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    -オーバーハングの誤差計算    Overhang adjustment on shell or bedplate: EXCEL files in Japanese

    -SME3009impの謎    Mystery of SME3009imp

                -アイクマン氏の製品化されなかったアーム    Interesting design by Aikman still awaiting to be embodied?

    -MICRO MA-505の測定    Test of MA-505 tone arm

    -バネ式キャンセラー    Simulation of anti-skating devices using spring wire or coil: CEC/Dual tone arms etc.

    -Keith Monksのマグネット式キャンセラー    Simulation of anti-skating device using magnets in case of Keith Monks M9BA MK3 tone arm

    -初めてのリニアトラック    Salvage of junk linear trackers

    -自作ワンポイントアームの実験    Experiment of one-ball-point arm & arm damping simulations

    -シェル周りのいろいろ    Various designs around head shells and cartridges

    -特許図に見る珍しいアーム    Uncommon arm designs and their patents

アームコード(Phono Cable)


    -テストレコード・コンプライアンス・共振周波数・機械インピーダンス・針圧など    Test records/compliance/resonance frequencies/mechanical impedance/tracking force etc. Recently (April 2021) I omitted some referenes to Stevenson/Bastiaans/Hunt/Yamamoto/JVC and others since these references are for my reading only and nobody cares now.

    -周波数基準レコード    LF-1003 Frequency Test Record from Toshiba EMI and responses of 4 monaural cartridges: AT-MONO3/LP, DL-102, SPU mono GM & XL-55mono. These manufacturers indicate output in mVrms for lateral modulation peak velocity 5cm/s at 1kHz. Hence simple division as sensibility (mV/cm/s) is invalid.

    -JVC TRS-1007 and a list of test records    Sweep Frequency Test Record by JVC: reference levels 3.54cm/s peak for 45degrees and 5cm/s peak for lateral or vertical -these reference levels seem to be common in Test Records made in Japan.

    -特許図に見る珍しいカートリッジ    Uncommon cartridge designs and their patents

    -PICKUP DESIGNS extracted from "THE GRAMOPHONE HANDBOOK" (1957) by Percy Wilson  モノラル時代のカートリッジの諸問題について示唆に富む解説がなされていたので抜粋しました(P72-P77)。 History of early pickup designs (crystal and MC and MI etc) including Generating System of VR (variable Reluctance) pickups by GE/Tannoy/Goldring once popular in monaural LP era. MI (Moving Iron) system for both recording and reproducing record started as Balanced Armature/Rocker System without any cantilever in SP era which was further developed to Variable Reluctance system with cantilever in LP era. Interestingly MM is not mentioned in this book (1957) since MM & MC cartridges are late bloomers in pickup history (invention of strong miniature magnet for MM from late 1950s and high SN step-up head-amp for MC).


    -DP-2000の測定(ワウフラッター計など)    Measurements of turntable DP-2000 & Wow-flutter meter LFM-39A

    -50Hz100/3回転専用ストロボ盤    Stroboscopic Disc for 50Hz 100/3rpm 

    -strobe patterns    Excel file in English: analysis of strobe patterns for 50Hz/60Hz containing the dot patterns for 33.3/45/78rpm

    -いろいろなレコードマット形状    Various shapes of record mats and various isolating designs


音響素材(Materials for tuning audio equipments)

フォノアンプ(Phono Amp)

    -MMの負荷計算    Calculation table of MM loading resistance & capacitance

    -イコライザーの再生波形    Reproduced wave form of equalizers

    -古いLP再生カーブ    Personal Notes on Old LP Reproducing Characteristics and Text of IEC98 Appendix

    -NAB meeting on 16 Sept. 1947    From Audio Engineering Magazine October 1947 P.32

    -再生カーブシミュレーション    Excel Sheets in English simulating various playback equalizations for LP records though these old characteristics are quite disputable. It contains four spread sheets: EXAM(history of records and equalizations), IEC Standard, LP (various equalizations during 1948-1954) and QUAD22 as an example of equalization set.

MUSICAL BALANCEに関連した考察    「周波数レンジの狭窄」frequency-range preferenceが意味するもの。 Percy WIlson in his book (1957) indicated  640000 Hz^2 rule. Similar passage about the product of the low and high cutoff frequencies as 500000 Hz^2 was found in book (1964) by Olson who introduced frequency-range preference by narrowing the range of reproduction similar to old record and radio sound. Some comments on old age hearing and the essence of music in this connection.

SP再生実験記(Experiment of easy SP Player)

自作か蒐集趣味か(Home-made or Junk Collector)

秋葉原(Akihabara Electric Town)

オーディオ誌(Audio Magazines)

レコードあれこれ(Record Collection and Note)

    -レーベル面とカートリッジ針のマーキング    Label Information and Markings for Cartridge etc.

    -ジャケット    Specifications of Jackets

    -忘れ去られたレーベル    Forgotten・Discontinued Labels

    -中古盤の格付け    Ratings of Second Hand Records

    -RIAJの統計より    An analysis of RIAJ statistics

    -カッター先端部の一例    An example of JVC cutting stylus, Westrex, Neumann and Ortofon cutter heads

            -90 degrees (difference) writing of stereophonic sound: L/V(0/90) & 45/45(135/45 in Cartesian coordinates)   
            An EXCEL SIMULATION in English to know stereophonic recording on single groove

            -US特許にみる録音自動補正の歴史    Historical overview of automatic tracing simulators & recording compensators

            -特殊な音溝特許    Some patent applications for Queer Sound Grooves including Edison Diamond Disc.

測定器(Measuring Instruments)

ポータブルCD用電源(Power Supply for Portable CD Players)

    -CDの再生波形    Reproduced wave form of CD


怪しい図解(Drawings for Crafts)

超音波洗浄の試作実験(Experiment of Supersonic Record Cleaner)

    -DG-1R(超音波洗浄機の改造製作記)    Modification of DG-1 Supersonic Cleaner

    -レコード洗浄用アイテム    Gallery of Record cleaning items


AUDIOTOOL (邦文エクセルファイル) dB換算/RMS/Unit換算/HPF/LPF/電解コンデンサー使用寿命の6シートからできています。Excel files in Japanese for dB, RMS, Unit, HPF, LPF and Electrolytic Condenser Life.


To Readers of my pages: I am audio hermit, not engineer nor specialist but simply interested in analog records and their history. My pages are not built as lecture to you, but my personal notes including plenty of odds and ends (foods for my further thinking). Fish bone (obsession) got stuck in my throat. It was my problem and not yours. / Fish bone got stuck in your throat. It was your problem and not mine. I feel sorry for your obsession if it is invoked by some passages in my pages.

The following pages are in English

Line-up: My Audio System in my hobbit hole

Personal Note on Record Specifications Too much detailed (dense?) in order to shut loose tongues

    -Comparative Table of Standards for 30cm LP: Dimensional Specifications defined by IEC/BS/DIN

    -JIS S8502-1973(Disk Records) etc: showing the dimensions and drawings of records specified by JIS. The drawings by IEC/BS are shown for comparison. DIMENSIONS OF SP (coarse groove) are also shown on trial for comparison and reference. 

    -VTA variation: Vertical Tracking Angle of Cartridges and related views

    -Distortions.xls: simulating various distortions peculiar to LP playback

Table of Tone Arm Data: Effective Length, Distance and Overhang

    -Armtrack.xls: simulations of lateral tracking of arms containing four worksheets "Overhang on shell", "Graph", "Designs" & "Arm Data"

    -Alignment.xls: showing Two Lateral Aligning Methods: Shift on shell/Shift on bedplate are similar in effect

    -Various Alignment Gauges: various designs of alignment tools in the past

The following EXCEL FILES are independent from other pages. These files can be modified at your end after downloading. Generally: values in yellow cells are parameters to get results in grey cells. You can change numerical values in yellow cells and see the corresponding results in grey cells.

Anti-skating device for 3009imp: simulating anti-skating and side forces.

Anti-skating device for AT-1005II - another simulation of representative line & hanger type bias mechanism explaining skating force and bias force. The bias lever distance from center of pivots, bias lever angle to bias hanger point and bias weight besides average friction coefficient are essential parameters for this simple mechanism. Accordingly you can design similar mechanism by yourself.

Anti-skating device at Dual1019 etc - simulation of representative spring bias mechanism.

Anti-skating device at Micro MA505 - another simulation of spring bias mechanism.

Bias Devices at Arms - An overview of applied anti-skating devices and my simulations about deformed arm pillar designs: CRESCENT and OVAL - you can laugh at these sheets as high-schoolboy's examinations.

Arm Data Calculator: supplied by Brian Kearns, my guru and modified by me. The modification is simple editorial matter: 1) indicating corresponding Overhang and Linear Offset Length  2) cancelling  "Protection" and enabling users to modify the sheets. Caution: check carefully at the time of closing these worksheets whether you want to save your modification or not. The file contains a sheet based on any optional inmost and outmost sizes of grooves - these are most important because the optimum alignment is varying according to the size and kind of record to be played on: LP or EP or SP (EP and SP are often recorded inner than LP).

Denon Cartridges: personal data base for technical specifications of Denon cartridges.

List of US Patents: related to analogue disk records - these are selected by my own interest. There we find many realised products or ideas to be realised or unrealisable ideas. It looks like virtual museum for analogue audio development.

MMLoad: simulating electric damping on Magnetic Cartridges.

Resonance: simulating/calculating resonance frequency/effective mass/compliance or stiffness.

Stevenson: My reading and application of Stevenson method etc.

Stylus: Contact area simulation of spherical tip on groove flank. Excerpt from Bastiaans/Walton papers. Also study of cutting stylus dimensions and maximum recordable velocities. Process of making bonded diamond stylus and block diamond stylus.

A history of patented auto-offsetting arms & moving pivots: These simulations in EXCEL are not related to actual embodiments. Trial and personal simulations only for understanding how they work.

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