diff --git a/lib_xua/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h b/lib_xua/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h
index 12fe554..e1e90c1 100644
--- a/lib_xua/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h
+++ b/lib_xua/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h
@@ -21,7 +21,7 @@
 // Enable BOS descriptor only when DFU is enabled since the only capability we advertise is the MSOS desc with DFU interface enumerating as WinUSB.
 // Enumerating with 0 capabilities doesn't seem to be allowed
 #if (XUA_DFU_EN)
-    #define _XUA_ENABLE_BOS_DESC (1)        //alexy 20250822
+    #define _XUA_ENABLE_BOS_DESC (0)        //alexy 20250822
 #else
     #define _XUA_ENABLE_BOS_DESC (0)
 #endif
@@ -1005,7 +1005,11 @@ USB_Config_Descriptor_Audio2_t cfgDesc_Audio2=
             .bAssocTerminal            = 0x00,
             .bCSourceID                = ID_CLKSEL,
             .bNrChannels               = NUM_USB_CHAN_OUT,
+#if (NUM_USB_CHAN_OUT == 8)
             .bmChannelConfig           = 0x0000063f, //0x00000000,                               /* TODO. Set me! */
+#else
+            .bmChannelConfig           = 0x00000000, //0x00000000,                               /* TODO. Set me! */
+#endif
             .iChannelNames             = offsetof(StringDescTable_t, outputChanStr_1)/sizeof(char *),
             .bmControls                =  0x0000,
             .iTerminal                 = offsetof(StringDescTable_t, usbInputTermStr_Audio2)/sizeof(char *)
@@ -1499,7 +1503,11 @@ USB_Config_Descriptor_Audio2_t cfgDesc_Audio2=
         UAC_FORMAT_TYPE_I,                      /* 5  bFormatType */
         STREAM_FORMAT_OUTPUT_1_DATAFORMAT,      /* 6:10  bmFormats (note this is a bitmap) */
         HS_STREAM_FORMAT_OUTPUT_1_CHAN_COUNT,   /* 11 bNrChannels */
+#if (NUM_USB_CHAN_OUT == 8)
         0x0000063f, //0x00000000,                             /* 12:14: bmChannelConfig */
+#else
+        0x00000000, //0x00000000,                             /* 12:14: bmChannelConfig */
+#endif
         .iChannelNames                 = offsetof(StringDescTable_t, outputChanStr_1)/sizeof(char *),
     },
 
@@ -1590,7 +1598,11 @@ USB_Config_Descriptor_Audio2_t cfgDesc_Audio2=
         UAC_FORMAT_TYPE_I,                      /* 5  bFormatType */
         STREAM_FORMAT_OUTPUT_2_DATAFORMAT,      /* 6:10  bmFormats (note this is a bitmap) */
         HS_STREAM_FORMAT_OUTPUT_2_CHAN_COUNT,   /* 11 bNrChannels */
+#if (NUM_USB_CHAN_OUT == 8)
         0x0000063f, //0x00000000,                             /* 12:14: bmChannelConfig */
+#else
+        0x00000000, //0x00000000,                             /* 12:14: bmChannelConfig */
+#endif
         .iChannelNames                 = (offsetof(StringDescTable_t, outputChanStr_1)/sizeof(char *)),
     },
 
@@ -1681,7 +1693,11 @@ USB_Config_Descriptor_Audio2_t cfgDesc_Audio2=
         UAC_FORMAT_TYPE_I,                      /* 5  bFormatType */
         STREAM_FORMAT_OUTPUT_3_DATAFORMAT,      /* 6:10  bmFormats (note this is a bitmap) */
         HS_STREAM_FORMAT_OUTPUT_3_CHAN_COUNT,   /* 11 bNrChannels */
+#if (NUM_USB_CHAN_OUT == 8)
         0x0000063f, //0x00000000,                             /* 12:14: bmChannelConfig */
+#else
+        0x00000000, //0x00000000,                             /* 12:14: bmChannelConfig */
+#endif
         .iChannelNames                 = offsetof(StringDescTable_t, outputChanStr_1)/sizeof(char *),
     },