diff --git a/Core/Inc/usbd_descriptors.h b/Core/Inc/usbd_descriptors.h
index 7b49b2a..83473ac 100644
--- a/Core/Inc/usbd_descriptors.h
+++ b/Core/Inc/usbd_descriptors.h
@@ -231,7 +231,7 @@ UCHAR device_framework_fs[] = {
     /* Endpoint descriptor size=7 */
     0x07,        // bLength
     0x05,        // bDescriptorType
-    0x81,        // bEndpointAddress
+    0x82,        // bEndpointAddress
     0x11,        // bmAttributes
     0x04, 0x00,  // wMaxPacketSize
     0x04,        // bInterval
diff --git a/Core/Src/audio/audio_amp.c b/Core/Src/audio/audio_amp.c
index 39cdacb..d6d7db9 100644
--- a/Core/Src/audio/audio_amp.c
+++ b/Core/Src/audio/audio_amp.c
@@ -28,7 +28,6 @@ uint8_t audio_amp_power(uint8_t up) {
     } else {
         HAL_GPIO_WritePin(A_AMP_UP_GPIO_Port, A_AMP_UP_Pin, GPIO_PIN_RESET);
     }
-
     return 1;
 }
 
@@ -49,16 +48,10 @@ uint8_t audio_amp_is_connected(void) {
 /**
  * @brief Enable amplifiers and set volume.
  * 
- * @param volume volume to be set (1 - 100)
+ * @param volume volume to be set (0 - 63)
  * @return uint8_t 0 - ERROR, everything else - OK
  */
 uint8_t audio_amp_set_volume(uint8_t volume) {
-    uint8_t converted_vol = 0;
-
-    if(volume > 0) {
-        converted_vol = (volume - 1) * 64 / 100;
-    }
-
     if (tpa6130a2_enable_channel(&s_tpa, TPA6130_CH_L | TPA6130_CH_R) != TPA6130_OK) {
         return 0;
     }
@@ -73,7 +66,7 @@ uint8_t audio_amp_set_volume(uint8_t volume) {
         return 0;
     }
 
-    if (tpa6130a2_set_volume(&s_tpa, converted_vol) != TPA6130_OK) {
+    if (tpa6130a2_set_volume(&s_tpa, volume) != TPA6130_OK) {
         return 0;
     }
 
diff --git a/Core/Src/main.c b/Core/Src/main.c
index bd45f47..8754c0e 100644
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -24,8 +24,6 @@
 
 #include <string.h>
 #include <math.h>
-#include "audio/audio_amp.h"
-#include "audio/audio_clocksel.h"
 
 #include "tx_api.h"
 #include "ux_api.h"
@@ -218,6 +216,7 @@ int main(void)
   MX_USB_OTG_FS_PCD_Init();
   /* USER CODE BEGIN 2 */
 
+
   tx_kernel_enter();
 
   /* USER CODE END 2 */
diff --git a/Core/Src/usbd_uac_process.c b/Core/Src/usbd_uac_process.c
index adae98a..4f8ef3c 100644
--- a/Core/Src/usbd_uac_process.c
+++ b/Core/Src/usbd_uac_process.c
@@ -1,14 +1,23 @@
+#include "stm32h7xx_hal.h"
+
+#include "audio/audio_amp.h"
+#include "audio/audio_clocksel.h"
+
 #include "usbd_uac_process.h"
 
 UX_DEVICE_CLASS_AUDIO_PARAMETER        audio_param;
 UX_DEVICE_CLASS_AUDIO_STREAM_PARAMETER audio_stream_param[1];
 UX_DEVICE_CLASS_AUDIO20_CONTROL        audio_control[1];
 
+UCHAR audio_buffer[256];
+
+extern SAI_HandleTypeDef hsai_BlockA3;
+
 static UINT usbd_uac_request_process(UX_DEVICE_CLASS_AUDIO *audio, UX_SLAVE_TRANSFER *transfer);
 static VOID usbd_uac_activate(VOID *args);
 static VOID usbd_uac_deactivate(VOID *args);
 
-static VOID usbd_uac_stream_change(UX_DEVICE_CLASS_AUDIO_STREAM *stream, ULONG alt_setting);
+static VOID usbd_uac_stream_change(UX_DEVICE_CLASS_AUDIO_STREAM *stream, ULONG alternate_setting);
 static VOID usbd_uac_frame_done(UX_DEVICE_CLASS_AUDIO_STREAM *stream, ULONG actual_len);
 
 UINT usbd_uac_class_register(void) {
@@ -16,10 +25,10 @@ UINT usbd_uac_class_register(void) {
     audio_control[0].ux_device_class_audio20_control_sampling_frequency = 48000;
     audio_control[0].ux_device_class_audio20_control_fu_id              = 0x30;
     audio_control[0].ux_device_class_audio20_control_mute[0]            = 0;
-    audio_control[0].ux_device_class_audio20_control_volume_min[0]      = 0;
-    audio_control[0].ux_device_class_audio20_control_volume_max[0]      = 100;
+    audio_control[0].ux_device_class_audio20_control_volume_min[0]      = -64;
+    audio_control[0].ux_device_class_audio20_control_volume_max[0]      = 0;
     audio_control[0].ux_device_class_audio20_control_volume_res[0]      = 1;
-    audio_control[0].ux_device_class_audio20_control_volume[0]          = 100;
+    audio_control[0].ux_device_class_audio20_control_volume[0]          = -64;
 
     audio_stream_param[0].ux_device_class_audio_stream_parameter_callbacks.ux_device_class_audio_stream_change =
         usbd_uac_stream_change;
@@ -53,8 +62,10 @@ UINT usbd_uac_request_process(UX_DEVICE_CLASS_AUDIO *audio, UX_SLAVE_TRANSFER *t
 
     switch (audio_control[0].ux_device_class_audio20_control_changed) {
         case UX_DEVICE_CLASS_AUDIO20_CONTROL_MUTE_CHANGED:
+            audio_amp_set_volume(0);
             break;
         case UX_DEVICE_CLASS_AUDIO20_CONTROL_VOLUME_CHANGED:
+            audio_amp_set_volume((uint8_t)(audio_control[0].ux_device_class_audio20_control_volume[0] * -1));
             break;
         default:
             break;
@@ -64,17 +75,30 @@ UINT usbd_uac_request_process(UX_DEVICE_CLASS_AUDIO *audio, UX_SLAVE_TRANSFER *t
 }
 
 static VOID usbd_uac_activate(VOID *args) {
-    //
+    audio_amp_power(1);
+    audio_clock_select(AUDIO_CLKIN_24M);
 }
 
 static VOID usbd_uac_deactivate(VOID *args) {
     //
 }
 
-static VOID usbd_uac_stream_change(UX_DEVICE_CLASS_AUDIO_STREAM *stream, ULONG alt_setting) {
-    //
+static VOID usbd_uac_stream_change(UX_DEVICE_CLASS_AUDIO_STREAM *stream, ULONG alternate_setting) {
+    if(alternate_setting == 0) {
+        memset(audio_buffer, 0x00, sizeof(audio_buffer));
+        return;
+    }
+
+    ux_device_class_audio_reception_start(stream);
 }
 
 static VOID usbd_uac_frame_done(UX_DEVICE_CLASS_AUDIO_STREAM *stream, ULONG actual_len) {
-    //
+    UCHAR *buf;
+    ULONG len;
+
+    ux_device_class_audio_read_frame_get(stream, &buf, &len);
+
+    HAL_SAI_Transmit_DMA(&hsai_BlockA3, buf, len);
+
+    ux_device_class_audio_read_frame_free(stream);
 }
\ No newline at end of file