diff --git a/Core/HW/SasAudio.cpp b/Core/HW/SasAudio.cpp
index e4beebf6d8..30f3823b94 100644
--- a/Core/HW/SasAudio.cpp
+++ b/Core/HW/SasAudio.cpp
@@ -758,12 +758,26 @@ void ADSREnvelope::Step() {
 	case STATE_OFF:
 		// Do nothing
 		break;
+
+	case STATE_KEYON:
+		height_ = 0;
+		SetState(STATE_KEYON_STEP);
+		break;
+	case STATE_KEYON_STEP:
+		// This entire state is pretty much a hack to reproduce PSP behavior.
+		// The STATE_KEYON state is a real state, but not sure how it switches.
+		// It takes 32 steps at 0 for keyon to "kick in", 31 should shift to 0 anyway.
+		height_++;
+		if (height_ >= 31) {
+			height_ = 0;
+			SetState(STATE_ATTACK);
+		}
+		break;
 	}
 }
 
 void ADSREnvelope::KeyOn() {
-	SetState(STATE_ATTACK);
-	height_ = 0;
+	SetState(STATE_KEYON);
 }
 
 void ADSREnvelope::KeyOff() {
@@ -779,7 +793,7 @@ void ADSREnvelope::End() {
 }
 
 void ADSREnvelope::DoState(PointerWrap &p) {
-	auto s = p.Section("ADSREnvelope", 1);
+	auto s = p.Section("ADSREnvelope", 1, 2);
 	if (!s) {
 		return;
 	}
@@ -793,8 +807,15 @@ void ADSREnvelope::DoState(PointerWrap &p) {
 	p.Do(sustainType);
 	p.Do(sustainLevel);
 	p.Do(releaseType);
-	p.Do(state_);
-	int stepsLegacy;
-	p.Do(stepsLegacy);
+	if (s < 2) {
+		p.Do(state_);
+		if (state_ == 4) {
+			state_ = STATE_OFF;
+		}
+		int stepsLegacy;
+		p.Do(stepsLegacy);
+	} else {
+		p.Do(state_);
+	}
 	p.Do(height_);
 }
diff --git a/Core/HW/SasAudio.h b/Core/HW/SasAudio.h
index 6779693607..451d11a57f 100644
--- a/Core/HW/SasAudio.h
+++ b/Core/HW/SasAudio.h
@@ -144,7 +144,7 @@ public:
 	void Step();
 
 	int GetHeight() const {
-		return height_ > (s64)PSP_SAS_ENVELOPE_HEIGHT_MAX ? (s64)PSP_SAS_ENVELOPE_HEIGHT_MAX : height_;
+		return height_ > (s64)PSP_SAS_ENVELOPE_HEIGHT_MAX ? PSP_SAS_ENVELOPE_HEIGHT_MAX : height_;
 	}
 	bool HasEnded() const {
 		return state_ == STATE_OFF;
@@ -162,14 +162,17 @@ public:
 	void DoState(PointerWrap &p);
 
 private:
-	void ComputeDuration();
-
+	// Actual PSP values.
 	enum ADSRState {
-		STATE_ATTACK,
-		STATE_DECAY,
-		STATE_SUSTAIN,
-		STATE_RELEASE,
-		STATE_OFF,
+		// Okay, this one isn't a real value but it might be.
+		STATE_KEYON_STEP = -42,
+
+		STATE_KEYON = -2,
+		STATE_OFF = -1,
+		STATE_ATTACK = 0,
+		STATE_DECAY = 1,
+		STATE_SUSTAIN = 2,
+		STATE_RELEASE = 3,
 	};
 	void SetState(ADSRState state);