Presonance Control for NFB Martin P Manning January, 2012

Rev. 1, March 2012

C1

R FB

R Tail

RV1

Presonance

Control Pot CW From

OT Tap

C

Pres

R1 = R FB

R2 = R Tail

R3 = 2 * R Tail

C1 = C Pres *(1 (R FB / R Tail) /40) C2 = C Pres * (R FB / R Tail) /40

(with the intent that C1 + C2 = C Pres)

RV1 = 2* R Tail to 4 * R Tail , 10% Audio Taper

C2

R1

R2

From

OT Tap

A

To Point A

Typical Feedback and Presence Control on

long-tailed pair phase inverter.

Presonance Control

Presonance control replaces existing FB and presence NW

at right. Choosing component values as described

replicates original Presence function (CW rotation from 50%) and adds Resonance function emphasizing bass (CCW rotation from 50%).

R3

Example:

Original circuit R FB =100k, R Tail =4k7, and C Pres =0.1uF

A

0.05uF

Presonance

10kA

CW

0.05uF

100k

4k7

From

OT Tap

Presonance Control

Presonance Control for NFB Martin P Manning January, 2012

Rev. 1, March 2012

10k