2022/11/30

Things I learned on Phono EQ curves, Pt. 7

前回 Pt.6 では、アセテート録音機の誕生、そこで使われていたカッターヘッドの記録特性、横振動盤再生時の高調波歪の論文、1938年時点での超軽量ピックアップの開発など、あれこれについて調べました。

On the previous part 6, I studied on the advent of instantaneous lacquer disc recorders, frequency responses of the instantaneous cutterheads, an important paper on harmonic distortion of phonograph reproduction, development of ultra-lightweight pickups in 1938, etc.

今回はその続きで、ジュークボックス の登場、圧電式ピックアップ の登場、時代の徒花(?) 定振幅録音特性システムの試み について学んでいきます。1942年（放送局トランスクリプション用）NAB録音再生カーブの策定、そして戦後のマイクログルーヴLP時代まで、あともう少しという感じです。

This time, I am going to continue learning the history, including an advent of “jukebox” players and piezoelectric pickups, as well as the attempt of “constant-amplitude” recording/reproducing that proved abortive.The standardization of the 1942 NAB curve (for electrical transcription discs) and the advent of microgroove LPs are just a few steps ahead.

source: “Sound recording and reproducing system”, US Patent 2,139,916, by Stuart W. Seeley.

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2022/11/18

Things I learned on Phono EQ curves, Pt. 6

前回は、ストコフスキーのエピソードの他、横振動トランスクリプション、RCA/NBC が1939年に発表した Orthacoustic 特性など、あれこれについて調べました。

On the previous part, I studied on the interesting episode of Leopold Stokowski with Bell Telephone Laboratories, lateral transcription discs, RCA/NBC’s Orthacoustic characteristic, etc.

今回はその続きで、アセテート録音機の登場、業界を震撼させた技術論文、および現代につながる超軽針圧ピックアップの開発などについて学んでいきます。放送局トランスクリプション用である1942年NAB録音再生カーブの話まで、あともう少しです。

This time, I am going to continue learning the history, including an advent of instantaneous disc (lacquer) recorders, the technical paper that shook the industry, and ultra-lightweight reproducing pickups that definitely was the pioneer of the modern pickups we now use. This article is coming a few steps toward the 1942 NAB standardization (for electrical transcription discs).

source: “Presto Recording Corp: Pioneers of ‘Instant’ Analog Disc Recording”, Preservation Sound website.

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2022/11/02

Things I learned on Phono EQ curves, Pt. 5

前回は、トーキー映画用のディスク録音、民生用長時間レコード、放送局用トランスクリプション盤、ベル研/WEの縦振動トランスクリプション盤など、あれこれについて調べました。

On the previous part, I studied on the history of the “sound-on-disc” soundtracks for talking motion pictures, “Program Transcription” long playing record for consumer, Electrical Transcription discs for radio industry, Bell/WE’s vertical transcription technology, etc.

今回はその続きで、放送局用の横振動記録トランスクリプション盤のあれこれ、及び初の録音再生統一カーブ “Orthacoustic” について学んでいきます。

This time, I am going to continue learning the history, including the lateral transcription records, as well as the first recording/reproducing curve ever published – called “Orthacoustic”.

source: “Adoustical Scoiety Hears New Vertical Recordings”, Bell Laboratories Record, Vol.10, No. 10, June 1932, p.370.

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2022/10/17

Things I learned on Phono EQ curves, Pt. 4

前回は、大恐慌時代の1930年代前半、WE特許使用料回避のため生まれたBlumleinシステムや、当時のRCA VictorやColumbiaの状況など、あれこれについて調べました。

On the previous part, I studied on the history of the improvement of disc recording technology for commercial discs, including the Blumlein system, situations of RCA Victor and Columbia in the 1930s (during the Great Depression), etc.

今回は、民生用ではなく、映画用・放送局向けのレコード技術 の話、そして初めてS/N比向上の目的で 意識的に高域プリエンファシスが用いられた録音技術 について学んでいきます。

This time, I am going to continue learning the history, from the disc recording technology for professional talking motion pictures and broadcast stations (not regular records for consumer market), and the very important technology that consiously used treble pre-emphasis for the first time in history, to increase S/N ratio.

Vertical cutting vs Lateral cutting (Read, 1952)

source: “The Recording and Reproduction of Sound”, Oliver Read, 2nd Edition, 1952, p.21, Fig. 3-3B.
縦振動記録（左）と横振動記録（右）の比較

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2022/10/10

Things I learned on Phono EQ curves, Pt. 3

前回は、電気録音黎明期のあれこれについて調べました。今回は、その後発展していく電気録音、そして 1930年前後の各レーベルの状況 について引き続き調べていきます。

On the previous part, I studied on more of the history of Electrical Recording in its very early years, along with several digressions… This time, I am going to continue learning the evolution of the electrical recording, as well as the situation of record labels around the 1930s.

American Epic; Recording The {Twenties, Thirties}

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2022/10/03

Things I learned on Phono EQ curves, Pt. 2

「Pt.0 (はじめに)」、そして「Pt.1 (定速度と定振幅、電気録音黎明期)」の続きです。

This article is a sequel to “Things I learned on Phono EQ curves, Pt.0” and “Things I learned on Phono EQ curves, Pt.1”.

前回は、いろいろ脱線しながら（笑）レコードに記録される2つの特性と、電気録音黎明期のあれこれについて調べました。今回は、EQカーブの話を離れて、電気録音黎明期のあれこれ についてもう少し調べていきます。

On the previous part, I studied on two recording characteristics (constant velocity and constant amplitude), as well as the history of Electrical Recording in its very early years, along with several digressions… This time, I am going to continue learning other things during the early days of electrical recording, apart from EQ curves.

Brunswick Panatrope Ad, The Talking Machine World, Feb. 15, 1927, p.5

source: Brunswick Panatrope Ad on “The Talking Machine World, February 15, 1927”, p.5.

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2022/09/27

Things I learned on Phono EQ curves, Pt. 1

Pt.0 (はじめに) の続きです。

This article is a sequel to “Things I learned on Phono EQ curves, Pt.0”.

レコードのEQカーブについて深掘りする前に、そもそも なぜイコライゼーションが生まれたのか、なぜ必要とされたのか、その歴史から調べてみることにしました。また、更にさかのぼって、音を溝に記録するとはどういうことか、についても学び直すことにしました。なので、カーブの話に到達するまでに長い道のりになってしまう予定です（笑）

Before digging deeper about EQ curves, I started to study from the very beginning: why the EQ curve was born, why it was/is needed for phonograph recording (and playback). Also, I tried to re-study the very basic – how the recording sounds are converted to a modulated spiral groove. So I’m afraid it will take very long before I reach the story of the EQ curve itself…

Audio Reconstruction of Mechanically Recorded Sound by Digital Processing of Metrological Data – Scientific Figure on ResearchGate.
Available from: https://www.researchgate.net/figure/Digital-image-of-the-surface-of-78-rpm-record-taken-with-optical-magnification-The_fig1_242606860 (accessed 4 Sep, 2022)

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2022/09/23

Things I learned on Phono EQ curves, Pt. 0

以下、持論・異論・珍説が飛び交う、議論多き「フォノEQカーブ」について、1920年代電気録音黎明期にまで歴史を遡り、録音・再生カーブのみならず、ディスク録音全般について、正しく理解するために勉強した軌跡です。長編になります。

Following is just the beginning of the long series of the study I have been doing for a while, regarding the controversial topic “Phono EQ Curves” – people having various opinions on it, although many of them are subjective and not scientifical. I started the study and research of the history of disc recording as a whole, from the very early electrical disc recording technology in the 1920s.

我が家では15年ほど前から、78rpm や非RIAA LP用に Esoteric Sound (Rek-o-kut) Re-Equalizer という簡易式アドオン型フォノイコライザを使用しています。実は昨年、Re-Equalizer III という最新バージョンに置き換えたのですが。

Since 2006, I’ve been using Esoteric Sound (Rek-o-kut) Re-Equalizer (actually I replaced it with the most recent version Re-Equalizer III in 2021) for 78rpms and pre-RIAA LPs. It’s a niche phono EQ compensator.