Two question about RBJ Peak filter
Maybe this thread helps you in this Q - Prewarping both resonant frequency $f_0$ and bandwidth (or $Q$) when using bilinear transform
H(s) is the s-plane transfer function

Analog prototype of RBJ peak filter (Octave):



K  = 10^(gain/40);
w0 = 2*pi*fc;
% H(s) = (s^2 + (K w0/Q)*s + w0^2) / (s^2 + w0 s/(K*Q) + w0^2)
BC = [1 K*w0/Q w0^2];
AC = [1 w0/(K*Q) w0^2];