Revert to full solution, this taylor expansion sucks && revert tube params

2 files changed, 22 insertions, 30 deletions

diff --git a/plugins/ZamTube/triode.cpp b/plugins/ZamTube/triode.cpp
index a847a2f..9796063 100644
--- a/plugins/ZamTube/triode.cpp
+++ b/plugins/ZamTube/triode.cpp
@@ -23,40 +23,24 @@ T Triode::compute(T a, T R, T Vg, T Vk) {
 	return b;
 }
 
-T Triode::getIa(T Vgk, T Vpk) {
-	static bool prepared = false;
-	static double coeff[3];
-
-	if (!prepared) {
-		const double L2 = log(2.0);
-		const double scale = 1e+6*pow(L2, kx-2.0)/(8.0*pow(kp, kx));
-		coeff[0] = 8.0*L2*L2*scale;
-		coeff[1] = kx*kp*L2*4.0*scale;
-		coeff[2] = (kp*kp*kx*kx + L2*kp*kp*kx - kp*kp*kx) * scale;
-		prepared = true;
-	}
-
+T Triode::getIa(T Vgk, T Vpk) const {
 	if (Vpk < 0.0) {
-		//printf("Less than zero!\n");
 		Vpk = 0.0;
 	}
 	if (Vgk > 0.0) {
 		Vgk = 0.0;
 	}
 
-	double A = 1./mu + Vgk / sqrt(kvb + Vpk*Vpk);
-	return Vpk*(coeff[0] + coeff[1]*A + coeff[2]*A*A) / kg1;
-
-	/* exact solution (takes > 3x longer)
-		e1 = Vpk*log1p(exp(kp*(1./mu+Vgk/sqrt(kvb+Vpk*Vpk))))/kp;
-		if (e1 < 0) {
-			return 0.;
-		}
-		return 1e+6*pow(e1, kx) / kg1;
-	*/
+	/* exact solution (expensive) */
+	T ee1 = Vpk*log1p(exp(kp*(1./mu+Vgk/sqrt(kvb+Vpk*Vpk))))/kp;
+	if (ee1 < 0) {
+		return 0.;
+	}
+	//printf("Vpk=%f ans=%f e1=%f exact_e1=%f\n", Vpk, ans, e1, ee1);
+	return 1e+6*pow(ee1, kx) / kg1;
 }
 
-T Triode::iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R){
+T Triode::iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R) const {
 	T xIak = getIa(Vgk, x);
 	T dxIak = getIa(Vgk, x + dx);
 	T xNew = x - dx*(x + R*xIak - a)/(dx + R*(dxIak - xIak));
@@ -65,10 +49,18 @@ T Triode::iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R){
 
 Triode::Triode()
 {
-	//12AX7 RSD-1
+	/* good for low gain, broken at high gain
 	kvb = 300.;
 	mu = 103.2;
 	kx = 1.26;
 	kg1 = 446.0;
 	kp = 3.4;
+	*/
+	
+	//12AX7 RSD-1 (custom)
+	mu = 100.;
+	kx = 1.4;
+	kg1 = 446.;
+	kp = 600.;
+	kvb = 300.;
 }
diff --git a/plugins/ZamTube/triode.h b/plugins/ZamTube/triode.h
index 1d3b927..2f678a0 100644
--- a/plugins/ZamTube/triode.h
+++ b/plugins/ZamTube/triode.h
@@ -32,13 +32,13 @@ typedef double T;
 
 class Triode {
 public:
-	T mu, kp, kvb, kg1, kx;
-
 	Triode();
 	T compute(T a, T R, T Vg, T Vk);
-	T getIa(T Vgk, T Vak);
-	T iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R);
 	bool insane;
+private:
+	inline T getIa(T Vgk, T Vak) const;
+	T iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R) const;
+	T mu, kp, kvb, kg1, kx;
 };
 
 #endif