diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c
index 0a3cb8fd7d00..a66ce0375fd9 100644
--- a/sound/usb/mixer_quirks.c
+++ b/sound/usb/mixer_quirks.c
@@ -594,85 +594,138 @@ static int snd_xonar_u1_controls_create(struct usb_mixer_interface *mixer)
 					  &snd_xonar_u1_output_switch, NULL);
 }
 
-/* Digidesign Mbox 1 clock source switch (internal/spdif) */
+/* Digidesign Mbox 1 helper functions */
 
-static int snd_mbox1_switch_get(struct snd_kcontrol *kctl,
-				struct snd_ctl_elem_value *ucontrol)
+static int snd_mbox1_is_spdif_synced(struct snd_usb_audio *chip)
 {
-	ucontrol->value.enumerated.item[0] = kctl->private_value;
-	return 0;
-}
-
-static int snd_mbox1_switch_update(struct usb_mixer_interface *mixer, int val)
-{
-	struct snd_usb_audio *chip = mixer->chip;
-	int err;
 	unsigned char buff[3];
+	int err;
+	int is_spdif_synced;
 
-	err = snd_usb_lock_shutdown(chip);
+	/* Read clock source */
+	err = snd_usb_ctl_msg(chip->dev,
+			      usb_rcvctrlpipe(chip->dev, 0), 0x81,
+			      USB_DIR_IN |
+			      USB_TYPE_CLASS |
+			      USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
 	if (err < 0)
 		return err;
 
-	/* Prepare for magic command to toggle clock source */
-	err = snd_usb_ctl_msg(chip->dev,
-				usb_rcvctrlpipe(chip->dev, 0), 0x81,
-				USB_DIR_IN |
-				USB_TYPE_CLASS |
-				USB_RECIP_INTERFACE, 0x00, 0x500, buff, 1);
-	if (err < 0)
-		goto err;
-	err = snd_usb_ctl_msg(chip->dev,
-				usb_rcvctrlpipe(chip->dev, 0), 0x81,
-				USB_DIR_IN |
-				USB_TYPE_CLASS |
-				USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
-	if (err < 0)
-		goto err;
+	/* spdif sync: buff is all zeroes */
+	is_spdif_synced = !(buff[0] | buff[1] | buff[2]);
+	return is_spdif_synced;
+}
 
-	/* 2 possibilities:	Internal    -> send sample rate
-	 *			S/PDIF sync -> send zeroes
-	 * NB: Sample rate locked to 48kHz on purpose to
-	 *     prevent user from resetting the sample rate
-	 *     while S/PDIF sync is enabled and confusing
-	 *     this configuration.
+static int snd_mbox1_set_clk_source(struct snd_usb_audio *chip, int rate_or_zero)
+{
+	/* 2 possibilities:	Internal    -> expects sample rate
+	 *			S/PDIF sync -> expects rate = 0
 	 */
-	if (val == 0) {
-		buff[0] = 0x80;
-		buff[1] = 0xbb;
-		buff[2] = 0x00;
-	} else {
-		buff[0] = buff[1] = buff[2] = 0x00;
-	}
+	unsigned char buff[3];
 
-	/* Send the magic command to toggle the clock source */
+	buff[0] = (rate_or_zero >>  0) & 0xff;
+	buff[1] = (rate_or_zero >>  8) & 0xff;
+	buff[2] = (rate_or_zero >> 16) & 0xff;
+
+	/* Set clock source */
+	return snd_usb_ctl_msg(chip->dev,
+			       usb_sndctrlpipe(chip->dev, 0), 0x1,
+			       USB_TYPE_CLASS |
+			       USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
+}
+
+static int snd_mbox1_is_spdif_input(struct snd_usb_audio *chip)
+{
+	/* Hardware gives 2 possibilities:	ANALOG Source  -> 0x01
+	 *					S/PDIF Source  -> 0x02
+	 */
+	int err;
+	unsigned char source[1];
+
+	/* Read input source */
 	err = snd_usb_ctl_msg(chip->dev,
-				usb_sndctrlpipe(chip->dev, 0), 0x1,
-				USB_TYPE_CLASS |
-				USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
+			      usb_rcvctrlpipe(chip->dev, 0), 0x81,
+			      USB_DIR_IN |
+			      USB_TYPE_CLASS |
+			      USB_RECIP_INTERFACE, 0x00, 0x500, source, 1);
 	if (err < 0)
-		goto err;
-	err = snd_usb_ctl_msg(chip->dev,
-				usb_rcvctrlpipe(chip->dev, 0), 0x81,
-				USB_DIR_IN |
-				USB_TYPE_CLASS |
-				USB_RECIP_ENDPOINT, 0x100, 0x81, buff, 3);
-	if (err < 0)
-		goto err;
-	err = snd_usb_ctl_msg(chip->dev,
-				usb_rcvctrlpipe(chip->dev, 0), 0x81,
-				USB_DIR_IN |
-				USB_TYPE_CLASS |
-				USB_RECIP_ENDPOINT, 0x100, 0x2, buff, 3);
+		return err;
+
+	return (source[0] == 2);
+}
+
+static int snd_mbox1_set_input_source(struct snd_usb_audio *chip, int is_spdif)
+{
+	/* NB: Setting the input source to S/PDIF resets the clock source to S/PDIF
+	 * Hardware expects 2 possibilities:	ANALOG Source  -> 0x01
+	 *					S/PDIF Source  -> 0x02
+	 */
+	unsigned char buff[1];
+
+	buff[0] = (is_spdif & 1) + 1;
+
+	/* Set input source */
+	return snd_usb_ctl_msg(chip->dev,
+			       usb_sndctrlpipe(chip->dev, 0), 0x1,
+			       USB_TYPE_CLASS |
+			       USB_RECIP_INTERFACE, 0x00, 0x500, buff, 1);
+}
+
+/* Digidesign Mbox 1 clock source switch (internal/spdif) */
+
+static int snd_mbox1_clk_switch_get(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
+	struct snd_usb_audio *chip = list->mixer->chip;
+	int err;
+
+	err = snd_usb_lock_shutdown(chip);
 	if (err < 0)
 		goto err;
 
+	err = snd_mbox1_is_spdif_synced(chip);
+	if (err < 0)
+		goto err;
+
+	kctl->private_value = err;
+	err = 0;
+	ucontrol->value.enumerated.item[0] = kctl->private_value;
 err:
 	snd_usb_unlock_shutdown(chip);
 	return err;
 }
 
-static int snd_mbox1_switch_put(struct snd_kcontrol *kctl,
-				struct snd_ctl_elem_value *ucontrol)
+static int snd_mbox1_clk_switch_update(struct usb_mixer_interface *mixer, int is_spdif_sync)
+{
+	struct snd_usb_audio *chip = mixer->chip;
+	int err;
+
+	err = snd_usb_lock_shutdown(chip);
+	if (err < 0)
+		return err;
+
+	err = snd_mbox1_is_spdif_input(chip);
+	if (err < 0)
+		goto err;
+
+	err = snd_mbox1_is_spdif_synced(chip);
+	if (err < 0)
+		goto err;
+
+	/* FIXME: hardcoded sample rate */
+	err = snd_mbox1_set_clk_source(chip, is_spdif_sync ? 0 : 48000);
+	if (err < 0)
+		goto err;
+
+	err = snd_mbox1_is_spdif_synced(chip);
+err:
+	snd_usb_unlock_shutdown(chip);
+	return err;
+}
+
+static int snd_mbox1_clk_switch_put(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
 {
 	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
 	struct usb_mixer_interface *mixer = list->mixer;
@@ -685,12 +738,12 @@ static int snd_mbox1_switch_put(struct snd_kcontrol *kctl,
 		return 0;
 
 	kctl->private_value = new_val;
-	err = snd_mbox1_switch_update(mixer, new_val);
+	err = snd_mbox1_clk_switch_update(mixer, new_val);
 	return err < 0 ? err : 1;
 }
 
-static int snd_mbox1_switch_info(struct snd_kcontrol *kcontrol,
-				 struct snd_ctl_elem_info *uinfo)
+static int snd_mbox1_clk_switch_info(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_info *uinfo)
 {
 	static const char *const texts[2] = {
 		"Internal",
@@ -700,27 +753,115 @@ static int snd_mbox1_switch_info(struct snd_kcontrol *kcontrol,
 	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
 }
 
-static int snd_mbox1_switch_resume(struct usb_mixer_elem_list *list)
+static int snd_mbox1_clk_switch_resume(struct usb_mixer_elem_list *list)
 {
-	return snd_mbox1_switch_update(list->mixer, list->kctl->private_value);
+	return snd_mbox1_clk_switch_update(list->mixer, list->kctl->private_value);
 }
 
-static const struct snd_kcontrol_new snd_mbox1_switch = {
+/* Digidesign Mbox 1 input source switch (analog/spdif) */
+
+static int snd_mbox1_src_switch_get(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	ucontrol->value.enumerated.item[0] = kctl->private_value;
+	return 0;
+}
+
+static int snd_mbox1_src_switch_update(struct usb_mixer_interface *mixer, int is_spdif_input)
+{
+	struct snd_usb_audio *chip = mixer->chip;
+	int err;
+
+	err = snd_usb_lock_shutdown(chip);
+	if (err < 0)
+		return err;
+
+	err = snd_mbox1_is_spdif_input(chip);
+	if (err < 0)
+		goto err;
+
+	err = snd_mbox1_set_input_source(chip, is_spdif_input);
+	if (err < 0)
+		goto err;
+
+	err = snd_mbox1_is_spdif_input(chip);
+	if (err < 0)
+		goto err;
+
+	err = snd_mbox1_is_spdif_synced(chip);
+err:
+	snd_usb_unlock_shutdown(chip);
+	return err;
+}
+
+static int snd_mbox1_src_switch_put(struct snd_kcontrol *kctl,
+				    struct snd_ctl_elem_value *ucontrol)
+{
+	struct usb_mixer_elem_list *list = snd_kcontrol_chip(kctl);
+	struct usb_mixer_interface *mixer = list->mixer;
+	int err;
+	bool cur_val, new_val;
+
+	cur_val = kctl->private_value;
+	new_val = ucontrol->value.enumerated.item[0];
+	if (cur_val == new_val)
+		return 0;
+
+	kctl->private_value = new_val;
+	err = snd_mbox1_src_switch_update(mixer, new_val);
+	return err < 0 ? err : 1;
+}
+
+static int snd_mbox1_src_switch_info(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_info *uinfo)
+{
+	static const char *const texts[2] = {
+		"Analog",
+		"S/PDIF"
+	};
+
+	return snd_ctl_enum_info(uinfo, 1, ARRAY_SIZE(texts), texts);
+}
+
+static int snd_mbox1_src_switch_resume(struct usb_mixer_elem_list *list)
+{
+	return snd_mbox1_src_switch_update(list->mixer, list->kctl->private_value);
+}
+
+static const struct snd_kcontrol_new snd_mbox1_clk_switch = {
 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 	.name = "Clock Source",
 	.index = 0,
 	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
-	.info = snd_mbox1_switch_info,
-	.get = snd_mbox1_switch_get,
-	.put = snd_mbox1_switch_put,
+	.info = snd_mbox1_clk_switch_info,
+	.get = snd_mbox1_clk_switch_get,
+	.put = snd_mbox1_clk_switch_put,
 	.private_value = 0
 };
 
-static int snd_mbox1_create_sync_switch(struct usb_mixer_interface *mixer)
+static const struct snd_kcontrol_new snd_mbox1_src_switch = {
+	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.name = "Input Source",
+	.index = 1,
+	.access = SNDRV_CTL_ELEM_ACCESS_READWRITE,
+	.info = snd_mbox1_src_switch_info,
+	.get = snd_mbox1_src_switch_get,
+	.put = snd_mbox1_src_switch_put,
+	.private_value = 0
+};
+
+static int snd_mbox1_controls_create(struct usb_mixer_interface *mixer)
 {
-	return add_single_ctl_with_resume(mixer, 0,
-					  snd_mbox1_switch_resume,
-					  &snd_mbox1_switch, NULL);
+	int err;
+	err = add_single_ctl_with_resume(mixer, 0,
+					 snd_mbox1_clk_switch_resume,
+					 &snd_mbox1_clk_switch, NULL);
+	if (err < 0)
+		return err;
+
+	return add_single_ctl_with_resume(mixer, 1,
+					  snd_mbox1_src_switch_resume,
+					  &snd_mbox1_src_switch, NULL);
 }
 
 /* Native Instruments device quirks */
@@ -3029,7 +3170,7 @@ int snd_usb_mixer_apply_create_quirk(struct usb_mixer_interface *mixer)
 		break;
 
 	case USB_ID(0x0dba, 0x1000): /* Digidesign Mbox 1 */
-		err = snd_mbox1_create_sync_switch(mixer);
+		err = snd_mbox1_controls_create(mixer);
 		break;
 
 	case USB_ID(0x17cc, 0x1011): /* Traktor Audio 6 */