diff --git a/components/services/battery.c b/components/services/battery.c
index 5208df0a..1af4a69a 100644
--- a/components/services/battery.c
+++ b/components/services/battery.c
@@ -60,7 +60,9 @@ static void battery_callback(TimerHandle_t xTimer) {
  */
 void battery_svc_init(void) {
 	battery.channel = CONFIG_BAT_CHANNEL;
+#ifdef CONFIG_BAT_SCALE	
 	battery.scale = atof(CONFIG_BAT_SCALE);
+#endif	
 
 #ifndef CONFIG_BAT_LOCKED
 	char *nvs_item = config_alloc_get_default(NVS_TYPE_STR, "bat_config", "n", 0);
diff --git a/components/services/led.c b/components/services/led.c
index f4094bff..de1be4d7 100644
--- a/components/services/led.c
+++ b/components/services/led.c
@@ -36,9 +36,9 @@ static struct led_s {
 
 static struct {
 	int gpio;
-	int state;
-} green = { CONFIG_LED_GREEN_GPIO, CONFIG_LED_GREEN_GPIO_LEVEL},
-  red = { CONFIG_LED_RED_GPIO, CONFIG_LED_RED_GPIO_LEVEL };
+	int active;
+} green = { CONFIG_LED_GREEN_GPIO, 0 },
+  red = { CONFIG_LED_RED_GPIO, 0 };
 
 /****************************************************************************************
  * 
@@ -162,19 +162,27 @@ void set_led_gpio(int gpio, char *value) {
 	
 	if (strcasestr(value, "green")) {
 		green.gpio = gpio;
-		if ((p = strchr(value, ':')) != NULL) green.state = atoi(p + 1);
+		if ((p = strchr(value, ':')) != NULL) green.active = atoi(p + 1);
 	} else 	if (strcasestr(value, "red")) {
-		red.state = gpio;
-		if ((p = strchr(value, ':')) != NULL) red.state = atoi(p + 1);
+		red.active = gpio;
+		if ((p = strchr(value, ':')) != NULL) red.active = atoi(p + 1);
 	}	
 }
 
 void led_svc_init(void) {
+	
+#ifdef CONFIG_LED_GREEN_GPIO_LEVEL
+	green.active = CONFIG_LED_GREEN_GPIO_LEVEL;
+#endif
+#ifdef CONFIG_LED_RED_GPIO_LEVEL
+	red.active = CONFIG_LED_RED_GPIO_LEVEL;
+#endif
+
 #ifndef CONFIG_LED_LOCKED
 	parse_set_GPIO(set_led_gpio);
 #endif
-	ESP_LOGI(TAG,"Configuring LEDs green:%d (active:%d), red:%d (active:%d)", green.gpio, green.state, red.gpio, red.state);
+	ESP_LOGI(TAG,"Configuring LEDs green:%d (active:%d), red:%d (active:%d)", green.gpio, green.active, red.gpio, red.active);
 
-	led_config(LED_GREEN, green.gpio, green.state);
-	led_config(LED_RED, red.gpio, red.state);
+	led_config(LED_GREEN, green.gpio, green.active);
+	led_config(LED_RED, red.gpio, red.active);
 }
diff --git a/components/services/monitor.c b/components/services/monitor.c
index d9fff0da..b68bfe88 100644
--- a/components/services/monitor.c
+++ b/components/services/monitor.c
@@ -21,6 +21,7 @@
 #include "globdefs.h"
 #include "config.h"
 #include "accessors.h"
+
 #define MONITOR_TIMER	(10*1000)
 
 static const char *TAG = "monitor";
@@ -30,8 +31,8 @@ static TimerHandle_t monitor_timer;
 static struct {
 	int gpio;
 	int active;
-} 	jack = { CONFIG_JACK_GPIO, CONFIG_JACK_GPIO_LEVEL },
-	spkfault = { CONFIG_SPKFAULT_GPIO, CONFIG_SPKFAULT_GPIO_LEVEL };
+} 	jack = { CONFIG_JACK_GPIO, 0 },
+	spkfault = { CONFIG_SPKFAULT_GPIO, 0 };
 
 void (*jack_handler_svc)(bool inserted);
 bool jack_inserted_svc(void);
@@ -91,13 +92,28 @@ void set_jack_gpio(int gpio, char *value) {
 		jack.gpio = gpio;	
 		if ((p = strchr(value, ':')) != NULL) jack.active = atoi(p + 1);
 	}	
- }
+}
+
+/****************************************************************************************
+ * 
+ */
+void set_spkfault_gpio(int gpio, char *value) {
+	if (strcasestr(value, "spkfault")) {
+		char *p;
+		spkfault.gpio = gpio;	
+		if ((p = strchr(value, ':')) != NULL) spkfault.active = atoi(p + 1);
+	}	
+}
 
 /****************************************************************************************
  * 
  */
 void monitor_svc_init(void) {
 	ESP_LOGI(TAG, "Initializing monitoring");
+	
+#ifdef CONFIG_JACK_GPIO_LEVEL
+	jack.active = CONFIG_JACK_GPIO_LEVEL;
+#endif
 
 #ifndef CONFIG_JACK_LOCKED
 	parse_set_GPIO(set_jack_gpio);
@@ -108,6 +124,10 @@ void monitor_svc_init(void) {
 		ESP_LOGI(TAG,"Adding jack (%s) detection GPIO %d", jack.active ? "high" : "low", jack.gpio);					 
 		button_create(NULL, jack.gpio, jack.active ? BUTTON_HIGH : BUTTON_LOW, false, 250, jack_handler_default, 0, -1);
 	}	
+	
+#ifdef CONFIG_SPKFAULT_GPIO_LEVEL
+	spkfault.active = CONFIG_SPKFAULT_GPIO_LEVEL;
+#endif	
 
 #ifndef CONFIG_SPKFAULT_LOCKED
 	parse_set_GPIO(set_spkfault_gpio);
diff --git a/components/squeezelite/a1s/ac101.c b/components/squeezelite/a1s/ac101.c
index bdd2bfa8..5ba59081 100644
--- a/components/squeezelite/a1s/ac101.c
+++ b/components/squeezelite/a1s/ac101.c
@@ -73,7 +73,6 @@ static int i2c_port;
 static bool init(int i2c_port_num, int i2s_num, i2s_config_t *i2s_config) {	 
 	esp_err_t res;
 	
-	ESP_LOGI(TAG, "Initializing AC101");
 	i2c_port = i2c_port_num;
 
 	// configure i2c
@@ -88,17 +87,21 @@ static bool init(int i2c_port_num, int i2s_num, i2s_config_t *i2s_config) {
 		
 	i2c_param_config(i2c_port, &i2c_config);
 	i2c_driver_install(i2c_port, I2C_MODE_MASTER, false, false, false);
-	ESP_LOGI(TAG, "DAC using I2C sda:%u, scl:%u", i2c_config.sda_io_num, i2c_config.scl_io_num);
+	
+	res = i2c_read_reg(CHIP_AUDIO_RS);
+	
+	if (!res) {
+		ESP_LOGW(TAG, "No AC101 detected");
+		i2c_driver_delete(i2c_port);
+		return 0;		
+	}
+	
+	ESP_LOGI(TAG, "AC101 DAC using I2C sda:%u, scl:%u", i2c_config.sda_io_num, i2c_config.scl_io_num);
 	
 	res = i2c_write_reg(CHIP_AUDIO_RS, 0x123);
 	// huh?
-	 vTaskDelay(100 / portTICK_PERIOD_MS); 
+	vTaskDelay(100 / portTICK_PERIOD_MS); 
 	
-	if (ESP_OK != res) {
-		ESP_LOGE(TAG, "AC101 reset failed! %d", res);
-		return false;
-	} 
-			
 	// enable the PLL from BCLK source
 	i2c_write_reg(PLL_CTRL1, BIN(0000,0001,0100,1111));			// F=1,M=1,PLL,INT=31 (medium)				
 	i2c_write_reg(PLL_CTRL2, BIN(1000,0110,0000,0000));			// PLL, F=96,N_i=1024-96,F=0,N_f=0*0.2;
diff --git a/components/squeezelite/external/dac_external.c b/components/squeezelite/external/dac_external.c
index 7e177006..49c5bf69 100644
--- a/components/squeezelite/external/dac_external.c
+++ b/components/squeezelite/external/dac_external.c
@@ -54,7 +54,7 @@ static bool init(int i2c_port_num, int i2s_num, i2s_config_t *config) {
 		i2s_driver_install(i2s_num, config, 0, NULL);
 		i2s_set_pin(i2s_num, &i2s_pin_config);
 
-		ESP_LOGI(TAG, "DAC using I2S bck:%u, ws:%u, do:%u", i2s_pin_config.bck_io_num, i2s_pin_config.ws_io_num, i2s_pin_config.data_out_num);
+		ESP_LOGI(TAG, "External DAC using I2S bck:%u, ws:%u, do:%u", i2s_pin_config.bck_io_num, i2s_pin_config.ws_io_num, i2s_pin_config.data_out_num);
 
 		return true;
 	} else {
diff --git a/components/squeezelite/output_i2s.c b/components/squeezelite/output_i2s.c
index 25e30656..e36d98ec 100644
--- a/components/squeezelite/output_i2s.c
+++ b/components/squeezelite/output_i2s.c
@@ -242,9 +242,6 @@ void output_init_i2s(log_level level, char *device, unsigned output_buf_size, ch
 		gpio_set_level(CONFIG_SPDIF_DO_IO, 0);
 #endif
 
-		// not very pretty ...
-		adac = &ADAC;
-
 		i2s_config.sample_rate = output.current_sample_rate;
 		i2s_config.bits_per_sample = bytes_per_frame * 8 / 2;
 		// Counted in frames (but i2s allocates a buffer <= 4092 bytes)
@@ -253,8 +250,13 @@ void output_init_i2s(log_level level, char *device, unsigned output_buf_size, ch
 		dma_buf_frames = DMA_BUF_COUNT * DMA_BUF_LEN;	
 		
 		// finally let DAC driver initialize I2C and I2S
-		adac->init(I2C_PORT, CONFIG_I2S_NUM, &i2s_config);
-	}
+		if (dac_tas57xx.init(I2C_PORT, CONFIG_I2S_NUM, &i2s_config)) adac = &dac_tas57xx;
+		else if (dac_a1s.init(I2C_PORT, CONFIG_I2S_NUM, &i2s_config)) adac = &dac_a1s;
+		else {
+			dac_external.init(I2C_PORT, CONFIG_I2S_NUM, &i2s_config);
+			adac = &dac_external;
+		}
+	}	
 
 	LOG_INFO("Initializing I2S mode %s with rate: %d, bits per sample: %d, buffer frames: %d, number of buffers: %d ", 
 			spdif ? "S/PDIF" : "normal", 
diff --git a/components/squeezelite/tas57xx/dac_57xx.c b/components/squeezelite/tas57xx/dac_57xx.c
index de451ca5..6a60dcb9 100644
--- a/components/squeezelite/tas57xx/dac_57xx.c
+++ b/components/squeezelite/tas57xx/dac_57xx.c
@@ -78,15 +78,8 @@ static int tas57_detect(void);
  * init
  */
 static bool init(int i2c_port_num, int i2s_num, i2s_config_t *i2s_config)	{	 
-	LOG_INFO("Initializing TAS57xx ");
-	
 	i2c_port = i2c_port_num;
 	
-	// init volume & mute
-	gpio_pad_select_gpio(VOLUME_GPIO);
-	gpio_set_direction(VOLUME_GPIO, GPIO_MODE_OUTPUT);
-	gpio_set_level(VOLUME_GPIO, 0);
-	
 	// configure i2c
 	i2c_config_t i2c_config = {
 			.mode = I2C_MODE_MASTER,
@@ -96,13 +89,26 @@ static bool init(int i2c_port_num, int i2s_num, i2s_config_t *i2s_config)	{
 			.scl_pullup_en = GPIO_PULLUP_ENABLE,
 			.master.clk_speed = 100000,
 		};
+		
 	i2c_param_config(i2c_port, &i2c_config);
 	i2c_driver_install(i2c_port, I2C_MODE_MASTER, false, false, false);
-	LOG_INFO("DAC using I2C sda:%u, scl:%u", i2c_config.sda_io_num, i2c_config.scl_io_num);
-	
-	// find which TAS we are using
+		
+	// find which TAS we are using (if any)
 	tas57_addr = tas57_detect();
 	
+	if (!tas57_addr) {
+		LOG_WARN("No TAS57xx detected");
+		i2c_driver_delete(i2c_port);
+		return 0;
+	}
+	
+	LOG_INFO("TAS57xx DAC using I2C sda:%u, scl:%u", i2c_config.sda_io_num, i2c_config.scl_io_num);
+	
+	// init volume & mute
+	gpio_pad_select_gpio(VOLUME_GPIO);
+	gpio_set_direction(VOLUME_GPIO, GPIO_MODE_OUTPUT);
+	gpio_set_level(VOLUME_GPIO, 0);
+
 	i2c_cmd_handle_t i2c_cmd = i2c_cmd_link_create();
 	
 	for (int i = 0; tas57xx_init_sequence[i].reg != 0xff; i++) {