Simplistic NJFET RIAA

[merlin el mago]

Remenber the cap over the voltage reference in the shunt must be very well chosen...

Ricardo

At shunt do you refer to C4 220uF/63V? If yes I chose Panasonic FC because I can not get Silmic II at this voltage range.

The rest of caps for shunt are:
C1 100uF/25V Silmic II
C2 1.000uF/63V Panasonic FC

I have several BG in other diy projects that now I am not using, if the Simplistic sounds good I will try to change (for example I am sure that I have 2 BG 10.000uF/63V for PS instead the Sikorels)

 

[RCruz]

There are several distinct schematics for the same shunt... would you post your´s please ?

I mean the cap // resistor+trimmer.

 

[merlin el mago]

 

[RCruz]

In this case, C2 determines the Tone so you will hear his cap above all. (Muse produces big bass but needs a film bypass - Silmic are quite good )

IMO C1 removes harsness and I noticed big improvements in low level detail by upgrading to 220u 35v Ruby ZA (Inexpensive and VERY efective at high freq).

C4 must be transparent so I am using dedicated nonpolars here... unfortunately these are only 35V so I guess you could use ZA also.

 

[merlin el mago]

Thks for advice, the big problem here is the high voltage needed for C2 & C4, I have 4 caps 220uF/100V Nichicon Muse, do you mind will be better for C1 & C4 instead the Silmic II? I believe wil lbe better the Silmic II except for C1 is only 25V & the Nichicon is 100V here the difference is big but for C4 the Silmic II is 63V & the Nichicon is 100V there is not a lot of difference & don't believe better sound changing to Nichicon, what do you mind?

 

[RCruz]

I mean c2 is determinant for Tone.

I would use Silmic II in C4.

 

[merlin el mago]

So C1 & C4 220uF/63V Silmic II, C2 I am looking for Sikorels but I am not sure to get it.

The 10.000uF/63V Sikorels are just arrived this morning, also arrived the Denon DL-103R

 

[Salas]

Nice. How much did you pay for the 103R?

 

[merlin el mago]

227€74 in EIFL Japan

An externally hosted image should be here but it was not working when we last tested it.

Incredibly flat till aprox. till 15 KHz & from 15KHz till 20Khz + 1dB!!!!!

Give 0,29mV both channels left & right, so I will have more gain (perfect).

 

[iko]

Congrats, nice cart!

P.S. The image is too small.

 

[RCruz]

Very nice cart !

Where did you get the Sikorel caps ?

 

[merlin el mago]

From RS Amidata Online Spain:

Pasivos | Condensadores | Condensadores ElectrolÃ*ticos de Aluminio

Link for 40V & 63V, 2 units each voltage availables 48 hours.

If you have problems to buy from Portugal let me know & I you want I buy for you in Spain

 

[merlin el mago]

Rcruz,

Sikorels 1.000uF does'nt exist, I look for at Epcos Web (manufacturer Sikorels)

BG & Elna Silmic II both only arrives till 50V.

For 1.000uF/63V I only get the Panasonics FC, any better alternative?

 

[merlin el mago]

sorry duplicated

 

[merlin el mago]

trimmer caps for RIAA

Hi everybody,

I am looking for good trimmer caps for RIAA, mine preferences are PTFE film or Air dielectric (but air dielectric is very expensive & only can get till 30pF max. so I can not buy them), due to the fact the russians mica are 15.720pF 0,3% tol. & the mica Pcx are 330pF 5% tol. results a total tolerance maximum of 63,66pf so I suppose that I need something like this:

1st option teflon PTFE "the best" after air
5-60pF 250V PTFE film Vishay 3€612 each (minimum order 5)
Vishay | Pasivos | Condensadores | Condensadores Variables (Trimmers) | PTFE Film |MCO228180908003

2nd option polypropylene PP
Digikey only PP 4,5-65pF 100V Sprague-Goodman 1€15 each (minimum order 1)
Digi-Key - SG3009-ND (Manufacturer - GYC65000)

An externally hosted image should be here but it was not working when we last tested it.

More comments will welcome.

 

[massimo]

Rcruz,

BG & Elna Silmic II both only arrives till 50V.

Not true, Elna makes 63V and 100V too. Near impossible to find them, that's true. See attached data sheet.

 

[merlin el mago]

I do not see any 1000uF rated 63 or 100V in mine attached Elna Silmic II data sheets specs.?

I can not open your attached file?

 

[Audiofanatic]

Hola Merlin

"For 1.000uF/63V I only get the Panasonics FC, any better alternative? "

If I where you I'd try Panasonic FM instead of FC, again if you can find them.

Saludos,

Audiofanatic

 

[RCruz]

IMO Pana is quite honest sounding and if you use 1000u, you will not loose bass.

I got a lot of 1000u 100v Super Through... I will try those and report the results

As for the trimmers I guess the max value is 7/150pF PTFE... not enough for the 16n... You will need a third cap (220p smica maybe).

I would try a fixed 330p mica and compare with a 390p mica // CCCP silver mica 15,72nF

Ricardo

 

[RCruz]

Just for fun, here you have my artwork.... This is the result of the several evolutions on the initial project... That is why some caps do not fit