diff --git a/src/sfizz/modulations/ModId.cpp b/src/sfizz/modulations/ModId.cpp
index 62729f9a..2d57a69b 100644
--- a/src/sfizz/modulations/ModId.cpp
+++ b/src/sfizz/modulations/ModId.cpp
@@ -112,6 +112,18 @@ int ModIds::flags(ModId id) noexcept
         return kModIsPerVoice|kModIsAdditive;
     case ModId::LFOVolumeDepth:
         return kModIsPerVoice|kModIsAdditive;
+    case ModId::LFOFilCutoffDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::LFOFilResonanceDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::LFOFilGainDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::LFOEqGainDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::LFOEqFrequencyDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::LFOEqBandwidthDepth:
+        return kModIsPerVoice|kModIsAdditive;
     case ModId::EGAmplitudeDepth:
         return kModIsPerVoice|kModIsMultiplicative;
     case ModId::EGPanDepth:
@@ -124,6 +136,18 @@ int ModIds::flags(ModId id) noexcept
         return kModIsPerVoice|kModIsAdditive;
     case ModId::EGVolumeDepth:
         return kModIsPerVoice|kModIsAdditive;
+    case ModId::EGFilCutoffDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::EGFilResonanceDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::EGFilGainDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::EGEqGainDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::EGEqFrequencyDepth:
+        return kModIsPerVoice|kModIsAdditive;
+    case ModId::EGEqBandwidthDepth:
+        return kModIsPerVoice|kModIsAdditive;
 
         // unknown
     default:
diff --git a/src/sfizz/modulations/ModId.h b/src/sfizz/modulations/ModId.h
index 59675785..b6a3e130 100644
--- a/src/sfizz/modulations/ModId.h
+++ b/src/sfizz/modulations/ModId.h
@@ -70,12 +70,24 @@ enum class ModId : int {
     LFOPositionDepth,
     LFOPitchDepth,
     LFOVolumeDepth,
+    LFOFilCutoffDepth,
+    LFOFilResonanceDepth,
+    LFOFilGainDepth,
+    LFOEqGainDepth,
+    LFOEqFrequencyDepth,
+    LFOEqBandwidthDepth,
     EGAmplitudeDepth,
     EGPanDepth,
     EGWidthDepth,
     EGPositionDepth,
     EGPitchDepth,
     EGVolumeDepth,
+    EGFilCutoffDepth,
+    EGFilResonanceDepth,
+    EGFilGainDepth,
+    EGEqGainDepth,
+    EGEqFrequencyDepth,
+    EGEqBandwidthDepth,
 
     _TargetsEnd,
     // [/targets] --------------------------------------------------------------
diff --git a/src/sfizz/modulations/ModKey.cpp b/src/sfizz/modulations/ModKey.cpp
index d82b1558..107b0b34 100644
--- a/src/sfizz/modulations/ModKey.cpp
+++ b/src/sfizz/modulations/ModKey.cpp
@@ -182,6 +182,18 @@ std::string ModKey::toString() const
         return absl::StrCat("LFOPitchDepth {", region_.number(), ", N=", 1 + params_.N, "}");
     case ModId::LFOVolumeDepth:
         return absl::StrCat("LFOVolumeDepth {", region_.number(), ", N=", 1 + params_.N, "}");
+    case ModId::LFOFilCutoffDepth:
+        return absl::StrCat("LFOFilCutoffDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::LFOFilResonanceDepth:
+        return absl::StrCat("LFOFilResonanceDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::LFOFilGainDepth:
+        return absl::StrCat("LFOFilGainDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::LFOEqGainDepth:
+        return absl::StrCat("LFOEqGainDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::LFOEqFrequencyDepth:
+        return absl::StrCat("LFOEqFrequencyDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::LFOEqBandwidthDepth:
+        return absl::StrCat("LFOEqBandwidthDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
     case ModId::EGAmplitudeDepth:
         return absl::StrCat("EGAmplitudeDepth {", region_.number(), ", N=", 1 + params_.N, "}");
     case ModId::EGPanDepth:
@@ -194,11 +206,143 @@ std::string ModKey::toString() const
         return absl::StrCat("EGPitchDepth {", region_.number(), ", N=", 1 + params_.N, "}");
     case ModId::EGVolumeDepth:
         return absl::StrCat("EGVolumeDepth {", region_.number(), ", N=", 1 + params_.N, "}");
+    case ModId::EGFilCutoffDepth:
+        return absl::StrCat("EGFilCutoffDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::EGFilResonanceDepth:
+        return absl::StrCat("EGFilResonanceDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::EGFilGainDepth:
+        return absl::StrCat("EGFilGainDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::EGEqGainDepth:
+        return absl::StrCat("EGEqGainDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::EGEqFrequencyDepth:
+        return absl::StrCat("EGEqFrequencyDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
+    case ModId::EGEqBandwidthDepth:
+        return absl::StrCat("EGEqBandwidthDepth {", region_.number(), ", N=", 1 + params_.N, ", X=", 1 + params_.X, "}");
 
     default:
         return {};
     }
 }
 
+ModKey ModKey::getSourceDepthKey(ModKey source, ModKey target)
+{
+    const NumericId<Region> region = source.region();
+    const ModKey::Parameters& tp = target.parameters();
+
+    switch (source.id()) {
+    case ModId::AmpLFO:
+        switch (target.id()) {
+        case ModId::Volume:
+            return ModKey::createNXYZ(ModId::AmpLFODepth, region);
+        default:
+            break;
+        }
+        break;
+
+    case ModId::PitchLFO:
+        switch (target.id()) {
+        case ModId::Pitch:
+            return ModKey::createNXYZ(ModId::PitchLFODepth, region);
+        default:
+            break;
+        }
+        break;
+
+    case ModId::FilLFO:
+        switch (target.id()) {
+        case ModId::FilCutoff:
+            return ModKey::createNXYZ(ModId::FilLFODepth, region);
+        default:
+            break;
+        }
+        break;
+
+    case ModId::PitchEG:
+        switch (target.id()) {
+        case ModId::Pitch:
+            return ModKey::createNXYZ(ModId::PitchEGDepth, region);
+        default:
+            break;
+        }
+        break;
+
+    case ModId::FilEG:
+        switch (target.id()) {
+        case ModId::FilCutoff:
+            return ModKey::createNXYZ(ModId::FilEGDepth, region);
+        default:
+            break;
+        }
+        break;
+
+    case ModId::LFO:
+        switch (target.id()) {
+        case ModId::Amplitude:
+            return ModKey::createNXYZ(ModId::LFOAmplitudeDepth, region, tp.N);
+        case ModId::Pan:
+            return ModKey::createNXYZ(ModId::LFOPanDepth, region, tp.N);
+        case ModId::Width:
+            return ModKey::createNXYZ(ModId::LFOWidthDepth, region, tp.N);
+        case ModId::Position:
+            return ModKey::createNXYZ(ModId::LFOPositionDepth, region, tp.N);
+        case ModId::Pitch:
+            return ModKey::createNXYZ(ModId::LFOPitchDepth, region, tp.N);
+        case ModId::Volume:
+            return ModKey::createNXYZ(ModId::LFOVolumeDepth, region, tp.N);
+        case ModId::FilCutoff:
+            return ModKey::createNXYZ(ModId::LFOFilCutoffDepth, region, tp.N, tp.X);
+        case ModId::FilResonance:
+            return ModKey::createNXYZ(ModId::LFOFilResonanceDepth, region, tp.N, tp.X);
+        case ModId::FilGain:
+            return ModKey::createNXYZ(ModId::LFOFilGainDepth, region, tp.N, tp.X);
+        case ModId::EqGain:
+            return ModKey::createNXYZ(ModId::LFOEqGainDepth, region, tp.N, tp.X);
+        case ModId::EqFrequency:
+            return ModKey::createNXYZ(ModId::LFOEqFrequencyDepth, region, tp.N, tp.X);
+        case ModId::EqBandwidth:
+            return ModKey::createNXYZ(ModId::LFOEqBandwidthDepth, region, tp.N, tp.X);
+        default:
+            break;
+        }
+        break;
+
+    case ModId::Envelope:
+        switch (target.id()) {
+        case ModId::Amplitude:
+            return ModKey::createNXYZ(ModId::EGAmplitudeDepth, region, tp.N);
+        case ModId::Pan:
+            return ModKey::createNXYZ(ModId::EGPanDepth, region, tp.N);
+        case ModId::Width:
+            return ModKey::createNXYZ(ModId::EGWidthDepth, region, tp.N);
+        case ModId::Position:
+            return ModKey::createNXYZ(ModId::EGPositionDepth, region, tp.N);
+        case ModId::Pitch:
+            return ModKey::createNXYZ(ModId::EGPitchDepth, region, tp.N);
+        case ModId::Volume:
+            return ModKey::createNXYZ(ModId::EGVolumeDepth, region, tp.N);
+        case ModId::FilCutoff:
+            return ModKey::createNXYZ(ModId::EGFilCutoffDepth, region, tp.N, tp.X);
+        case ModId::FilResonance:
+            return ModKey::createNXYZ(ModId::EGFilResonanceDepth, region, tp.N, tp.X);
+        case ModId::FilGain:
+            return ModKey::createNXYZ(ModId::EGFilGainDepth, region, tp.N, tp.X);
+        case ModId::EqGain:
+            return ModKey::createNXYZ(ModId::EGEqGainDepth, region, tp.N, tp.X);
+        case ModId::EqFrequency:
+            return ModKey::createNXYZ(ModId::EGEqFrequencyDepth, region, tp.N, tp.X);
+        case ModId::EqBandwidth:
+            return ModKey::createNXYZ(ModId::EGEqBandwidthDepth, region, tp.N, tp.X);
+        default:
+            break;
+        }
+        break;
+
+    default:
+        break;
+    }
+
+    return {};
+}
+
 } // namespace sfz
 
diff --git a/src/sfizz/modulations/ModKey.h b/src/sfizz/modulations/ModKey.h
index 69dc50b3..92f11ca4 100644
--- a/src/sfizz/modulations/ModKey.h
+++ b/src/sfizz/modulations/ModKey.h
@@ -42,6 +42,12 @@ public:
     bool isTarget() const noexcept;
     std::string toString() const;
 
+    /**
+     * @brief Obtain the modulation key of the source depth, in the connection
+     * between source and target, if such a key exists.
+     */
+    static ModKey getSourceDepthKey(ModKey source, ModKey target);
+
     struct RawParameters {
         union {
             //! Parameters if this key identifies a CC source