Difference between revisions of "User:Wolfgang Leister"

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(reworked Tab1 (new Copeland entries, updated list from EsotericSound), reworked Remarks & Sources for Tab1, added explanation to Acoustic Recordings, reworked Tab2 follows!)
(updated link to Esoteric manual)
Line 583: Line 583:
 
:::'''Sources:'''
 
:::'''Sources:'''
 
:::*Hi ... High Fidelity Magazine, October 1955  with revised “Dialing Your Disks” table.
 
:::*Hi ... High Fidelity Magazine, October 1955  with revised “Dialing Your Disks” table.
:::*ES ... Esoteric Sound [http://www.esotericsound.com/] and the updated EQ list from the manual of their re-equalizer preamp [http://www.manualslib.com/manual/778394/Esoteric-Sound-Re-Equalizer.html?page=6#manual] 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.
+
:::*ES ... Esoteric Sound [http://www.esotericsound.com/] and the updated EQ list from the manual of their re-equalizer preamp [http://www.esotericsound.com/Electronics/REQ2MAN.pdf] 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
 
:::*GH ... Graumann, Heinz; Schallplatten-Schneidkennlinien und ihre Entzerrung, in: FUNKSCHAU 1958, Heft 15, pp 359 ff
 
:::*ia ... iasa – International Association of Sound and Audiovisual Archives  iasa-replay-eq [http://www.iasa-web.org/tc04/mechanical-carriers-replay-equalisation]   
 
:::*ia ... iasa – International Association of Sound and Audiovisual Archives  iasa-replay-eq [http://www.iasa-web.org/tc04/mechanical-carriers-replay-equalisation]   

Revision as of 11:53, 19 May 2016

Gale 03May16: @Wolfgang, tables should be tables when published on Wiki, not images. Visually impaired users cannot have images read to them by screen reader software.
  • Gale 04May16: @Wolfgang, thanks for struggling with the table. I would like to see "Region", "Timeperiod", "Curve Name, alias names" and "Code" as table headings, not sub-headings. Also the empty rows as dividers don't look good to me. I styled the top border of one row "solid thick red" as an example of what you could do to make the divisions look nicer. You can color the text differently too.
  • Gale 10May16: Is this content ready now for integration into the article?
Example.png

This page is a User "Work in Progress"

Please let the claimant work with it at least two weeks after this sticker was put up (or until this sticker has been removed, if earlier).

Suggestions may be made to the claimant by clicking on the page's "discussion" tab.

This page serves as a library of additional EQ curves for old disc recordings that can be used in the Equalization effect in current Audacity.
While this page deals mainly with 78rpm playback equalization curves, some detail on early (pre-1955) LP curves is also included.
 
Related article(s):

The audio on almost every phonograph record is not the same as the one once performed. For technical reasons the signal had to be modified before the discs were cut. Playback equalization (EQ or de-emphasis) will modify the signal back to original. Only by this music lovers can enjoy the original sound of the music performed long ago from their rare discs.



Usage

The most relevant EQ curves are presented as Table1

  • You can download some of them from LIBRARY and import them into Audacity Effect > Equalization
  • You can generate them yourself with “78 rpm EQ Curve Generator”
  • You can set the sliders of any digital or analogue graphic equalizer manually
  • You can determine appropriate settings for any adjustable analogue pre amplifier.

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

  • for 78 rpm shellacs in table 2
  • for early LPs in table 3


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 Record 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 78rpm 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) 78rpm records have a 'flat' EQ curve, i.e. with no bass boost or treble cut and, in some early electric EQ curves, while there is a bass boost curve, the 10 kHz Gain Rolloff is zero, i.e. there is no treble cut.

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 +/- 0.5%.

EQ Curves

The most relevant EQ curves are presented in Table1. 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 the 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.)


Table1 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 … (“No”) if no bass shelving is applied, or
X … 12 dB (this is never used)
C … 14 dB (possibly named C after Columbia LP curve)
A … 16 dB
B … 18 dB
R … 20 dB (possibly named R after RCA or RIAA)
  • 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 + 14 0 (flat) 250N-0
Europe 1926 - 1950 "European 500" 318 500 + 19 0 (flat) 500N-0
America 1926 - 1951 "American 78" 636 250 5792* + 14 - 6 250N-6
America 1926 - 1951 "American 78" 636 250 4340* + 14 - 8 250N-8
Amer.(CBS) 1938 - 1948 "Columbia 78" 530 100 300 1592 + 16,7 - 15,0 300N-16
Eur., Brit. 1944 - 1956 "DECCA 78" 531 25 300 6366 + 11 - 5.7 300N-5.7
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 3180 450 50 50 354 3183 + 16 + 14,0 - 10,5 350A-10.5
Microgroove, 33⅓ & 45
America 1942 - 1949 NAB (broadcast transcriptions, 1942) 318 100 500 1592 + 20,5 - 15,6 500N-16
America 6/1948 - 1956 "Columbia LP", Columbia 33, "LP" [3] 1590 318 100 100 500 1592 + 14,5 + 13,6 - 15,5 500C-16
America 4/1949 - 1958 "NAB", NARTB (standard 1949) 3180 318 100 50 500 1592 + 20 + 17,5 - 15,6 500"B"-16
America 1/1951 - 1958 "AES" (standard 1951) 397,9 63,7 400 2500 + 18,1 - 12,3 400N-12
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 (May 1955)
Amer., Brit. 1949 - 1956 "LONDON LP", London ffrr, Decca ffrr [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
Brit., Eur. 1954 - 1958(?) "EMI-HMV LP" , His Master's Voice LP 2274 318 63,7 70 500 2500 16,5 or 19 + 16,7 - 12,6



Table1 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/Decca releases in US, 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


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".


Limits

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 (“flat”), simply because a modulation of the signal was impossible before electric microphones and amplifiers came into use. So the signal on the disc has a clean constant-amplitude characteristic. This is fine as long as you play back with a gramophone needle or a piezoelectric crystal pickup. But you will probably use a magnetic cartridge which – by its constant velocity characteristic – will double the amplitude whenever the frequency doubles. To compensate this Robinson (MidiMagic) recommends a “800N-16” EQ curve, which comes close to the theoretical characteristic of a constant velocity device – a straight line from +20 dB at 100 Hz to -20 dB at 10,000 Hz with constant slope of 6 dB/octave. On Audacity’s Equalizer a very simple “curve” to set!

MidiMagic [1] 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)[2]
and at ARSC (Association for Recorded Sound Collections)[3].

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. 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 LINK

British 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 her LINK


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 78.26 rpm, cut is always lateral (same as modern 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 analogue de-equalization) and apply the necessary EQ after digitalization with Audacity Effect > Equalization.

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 (beta 2016 May 19)

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 N 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, with M in a circle BBC 2dB/oct. PC
Aeolian-Vocalion 1926 - 1933, with M in a circle BBC 2dB/oct. PC
American Rec. Co. 500  ? PC
Argo American 78 250N-6 250 N -6 mm
Ariel 1925 - 1931 UK, with Δ after matrix no. or with W in a circle [W.E.] 250 W.E.mike PC
Artist 500 -16 ES
Audiophile 1948-1958 Audiophile 500N-8 500 N -8 mm
Autograph Marsh electrical 1000 0 ES
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 N -5,7 PC
Bluebird sub-label of RCA, see: RCA-Victor ES
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
Bluebird 1932 - 1949, with High Cut at 8500Hz 500-FLAT 500 0, later -12 PC
Broadcast American 78 250N-6 250 N -6 mm
Broadcast 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Brunswick 1925 European 78 250N-0 250 N 0 ES,GH
Brunswick 1944 - 1955, ffrr, a Brit. Decca label Decca 78 300N-5.5 300 N -5,7 PC
Brunswick 1946 500N-16 500 -16 ES
Brunswick (American) 500-FLAT 500N-0 500 N 0 ia,JP,RF,PC
Brunswick to 1951 630N-8 629 N -8 mm
Brunswick 1946 - 1954 630N-12 629 -12 ES
Capitol earliest 78s 1000 PC
Capitol 1942 (founded) to 1951 American 78 250N-8 250 N -8 mm
Capitol 1942 - ?; probably "Capitol 400N-12.7" [CAP] 400 -12 ia,ES,mil,JP,RF
Capitol / Capitol Cetra 1951-1955 Capitol [CAP] 400N-12.7 400 N -12,7 mm
Capitol to 1954 800 -10 ES
Capitol - Telefunken 500-FLAT 500N-0 500 N 0 ES,mil
Capitol (Europ.) 1944 - 1955, ffrr, prod. by Decca UK, matrix prefix DCAP Decca 78 300N-5.5 300 N -5,7 PC
Cetra founded 1930s by RAI, Italy European 78 250N-0 250 N 0 GH
Cetra-Soria founded 1949, Cetra prod. in US European 78 250N-0 250 N 0 mm
Chappell 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 N 0 PC
Coliseum 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Columbia (American) 1926 [W.E.] American 78 250N-5 250 N -5 ES,mil
Columbia (American) 1926 [W.E.] 200 -7 ia,mil,JP,RF
Columbia (American) 1926 - 1940 (?) [W.E.] American 78 250N-8 250 N -8 mm
Columbia (American) 1938 - end, most ("Columbia Rec." a CBS label since 1938) Columbia 78 300N-16 300 N -16 ia,GH,ES,mil,mm,JP,RF
Columbia (British) 1925 - 1931, with W in a circle [W.E.] 250 W.E.mike PC
Columbia (British) from 1926, from 1931 EMI(UK) - 1953 European 78 250N-0 250 N 0 ia,GH,ES,JP,RF
Columbia (British) 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 N 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 N 0 PC
Concert Hall 500 -5 ES
Coral 1946 - 1954 629 -12 ES
Coral AES 400N-12 400 N -12 ES,JP
Decca (American) 1934 -, (Decca US established in 1934) AES 400N-12 400 N -12 ia,JP,RF
Decca (American) pre 1946 Blumlein300 300N-0 300 N 0 ES
Decca (American) very few, to try a combination of 500Hz / 6300 Hz 500N-5.5 500 N -5,5 mm
Decca (American) 1946 - 1951 Decca 78 300N-5.5 300 N -5,7 mm
Decca (American) 1946 - 1954 (??? 629 Hz ???) 629 -12 ES
Decca (American) 1951 - 1953 AES 400N-12 400 N -12 mm
Decca (American) 1953-Nov 1955 NAB 500B-16 500 B -16 mm
Decca (British) 1935 - 1944, matrix up to DR8485-2; test disc: Decca K.1803, London T.4997 Blumlein300 300N-0 300 N 0 PC
Decca (British) to 1944 European 78 250N-0 250 N 0 ES,mm
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 N -5,7 PC
Decca (British) 1944 - 1956 (to DR8485-2) Decca 78 300N-5.5 300 N -5,7 ES,mm
Decca (British) some 1949-1956 London 500C-10.5 500 C -10,5 mm
Decca (European) to 1944 European 78 250N-0 250 N 0 mm
Decca (European) 1944-1950 Decca 78 300N-5.5 300 N -5,7 ES,mm
Decca (European) 1950-1954, (Telefunken + Decca UK = TELDEC since 1950) Telefunken 400N-0 400 N 0 mm
Decca (European) some 1954-1962 CCIR 78 350N-10.5 354 N -10,5 mm
Decca ffrr 1946, same as London ffrr Decca 78 300N-5.5 300 N -5,7 ia,mil,JP,RF
Deutsche Grammophon alias "DGG", taken over by Telefunken 1937 300 -5 ES,mil
Deutsche Grammophon 1944 ca. - 1953 ca. (???) European 78 250N-0 250 N 0 PC
Dial 78s used same EQ as 33⅓ and 45s Columbia LP 500C-16 500 C -16 ES,mil
Dot to 1958 AES 400N-12 400 N -12 mm
Electrola 800 -10 ES,mil
EMI-HMV (British) some, re-releases of acoustics mastered 1909-1926 800N-12 800 N -12 mm
EMI-HMV (British) 1927 - 1953, prod. by EMI(UK) European 78 250N-0 250 N 0 GH,ES,mil,mm
EMI-HMV (British) 1931 - 1944, with □ after matrix no., [Bc] Blumlein300 300N-0 300 N 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 N 0 ia,ES,mil,JP,RF,PC
EMI-HMV (British) 11/1943 - 7/1953, matrix nos. from 2EA17501 to 0EA17576 European 78 250N-0 250 N 0 PC
EMI-HMV (British) 1955 - end, test disc: EMI JGS812, BBC DOM86 CCIR 78 350N-10.5 354 N -10,5 PC
Exclusive all, 1944 - 1949 Decca 78 300N-5.5 300 N -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 N 0 ES,mil
Harmony Acoustics to Aug 1929 300 -16 mil
His Master's Voice (Brit.) some, re-releases of acoustics mastered 1909-1926 800N-12 800 N -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.) 1927 - 1953, prod. by EMI(UK) European 78 250N-0 250 N 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 N 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 ES,mil
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 N 0 PC
Keynote 500-FLAT 500N-0 500 N 0 ES
King 500 -16 ES,mil
Linguaphone 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Linguaphone Blumlein300 300N-0 300 N 0 ES,mil
L'Oiseau-Lyre 1944 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 N -5,7 PC
London early , 1947-1948 ? European 78 250N-0 250 N 0 mil
London 1947 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 N -5,7 PC
London ffrr 1949, same as Decca ffrr (to DR8485-2) Decca 78 300N-5.5 300 N -5,7 ia,mil,JP,RF
MacGregor to 1965? American 78 250N-8 250 N -8 mm
Majestic 500 -16 ES
Marsh Laboratories (electrical) 1000 0 ES
Mercury to 1951 American 78 250N-8 250 N -8 mm
Mercury 1951 - Oct 1954; to matrix MG50026, 7000 AES 400N-12 400 N -12 ia,ES,mm,JP,RF
MGM (American) founded 1946; up to E3071 MGM [MGM] 500N-12 500 N -12 ia,ES,mil,JP,RF
MGM (British) 1949 - 7/1953, matrix no. 0SM420 500-FLAT 500N-0 500 N 0 PC
Musicraft 800 RIAA ES
Musicraft 700 or 750 -14 ES,mil
Nat. Gramophonic Soc. 1926 - 1933, with M in a circle, cat. HHH to TTT and NGS.65 to NGS.102 BBC 2dB/oct. PC
Octacros 1931 - ?, Britain, a Synchrophone label Blumlein300 300N-0 300 N 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) 400 100Hz 0 PC
Odeon 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 N 0 PC
Odeon to 1953, (1926 sub. of Brit. Columbia , 1931 sub. of EMI) Blumlein300 300N-0 300 N 0 ES,mil
OKeh 1926 - 1941 (a Columbia label since 1926) American 78 250N-8 250 N -8 mm
OKeh electricals, probably American78 250N-8 300 0 or -8.5 ES,mil
OKeh 1941 - 400N-8 400 N -8 mm
Parlophone 1925 - 1931, with W in a circle [W.E.] 250 W.E.mike PC
Parlophone 1925 - 1953 European 78 250N-0 250 N 0 GH,ES
Parlophone 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 N 0 PC
Parlophone 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 1949 - 7/1953, EMI UK, matrix nos. from CE14643 to CE14689 500-FLAT 500N-0 500 N 0 ia,PC,JP,RF
Parlophone-Odeon 1925 - 1928, with W in a circle, Odeon in Brit. [W.E.] 250 W.E.mike PC
Parlophone-Odeon 1928/29, matrix with ₤ in a circle, Odeon in Brit. 400 100Hz 0 PC
Pathé 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 N 0 PC
Philips to 1953 Philips 400N-6 400 N -6 mm
Polydor sub-label of Deutsche Grammophon 300 -8,5 or -10 ES,mil
Radiofunken Telefunken 400N-0 400 N 0 mil
RCA Victor 12/1931 - 2/1932 "long-playing" shellacs at 33⅓ rpm 500 - 700 0 PC
RCA Victor 1931/2 "long-playing" shellac, N-groove played at 33⅓ American 78 250N-6 250 N -6 mm
RCA Victor 1931 - , test disc Victor84522 500-FLAT 500N-0 500 N 0 PC,ES
RCA Victor 1931 - ?, with swastika after matrix no., (EMI reissues) European 78 250N-0 250 N 0 PC
RCA Victor 1931 - 1941 American 78 250N-6 250 N -6 mm
RCA Victor 1931 - 1944, with □ after matrix no., EMI UK reissues, [Bc] Blumlein300 300N-0 300 N 0 PC
RCA Victor 1933 375 -8,5 mil
RCA Victor 1935 300 or 500 -5 ES
RCA Victor /Victrola 1932 - 1949, with High Cut at 8500Hz 500-FLAT 500 0, later -12 PC
RCA Victor 1938 (or earlier), used High Cut at 8500Hz Old Ortho. 500N-12.3 500 N -12,6 PC
RCA Victor 1938 - 1947 500 -7 ia,JP,RF
RCA Victor 1938 - 1948 500 0 to -12 mil
RCA Victor 1938 - 1954 500 -8 ES,mil
RCA Victor 1941 - 1947 (some to Sept 1952) Old RCA 800N-8 800 N -8 mm
RCA Victor 1947 - 1951 RCA 45 800N-12.3 800 N -13,8 mm
RCA Victor 1947 (or 1950) - Aug 1952 Old Ortho. 500N-12.3 500 N -12,6 ia,mm,JP,RF
RCA Victor RIAA after 8/52, after matrix E2RP4094 RIAA 500R-13.7 500 R -13,7 ES
RCA Victor (European) 1930 - 1950 European 78 250N-0 250 N 0 ES
Regal 1925 - 1931 UK, 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 N 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 N 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 N 0 PC
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 N 0 ES,mil
Synchrophone 1931 - ?, Britain Blumlein300 300N-0 300 N 0 PC
Technichord American, all N78 from 1938 [TCH] Technichord 800N-12 800 N -12 ES,mil,mm
Telefunken 1944 - 1955, ffrr, prod. by Decca UK, Decca 78 300N-5.5 300 N -5,7 mm,PC
Telefunken 1951-1953, (Telefunken + Decca UK = TELDEC since 1950) Telefunken 400N-0 400 N 0 mm
Tempo (American) 400N-6 400 N -6 mm
Theme all N78 American 78 250N-6 250 N -6 mm
Turicaphon Switzerland, 1930 - , a subsid.of Ultraphon Telefunken 400N-0 400 N 0
Ultraphon Europe 1929-1932, taken over by Telefunken Telefunken 400N-0 400 N 0 ES,mil
Unison 1926 - 1933, with M in a circle BBC 2dB/oct. PC
Victor 1925 [W.E.] 200 - 500 -7 ia,JP,RF
Victor 1925 [W.E.] 250 or 300 0 or -5 ES,mil
Victor 1926 -1931 [W.E.] American 78 250N-6 250 N -6 mm
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
Victor see: RCA-Victor (bougt by RCA in 1930) ES
Vocalion a Brunswick label, 1926 - 1940 European 78 250N-0 250 N 0 ES,mil
Vocalion 1926 - 1933, to cat. X10029 A.0269 and K05312, with M in a circle BBC 2dB/oct. PC
Vocalion 1944 - 1955, ffrr, prod. by Decca UK, series V1000 Decca 78 300N-5.5 300 N -5,7 PC
Voice of the Stars 1931 - 1944, with © before matrix no., [Bc] Blumlein300 300N-0 300 N 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 N 0 PC
Zonophone 1931 - 1944, with □ after matrix no., [Bc] Blumlein300 300N-0 300 N 0 PC


Remarks:
  • [CAP]... used its own “Capitol curve” 400N-12.7. Play back with “AES” 400N-12!
  • [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.
  • [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: PDF An experimental replay EQ curve for this microphone / pre-emphasis combination can be downloaded here: LINK
  • [MGM] ... and Audiophile used a special “MGM curve” 500N-12. Play back with “RCA Old Orthophonic” 500N-12.3!
  • [TCH] ... Technichord used its own “Technichord curve” 800N-12. Play back with “RCA 45” 800N-12.3!
Sources:
  • Hi ... High Fidelity Magazine, October 1955 with revised “Dialing Your Disks” table.
  • ES ... Esoteric Sound [4] and the updated EQ list from the manual of their re-equalizer preamp [5] 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
  • ia ... iasa – International Association of Sound and Audiovisual Archives iasa-replay-eq [6]
  • JP ... James R. Powell Jr., “Audiophile’s Guide to Phonorecord Playback Equalizer Settings”, in: ARSC Journal 20-1, Spring 1989, pp 14-23
  • mil ... Millennia Music and Media Systems [7] and their list: MM Legacy Recordings 78 EQ Chart.pdf
  • mm ... MidiMagic [8] is probably the most comprehensive and reliable websource. Data were researched in the 1970s and are based on publications of the 1950s.
  • RB ... Richard Brice in PspatialAudio [9]
  • RF ... Russell Fisher / W.A.M.S. (Wolverine Antique Music Society) [10]
  • PC ...Peter Copeland, Manual of Analogue Sound Restoration Techniques, The British Library, 2014, [11] (Some of Copeland’s EQ curves and some of his sources are disputable!)


Recommended analogue 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.
  • Fritz Langford-Smith, Radiotron Designer's Handbook, Wireless Press, Sydney, Fourth edition, 1952.
  • James Moir, High Quality Sound Reproduction, Chapman & Hall Ltd., London, 1958



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.

In case that sources did not agree on one EQ curve, their different opinions are listed and you will have to trust your ears. Later recordings on the labels listed should be all RIAA. The following label should have used only RIAA all the time: Bethlehem, Classic Editions, Chess, Clef, Composer Recordings, McIntosh, Montilla, New Jazz, Norgram, Prestige, Romany, Roulette, Savoy and Walden [High Fidelity Magazine, MidiMagic].


Table 3: Early 33⅓ LP Labels And Their EQ (beta 2016 May 3)

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,mm
Allied to 1958 (!) Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm
Allied NAB??? 500 -16 JP
American Recording Society to 1958 (!) AES 400N-12 400 N -12 Hi,mm,JP
American Recording Society (4095 / E2KP>9607 RIAA 500R-13.7 500 R -13,7 ES
Concert Hall Marked AES, E1KP/E2KP matrix AES 400N-12 400 N -12 ES,mil,mm,RF
Concert Hall (British) to 1956 (or 1954) London 500C-10.5 500 C -10,5 Hi,mm,JP
Concert Hall (American) to 1954, XTV matrix to 20386 Columbia LP 500C-16 500 C -16 Hi,ES,mm,JP,RF
Contemporary 2504 NAB 500B-16 500 B -16 Hi,ES,mm
Contemporary 2001-02, 2501-02, 2505, 2507, 3501 AES 400N-12 400 N -12 Hi,ES,mm,JP
Contemporary after AP121 no such # in discography RIAA 500R-13.7 500 R -13,7 ES
Cook to 1958?, regular mono records 500N-15 500 N var. -12 to -15 ES,mm
Cook Labs. NAB 500 -16 JP
Cook (binaural) binaural: inside band -0 rolloff, outs.-11 dB 500 0 ins./-11 outs. Hi,ES,mil
Coral up to MG4400, (w/raised matrix) 700 -5 ES
Coral est. 1949, to 1958? (a DECCA subsidiary) NAB 500B-16 500 B -16 Hi,mm,JP
Coral 400 -12 JP
Coral 400 or 750 -12 or -16 mil
Decca (up to MG4400)(w/raised matrix) 700 -5 or -10 ES
Decca (American) 1949-1951 London 500C-10.5 500 C -10,5 mm
Decca (American) 1953, 33⅓ and 45s AES 400N-12 400 N -12 mm,JP,RF
Decca (American) 1953 - Nov 1955, 33⅓ and 45s NAB 500B-16 500 B -16 Hi,mm,JP,RF
Decca (British) 1949-1956 London 500C-10.5 500 C -10,5 mm
Decca (European) 1949-1954 Telefunken 400N-0 400 N 0 mm
Decca (European) most from 1954 RIAA 500R-13.7 500 R -13,7 mm
Decca (European) some 1954-1962 CCIR 350N-10.5 350 N -10,5 mm
Decca ffrr 1951 - 300 -14 JP,RF
Decca ffrr 1953 -  ???London 450 -10 or -11 JP,RF
Decca ffrr (>ARL1173)#  ???London 500 -10 ES
Decca ffrr (>ARL2530)# RIAA 500R-13.7 500 R -13,7 ES
Deutsche Grammophon 1952 - 1955, possibly modified with 16dB/50Hz bass shelf to IEC 78 / B.S.78 CCIR 78 350N-10.5 350 N -10,5 GH,RB
Deutsche Grammophon alias "DGG" LP -10 ES
Dial 1948-1954, 33⅓ and 45s Columbia LP 500C-16 500 C -16 ES,mil,mm,JP
Dial* bass of EP 45s improved by 700Hz t/o 500 -16 ES
Dot to 1958, 33⅓ and 45s AES 400N-12 400 N -12 mm
Ducretet-Thomson 450 -11 RF
Elektra EKL 2-15, 18-20, 24-26 (rel. 1952-55) Bartok 630N-16 629 N -16 Hi,ES,mil,mm,JP
Elektra EKL 17, 22 (released 1954) AES 400N-12 400 N -12 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 1949-1953 500 0??? ES
EMI from July 17, 1953 RIAA 500R-13.7 500 R -13,7 ES
EMI 500 -16 JP
EMI 33⅓ LP 500 -12 mil
EMI-Angel to 1952, Deutsche Grammophon sold in US 500N-16 500 N -16 mm
EMI-HMV 1951-1954 NAB 500B-16 500 B -16 mm
EMI-HMV 1954-1958? EMI-HMV LP 500R-16 500 R -16 mm
EMS 1951-1956 AES 400N-12 400 N -12 Hi,ES,mil,mm,JP,RF
Epic 1948-1954 Columbia LP 500C-16 500 C -16 ES,mil,mm,JP,RF
Esoteric (E2KP to 9607) RIAA -12 ES
Esoteric ES 500,517 and EST 5,6 AES 400N-12 400 N -12 Hi,ES,mil,mm,RF,JP
Esoteric New (Oct 1955) RIAA 500R-13.7 500 R -13,7 Hi
Festival to 1955 Columbia LP 500C-16 500 C -16 ES,mil,mm
Folkways all (1948 - 1955) Columbia LP 500C-16 500 C -16 Hi,ES,mm,JP,RF
Fraternity Records up to F-1013 RIAA 0 ES
Good-Time Jazz 1, 5-8 NAB 500B-16 500 B -16 Hi,ES,mm,JP
Good-Time Jazz 2, 4, 20 -; from Oct 1955, re-recording RIAA 500R-13.7 500 R -13,7 Hi,mm
Good-Time Jazz 3, 9-19 AES 400N-12 400 N -12 Hi,ES,mil,mm,JP
Handel Society to 1957 Columbia LP 500C-16 500 C -16 ES,mil,mm
Haydn Society to 1957; (ARL1173)# 500 -10 ES
London ffrr (>ARL2530)# RIAA 500R-13.7 500 R -13,7 ES
Lyrichord 1948-1951 Columbia LP 500C-16 500 C -16 mil,mm,JP,RF
Lyrichord 1951-1957? NAB 500B-16 500 B -16 Hi,mm
Lyrichord (XTV matrix) 500  ? -16 ES
Lyrichord 400 -16 mil,JP,RF
Lyrichord before 1953, (E0-E3 matrix) 400 -12 ES
Lyrichord if "629" listed on jacket, "newer" 629 -16 ES,mil,JP,RF
Mercury (MG10000 series-approx fit) 500 -10 ES
Mercury 1951 - Oct 1954, 33⅓ and 45s, ( E0LRC3981)# Old Ortho. 500N-12.7 500 N -12,7 ES,mil,mm,JP,RF
RCA Victor from Aug 1952 -; (>E2RP4094) 33⅓ and 45s RIAA 500R-13.7 500 R -13,7 Hi,GH,ES
RCA Victor to 1954 AES 400N-12 400 N -12 Hi
Remington to 1958? (up to 199-135)# NAB 500B-16 500 B -16 Hi,ES,mil,mm,JP,RF
Renaissance 1949-1952 Columbia LP 500C-16 500 C -16 mm
Renaissance 1952-1954 Pacific Jazz 500C-12 500 C -12 ES,mil,mm
Riverside to Sept (?) 1955 AES 400N-12 400 N -12 Hi,ES,mil,mm,JP
Stradivari to 1958 Columbia LP 500C-16 500 C -16 ES,mil,mm
Telefunken 1951-1953 Telefunken 400N-0 400 N 0 mil,mm
Telefunken 1954-1962 CCIR 350N-10.5 350 N -10,5 mm,RB
Tempo 1948-1953 Columbia LP 500C-16 500 C -16 ES,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 to 1954; most Columbia LP 500C-16 500 C -16 mil,mm,RF
Urania most NAB ??? 500 -16 JP
Urania 224, 603, 7059, 7063, 7065-66, 7069 AES 400N-12 400 N -12 Hi,ES,mm,JP,RF
Vanguard 1948-1951 Columbia LP 500C-16 500 C -16 GH,mm
Vanguard 411-42, 6000-18, 7001-11, 8001-04 AES 400N-12 400 N -12 mm
Vanguard 411-22, 6000-18 Columbia LP 500C-16 500 C -16 RF
Vanguard 411-42, 6000-18, 7001-11, 8001-04. Columbia LP 500 -16 JP
Vanguard 411-22, 6000-18, 7001-11, 8001-04 COL* or 750 -16 mil
Vanguard 411-42, 6000-18, 7001-11, 8001-04, (up to XTV20386) 500 -16 Hi,ES
Vanguard since ca 1954 RIAA 500R-13.7 500 R -13,7 Hi
Vox labeled AES AES 400N-12 400 N -12 mm
Vox (up to XTV20386), PL8400)# RIAA NAB ES
Vox 1948-1951 or labeled "LP" Columbia LP 500C-16 500 C -16 GH,mil,mm,JP
Vox 1951 - Oct 1954 NAB 500B-16 500 B -16 Hi,mil,mm,JP,RF
Westminster labeled AES; up to E2KP 9607 AES 400N-12 400 N -12 Hi,ES,mil,mm,JP,RF
Westminster labeled NARTB NAB 500B-16 500 B -16 GH,JP
Westminster to Oct 1955, up to XTV20386 Columbia LP 500C-16 500 C -16 Hi,ES,mil,mm,JP,RF


For Remarks and Sources please see below Table 1.