diff --git a/lib_xua/src/core/buffer/decouple/decouple.xc b/lib_xua/src/core/buffer/decouple/decouple.xc
index fe730776..f358d0f3 100644
--- a/lib_xua/src/core/buffer/decouple/decouple.xc
+++ b/lib_xua/src/core/buffer/decouple/decouple.xc
@@ -772,6 +772,11 @@ void XUA_Buffer_Decouple(chanend c_mix_out
     aud_to_host_flag = 0;
     SET_SHARED_GLOBAL(g_aud_to_host_flag, aud_to_host_flag);
 
+    for(int i=1; i<(MAX_DEVICE_AUD_PACKET_SIZE_IN >> 2); i++)
+    {
+        inZeroBuff[i] = 5678 << 8;
+    }
+
     /* NOTE: For UAC2 IN EP not marked ready at this point - Initial size of zero buffer not known
      * since we don't know the USB bus-speed yet.
      * The host will send a SetAltInterface before streaming which will lead to this core
diff --git a/lib_xua/src/core/clocking/clockgen.xc b/lib_xua/src/core/clocking/clockgen.xc
index ac172b8f..55c14baf 100644
--- a/lib_xua/src/core/clocking/clockgen.xc
+++ b/lib_xua/src/core/clocking/clockgen.xc
@@ -833,13 +833,13 @@ void clockGen ( streaming chanend ?c_spdif_rx,
                 if (adatUnderflow)
                 {
                     /* ADAT underflowing, send out zero samples */
-                    g_digData[2] = 0;
-                    g_digData[3] = 0;
-                    g_digData[4] = 0;
-                    g_digData[5] = 0;
-                    g_digData[6] = 0;
-                    g_digData[7] = 0;
-                    g_digData[8] = 0;
+                    g_digData[2] = 1234 << 8;
+                    g_digData[3] = 1234 << 8;
+                    g_digData[4] = 1234 << 8;
+                    g_digData[5] = 1234 << 8;
+                    g_digData[6] = 1234 << 8;
+                    g_digData[7] = 1234 << 8;
+                    g_digData[8] = 1234 << 8;
                     g_digData[9] = 0;
                 }
                 else