Kohji Matsubayashi (松林弘治)

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…

Digital image of the surface of 78 rpm record taken with optical magnification. The illumination is coaxial (the light falls vertically onto horizontal record), therefore only horizontal parts of the record reflect the light back into the optical system. These include the inter-groove surface of the record represented by the wide bands in the picture, and the bottom portion of the groove, represented by the thin lines. The scratches on the inter-groove surface are clearly seen. The size of the imaged surface is 2.35 x 2.19 mm 2 .

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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Kohji Matsubayashi (松林弘治)

Things I learned on Phono EQ curves, Pt. 0


Following is 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.

Esoteric Sound Re-Equalizer

Esoteric Sound Re-Equalizer III (above), bought in 2021
Esoteric Sound Re-Equalizer (bottom), bought in 2006

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Kohji Matsubayashi (松林弘治)

Replacing Phonomena BPS Batteries

日本に正規輸入されていないフォノイコライザ Musical Surrounding Phonomena と専用バッテリ電源キットを海外から中古で 購入 してから 5年以上が経過。さすがに充電式バッテリ電源ユニットもヘタってきたので、内部の充電池を交換。

Over five years have passed since I bought a second-hand set of Musical Surroundings Phonomena (and a companion Battery Power Supply unit) – nowadays BPS doesn’t work as expected, and it seems the rechargable batteries (in the BPS unit) have to be replaced.

[Phonomena + BPS]

Musical Surroundings Phonomena (top) and Battery Power Supply unit (bottom)
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Kohji Matsubayashi (松林弘治)


[Phonomena + BPS]

1月3日,実家から帰宅した直後にブツが到着.昨年11月末の誓い を早速破って(笑)発注していたものです.年末年始は仕事で死んでいたので,まともにセッティングしたのはその仕事が終わってから.

手持ちのカートリッジのバリエーションが少しづつ増えてきて,特に SPU Royal N や CG25Di 等,低インピーダンスのものが手元に来るに至り,今まで暫定的に (?) 使って来た コストパフォーマンスは非常に高くて手頃な値段のフォノイコライザーアンプ をリプレースしようと思ったのでした. 昇圧トランスを買う,という選択肢もあったのですが,この際フォノイコライザーアンプ自体をグレードアップしてみよう,と.

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Kohji Matsubayashi (松林弘治)

Musical Surroundings Phonomena