~ RIAA – 4 Configuration Calculator ~

Calculates the component values to make a passive 'all in one' or 'lumped' RIAA replay equalisation [EQ] network of my type RIAA–4 as shown in this pdf and below ~ This 2 terminal 2CR topology can be used for record or replay EQ developing a voltage across it or current through it depending how it is driven and terminated but it cannot be 'opened' into a 4 terminal network for passive EQ

T3   µ	T2  µs	T1  µs	Sig. Figures
ƒ=  Hz	ƒ=  Hz	ƒ=  Hz	Calculated –3dB corner frequency ƒ=1/2πT
The table below has one component Value in each row that can be changed to accurately calculate the other 3
R7  kΩ	R8  kΩ	C7  nF	C8  nF
R7  kΩ	R8  kΩ	C7  nF	C8  nF
R7  kΩ	R8  kΩ	C7  nF	C8  nF
R7  kΩ	R8  kΩ	C7  nF	C8  nF

I refer to these 2 terminal 2CR networks as 'current driven' because they can be used as the output load of a Transconductance amplifier which could be the collector of a transistor with un-bypassed emitter resistor or the anode circuit of Cascode or Pentode where the current develops the RIAA equalised output voltage across the network

This is my least preferred topology for an RIAA network as the values do not fit the standard available so it should suit those who like making odd values from multiple capacitors ~ It does like my favorite RIAA-1 allow the outer foils of both capacitors to be 'near' or connected to signal ground so they can be against a ground plane without affecting the response

Unlike the networks RIAA–1 and RIAA–2 this topology and RIAA– 3 cannot readily be corrected for response errors due to the impedances either side or across the network due to high values Rfb [NFB] and amplifier output impedance which upset the response and cannot be fully corrected by making R7 larger as some designs do ΐ

" The busy world was not for me ~ So I went and found my own "