Simplistic NJFET RIAA

[merlin el mago]

@Salas

Added 10nF VISHAY-RODERSTEIN MKP-1837 Metalized Polypropylene Film Capacitor in parallel to C10 4.700uF HQ 10V, incredible perfomance in highs, now I'm other new member in the list "can't live without them"

 

[Salas]

Has many ways to play. Fun project.

 

[maxpou]

Hi Guys,
here is a PCB preview of my Salas phono. Comments are welcome. Maxpou

 

[Salas]

Could return all ground lines to a star?

 

[merlin el mago]

Very good Salas advice, also I do it te star ground in the regulators, is far better solution against noise.

 

[maxpou]

Could return all ground lines to a star?

HI Salas,
the buss ground is good too if I trust the document I posted here. Maxpou

 

[massimo]

HI Salas,
the buss ground is good too if I trust the document I posted here. Maxpou

It works better when it's straight.

 

[maxpou]

It works better when it's straight.

Hi massimo,
i don't understand why straight. Maxpou

 

[Salas]

Bus bar is good. But I make it p2p and its a real thick copper bus. Since you make PCB its easier to be a star.

 

[maxpou]

Hi guys,
star ground like this. Maxpou

 

[massimo]

Merlin, most probably a proper star ground configuration don't need too many wires (or pcb tracks). IMO you can group components sharing the same potential. I.e. R2 and C10 can be linked togheter and then routed to star ground.

Here are the possible groups: Rloadx alone; D4 alone; R2&C10; C2,C3&R5; C5&R6; C6&R7, R8 alone; C9&V1 (star point). Thus you can reduce the wires from 13 to 8.
Another way is to group the signal ground all together (Rloadx, R2, C10, C2,C3, R5, R8) in bus and refer it to star ground. Moreover, D4 alone, C5&R6; C6&R7, C9&V1 (star point). Now from 13 to (only) 5 links.

Ricardo: I'm working on a similar pcb One side, can be etched at home.

....or as I suggested to Merlin.

 

[Joao@AltheaMusica]

Hi guys,
star ground like this. Maxpou

Well done

what about to use 6 pcs. 2SK170 for the input to get a better SN and an 2SK389 for the output stage?

 

[AndrewT]

2SK170 for the input to get a better SN and an 2SK389 for the output stage

Hi,
why do you think a 2sk170 will be less noisy than a 2sk389?
Why substitute an even more difficult to source obsolete devices for another obsolete device?

 

[merlin el mago]

As I know LSK389 is "on production" by Linear Integrated Systems.

 

[Salas]

Well done

what about to use 6 pcs. 2SK170 for the input to get a better SN and an 2SK389 for the output stage?

6 will oscillate. Up to 4.

 

[Joao@AltheaMusica]

6 will oscillate. Up to 4.

Thanks Salas

have you experimented with bypass caps?

 

[massimo]

Forza Inter

Merlin, would you say it again on April 20th?

 

[merlin el mago]

Massimo, not I'm sorry I only want that always Barça wins, if it's against Inter I can't say Forza Inter or Força Barça that's verys similar, I will say that's win the better playing football

 

[Salas]

Thanks Salas

have you experimented with bypass caps?

Where? Rs?

 

[merlin el mago]

Thanks Salas

have you experimented with bypass caps?

Interstage?