Simplistic NJFET RIAA

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That is 2nd stage. You got it OK. If you want to play with gain you vary R2 slightly. That one drops more on R1 and ups gain or vice versa. Because the signal level is slight there, THD remains about the same. I don't recommend playing with 2nd stage for gain because it influences the total gain less drastically but changes THD by moving the bias point of the Q5 buffer. You may try optimize the distortion profile to your ears there, 10-11V Q2D-GND is where it measures best in general. Whatever you may like, stays matched between channels on second stage. First stage is much more suitable to balance out any total gain differences between channels. Takes output measurement capability when steady under mV signal is present on input somehow.
 
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Its already set by design. But jfet differences always hover around optimum if you got FFT to see THD or listen critically. The 2nd stage's drain voltage sets it. If you use a trimmer instead of a source resistance in second stage and play, don't exceed the buffer Jfet's Idss judging by the drop on its source resistor/value.
 
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Hi,
Merlin,
You prefer the Obligatos over the Auricaps, can you explain/elaborate.
I was thinking about getting auricaps for the output.
Thanks
Pete

Hi psgr,

All depends what are you looking for, if you are looking for a warm/round sound without lost a lot of definition your election must be Auricaps or if you are looking for more resolution I will choose Obbligato's, that's are mine subjective opinion & of course all depends the system and your personal taste.

Both are very good caps at a very reasonable prices & worth the penny.

If possible try with the maximum voltage possible because subjectively there is a lot of difference of quality with more voltage.

Best,
Felipe
 
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Do you believe these would be suitable replacements for shinkoh in the cart load ?

Of course, in the cart load & in the RIAA, if you can afford use it minimum in the signal way or critic places.

You get more harmonics due to the low noise: transparent / clear sound, the bass more defined never lost & deep, the mids incredibles it' impossible hear more things & the highs simply perfects.

Versus Shinkoh the difference is that the mids & mids/bass are not inflated but with body, the bass is more controlled & deep, the highs aren't liquids like the Shinkoh but have more air or atmosphere for me are more real, is really difficult to express all in words.