Simplistic NJFET RIAA

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Do you trust?
 

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  • Anti RIAA without lost constant parameter.png
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  • inverse riaa for 600R signal generator.gif
    inverse riaa for 600R signal generator.gif
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Merlin,
if you read Williamson and adopt his a) version you get exact values for the Rs & Cs when the Source impedance is zero.

Now read Hagerman and you will see that the Williamson values exactly match the early version fig 2.
Hagerman then goes on to show how to correct for a non zero source impedance and comes up with the final values fig 6.
Compare those to what is in post 16606
All the formulae for deriving the non zero source impedance values are given.
You could turn these into a spreadsheet to ease the arithmetic.
 

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  • riaaHagerman.pdf
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Last edited:
Member
Joined 2009
Paid Member
Merlin,
if you read Williamson and adopt his a) version you get exact values for the Rs & Cs when the Source impedance is zero.

Now read Hagerman and you will see that the Williamson values exactly match the early version fig 2.
Hagerman then goes on to show how to correct for a non zero source impedance and comes up with the final values fig 6.
Compare those to what is in post 16606
All the formulae for deriving the non zero source impedance values are given.
You could turn these into a spreadsheet to ease the arithmetic.

Thanks Andrew, is possible to mod the schematic for use 600R signal generator?
 
I think your capacitor ratios are wrong and that will give the wrong resistor values.
Check the numbers in the formulae.
Use Williamson for first guess to see if you are in the correct ballpark.

I did my own calc and poles are within 1%. But most important this schematic is used more than hundred times to measure commercial and DIY phonostages. The ones who where in compliance with the inverse RIAA where always the best sounded stages. So get rid of your spice simulation and start to listen.

My signal generator has 50 Ohm intern resistance.