diff --git a/sound/usb/usbquirks.h b/sound/usb/usbquirks.h
index edb8887..bb7829c 100644
--- a/sound/usb/usbquirks.h
+++ b/sound/usb/usbquirks.h
@@ -294,7 +294,8 @@
 	}
 },
 {
-	/* a later revision uses ID 0x0099 */
+	/* Has ID 0x0099 when not in "Advanced Driver" mode.
+	 * The UM-2EX has only one input, but we cannot detect this. */
 	USB_DEVICE(0x0582, 0x0005),
 	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
 		.vendor_name = "EDIROL",
@@ -385,7 +386,7 @@
 	}
 },
 {
-	/* a later revision uses ID 0x009d */
+	/* has ID 0x009d when not in "Advanced Driver" mode */
 	USB_DEVICE(0x0582, 0x0009),
 	.driver_info = (unsigned long) & (const struct snd_usb_audio_quirk) {
 		.vendor_name = "EDIROL",