diff --git a/packages/superdough/modulators.mjs b/packages/superdough/modulators.mjs
index 32ebae265..96c68d4bf 100644
--- a/packages/superdough/modulators.mjs
+++ b/packages/superdough/modulators.mjs
@@ -19,7 +19,11 @@ const getNodeParam = (node, name) => {
     }
   }
   // Built-in node case
-  const p = node?.[name];
+  let p = node?.[name];
+  if (p === undefined && name === 'frequency') {
+    // Fallbacks for source nodes without 'frequency' params (e.g. soundfonts)
+    p = node?.['detune'] ?? node?.['playbackRate'];
+  }
   if (p instanceof AudioParam) {
     return p;
   }
diff --git a/packages/superdough/zzfx.mjs b/packages/superdough/zzfx.mjs
index f3dc710b1..3d6b8e9f5 100644
--- a/packages/superdough/zzfx.mjs
+++ b/packages/superdough/zzfx.mjs
@@ -75,7 +75,6 @@ export const getZZFX = (value, t) => {
   source.start(t);
   return {
     node: source,
-    nodes: { source: [source] },
   };
 };
 
@@ -91,6 +90,7 @@ export function registerZZFXSounds() {
         });
         return {
           node: o,
+          nodes: { source: [o] },
           stop: () => {},
         };
       },