Matlab & Gen

Thanks for clarifying, Luigi! I implemented your correction and suggestion and it sounds a lot better now :)

I'm at a stage where I'd like to implement the Transistor Booster Stage of the Boss DS-1 emulation, but I'm not quite sure what to make of A = [A0, A1 ,A2];
B = [B0, B1, B2];I understand that A / B are filter coefficients, but I don't know what it means that they get calculated by their respective array of A1/A2/A2 or B0/B1/B2.
Also, what type of filter is the standard filter function in Matlab?

% Transistor Booster Stage
% Implementation by Nestor Napoles Lopez
% based on the paper by Yeh et al. (2007)

function y = bjtfilt(x, fs)

% After working the math, I put all the discrete-time
% coefficients in terms of this variable coeff
coeff = pi/fs;

B0 = 1;
B1 = -2;
B2 = 1;

A0 = 1800.*coeff.^2 + 603.*coeff + 1;
A1 = 3600.*coeff.^2 - 2;
A2 = 1800.*coeff.^2 - 603.*coeff + 1;

% We obtain the gain from
% 36dB = log10(x) * 20
amp = 10.^(36/20);
B = amp .* [B0, B1, B2];
A = [A0, A1, A2];

y = filter(B, A, x);

end