他四十多年間，一直在做唱頭!

他 松平吉男 四十多年間，一直在做唱頭!

這位松平先生在過去四十多年間，一直在做唱頭，
也在日本許多家著名的小型Hi-End音響公司工作過，
有些極為出名的唱頭如Koetsu、Miyabi也都是出自他之手，
直到2003年，他終於自己設立了一家公司，稱之為My Sonic Lab.，
專事研究及生產低阻抗、高輸出的MC唱頭， PC-1 就是他的傑作。

高輸出的MC唱頭很難做嗎？
松平先生有詳細的說明，
他說 :三十多年來，製作唱頭的材料一直在改變，
各種很難加工的材料都已經被充分應用，
例如釤鈷磁鐵、釹磁鐵、硼針桿、紅寶石針桿、金屬外殼等等，
但是卻一直無法提高MC唱頭的輸出，特別是低阻抗的MC唱頭，
輸出電壓始終在0.2mV左右，為什麼呢？

MC唱頭低阻抗高輸出的難處

他說 : 那是因為唱頭內部的導磁鐵芯材料一直無法突破的緣故，

若要獲得高輸出，線圈繞的圈數就要多，但圈數一高內阻就高，

好不容易由唱針振動獲得的能量就會耗在線圈之中，所以音質無法好，

若是圈數低，輸出電壓就一定低，無論是動態、背景噪音都不理想，

所以低阻抗MC唱頭只能輸出0.2mV的障礙，幾十年來就是無法突破。

所以，松平吉男近年來一直在從事導磁鐵芯原料的研究，

結果終於發明了一種超高μ值原料（Ultra-hi-μ core），

稱之為SH-μX，以這種材料作成的鐵芯，有極佳的導磁性，

聚集的磁束密度，比一般的Hi-μ原料高出三倍以上，所以，

只要很少的圈數就能獲得高電壓輸出，進一步提升MC唱頭的音質，

因此PC-1這只唱頭，在2.5Ω的阻抗下，於1KHz處即能輸出0.6mV的電壓，

就低阻抗的MC唱頭而言，是一大創舉。

令人神往的規格 Phono stage amplifier

令人神往的規格 Phono stage amplifier

 

RIAA curve (曲線) ....音樂在聽RIAA是啥!

Recording 是指現場錄音麥克風收錄的音壓曲線.

1khz 以下很差大致是錄音麥克風低頻響應靈敏度差也就是性能差之故.

再此意指播放還原音壓低頻響應曲線要拉高之故.

Reproduce (也就是 playback curves)是指播放音樂時 LP放大器, 前極, 後極, 分音器, 喇叭 ....還原音壓曲線(profile)的總和.　

Magic 2 MONO equalizer design ---這DIY怎校驗ㄚ?

 LP playback curves equalizer  AKEQ-2 mono

Tube in shielding case.

LP playback curves equalizer  AKEQ-2 mono

Front view.

LP playback curves equalizer  AKEQ-2 mono

front panel

below only ....WiKi explain what's FFRR78

78rpm playback curves

Usage

These EQ curves are presented as a table of "Bass Turnover Frequencies" and "10 kHz Gain Rolloffs". 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 the list below.
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 dialogue.
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".

Now ...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.

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.

EQ Curve List

Table 1: 78rpm Playback Equalisation Curves

Label	Series	Bass Turnover Frequency (Hz)	10 kHz Gain Rolloff (dB)	LF Shelving Frequency (Hz)	Source
Acoustic Recording (such as cylinders, etc..)		0 (or as required)	0 (or as required)		1
AES	standard	400	-12		1
AFRS Transcriptions		500	0 or -5		1
Allegro		750	-16		1
Allied		500	-16		1
American Recording Society		500	-12 or –13.7		1
Angel		500	-12		1
Arizona		400	-12		1
Artist		500	-16		1
Atlantic		500	-16		1
Audiophile		300	-8		1
BBC Transcriptions	1949	500	-5		1
BBC Transcriptions	most	250-300	0 to -5		1
Bach Guild	501-529	500-750	-16		1
Banner	adjust as required	500	-16		1
Bartok		629	-16		1
Bartok	301-304, 309, 906-920	700	-16		1
Berliner	speed = 71.29 RPM	0	0		1
Blue Bird		800	-10		1
Blue Note Jazz		400	-12		1
Blumlein		250	0	50	2
Boston		COL*	-16		1
Brunswick	rare	1000	-8.5		1
Brunswick	from 1946	300	-16		1
Brunswick	early	300-500	0 or -16		1
Brunswick		500	0		3
BSI 78		353	-10.5	50 [2]	1, 2
Caedmon		629	-11		1
Caedmon	1001-1022	700	-12		1
Cameo	inconsistent, adjust as required				1
Canyon		400	-12		1
Capitol	FDS	400	-12		1
Capitol-Telefunken		500	0		1
Capitol		500	-12		1
Capitol	1942	400	-12		3
Cetra Soria		400	-12 or -16		1
Cetra		400	-11		1
Coliseum		400	-12		1
Columbia*	1925	200	-7		1, 3
Columbia*	1926	250	-5		1
Columbia*	1938-most	300	-16		1, 3
Columbia*	various	COL*	-16		1
Columbia*	European	300	-5		1
Columbia	English	250	0		3
Concert Hall		400	-12		1
Contemporary		400	-11		1
Cook Laboratories		500	-11		1
Cook Laboratories	binaural inside band	500	0		1
Coral		400 or 750	-12 or -16		1
Decca	early	150 or 300	0 or -6		1
Decca 78		150	-9		2
Decca	1946-	400 or 500	-12		1
Decca FFRR	1949	250	-5		1, 3
Decca FFRR	1951	300	-14		1
Decca	1934	400	-12		3
Deutsche-Grammophone		300	-5		1
Dial		500 or 750	-16		1
Disc		300	-16		1
Ducretet-Thomson		450	-11		1
EMI	1931	250	0		1, 3
EMI	33 LP	500	-12		1
EMS		375	-12		1
Edison		0	0		1
Electrola		800	-10		1
Elektra		629	-16		1
Epic	thru 1954	COL* or 750	-16		1
Esoteric		400 or 500	-12		1
European		280	0		1
Festival		750	-16		1
FFRR 78		300	-5	40	2
Folkways		629	-16		1
Good Time Jazz		400	-12		1
Gramophone		300	-10		1
HMV	1925-1946	250	0		1, 3
HMV	1946	400	-10		1
HMV	1946-1954	500 or 800	-16		1
HMV	American	400	-12		1
Handel Society		750	-16 or -17		1
Haydn Society		750	-16 or -17		1
Harmony Acoustics	thru 8/29	300	-16		1
Hit of the Week		500	-5		1
Kapp		700	-16		1
Kendall		629	-16		1
King		500	-16		1
Linguaphone		300	0		1
L’Oiseau-Lyre		500	-10		1
London	early	300	0		1
London	up to LL846	500 or 750	-10.5		1
London FFRR	1949-	250 or 280	-5		1
London FFRR	1949	250	-5		3
Lyrichord	early	400 or COL*	-16		1
Lyrichord	newer	629	-16		1
Mercury	thru 10/54	400	-12		1, 3
MGM		500	0 or -12		1
MGM		500	-12		3
Montilla		500	-12		1
Musicraft		750	-14		1
NAB	standard	500	-16		1
New Records		750	-16		1
Nocturne		400	-12		1
Oceanic		COL* or 750	-16		1
Odeon	early electricals	700	0		1
Odeon	pre-1947	300	-8.5		1
Oiseau-Lyre	thru 1954	COL*	-8.5		1
Okeh	electricals	300	0 or -8.5		1
Oriole	inconsistent, adjust as required				1
Orthoacoustic Transcriptions		500	-16		1
Overtone		400 or 500	-16		1
Oxford		750	-16		1
Pacific Jazz		400	-12		1
Parlophone	varies with era	300 or 500	0 or –8.5		1
Parlophone		500	0		3
Pathe	inconsistent, adjust as required				1
Period		500	-16		1
Polydor		300	-8.5		1
Philharmonia		400	-12		1
Polymusic		500	-16		1
Polymusic	binaural inside band	500	0		1
RCA Victor	early acoustics 71.29 RPM	0	0		1
RCA Victor	later acoustics 76.59 RPM	0	0		1
RCA Victor	1925 78 RPM	250 or 300	0 or -5		1
RCA Victor	1931 LP only	700 or 800	0 to –10.5		1
RCA Victor	1933	375	-8.5		1
RCA Victor	1935	300 or 500	0		1
RCA Victor	1938	500	-5		1
RCA Victor	1938 – 1948	500	0 to -12		1
RCA Victor	1938 – 1947	500	-7		3
RCA Victor	1948	500	-10.5		1
RCA Victor	1949-	500	-12 or -13		1
RCA Victor	1947 - 1952	500	-12		3
Rachmaninoff Society		750	-16		1
Radiofunken		400	0		1
Remington		500	-16		1
Renaissance		750	-12		1
RIAA	standard	500	-13.7	50	1
Riverside		400	-12		1
Romeo	inconsistent, adjust as required				1
Schirmer		1000	-24		1
Stradivari		750	-16		1
Supraphone		400	0		1
Technicord		800	-12		1
Telefunken		400	0		1
Transcriptions	various, typical	500	-16		1
Ultraphone		400	0		1
Urania	most	COL* or 750	-16		1
Urania	newer	400	-12		1
Vanguard	411-22, 6000-18, 7001-7011, 8000-8004	COL* or 750	-16		1
Velvet Tone	acoustics to 8/29	300	-16		1
Victor	1925 (see RCA Victor for 1929-)	200 to 500	-7		3
Vitaphone		950	-18.5		1
Vitaphone	motion picture	300	0		1
Vocalion	electricals	300	0		1
VOX		500 or 750	-16		1
War Department	12” Special Services	700	-5		1
Western Electric	early transcriptions	300	0		1
Westminster	pre-1956	500 or 750	-16		1
Westminster	“AES” printed on jacket	400	-12		1
Westrex		200	0		1, 2
Westrex (later)		300 or 500	0		2
Zonophone	early 71.29 RPM	0	0		1
Zonophone	most	300	0		1

• COL - Some recordings require a Bass Turnover of 300 Hz or 500 Hz, a 10 kHz rolloff of -16 dB and a LF Shelving filter at 100Hz.

This is often referred to as a "Columbia curve".

Table 2: Pre-1955 LP Playback Equalisation Curves

Label	Series	Bass Turnover Frequency (Hz)	10 kHz Gain Rolloff (dB)	LF Shelving Frequency (Hz)	Source
Angel		500	-12		3
Audio Fidelity		500	-16		3
Bach Guild	501-529	500	-16		3
Bartok	301-304, 309, 906-920	629	-16		3
Boston		500	-16		3
Caedmon	1001-1022	629	-16		3
Capitol		400	-12		3
Capitol-Cetra		400	-12		3
Cetra-Storia		(a)500 or (b)400	(a)-16 or (b)-12		3
Colosseum		(a)400 or (b)500	(a)-12 or (b)-16		3

New handmade DAC

New handmade DAC CS8416-WM8742-E88CC with volume control

Friend's DAC and XMOS dongle.

Friend's DAC and XMOS dongle.

XMOS dongle convert USB to RCA spdif signal.

ToyX project EQ Linearizer study ....Add Output transformer

Attach modify schematic drawing.
Fix impedance for better audio matching.

Modify R channel wire connection and add OTP.


Modify L channel wire connection and add OTP.



First time just modify one channel and after A-B test decide to replace two channel together.
響應較佳 ,音像刻化, 音場,音色線條深刻都有更進一步, 自然.

Toy3 D/A couple capacitor of Balance output estimate -2 more cap. & different value

D/A couple  capacitor of Balance output estimate -2 more cap. & different value


Unknown PP couple capacitor.
Audio shallow, Sounds too rough.


Bennic PP couple capacitor.
Sounds not rich.


Old CDET 2.2uf/200v  PP couple capacitor
Clear body line sound cool & thin.
.

New CDET 5uF/100V PP couple capacitor.
Clear body line sound better than before.


ROE 10uf/68V pole couple capacitor
Clear body line sound got a little lite mean sound density not enough.



ERO 4.7uf/100V PP couple capacitor
More sound detail ,sound density enough but Low frequency responce not good feel empty.


ERO 6.8uf/100V PP couple capacitor
More sound detail ,sound density enough Low frequency responce  feel better now.


ERO 10uf/250vV PP couple capacitor.
Better response ,sound field of the deep carved ,Low freq. got vigorous tone.
All benchmark base on WM8741+PWM Filter OP AD827AQ+ Differential combiner OP AD797AN.
Sonic Frontiers Corp. have a research paper mention one type D/A usage same value 10uf cap. is better too .
For your reference.

ToyX project EQ Linearizer study ....Battery Power

EQ Linearizer 電源是大問題,喇叭效率超過95dB時,100hz以下AC 60hz容易peak進去,over 4khz以上又容易有高頻訊噪,高音會ㄘㄘ聲,解了下面100hz訊噪,over 4k 訊噪不好解 ,所以用電池.





The Battery box usage 4 cells (2S2P) Li-ion output 8.2V/5.2A (peak current limited in 5A).
No fuse and auto Over current ,Low Voltage,Over Temperture protection.




The EQ Linearizer remote power circuit clamp chock to reduce EMI influence.
L Channel and R Channel power path add diode to separate cross influence.




The battery module could stand alone into charge mode . So no AC noise.

The battery cells will  separate to open and charging by single cell  charger therefor no unbalance issue.

Toy13 D/A with tube amplifier

D/A High voltage use R-L-C-L-C net to generate 230V for Tube 6922 plate-voltage.
Rectifier is 6Z4 and put in delay-on function.


D/A output OP +15/-15V power supply by switching power.


Spdif receiver is CS8416 and Codec is WM8741.


All circuit design usage SMT components.
Serial audio path usage DIP components for high Q factor issue.


The view of Audio signal switching and audio-input of tube.


D/A Top view picture.


Add 6922 heater R & C components.



Add Tub output OPT for good sound.

ToyX project EQ Linearizer study case5

Put L channel EQ module and check out the hole of screws.


Assemble copper cylinder prepare for put on R channel EQ module.


Check out two channel EQ modules structure.Meet design or not.


Another view.


Assemble Fuse,RCA connectors,Volume knob,power switch.

Finish wires jump between each band and volume knob.

Another view.