Simplistic NJFET RIAA

I used the styroflex with no audible change and also few minutes ago i changed Cout with some Mundorf Mcap and the coupling capacitors between stages from 47n polyester with 100nF mylar and there is a slight improvement in vocals but still sounds thin with not enough bass. I can hear every small piese of dust from disc :)
Tommorow i will try to build the shunt to see the difference.
 
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Hi atupi

Did you measure the riaa capacitors and resistors with a dmm ?

Can you post the actual measured values ?

salas riaa should not sound "thin"... maybe you did not use the exact values stated in the pdf....

This design is powerfull sounding if carefull matching is done between channels
 
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I have only a Fluke 177 and resolution for capacitors is 1nf. Before soldering on pcb i checked all the components to see actual values.
Maybe my cart is too cheap but with my other preamp opamps based sounds fuller, rounder.
I've just tried to disconect\conect 220pf capacitor during music and i cannot hear any change with\without this capacitor. Only audible change is related to the value of loading resistr.
 
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Here is a good tip... try placing a 1mega ohm resistor parallel to R4 (6k8r).. you can use miniature aligators to do it so you do not need to solder anything.

Lowering R4 produces a more rouder sound, less harshness and less nasality.

Also If R3 (47k) is too low, you loose bass presence ... Some like to call R3 the "bass resistor"... it should be spot on 47k
 
Resistors: 2,36k and 47,3k
2,38k and 47,07 k and i think they are carbon. Unfortunately our local dealers dont provide better options only basic stuff.

For 15,6nf i have tried poliester and mylar with same sonic results.

After setting 11V for the second stage as Salas recommended the sound changed to a better way for may ears but on some types of music the sound is muddy so i changed back to 13V.
Should i expect some noticeable sonic changes when i will have the shunt ready ?
 
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If they are lit brightly and you see no oscillation on the rails with your oscope as you thoroughly described, then I have no way to suspect something else. Stick a metal Pi shaped leaf on top of those transistors with some resin to keep them cool at least.

I've sorted it finally, I had mis-labelled my 3.3k resistors when I got them, so R5 and R6 ended up being 330 ohm!

I've replaced R5,R6,Q3,Q4 and D1 to be on the safe side. All is fine now. I'm usinr 4R7 for R1 and wouldn't want to go any lower, I'm using the pre-amp chassis as the heatsink and it gets to about 60-70C. Once again, thankyou Salas. The Simplistic phono just gets better and better!
 
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After setting 11V for the second stage as Salas recommended the sound changed to a better way for may ears but on some types of music the sound is muddy so i changed back to 13V.
Should i expect some noticeable sonic changes when i will have the shunt ready ?

There is 12V midway also to check. Yes, the shunt helps in tonality and apparent ''body'' of sound.
 
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I've sorted it finally, I had mis-labelled my 3.3k resistors when I got them, so R5 and R6 ended up being 330 ohm!

I've replaced R5,R6,Q3,Q4 and D1 to be on the safe side. All is fine now. I'm usinr 4R7 for R1 and wouldn't want to go any lower, I'm using the pre-amp chassis as the heatsink and it gets to about 60-70C. Once again, thankyou Salas. The Simplistic phono just gets better and better!

When there is smoke there is fire... it was a typical value mistake, now its explained. Fine, have many good record playing sessions.
 
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Resistors: 2,36k and 47,3k
2,38k and 47,07 k and i think they are carbon. Unfortunately our local dealers dont provide better options only basic stuff.

For 15,6nf i have tried poliester and mylar with same sonic results.

After setting 11V for the second stage as Salas recommended the sound changed to a better way for may ears but on some types of music the sound is muddy so i changed back to 13V.
Should i expect some noticeable sonic changes when i will have the shunt ready ?

Try placing a 1mega ohm resistor parallel to R4 (6k8r).. you can use miniature aligators to do it so you do not need to solder anything.
 
So i finalized my shunt. Worked from start. Thanks to Klewis i had a pcb design and work was faster. I need to find proper heatsinks also. I used IRFP9140 for Q1 and IRF9540 for Q4. For Q2 i used BF245A.
Q1 is just a bit warm but Q4 is really hot. Set the output voltage to 20V like Salas says.
Now, with the shunt, i think the sound changed a bit and tomorrow i will try some new adjustents for the buffer and maybe the loading. The preamp is not so bright now like it was before shunt.
Now i'm very nervous waiting for my new Nagaoka cartridge to see how it sounds.
Hopefully i will find some good capacitors for interstage coupling (teflon maybe) to see how they sound.
Thanks Salas and the other guys for help.
 

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Its coming out nicer bit by bit, that is cool. The two black electrolytics in your regulator can be influential. You may try Nichicon KZ (balanced resolute sound), Silmic II (deeper rounder sound a bit slow) at a point for those. And of course a bigger sink for the output Mosfet. Keep us posted about your progress.