct” EQ, there will be the welcome side effect of moderately amplifying midrange frequencies. This will bring life to the core octaves of a piece of music by improving instrument and vocal characteristics.

  • The primary thing YOU can do to improve this page is to share your knowledge about EQ curves and their usage with us. If you have reliable information which record label used which recording curve, please do let us know!
  • Please let us have YOUR feedback on this page! What did work well – and what didn’t? What was easy to adopt – and what was confusing?
  • To give feedback on this page please email us. If you already have an account on this Wiki, please post your comments directly on this article's Talk Page.

Acoustic recordings and Broadcast Transcription Discs

Acoustic recordings (before 1926) are beyond the scope of this page. In these pioneer years speeds varied from 70 to 90 rpm, groove modulation could be lateral, vertical or diagonal and some records were even cut outward with the audio starting at the center. A special turntable and a range of styli / needles are needed to replay.

All acoustics were recorded without any pre-equalization, simply because a modification of the audio was impossible before electric microphones and amplifiers came into use. Nonetheless there are conflicting opinions as to the result:

According to various authors the acoustical recording process had an "inherent mechanical equalization", which results – within the limited frequency range of approx. 150 to 4000 Hz – in a constant velocity characteristic one would only expect from a magnetic cutter. With a magnetic cartridge this would command to be replayed “flat”. Please note that the acoustical recording characteristic is not equalized at all.

According to Robinson an acoustical recording must have a constant-amplitude characteristic which will be correctly reproduced by playing back with a gramophone needle or a piezoelectric crystal pickup. A magnetic cartridge will – by its constant velocity characteristic – double the amplitude whenever the frequency doubles. To compensate for the magnetic pickup MidiMagic recommends an “800N-16” EQ curve, which comes close to the theoretical characteristic of a constant velocity device. Some more information is here on record labels and on technical background. Please note that the acoustical recording characteristic is not equalized at all.

Kolkowski’s results of a reenactment of an acoustic recording session show that bass needs heavy equalization if the losses in the recording horn (here below 400 Hz) shall be compensated for. Parametric equalization may be used at resonant frequencies. Treble should be amplified (!) to compensate for the high-frequency rolloff of the recorder. Due to the individual properties (defects) of recording horns and recorders there will be no “general characteristic” of acoustics and therefore no general EQ.


MidiMagic gives useful information on vintage labels as Edison, Berliner, Pathé or Zonophone and playback EQ recommendations.

Scientific help regarding valuable historic recordings can be found at IASA (International Association of Sound and Audiovisual Archives) and at ARSC (Association for Recorded Sound Collections).

Broadcast Transcription Discs are not in the focus of this page either. Those were recordable lacquer discs, mostly 16 inch in diameter, played at 33⅓ or 78 rpm. They were professionally used by radio broadcasters. Some more information is in this PDF.

In America many of these discs were recorded under the standard of the National Association of Broadcasters (NAB) of 1942. The very same recording curve had been used by NBC under the name “Orthacoustic” since mid 1930s. This “NAB Transcription (1942)” playback EQ setting can be downloaded here.

The British Broadcasting Corporation (BBC) used a rather exotic curve as a house standard. The version in use after 1949 has been reconstructed from Longford-Smith’s publication of 1952 as an Audacity EQ setting “BBC Transcription (1949)” and can be downloaded here.


78 rpm shellac labels and their EQ

This page is about electrical recordings since 1925 on 78 rpm discs made of shellac! The invention of the Electrical Recording System by Bell Laboratories / Western Electric which was licensed to industry leaders Columbia Records and Victor set some de-facto standards: speed is always 78 rpm, cut is always lateral (same as later mono LPs) and the groove type is always Normal Groove (also named coarse groove). Therefore shellacs are sometimes referred to as N78 (which stands for normal groove discs, played at 78 rpm).

A turntable capable of 78 rpm will be useful. You will need a MONO stylus with 2.5 mil (64 μm), for early electricals possibly one with 3 mil (76 μm) and this Audacity Wiki!

It is assumed that you replay your discs “flat” (without any analog de-equalization) and apply the necessary EQ after digitizing with Audacity Effect > Equalization. If it is necessary to play the record through a system that applies modern RIAA equalization, select the "RIAA" curve in Audacity's Equalization effect and use the Invert button to invert and thus remove the incorrect RIAA equalization before applying the appropriate equalization to the recording.

In case sources did not agree on one EQ curve, their different opinions are listed and you will have to trust your ears.


Table 2: 78 rpm Shellac Labels and Their EQ

Label Remarks Curve Name Code turnover
bass [Hz]
bass
shelf
treble rolloff
[dB @ 10kHz]
Source
_Electrical 78's (general) 1925-1938 300 0 ES
_Electrical 78's (general) 1932-1938, mid 30s 500-FLAT 500N-0 500 0 ia,ES,JP,RF
_Electrical 78's (general) 1938-1946 300 or 500 0 or -5 ES
_Electrical 78's (general) 1947-1954 300 or 500 -16 ES
Aco 1926 - 1933, British, with M in a circle BBC 2dB/oct. PC
Aeolian-Vocalion 1926 - 1933, British, with M in a circle BBC 2dB/oct. PC
ARC American Record Corporation = Cameo + Pathé + Plaza Group; 1929 - 1930 500 0 or -5 PC,JP
ARC American Record Corporation; 1930 - 1939 (some early also 500-5) 500 -8.5 JP
Argo American 78 250N-6 250 -6 mm
Ariel 1925 - 1931, British, with Δ after matrix no. or with W in a circle [W.E.] 250 W.E.mike PC
Artist 500 -16 ES
Audiophile 1952 - 1955, 78 rpm microgroove (!) records, up to AP-30; may also be replayed with "flat" treble Audiophile78 300N-8 300 -8 RH,Mc,AT
Autograph Marsh Laboratories, ca. 1924 - 1926 1000 0 ES,JP
Banner 1926 - 1929, an ARC label from 1929 500 0 JP
Balkan 500 -5 ES
Beltona 1926 - 1933, from cat. 1194 to 1282, with M in a circle BBC 2dB/oct. PC
Beltona 1944 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 -5,7 PC
Bluebird sublabel of RCA, see: RCA-Victor
Bluebird 1925 - 1931, with VE in an oval or "Orthophonic Recording" or with Δ after matrix no. (recorded in Europe) [W.E.] 250 W.E.mike PC
Broadcast (American) American 78 250N-6 250 -6 mm
Broadcast (American) 1940s 500 -12 JP
Broadcast (British) 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Brunswick (American) 1925 - 1930 500-FLAT 500N-0 500 0 ia,JP,RF,PC
Brunswick (American) 1929 - 1935, an ARC label from Dec 1931 to 1940 500 -5 JP
Brunswick (American) 1935 - 1939 500 -8.5 JP
Brunswick (American) 1946 - 1951 or 1954, a Decca (Amer.) label since 1941 630N-? 629 -8 or -12 ES,mm
Brunswick (British) 1925 - 1944, a Decca label since 1932; see: Decca (Brit.) European 78 250N-0 250 0 ES,GH
Cameo 1926 - 1929, probably W.E.; an ARC label from 1929 [W.E.] 250 0/W.E. JP
Capitol earliest 78s 1000 PC
Capitol 1942 - 1953; Capitol founded in 1942; since 1954 => RIAA Capitol [CAP] 400N-12.7 400 -12.7 ia,ES,mil,JP,Mc
Capitol 1942 - 1951 American 78 250N-8 250 -8 mm
Capitol to 1954 800 -10 ES
Capitol / Capitol Cetra 1951-1955 Capitol [CAP] 400N-12.7 400 -12.7 mm
Capitol - Telefunken 500-FLAT 500N-0 500 0 ES,mil
Capitol (British) 1944 - 1955, "ffrr", prod. by Decca UK, matrix prefix DCAP Decca 78 300N-5.5 300 -5,7 PC,JP
Cetra founded 1930s by RAI, Italy European 78 250N-0 250 0 GH
Cetra-Soria founded 1949, Cetra prod. in US European 78 250N-0 250 0 mm
Chappell 1931 - 1944, British, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Coliseum 1926 - 1933, British, with M in a circle BBC 2dB/oct. PC
Columbia (American) 1925 - 1931 (some -1934) [W.E.] 200 - 250 -5 / W.E. AT,ES,mil,ia,JP
Columbia (American) 1931 - 1937 American 78 250N-8 250 -8 AT,mm,JP
Columbia (American) 1939 - 1956; "Columbia Rec." a CBS label since 1938; from 1955 change to RIAA Columbia 78 300N-16 300 -16 ia,GH,ES,mil,mm, JP,Mc,AT
Columbia (British) 1925 - 1931, with W in a circle [W.E.] 250 W.E.mike PC
Columbia (British) 1931 - 1953, an EMI UK label from 1931 European 78 250N-0 250 0 ia,GH,ES,JP,RF
Columbia (British) 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Columbia (British) 1932 - 1949, with W in a circle or matrix prefix W (US COL/OKeh reissues) 500-FLAT 500 0, later -12 PC
Columbia (British) 1949 - 7/1953, EMI UK, matrix nos. from CA22600 to CA22610, and at CAX11932 500-FLAT 500N-0 500 0 PC
Concert Hall 500 -5 ES
Coral 1948 - 1954 629 -12 ES
Coral 1948 - 1953, sublabel of Decca US; from 1953 => RIAA AES 400N-12.3 400 -12.3 JP
Decca (American) 1934 - 1937, (Decca US established in 1934) American 78 250N-8 250 -8.5 JP
Decca (American) 1937 - 1946 ca AES 400N-12.3 400 -12.3 ia,JP,RF
Decca (American) pre 1946, imports from Britain? Blumlein300 300N-0 300 0 ES
Decca (American) very few, to try a combination of 500Hz / 6300 Hz 500N-5.5 500 -5,5 mm
Decca (American) 1946 - 1951, if labeled "ffrr" Decca 78 300N-5.5 300 -5,7 mm
Decca (American) 1946 - 1954 (??? 629 Hz ???) 629 -12 ES
Decca (American) 1951 - 1953, from 1953 => RIAA AES 400N-12.3 400 -12.3 mm
Decca (British) 1929 - 1944 European 78 250N-0 250 0 ES,mm
Decca (British) 1935 - 1944, matrix up to DR8485-2; test disc: Decca EXP55 or Z718 Blumlein300 300N-0 300 0 PC
Decca (British) 1944 - 1955, ffrr, cat. nos. from F.8440, K.1032, M.569 and X.281 (some exceptions); matrix nos. 8486 to 18000; test disc: Decca K.1802, London T.4996 Decca 78 300N-5.5 300 -5,7 PC,ES,mm,JP
Decca (British) some 1949-1956 London LP 500C-10.5 500 C -10,5 mm
Decca (European) to 1944 European 78 250N-0 250 0 mm
Decca (European) 1944-1950 Decca 78 300N-5.5 300 -5,7 ES,mm
Decca (European) 1950-1954, (Telefunken + Decca UK = TELDEC since 1950) Telefunken 400N-0 400 0 mm
Decca (European) some 1954-1962 CCIR 78 350N-10.5 354 -10,5 mm
Deutsche Grammophon alias "DGG", taken over by Telefunken 1937 300 -5 ES,mil
Deutsche Grammophon 1944 ca. - 1953 ca. (???) European 78 250N-0 250 0 PC
Dial 78s used same EQ as 33⅓ and 45s Columbia LP 500C-16 500 C -16 ES,mil
Domino 1926 - 1929, an ARC label from 1929 500 -5 JP
Dot to 1958 AES 400N-12.3 400 -12.3 mm
Electrola 800 -10 ES,mil
EMI-HMV (British) some, re-releases of acoustics mastered 1909-1926 800N-12 800 -12 mm
EMI-HMV (British) 1927 - 1953 European 78 250N-0 250 0 GH,ES,mil,mm
EMI-HMV (British) 1931 - 1944, with □ after matrix no., [Bc] Blumlein300 300N-0 300 0 PC
EMI-HMV (British) 1931 - 1949, with ◊ after matrix no. 500-FLAT 500 0, later -12 PC
EMI-HMV (British) 1931 - 1953, (test disc HMV DB4037) European 78 250N-0 250 0 ia,ES,mil,JP,PC
EMI-HMV (British) 11/1943 - 7/1953, matrix nos. from 2EA17501 to 0EA17576 European 78 250N-0 250 0 PC
EMI-HMV (British) 1955 - end, test disc: EMI JGS812, BBC DOM86 CCIR 78 350N-10.5 354 -10,5 PC
Exclusive 1944 - 1949 Decca 78 300N-5.5 300 -5,7 mm
Gramophone Company 1925 - 1931 UK, with Δ after matrix no. [W.E.] 250 W.E.mike PC
Gramophone Company Blumlein300 300N-0 300 0 ES,mil
Harmony 1929 - 1931 250 -5 JP
His Master's Voice (Brit.) some, re-releases of acoustics mastered 1909-1926 800N-12 800 -12 mm
His Master's Voice (Brit.) 1925 - 1931 British, with Δ after matrix no. [W.E.] 250 W.E.mike PC
His Master's Voice (Brit.) 1931 - 1953, prod. by EMI(UK) European 78 250N-0 250 0 ia,GH,mm,JP,RF
His Master's Voice (Brit.) 1932 - 1949, with ◊ after matrix no. 500-FLAT 500 0, later -12 PC
His Master's Voice (Brit.) 11/1943 - 7/1953, EMI UK, matrix nos. from 2EA17501 to 0EA17576 500-FLAT 500N-0 500 0 PC
Hispanophone 1926 - 1931 , with Δ after matrix no. [W.E.] 250 W.E.mike PC
Hit of the Week 1930 - 1932 500 -5 or -8.5 ES,mil,JP
Homochord 1926 - 1928, matrix no. HH, JJ, HR, JR, Ee (made by Gramophone Co.) [W.E.] 250 W.E.mike PC
Hugophone 1925 - 1931, with W in a circle [W.E.] 250 W.E.mike PC
Hugophone 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Jewel 1926 - 1929, an ARC label from 1929 500-FLAT 500N-0 500 0 JP
Keynote 500-FLAT 500N-0 500 0 ES
Keynote 1940s 500 -12 JP
King 1946 - 1953, since 1953 => RIAA 500 -8.5 or -16 ES,mil,JP
Lincoln sublabel of Cameo, 1926 - 1929, probably W.E. [W.E.] 250 -5 / W.E. JP
Linguaphone 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Linguaphone Blumlein300 300N-0 300 0 ES,mil
L'Oiseau-Lyre 1944 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 -5,7 PC
London 1948 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 -5,7 PC,mil,JP
MacGregor 1930 - 1950s, a Hollywood recording studio; produced by Brunswick, ARC, Capitol,...; various EQs (250-5, 250-8, 400-12.7, 500-12) mm,JP,AT
Majestic 1942 - 1948 500 -16 ES,JP
Marsh Laboratories (electrical) 1000 0 ES
Melotone 1931 - 1938, a Brunswick budget label; see Brunswick (Amer.)
Mercury 1945 - 1953; approx. to matrix YB9700; since late 1953 => RIAA AES 400N-12.3 400 -12.3 ia,ES,mm,JP,Mc
MGM (American) founded 1946; up to E3071 MGM [MGM] 500N-12 500 -12 ia,ES,mil,JP,RF
MGM (British) 1949 - 7/1953, matrix no. 0SM420 500-FLAT 500N-0 500 0 PC
Musicraft  ??? RCA Old Ortho.??? 700-800 -13.7 ES,mil
Musicraft 500 -8.5 or -12 JP
Nat. Gramophonic Soc. 1926 - 1933, with M in a circle, cat. HHH to TTT and NGS.65 to NGS.102 BBC 2dB/oct. PC
Nixa 1950 - ?, Britain, shellacs produced by Decca UK Decca 78 300N-5.5 300 -5.7 ris
Octacros 1931 - ?, Britain, a Synchrophone label Blumlein300 300N-0 300 0 PC
Odeon some early electricals 800 0 ES,mil
Odeon 1925 - 1928, with W in a circle (a Lindström label) [W.E.] 250 W.E.mike PC
Odeon 1928 - 1936, matrix with ₤ in a circle ( a Lindström label); bass shelf at 100Hz 400 C 0 PC
Odeon 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Odeon to 1953, (1926 sub. of Brit. Columbia , 1931 sub. of EMI) Blumlein300 300N-0 300 0 ES,mil
OKeh 1926 - 1935, a Columbia label since 1926 [W.E.] 250 -5 / W.E. AT,JP,mm
OKeh 1931 - 1935, some; probably American78 American 78 250N-8 250-300 0 or -8.5 ES,mil
OKeh 1940 - 1945 and 1951 - 1955; since 1955 => RIAA Columbia 78 300N-16 300 -16 AT,JP
Oriole 1926 - 1929, an ARC label from 1926 500 -5 JP
Parlophone (Amer.,Brit.) 1925 - 1931, with W in a circle [W.E.] 250 -5 / W.E. PC,JP
Parlophone (British) 1925 - 1953 European 78 250N-0 250 0 GH,ES
Parlophone (British) 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Parlophone (British) 1932 - 1949, with W in a circle or matrix prefix W (US COL/OKeh re-issues for UK) 500-FLAT 500 0, later -12 PC
Parlophone (British) 1949 - 7/1953, EMI UK, matrix nos. from CE14643 to CE14689 500-FLAT 500N-0 500 0 ia,PC,JP,RF
Parlophone-Odeon 1925 - 1928, Odeon in Brit.; with W in a circle [W.E.] 250 W.E.mike PC
Parlophone-Odeon 1928/29, Odeon in Brit.; matrix with ₤ in a circle, bass shelf at 100Hz 400 C 0 PC
Pathé (American) 1926 - 1929, probably W.E., some 500-5; an ARC label from 1929 [W.E.] 250 -5 / W.E. JP
Pathé (French) 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Perfect 1926 - 1929, probably W.E., sublabel of Pathé (Amer.) [W.E.] 250 -5 / W.E. JP
Philips to 1953 Philips 400N-6 400 -6 mm
Polydor sub-label of Deutsche Grammophon 300 -10 ES,mil
Radiofunken Telefunken 400N-0 400 0 mil
RCA Victor 12/1931 - 2/1932 "long-playing" shellacs, N-groove, played at 33⅓ rpm ≈Old Ortho. 500N-13.7 500 or up -13.7 RM,PC
RCA Victor 1931 ca., test disc Victor 84522 without treble pre-emphasis 500-FLAT 500N-0 500-600 0 PC,ES
RCA Victor 1931 - 1938, used high cut at 5500 Hz [R-B] ≈Old Ortho. 500N-13.7 500 or up -13.7 RM,PC
RCA Victor 1938 - 1947, used High Cut at 8500 Hz, [R-C] Old Ortho. 500N-13.7 500 -13.7 RM,PC,ia,JP,ES, mil
RCA Victor 1941 - 1947 (some to 1952) Old RCA 800N-8 800 -8 mm
RCA Victor 1947 - 1951 [R-D] RCA 45 800N-13.7 800 -13.7 mm
RCA Victor 1947 - Aug 1952 [R-D] Old Ortho. 500N-13.7 500 -13.7 RM,ia,mm,JP,RF
RCA Victor since Aug 1952 => "New Orthophonic" = RIAA, from matrix E2RP4094 RIAA 500R-13.7 500 R -13.7 RM,ES
RCA Victor (British) 1931 - ?, with swastika after matrix no., re-issued by EMI UK European 78 250N-0 250 0 PC
RCA Victor (British) 1931 - 1944, with □ after matrix no., re-issued by EMI UK, [Bc] Blumlein300 300N-0 300 0 PC
RCA Victor (European) 1930 - 1950 European 78 250N-0 250 0 ES
Regal (American) 1926 - 1929, an ARC label from 1929 500 -5 JP
Regal (British) 1925 - 1931, with W in a circle [W.E.] 250 W.E.mike PC
Regal Zonophone (Brit.) budget label of EMI/Columbia European 78 250N-0 250 0 ES,mil
Regal Zonophone (Brit.) 1925 - 1931 UK, with Δ after matrix no. or with W in a circle [W.E.] 250 W.E.mike PC
Regal Zonophone (Brit.) 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Regal Zonophone (Brit.) 1932 - 1949, with W in a circle or matrix prefix W (US COL/OKeh reissues for UK) 500-FLAT 500 0, later -12 PC
Regal Zonophone (Brit.) 1949 - 7/1953, matrix no. CAR6800 500-FLAT 500N-0 500 0 JP
Romeo 1926 - 1929, sublabel of Cameo; probably W.E. [W.E.] 250 0 / W.E. JP
Scala 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Schirmer 1000 -24 mil
Supraphone Czech, since 1932, a subsid.of Ultraphon Telefunken 400N-0 400 0 ES,mil
Synchrophone 1931 - ?, Britain Blumlein300 300N-0 300 0 PC
Technichord American, all N78 from 1938 [TCH] Technichord 800N-12 800 -12 ES,mil,mm
Telefunken 1944 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 -5,7 mm,PC
Telefunken 1951-1953, (Telefunken + Decca UK = TELDEC since 1950) Telefunken 400N-0 400 0 mm
Tempo (American) Tempo Record Co. of America, Hollywood, CA; ca 1947 - late 1950s 500 -12 JP
Tempo (American) 400N-6 400 -6 mm
Theme sublabel of Tempo (Amer.) 500 -12 JP
Theme all N78 American 78 250N-6 250 -6 mm
Turicaphon Switzerland, 1930 - , a subsid.of Ultraphon Telefunken 400N-0 400 0
Ultraphon Europe 1929-1932, taken over by Telefunken Telefunken 400N-0 400 0 ES,mil
Unison 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Victor 1925 - 1931, Western Electric System [W.E.] 200 - 300 0 to -7 ia,JP,ES,mil,mm
Victor Victor was taken over by RCA in 1930; see: RCA-Victor
Victor / Victrola 1925 - 1931, with VE in an oval or "Orthophonic Recording" or with Δ after matrix no. (recorded in Europe) [W.E.] 250 W.E.mike PC
Vocalion (American) a Brunswick label since 1924; see: Brunswick (Amer.)
Vocalion (British) 1926 - 1940; a Brunswick and since 1932 a Decca UK label European 78 250N-0 250 0 ES,mil
Vocalion (British) 1926 - 1933, to cat. X10029 A.0269 and K05312, with M in a circle BBC 2dB/oct. PC
Vocalion (British) 1944 - 1955, "ffrr", prod. by Decca UK, including V1000 series Decca 78 300N-5.5 300 -5,7 PC
Voice of the Stars 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Zonophone 1925 - 1931 UK, with Δ after matrix no. [W.E.] 250 W.E.mike PC
Zonophone 1931 - ?, with swastika after matrix no. European 78 250N-0 250 0 PC
Zonophone 1931 - 1944, with □ after matrix no., [Bc] Blumlein300 300N-0 300 0 PC
Remarks:
  • [Bc] ... Due to changes in the setup of the Blumlein cutter the characteristic of the recordings could vary between 180 Hz-FLAT and 500 Hz-FLAT, resulting in +/- 4 dB at 50 Hz. Copeland suggests 300 Hz as an average value.
  • [CAP]... used its own “Capitol curve” 400N-12.7. Play back with “AES” 400N-12.3!
  • [MGM] ... used a special “MGM curve” 500N-12. Play back with “RCA Old Orthophonic” 500N-13.7!
  • [R-D] ... Rolloff is frequently listed as between 10 and 12 dB. But this “flattening off” to ca 10 dB at 10 kHz was an intentional high cut which must not be compensated for in playback. Thus a setting of 13.7 dB is correct!
  • [R-C] ... RCA recommends replaying with “Old Ortho.”. High frequencies were cut off more deliberately at 8,500 Hz (with no effect on playback EQ!) than in later years. [cf. Moyer]
  • [R-B] ... From c. 1931 to 1938 high frequencies were even cut off at 5,500 Hz! The bass curve is “subject to some question, however,” since it was extensively modified by electronic filters and mechanical damping. But RCA found 500 Hz to be the best average characteristic and used this in re-recording pre-1938 masters. So in principle: “Old Ortho.” for playback again! [cf. Moyer]
  • [TCH] ... Technichord used its own “Technichord curve” 800N-12. Play back with “RCA 45” 800N-13.7!
  • [W.E.] ... Very early Columbia and Victor recordings (1926) used a bass turnover frequency of 250 or 300 Hz but their treble is described as “flat”. The perceived treble amplification was possibly only the result of resonant peaks of the early Western Electric condenser microphones used in recording. Background information is given in this PDF. An experimental replay EQ curve for this microphone / pre-emphasis combination can be downloaded ‎here.

Early 33⅓ LP labels and their EQ

After the launch of the “long-playing record 33⅓ rpm” by Columbia in 1948 (which used vinyl discs and a narrower groove width – microgroove records or M33) record producers experimented a lot to fully exploit the potential of the new medium. Bass shelving came into use to limit the necessary bass boost in playback and – as a consequence of the extended frequency range – necessary gain reached values as high as +/- 20 dB. So recording characteristics varied considerably!

The “poor sound quality” of some early LPs is nowadays considered to be mostly a result of the wrong EQ in playback.

Standardization was reached with the “New Orthophonic” curve of RCA which was to become the world standard by the name of RIAA. In America most labels switched to RIAA around 1955 – Europe followed by 1962.

How to identify RIAA recordings:

  • “ORTHOphonic” or “New Orthophonic” (after August 1952), “NARTB” or “New NARTB” (after June 1953) or “New AES” (after 1954) indicate RIAA equalization.
  • The following labels should have used only RIAA all the time: Argo, Bethlehem, Classic Editions, Chess, Clef, Composer Recordings, McIntosh, Montilla, New Jazz, Norgram, Prestige, Romany, Roulette, Savoy, Vocalion and Walden [High Fidelity Magazine, MidiMagic].
  • A “HIFi+” sticker on American Columbias or the catalogue number written in an inverted triangle on German records (like Deutsche Grammophon) is a symbol for RIAA.
  • Later recordings on the labels listed below should all be RIAA.

In case that sources did not agree on one EQ curve, their different opinions are listed and you will have to trust your ears.


Table 3: Early 33⅓ LP Labels And Their EQ

Label Remarks Curve Name Code turnover
bass [Hz]
bass
shelf
treble rolloff
[dB @ 10kHz]
Source
Allegro 1948 - 1956 Columbia LP 500C-16 500 C -16 ES
Allied to 1958 NAB or Col.LP 500?-16 500 B/C -16 JP,Hi,ES,mil,mm
American Recording Society to matrix E2KP9607, mastered by RCA Old Ortho. [R-D] 500N-13.7 500 N 13.7 ES,Mc
American Recording Society to 1958 AES 400N-12.3 400 N -12.3 Hi,mm,JP
Angel (2XEA213-392/XAX561-817)(1N,2N) 500-FLAT 500N-0 500 N 0 ES
Angel to 1952; to 35022 Old Ortho. [R-D] 500N-13.7 500 N 13.7 mil,mm,RF,Mc
Arizona to Sept(?) 1955 Capitol [CAP] 400N-12.7 400 N -12,7 Hi,ES,mil,mm,JP
Artist NAB 500B-16 500 B -16 GH,mil
Atlantic to 1953, produced by MGM NAB 500B-16 500 B -16 ES,mil,mm,JP,Mc
Audio Fidelity no. 901-903 NAB 500B-16 500 B -16 ES,mm,JP,RF
Audiophile 1952 - 1976 (!); regular 33⅓ LPs up to AP-125; may also be replayed with "flat" treble; probably never used RIAA Audiophile33 600N-10 600 N -10.3 RH,AT
Bach Guild sublabel of Vanguard; BG-501 to 529 (1950 to 52) Columbia LP 500C-16 500 C -16 GH,ES,Hk,Hi,AT
Banner to 10002 Columbia LP 500C-16 500 C -16 ES,mil,mm
Bartók to 1952 Columbia LP 500C-16 500 C -16 ES,mm
Bartók 1952-1953 AES 400N-12.3 400 N -12.3 mm
Bartók no. 301-307, 309, 906-920 Bartok 630C-16 629 C -16 ES,mil,mm,JP,Mc
Bartók no. 308, 310-11, 901-05 and from 921 RIAA 500R-13.7 500 R -13,7 Hi
Blue Note to Sept(?) 1955, 33⅓ and 45s AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP, Hk,Mc
Bluebird Bluebird Classic (BC), a sublabel of RCA, see: RCA-Victor
Boston to 1958, up to B202 Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm,JP, RF
Brunswick to matrix MG4400; with raised matrix** Old RCA 800N-8 800 N -8 ES
Brunswick 1951-1955 AES 400N-12.3 400 N -12.3 mm
Caedmon (American) founded 1952, TC1002 - TC1022 (1955) Bartok 630N-16 629 N -16 Hi,ES,mil,mm,JP
Caedmon (American) 629 -11 or -12 ES,Mc
Caedmon (British) early LPs "made in England", from 1953 CCIR 78 350N-10.5 350 N -10,5 PC
Canyon to C6160 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP, Hk,Mc
Capitol / Capitol-Cetra 1949 - 1955 (sold to EMI-UK in 1955); 33⅓, Capitol [CAP] 400N-12.7 400 N -12,7 Hi,ES,mm,JP,RF, Hk,Mc
Capitol / Capitol-Cetra 1949 - 1954; 45 rpm NAB 500B-16 500 B -16 GH,mm
Capitol to 1954, weak bass on 45 rpm can be improved (+ 4.5 dB) by 800 Hz t/o 500 -12 ES,Mc
Cetra-Soria Am. releases of Cetra, 1948-1953 (Cetra-Soria sold to Capitol) Columbia LP 500C-16 500 C -16 Hi,GH,ES,mm,JP, RF
Colosseum AES 400N-12.3 400 N -12.3 ES,mil,RF,Mc
Colosseum to Jan 1954 NAB 500B-16 500 B -16 Hi,mm,JP,RF
Colosseum some long operas 1000 -5 ES
Columbia (American) 1947-1955; to matrix ML4895, XLP3200 Columbia LP 500C-16 500 C -16 Hi,GH,ES,mil,mm, JP,RF,Hk
Columbia (American) 1948 - 1953; 45 rpm NAB 500B-16 500 B -16 ES,mm,Mc
Columbia (American) 45 rpm AES 400N-12.3 400 N -12.3 JP
Columbia (American) 1955 - ; after matrix XLP3200 or with "HiFi+" sticker RIAA 500R-13.7 500 R -13.7 ES
Columbia (British) 1949 - 7/1953, matrix nos. LPs: from XA561 to XAX817; XRX12; EPs: 7TCA 7, 7TCO 6; SPs: 7XCA185, 7XCO 87 500-FLAT 500N-0 500 N 0 PC,ES
Concert Hall (American) most! 1948-1954, XTV matrix to 20383 (low take nos) produced by COL Columbia LP 500C-16 500 C -16 Hi,ES,mm,JP,RF
Concert Hall E0 matrix, mastered by RCA, ca. 1950/51 Old RCA 800N-8 800 N -8 ES
Concert Hall E1KP/E2KP matrix, mastered by RCA, ca. 1951/53 Old Ortho. [R-D] 500N-13.7 500 N 13.7 ES
Concert Hall marked AES, AES 400N-12.3 400 N -12.3 mil,mm,RF,Mc
Concert Hall CH matrix? 500 -10 ES
Concert Hall matrix E2RP from 4095 / E2KP from 9607 RIAA 500R-13.7 500 R -13,7 ES
Concert Hall (British) to 1956 (or 1954) London LP 500C-10.5 500 C -10.5 Hi,mm,JP
Contemporary 2001-02, 2501-02, 2505, 2507, 3501 AES 400N-12.3 400 N -12.3 Hi,ES,mm,JP,Mc
Contemporary 2504 NAB 500B-16 500 B -16 Hi,ES,mm
Contemporary after matrix AP121 RIAA 500R-13.7 500 R -13.7 ES
Cook to 1958(?), regular mono records Cook 500 N var. -12 to -15 ES,mm
Cook Cook Laboratories NAB 500B-16 500 B -16 JP
Cook (binaural) inside band -0 rolloff, outs.-11 dB 500 0 ins./-11 outs. Hi,ES,mil,mm
Coral sublabel of Decca (Amer.), est. 1949, up to MG4400, with raised matrix Old RCA 800N-8 800 N -8 ES
Coral AES 400N-12.3 400 N -12.3 JP,Mc
Coral to 1958(?) NAB 500B-16 500 B -16 Hi,mm,JP
Decca (American) up to MG4400, with raised matrix Old RCA 800N-8 800 N -8 ES
Decca (American) 1949-1951 London LP 500C-10.5 500 C -10.5 mm
Decca (American) 1953, 33⅓ and 45 rpm AES 400N-12.3 400 N -12.3 mm,JP,RF
Decca (American) 1953 - Nov 1955, 33⅓ and 45 rpm NAB 500B-16 500 B -16 Hi,mm,JP,RF
Decca (British) 1950-1956 London LP 500C-10.5 500 C -10.5 mm
Decca (British) ffrr (from ARL1186-1B)***  ???London 500 -10 ES
Decca (British) ffrr (after 6/50)*** 500-FLAT 500N-0 500 N 0 ES
Decca (British) ffrr (from ARL2530-2A) RIAA 500R-13.7 500 R -13.7 ES
Decca (European) 1949 - 1954, (Telefunken + Decca UK = TELDEC since 1950) Telefunken 400N-0 400 N 0 mm
Decca (European) some 1954-1962 CCIR 78 350N-10.5 350 N -10.5 mm
Decca (European) most from 1954 RIAA 500R-13.7 500 R -13.7 mm
Decca ffrr 1951 [Disputed!][1] 300 -14 JP,RF
Deutsche Grammophon alias "DGG" LP -10 ES
Deutsche Grammophon 1952 - 1955, early LPs, cat. no in a rectangle, bass shelf 50 Hz IEC N78 350A-10.5 350 A -10.5 PC,GH,RB
Deutsche Grammophon cat. no. in an inverted triangle (RIAA symbol) RIAA 500R-13.7 500 R -13.7 PC
Deutsche Grammophon 1957, test disc DG 99105, possibly the only disc to DIN 45533 TELDEC 500R-11 500 R -11 PC
Dial 1948 - 1954, 33⅓ and 45 rpm, bass of EP 45s can be improved by 700Hz t/o Columbia LP 500C-16 500 C -16 ES,mil,mm,JP
Dot to 1958, 33⅓ and 45 rpm AES 400N-12.3 400 N -12.3 mm
Ducretet Thomson 10/1954 - 1958, British releases issued by London/Decca UK London LP 500C-10.5 500 C -10.5 RF
Elektra EKL 2-15, 18-20, 24-26 (rel. 1952-55) Bartok 630N-16 629 N -16 Hi,ES,mm,JP,Mc
Elektra EKL 17, 22 (released 1954) AES 400N-12.3 400 N -12.3 Hi,ES,mm,JP
Elektra EKL 16, 21, 23 (rel. 1955) and from 27 up RIAA 500R-13.7 500 R -13.7 Hi,ES,mm
EMI-Angel to 1952, Deutsche Grammophon releases in US Old Ortho. [R-D] 500N-13.7 500 N 13.7 mm
EMI-HMV 1949 - 1953; matrix 2XEA213-392/XAX561-817 (1N,2N) 33⅓ and 45 rpm 500-FLAT 500N-0 500 N 0 ES
EMI-HMV 1951 - 1954 NAB 500B-16 500 B -16 mm
EMI-HMV 1954 - 1958? Columbia LP 500C-16 500 C -16 mm,JP
EMI-HMV since July 1953 RIAA 500R-13.7 500 R -13.7 ES,PC
EMS 1951 - 1956 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP, RF,Hk,Mc
Epic 1948 - 1954, a Columbia sublabel Columbia LP 500C-16 500 C -16 ES,mil,mm,JP,RF
Esoteric ES 500,517 and EST 5,6 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP
Esoteric to matrix E2KP 9607, mastered by RCA; from ES 533 => RIAA Old Ortho. [R-D] 500N-13.7 500 N 13.7 ES,Mc
Festival to 1955 Columbia LP 500C-16 500 C -16 ES,mil,mm
Folkways 1948 - 1955; all Columbia LP 500C-16 500 C -16 Hi,ES,mm,JP,RF
Fraternity Records up to F-1013 500-FLAT 500N-0 500 N 0 ES
Good-Time Jazz 1, 5-8 NAB 500B-16 500 B -16 Hi,ES,mm,JP
Good-Time Jazz 3, 9-19 AES 400N-12.3 400 N -12.3 Hi,ES,mm,JP,Mc
Good-Time Jazz 2, 4, 20 and up; since Oct 1955 => RIAA RIAA 500R-13.7 500 R -13.7 Hi,mm
Handel Society sublabel of Concert Hall, mostly produced by COL, 1951-1954; others see Concert Hall Columbia LP 500C-16 500 C -16 ES,mil,mm
Haydn Society sublabel of Urania; to matrix XTV20383, mastered by COL; to cat. HS-3062, HSL-84; 1949 to 1954 Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm,JP, Hk,AT
His Master's Voice (Amer.) sublabel of RCA; to 1952; since Aug 1952 => "New Ortho." = RIAA Old Ortho. [R-D] 500N-13.7 500 N 13.7 ES,GH,RM
His Master's Voice (British) 1949 - 7/1953, EMI-UK, matrix nos. LPs: 2XEA213 - 392 and 0XAV145; EPs: 7TEA 19, 7TAV 28; SPs: 7XBA14 - 21 and 7XCS 23, 7XLA 2, 7XRA 30, 7XSB 6, 7XVH 70, 7XEA688, 7XAV227 500-FLAT 500N-0 500 N 0 PC,ES
His Master's Voice (British) Columbia LP 500C-16 500 C -16 GH,JP,RF
Kapp no. 100-103, 1000-1001 Kapp 800N-16 800 N -16 Hi,ES,mil,mm,JP
Kendall to 1958(?) NAB 500B-16 500 B -16 Hi,ES,mil,mm,JP
L'Oiseau-Lyre to 1954, to matrix OL50018, prod. by Decca London LP 500C-10.5 500 C -10.5 Hi,ES,mil,mm,JP
London first few Columbia LP 500C-16 500 C -16 mm
London ffrr; after 6/1950***; to matrix ARL1186-1B 500-FLAT 500N-0 500 N 0 ES
London ffrr; to LL-846; to matrix ARL2530-2A London LP 500C-10.5 500 C -10.5 Hi,mil,mm,ES
Lyrichord 1948 - 1951, XTV matrix, mastered by COL Columbia LP 500C-16 500 C -16 mil,mm,JP,RF,ES
Lyrichord 1951 - 1957(?) NAB 500B-16 500 B -16 Hi,mm
Lyrichord 1950 - 1952, mastered by RCA Old Ortho. [R-D] 500N-13.7 500 N 13.7 PC
Lyrichord 400 -16 mil,JP,RF
Lyrichord before 1953, (E0-E3 matrix)  ???AES 400 -12 ES
Lyrichord if labeled "629" Bartok 630C-16 629 C -16 ES,mil,JP,Mc
Mercury 1948 - 1952, marked "2000Hz/3dB p.octave", MG10000 series 500 -7 (3 dB/oct.) PC,ES
Mercury 1953 - Oct 1954, 33⅓ and 45s, to matrix MG50026, 7000 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP, PC,Hk,Mc
MGM to 1952 NAB 500B-16 500 B -16 GH,mm
MGM to 1953; to matrix M-G-M E3071; 33⅓ and 45 rpm; bass of 45s can be improved by 700 Hz MGM [MGM] 500N-12 500 N -12 ES,mm,JP,Hk,AT, Mc
MGM (British) 1949 - 7/1953, matrix nos. SPs: 7XSM203 500-FLAT 500N-0 500 N 0 PC
Music Treasures all Columbia LP 500C-16 500 C -16 mm
New Records to 1954 Columbia LP 500C-16 500 C -16 ES,mil,mm
New Records mastered by RCA Old Ortho. [R-D] 500N-13.7 500 N 13.7 ES
Nixa (British) 1950 (founded) to 1955, US matrixes from Westminster Columbia LP 500C-16 500 C -16 mm,PC
Nixa (British) to 1955, if labeled AES AES 400N-12.3 400 N -12.3 mm
Nixa (British) to 1955, if labeled NAB NAB 500B-16 500 B -16 mm
Nixa (British) US matrixes from Polymusic or Urania; mastered by RCA Victor Old Ortho. [R-D] 500N-13.7 500 N 13.7 PC
Nixa (British) US matrixes from Lyrichord; see: Lyrichord PC
Nocturne LP1-LP3 ,LP5; XP1-XP10 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP
Oceanic to 1958; to matrix XTV20383, low take nos. Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm,JP, Hk
Odeon 300 -10 ES
Overtone nos. 1-5 produced by COL; from no. 6 => RIAA Columbia LP 500C-16 500 C -16 ES,TP,AT
Oxford to 1958? Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm,JP
Pacific Jazz to 1953 Pacific Jazz 500C-12 500 C -12 mm
Pacific Jazz PJLP 1-13; 10" LPs issued in 1953/54 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP
Parlophone 1947-1954 300 -10 ES
Parlophone 1949 - 7/1953, EMI UK, matrix nos. LPs: XEX 60; SPs: 7XCE135; (EPs were probably all RIAA) 500-FLAT 500N-0 500 N 0 PC,ES
Period 1949-1953; up to 576 NAB 500B-16 500 B -16 ES,mil,mm,Mc
Philharmonia to 1958? AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP, Hk,Mc
Philips to 1953, 33⅓ and 45s Philips 400N-6 400 N -6 mm
Philips (British) 1953 - ?, LPs with re-issues of 78s masters CCIR 78 350N-10.5 350 N -10.5 PC,RB
Polydor sub-label of Deutsche Grammophon 300 -10 ES,mil
Polymusic to 1958 (regular mono records) NAB 500B-16 500 B -16 ES,mil,mm,JP,RF
Polymusic (binaural) inside band -0 rolloff, outs.-11 dB (Cook system) 500 0 ins./-11 outs. Hi,ES,mil,mm
Rachmaninoff Society to 1958? Columbia LP 500C-16 500 C -16 ES,mil,mm
RCA Victor 1949 - 1950, some 33⅓ and 45s; matrix from D9 to E0LRC3980 Old RCA 800N-8 800 N -8 or -10 ES,mm,Mc
RCA Victor 1949 - 8/1952, first 45 rpm discs (also some 33⅓) RCA 45 [R-D] 800N-13.7 800 N -13.7 RM,mm,PC
RCA Victor 1950 - 8/1952, 33⅓ only; matrix from E0LRC3981 Old Ortho. [R-D] 500N-13.7 500 N 13.7 RM,ES,mm,JP,PC, Hk
RCA Victor since Aug. 1952: "New Orthophonic"; all LM,WDM,DM cat. from 1701; LCT,WCT from 1112; all LHMV,WHMV,LBC,WBC and Extended Play 45s; (from E2RP4094) RIAA 500R-13.7 500 R -13.7 RM,Hi,GH,ES,PC
Remington to 1958(?); to matrix 199-135 NAB 500B-16 500 B -16 Hi,ES,mm,JP,Mc
Renaissance 1949 - 1952 Columbia LP 500C-16 500 C -16 mm
Renaissance 1952 - 1954 Pacific Jazz 500C-12 500 C -12 ES,mil,mm,Mc
Riverside to Sept (?) 1955 AES 400N-12.3 400 N -12.3 Hi,ES,mil,mm,JP
Stradivari to 1958 Columbia LP 500C-16 500 C -16 ES,mil,mm
Telefunken 1951 - 1953, (Telefunken + Decca UK = TELDEC since 1950) Telefunken 400N-0 400 N 0 mil,mm
Telefunken 1954 - 1962 CCIR 78 350N-10.5 350 N -10.5 mm,RB
Tempo 1948 - 1953 Columbia LP 500C-16 500 C -16 mm
Tempo 1954 - 1958(?) NAB 500B-16 500 B -16 Hi,GH,ES,mm,JP
Transradio to 1958(?) Columbia LP 500C-16 500 C -16 Hi,ES,mm,JP
Urania most; to matrix XTV20383 (low take nos), mastered by COL; 1949 to 1954; since 1953 change to RIAA Columbia LP 500C-16 500 C -16 Hi,mil,mm,ES,Hk, AT
Urania Cat. nos. URLP 224, 603, 7059, 7063, 7065, 7066, 7069; ca 1952/53 AES 400N-12.3 400 N -12.3 Hi,mm,JP,Mc,AT
Urania to matrix E2KP9243, mastered by RCA; 1950 to 1953 Old Ortho. [R-D] 500N-13.7 500 N 13.7 PC,ES,AT
Vanguard VRS 411-42, 6000-18, up to XTV20386; VRS 7001-11, 8001-04; since 1954 RIAA Columbia LP 500C-16 500 C -16 Hi,ES,JP,GH,Hk AT
Vox 1948 - 1954; up to matrix XTV20386, PL8400 or labeled "Lp"; mastered by COL Columbia LP 500C-16 500 C -16 GH,mil,mm,JP,ES, PC,Hk
Vox labeled AES AES 400N-12.3 400 N -12.3 mm
Vox 1951 - Oct 1954 NAB 500B-16 500 B -16 Hi,mil,mm,JP,RF
Westminster 1948 - Oct 1955, to matrix XTV20383 low take nos.; mastered by Columbia Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm,JP, PC
Westminster EO matrix Old RCA 800N-8 800 N -8 ES
Westminster to matrix E2KP9607, mastered by RCA Old Ortho. [R-D] 500N-13.7 500 N 13.7 ES
Westminster labeled AES AES 400N-12.3 400 N -12.3 Hi,mil,mm,JP,RF
Westminster labeled NARTB NAB 500B-16 500 B -16 GH,JP
Remarks:
  • [1]... This EQ can be traced back to Langford-Smith (1952), who vaguely describes a “London LP curve (Jan. 1951)”. Powell reads this as 300Hz (wrong!) and -14 dB (correct!). Copeland judges evidence “to be very defective.” No evidence of usage.
  • [CAP]... used its own “Capitol curve” 400N-12.7. Play back with “AES” 400N-12.3!
  • [MGM] ... used a special “MGM curve” 500N-12. Play back with “RCA Old Orthophonic” 500N-12.3!
  • [R-D] ... Rolloff is frequently listed as between 10 and 12 dB. But this “flattening off” to ca 10 dB at 10 kHz was an intentional high cut which must not be compensated for in playback. Thus a setting of 13.7 dB is correct!
  • [R-C] ... RCA recommends replaying with “Old Ortho.”. High frequencies were cut off more deliberately at 8,500 Hz (with no effect on playback EQ!) than in later years. [cf. Moyer]
  • [R-B] ... From c. 1931 to 1938 high frequencies were even cut off at 5,500 Hz! The bass curve is “subject to some question, however,” since it was extensively modified by electronic filters and mechanical damping. But RCA found 500 Hz to be the best average characteristic and used this in re-recording pre-1938 masters. So in principle: “Old Ortho.” for playback again! [cf. Moyer]

Sources, links and reading references

Sources of tables 2 and 3:

  • AT ... AudacityTeam own research
  • ES ... Esoteric Sound and the updated EQ list from the manual of their re-equalizer preamp in which they also have very useful tips how to identify LPs by their matrix number (British London / Decca, American Decca, American Columbia, RCA Victor). Please mind that they quote settings of their device which have to be translated back into parameters of EQ curves.
  • GH ... Graumann, Heinz; Schallplatten-Schneidkennlinien und ihre Entzerrung, in: FUNKSCHAU 1958, Heft 15, pp 359 ff
  • Hi ... High Fidelity Magazine, October 1955 with revised “Dialing Your Disks” table.
  • Hk ... Heathkit; Preamplifier WA-P2 manual; Heath Comp., Benton Harbor, Michigan; 1954
  • ia ... iasa – International Association of Sound and Audiovisual Archives: replay EQ
  • JP ... James R. Powell Jr., “Audiophile’s Guide to Phonorecord Playback Equalizer Settings”, in: ARSC Journal 20-1, Spring 1989, pp 14-23
  • Mc ... McIntosh Audio Compensator C-8 manual (1956). Please note that McIntosh lists all labels using "Columbia LP" curve with 750 Hz in error.
  • mil ... Millennia Music and Media Systems manufacturer of LOCi preampand other high end professional audio recording products. Their EQ chart was initially part of the manual of the LPE-2 preamp. A revised version was released in 2010 as “MM Legacy Recordings“ chart.
  • mm ... MidiMagic is probably the most comprehensive and reliable websource. Data were researched in the 1970s and are based on publications of the 1950s.
  • PC ...Peter Copeland, Manual of Analogue Sound Restoration Techniques, The British Library, 2014
  • RB ... Richard Brice in PspatialAudio
  • RF ... Russell Fisher / W.A.M.S.
  • RM ... Robert C. Moyer, Evolution of a Recording Curve; in: Audio Engineering, vol.37, no.7, July 1953; pp 19-22, 53-54. (about "New Orthophonic" and previous RCA curves)
  • TP ... Tom Packard of Packburn Electronics, Inc. Personal correspondence re Overtone.
  • Discographical information about catalogue numbers, matrix numbers and release dates is based on Both Sides Now, The Online Discographical Project, 45worlds (who also show 78 rpm and LPs), Decca Classical discography by Philip Stuart (July 2009 edition], Record Information Services (post-war UK labels), Yale University, Music Cataloging, Grammophon-Platten.de (German/European labels) and Discogs (database and trading platform) as well as some discographies specialized on specific labels.

Recommended analog reference:

  • James R. Powell, Jr. and Randall G. Stehle, "Playback Equalizer Settings for 78 RPM Recordings", Third Edition, Gramophone Adventures, Portage, MI, 1993, 2002, 2007. A compilation of Powell’s subjective recommendations of Owl 1 settings for approx. 1800 discs / 400 labels (mostly American and Jazz). Reprint of 3rd edition available at Nauck’s.
  • Fritz Langford-Smith, Radiotron Designer's Handbook, Wireless Press, Sydney, Fourth edition, 1952.
  • James Moir, High Quality Sound Reproduction, Chapman & Hall Ltd., London, 1958
Personal tools

Donate securely by PayPal, using your credit card or PayPal account!