diff --git a/app/static/js/services/soundfontPlayer.js b/app/static/js/services/soundfontPlayer.js
index 59227ee..491bf6e 100644
--- a/app/static/js/services/soundfontPlayer.js
+++ b/app/static/js/services/soundfontPlayer.js
@@ -103,7 +103,13 @@
                 }
             }
             try {
-                await _synthInstance.soundBankManager.addSoundBank(buffer, sfId);
+                // Clone buffer before sending to worklet (avoids transfer neutering)
+                const bufCopy = buffer.slice(0);
+                await _synthInstance.soundBankManager.addSoundBank(bufCopy, sfId);
+                await _synthInstance.isReady;
+                // Force program 0 on channel 0 to activate loaded bank
+                this.controllerChange(0, 0, 0);
+                this.programChange(0, 0);
                 _currentSfId = sfId;
                 console.log("[SonicSF] SoundFont loaded:", sfId);
             } catch (e) {