Simplistic NJFET RIAA

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Salas

Salas

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vgeorge said:
Looks very good Salas!
Maybe you already seen that, but I would put one more hole for the trimmers, a la BIB, in order to accommodate the various pinouts. I like the switchable
input resistors and the tight layout.
Also nice that inputs and outputs are on the back of the board, so to be close on the connectors on the back of the chassis.
Click to expand...

Many things are in the details list, also the two type pins trimmers as in the Bib1.1. This is just the vias and general layout has no designations yet.
 
RCruz

RCruz

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Salas said:
Many things are in the details list, also the two type pins trimmers as in the Bib1.1. This is just the vias and general layout has no designations yet.
Click to expand...

Can you provide caps sizes ?

I like to use 17mm diameter EL cap and big FT-3 interstage.

Output cap in the shunt could also be slightly larger so I could acomodate a 2.5cm diameter mkp verticaly ?

And one more resistor for the 47k bypass would be very good.

I really like the simetric layout :)
 
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M

massimo

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Joined 2002
RCruz said:
Can you provide caps sizes ?

I like to use 17mm diameter EL cap ....
Click to expand...

Worst case scenario (i.e. biggest elcaps) are Elna Silmic II. For the suggested values, diameters are: 1000uF/50V = 18mm and 100uF/50V = 12.5mm
Leds bypass elcap can be smaller, as I do think $$$ Silmic II isn't mandatory here: Pana FC 1000uF/16V is only 10mm, but a footprint of 12.5mm won't hurt IMO.
 
Salas

Salas

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Checking parts dimensions now. Needs little bigger diam lytics to can take Silmic II or Muse, want to add 5mm pads for certain resistors to can be Z Foil also. Various other details.
 

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RCruz

RCruz

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Please consider the option for two resistors in parallel for the 47k and the 6k8 on the riaa section.

It would also be good to have provision for two parallel caps on the 15n and the 47n.

I really like the obbligato gold for the 47n.... can it's size be acomodated ?
 
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Salas

Salas

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Tea-Bag said:
Mount too big caps on bottom like a pontoon party boat they call them here.
Click to expand...

Its trade off between loop area and subjectivity. First stage and passive Riaa should be tightly nit technically. 5mm lead spacing 1% film & foil filter caps are naturals there. PCB is PCB, it has to have some architecture and allows few certain options the most.
 
RCruz

RCruz

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The 2sk363BL came yesterday.... could not resist....

Replaced the 3 x k170 by just one k363 in each side.

K363 are 12mA so according to my calculations I got 40.6dB in the first stage and 58.6dB total Gain.

Both boards powered by the full film BiB and my initial impressions are:

Tighter bass in an overall much more cohesive sound picture presentation.... everything becomes more real... piano sounds much more like it :)

Leading edges are better defined.... must listen more

Slightly more noisy than the 2 x k170 or the 3 x k170, but noise is less high pitched.
 
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