Improvement, less squeal - just smoother, insane now no-op

7 files changed, 92 insertions, 84 deletions

diff --git a/plugins/ZamTube/Makefile b/plugins/ZamTube/Makefile
index c440694..4f2ed3f 100644
--- a/plugins/ZamTube/Makefile
+++ b/plugins/ZamTube/Makefile
@@ -14,8 +14,8 @@ NAME = ZamTube
 
 FILES_DSP = \
 	ZamTubePlugin.cpp \
-	triode.cpp \
-	tonestacks.cpp
+	tonestacks.cpp \
+	triode.cpp 
 
 FILES_UI  = \
 	ZamTubeArtwork.cpp \
diff --git a/plugins/ZamTube/ZamTubePlugin.cpp b/plugins/ZamTube/ZamTubePlugin.cpp
index 01cf557..1eb1328 100644
--- a/plugins/ZamTube/ZamTubePlugin.cpp
+++ b/plugins/ZamTube/ZamTubePlugin.cpp
@@ -225,6 +225,7 @@ void ZamTubePlugin::loadProgram(uint32_t index)
     tonestack = 0.0f;
     mastergain = 0.0f;
     insane = 1.0f;
+    insaneold = 1.0f;
 
     /* Default variable values */
 
@@ -250,8 +251,8 @@ void ZamTubePlugin::activate()
 	co[0] = 10e-9;
 	ro[0] = 1e+6;
 
-	/* Matt's preamp */
-	ci[1] = 1.0e-7;
+	/* Matt's preamp
+	ci[1] = 100e-9;
 	rg[1] = 1.;
 	rk[1] = 820.;
 	ck[1] = 50e-6;
@@ -259,6 +260,7 @@ void ZamTubePlugin::activate()
 	er[1] = 120e+3;
 	co[1] = 4.7e-9;
 	ro[1] = 470e+3;
+	*/
 
 	/* CLA's preamp (not good with all tonestacks)
 	ci[1] = 1.0e-7;
@@ -271,28 +273,9 @@ void ZamTubePlugin::activate()
 	ro[1] = 220e+3;
 	*/
 
-	// 12AX7 triode model RSD-1
-	v.g = 2.242e-3;
-	v.mu = 103.2;
-	v.gamma = 1.26;
-	v.c = 3.4;
-	v.gg = 6.177e-4;
-	v.e = 1.314;
-	v.cg = 9.901;
-	v.ig0 = 8.025e-8;
-
-	// 12AX7 triode model EHX-1
-	v.g2 = 1.371e-3;
-	v.mu2 = 86.9;
-	v.gamma2 = 1.349;
-	v.c2 = 4.56;
-	v.gg2 = 3.263e-4;
-	v.e2 = 1.156;
-	v.cg2 = 11.99;
-	v.ig02 = 3.917e-8;
-
-	int pre = insane < 0.5 ? 0 : 1;
+	int pre = 0;
 	ckt.updateRValues(ci[pre], ck[pre], co[pre], e[pre], er[pre], rg[pre], 0., rk[pre], 136e+3, ro[pre], Fs, v);
+	ckt.t.insane = insane;
 	ckt.warmup_tubes();
 
         fSamplingFreq = Fs;
@@ -356,29 +339,36 @@ void ZamTubePlugin::run(const float** inputs, float** outputs, uint32_t frames)
 	float 	fSlow46 = (fSlow44 - (fConst1 * (fSlow36 + fSlow38)));
 
 	float tubeout = 0.f;
-	int pre = insane < 0.5 ? 0 : 1;
+	
+	if (insaneold != insane) {
+		ckt.t.insane = insane;
+		insaneold = insane;
+	}
+	int pre = 0;
 	float volumepot = tubedrive / 11. * 1e+6;
 	ckt.updateRValues(ci[pre], ck[pre], co[pre], e[pre], er[pre], rg[pre], volumepot, rk[pre], 136e+3, ro[pre], getSampleRate(), v);
 
+	double pregain = from_dB(tubedrive*3.6364 + 15.);
+	double postgain = from_dB(mastergain*3.) / e[pre];
+	
 	for (uint32_t i = 0; i < frames; ++i) {
 
 		//Step 1: read input sample as voltage for the source
-		double in = sanitize_denormal(inputs[0][i]);
+		double in = inputs[0][i] * pregain;
 
 		// protect against overflowing circuit
 		in = fabs(in) < DANGER ? in : 0.f;
 
-		double pregain = from_dB(tubedrive*3.6364 + 15.); // 0 to +40dB with -15dBFS in
-		double postgain = from_dB(mastergain);
-
-		tubeout = ckt.advanc(in*pregain) * postgain / e[pre];
+		tubeout = ckt.advanc(in) * postgain;
 
 		//Tone Stack (post tube)
 		fRec0[0] = ((float)tubeout - (fSlow31 * (((fSlow30 * fRec0[1]) + (fSlow29 * fRec0[2])) + (fSlow27 * fRec0[3]))));
 		outputs[0][i] = sanitize_denormal((float)(fSlow31 * ((((fSlow46 * fRec0[0]) + (fSlow45 * fRec0[1])) + (fSlow43 * fRec0[2])) + (fSlow41 * fRec0[3]))));
 
 		// update filter states
-		for (int i=3; i>0; i--) fRec0[i] = fRec0[i-1];
+		fRec0[3] = fRec0[2];
+		fRec0[2] = fRec0[1];
+		fRec0[1] = fRec0[0];
 	}
 }
 
diff --git a/plugins/ZamTube/ZamTubePlugin.hpp b/plugins/ZamTube/ZamTubePlugin.hpp
index a77d3d1..1a39810 100644
--- a/plugins/ZamTube/ZamTubePlugin.hpp
+++ b/plugins/ZamTube/ZamTubePlugin.hpp
@@ -157,7 +157,7 @@ Wave digital filter physical model of a triode tube amplifier stage, with modell
     // -------------------------------------------------------------------
 
 private:
-	float tubedrive,bass,middle,treble,tonestack,mastergain,insane; //parameters
+	float tubedrive,bass,middle,treble,tonestack,mastergain,insane,insaneold; //parameters
 
 	float ts[25][7];
 
diff --git a/plugins/ZamTube/lut_current.m b/plugins/ZamTube/lut_current.m
new file mode 100644
index 0000000..3d42d6e
--- /dev/null
+++ b/plugins/ZamTube/lut_current.m
@@ -0,0 +1,30 @@
+1;
+
+function I = ip (vgk, vpk)
+  mu=103.2
+  kx=1.26
+  kg1=446.0
+  kp=3.4
+  kvb=300.0
+  e1=vpk .* log(1. + exp(kp .* (1.0/mu + vgk ./ (kvb + vpk .* vpk) .^ 0.5))) / kp
+  if e1 < 0
+    I = 0
+    return
+  endif
+  I = double((e1 .^ kx)/kg1)
+endfunction
+
+gridsizeg = 2001
+gridsizep = 2001
+vgk = linspace(-20, 20, gridsizeg)
+vpk = linspace(0, 500, gridsizep)
+[vg, vp] = ndgrid(double(vgk), double(vpk))
+cur = 1e+6*ip(double(vg), double(vp))
+surf(vg,vp,cur)
+
+more off
+for i=1:gridsizeg
+  for j=1:gridsizep
+    fprintf("%f,\n", cur(i,j))
+  endfor
+endfor
diff --git a/plugins/ZamTube/triode.cpp b/plugins/ZamTube/triode.cpp
index a32bbf3..35e0b35 100644
--- a/plugins/ZamTube/triode.cpp
+++ b/plugins/ZamTube/triode.cpp
@@ -5,24 +5,17 @@
 using std::abs;
 #define DUMP(x) x
 
-T Triode::compute(T a, T R, T Vgate, T Vk) {
+T Triode::compute(T a, T R, T Vg, T Vk) {
 	T VakGuess = 100.;
-	
-	T Vgk = Vgate - Vk;
-
-	T Vak = VakGuess; // initial guess
+	T Vgk = Vg - Vk;
+	T Vak = VakGuess;
 	int iteration = 0;
 	T err = 1e6;
-	while (fabs(err)/fabs(Vak) > 1e-9){
-		VakGuess = iterateNewtonRaphson(Vak, 1e-6, Vgk, a, R);
+
+	for (iteration = 0; (fabs(err)/fabs(Vak) > EPSILON) && (iteration <= ITER); iteration++){
+		VakGuess = iterateNewtonRaphson(Vak, TOLERANCE, Vgk, a, R);
 		err = Vak - VakGuess;
 		Vak = VakGuess;
-
-		if (iteration > 100){
-			printf("Convergence failure!");
-			break;
-		}
-		++iteration;
 	}
 	T b = Vak - R*getIa(Vgk, Vak);
 
@@ -30,25 +23,23 @@ T Triode::compute(T a, T R, T Vgate, T Vk) {
 	return b;
 }
 
-T Triode::getIa(T Vgk, T Vak) {
-	if (Vak < 0.0) {
-		printf("Less than zero!\n");
-		Vak = 0.0;
+T Triode::getIa(T Vgk, T Vpk) {
+	if (Vpk < 0.0) {
+		//printf("Less than zero!\n");
+		Vpk = 0.0;
 	}
 	if (Vgk > 0.0) {
 		Vgk = 0.0;
 	}
-	T mu = 100.;
-	T kx = 1.4;
-	T kg1 = 3.981e-8;
-	T kp = 600.;
-	T kvb = 300.;
 
-	T e1 = Vak*log(1.+exp(kp*(1./mu+Vgk/pow(kvb+Vak*Vak, 0.5))))/kp;
+	T e1 = Vpk*log1p(exp(kp*(1./mu+Vgk/pow(kvb+Vpk*Vpk, 0.5))))/kp;
 	if (e1 < 0) {
 		return 0.;
 	}
-	return (pow(e1, kx) / kg1);
+	T test = 1e+6*pow(e1, kx) / kg1;
+	//printf("XXX Ip=%f lut=%f diff=%f  vgk=%f vpk=%f\n", test, test2, test2-test, Vgk, Vpk);
+	return test;
+
 }
 
 T Triode::evaluateImplicitEquation(T Vak, T Vgk, T a, T R){
@@ -64,8 +55,13 @@ T Triode::iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R){
 
 Triode::Triode()
 {
-	vg = 0.0;
-	vk = 0.0;
-	vp = 0.0;
-	insane = false;
+	insane = true;
+
+	//12AX7 EHX-1
+	kvb = 300.;
+	mu = 103.2;
+	kx = 1.26;
+	kg1 = 446.0;
+	kp = 3.4;
 }
+
diff --git a/plugins/ZamTube/triode.h b/plugins/ZamTube/triode.h
index 36e1036..5a4e3d3 100644
--- a/plugins/ZamTube/triode.h
+++ b/plugins/ZamTube/triode.h
@@ -21,14 +21,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
 #include <math.h>
 
-#define BIG 1e12
-#define SMALL 1e-14
 #define EPSILON 1e-9
 #define ITER 50
-#define SWAP_PP(x,y) {T tmp=y; y=x; x=tmp;}
-#define SWAP_PN(x,y) {T tmp=y; y=-x; x=tmp;}
-#define SWAP_NP(x,y) {T tmp=y; y=x; x=-tmp;}
-#define SWAP_NN(x,y) {T tmp=y; y=-x; x=-tmp;}
 #define TOLERANCE 1e-6
 
 #define MAX(x, y) (( (x) > (y) ) ? x : y )
@@ -45,21 +39,15 @@ sanitize_denormal(float v) {
 
 class Triode {
 public:
-	T Kb, Gb, Pb;
-	T Kr, Gr, Pr;
+	T mu, kp, kvb, kg1, kx;
 
-	T vg, vk, vp;
-	T g, mu, gamma, c, gg, e, cg, ig0;
-	T g1, mu1, gamma1, c1, gg1, e1, cg1, ig01;
-	T g2, mu2, gamma2, c2, gg2, e2, cg2, ig02;
-
-	bool insane;
-	
 	Triode();
-	T compute(T Kbb, T Gbb, T Pbb, T R);
+	T compute(T a, T R, T Vg, T Vk);
 	T getIa(T Vgk, T Vak);
 	T evaluateImplicitEquation(T Vak, T Vgk, T a, T R);
 	T iterateNewtonRaphson(T x, T dx, T Vgk, T a, T R);
+	const float *lut_ip;
+	bool insane;
 };
 
 #endif
diff --git a/plugins/ZamTube/wdfcircuits.h b/plugins/ZamTube/wdfcircuits.h
index e2b9547..02dfee8 100644
--- a/plugins/ZamTube/wdfcircuits.h
+++ b/plugins/ZamTube/wdfcircuits.h
@@ -10,23 +10,27 @@ public:
 	bool on;
 
 	TubeStageCircuit() {
-		Cia = 0.0;
-		Cka = 0.0;
-		Coa = 0.0;
-		Vk = 0.0;
-		Vg = 0.0;
 		on = false;
+		reset_tubes();
 	}
 
 	void warmup_tubes(void) {
 		int i;
 		on = false;
-		for (i = 0; i < 8000; i++) {
+		for (i = 0; i < 100; i++) {
 			advanc(0.0);
 		}
 		on = true;
 	}
 
+	void reset_tubes(void) {
+		Cia = 0.0;
+		Cka = 0.0;
+		Coa = 0.0;
+		Vg = 0.0;
+		Vk = 0.0;
+		warmup_tubes();
+	}
 
 
 	void updateRValues(Real C_Ci, Real C_Ck, Real C_Co, Real E_E500, Real R_E500, Real R_Rg, Real R_Ri, Real R_Rk, Real R_Vi, Real R_Ro, Real sampleRate, Triode& tube) {
@@ -124,7 +128,7 @@ public:
 		Real Roa = S3_3b2;
 		Vk = -P1_3b3;
 		//printf("Vk=%f Vg=%f Vpk(b)=%f(%f)  in=%f out=%f\n", Vk,Vg,P2_3b3,b, ViE,Roa);
-		return (Roa);
+		return Roa;
 	}
 
 private: