diff --git a/MicroDexed.ino b/MicroDexed.ino
index 4a6197e..99b767b 100644
--- a/MicroDexed.ino
+++ b/MicroDexed.ino
@@ -92,12 +92,12 @@ AudioConnection          patchCord24(stereomono1, 1, usb1, 1);
 #if defined(TEENSY_AUDIO_BOARD)
 AudioOutputI2S           i2s1;
 AudioConnection          patchCord25(stereomono1, 0, i2s1, 0);
-AudioConnection          patchCord26(stereomono1, 0, i2s1, 1);
+AudioConnection          patchCord26(stereomono1, 1, i2s1, 1);
 AudioControlSGTL5000     sgtl5000_1;
 #elif defined (I2S_AUDIO_ONLY)
 AudioOutputI2S           i2s1;
 AudioConnection          patchCord27(stereomono1, 0, i2s1, 0);
-AudioConnection          patchCord28(stereomono1, 0, i2s1, 1);
+AudioConnection          patchCord28(stereomono1, 1, i2s1, 1);
 #elif defined(TGA_AUDIO_BOARD)
 AudioOutputI2S           i2s1;
 AudioConnection          patchCord29(stereomono1, 0, i2s1, 0);
@@ -252,7 +252,7 @@ void setup()
 #endif
 
   // start SD card
-#ifndef __IMXRT1062__
+#ifndef TEENSY4
   SPI.setMOSI(SDCARD_MOSI_PIN);
   SPI.setSCK(SDCARD_SCK_PIN);
 #endif
diff --git a/config.h b/config.h
index 18165e6..c42f371 100644
--- a/config.h
+++ b/config.h
@@ -30,6 +30,7 @@
 
 // ATTENTION! For better latency you have to redefine AUDIO_BLOCK_SAMPLES from
 // 128 to 64 in <ARDUINO-IDE-DIR>/cores/teensy3/AudioStream.h
+#define AUDIO_BLOCK_SAMPLES 64
 
 // If you want to test the system with Linux and withous any keyboard and/or audio equipment, you can do the following:
 // 1. In Arduino-IDE enable "Tools->USB-Type->Serial + MIDI + Audio"
@@ -38,6 +39,7 @@
 // $ aplaymidi -p 20:0 <MIDI-File> # e.g. test.mid
 // $ arecord -f cd -Dhw:1,0 /tmp/bla.wav
 
+
 #define VERSION "0.9.7"
 
 //*************************************************************************************************
@@ -53,7 +55,8 @@
 
 // AUDIO
 // If nothing is defined Teensy internal DAC is used as audio output device!
-// Left and right channel audio signal is presented on pins A21 and A22.//#define AUDIO_DEVICE_USB
+// Left and right channel audio signal is presented on pins A21 and A22.
+//#define AUDIO_DEVICE_USB
 //#define TEENSY_DAC
 //#define TEENSY_DAC_SYMMETRIC
 //#define TEENSY_AUDIO_BOARD
@@ -111,28 +114,37 @@
 //* UI
 //*************************************************************************************************
 #define ENABLE_LCD_UI 1
+#define STANDARD_LCD_I2C
+//#define OLED_SPI
+
+
 // LCD Display
 //I2C_DISPLAY only
+#ifdef STANDARD_LCD_I2C
 #define LCD_I2C_ADDRESS 0x27
 //#define LCD_I2C_ADDRESS 0x3f
 //Display size, must be set for U8X8 as well
 #define LCD_cols  16
 #define LCD_rows  2
-//#define LCD_rows  4
+#define I2C_DISPLAY
+// [I2C] SCL: Pin 19, SDA: Pin 18 (https://www.pjrc.com/teensy/td_libs_Wire.html)
+//#define LCD_GFX 1
+#endif 
 
+#ifdef OLED_SPI
+#define LCD_cols  16
+#define LCD_rows  4
 //enable U8X8 support
-//#define U8X8_DISPLAY
+#define U8X8_DISPLAY
 //enable SPI CS switching 
-//#define DISPLAY_LCD_SPI
-//#define U8X8_DISPLAY_CLASS U8X8_SSD1322_NHD_256X64_4W_HW_SPI
+#define DISPLAY_LCD_SPI
+#define U8X8_DISPLAY_CLASS U8X8_SSD1322_NHD_256X64_4W_HW_SPI
 //#define U8X8_DISPLAY_CLASS U8X8_SSD1306_128X64_NONAME_HW_I2C
-//#define U8X8_CS_PIN 9
-//#define U8X8_DC_PIN 15
-//#define U8X8_RESET_PIN 14
-//Standard 16x2 LCD display (SPI/PCF8874)
-#define I2C_DISPLAY
-// [I2C] SCL: Pin 19, SDA: Pin 18 (https://www.pjrc.com/teensy/td_libs_Wire.html)
-//#define LCD_GFX 1
+#define U8X8_CS_PIN 9
+#define U8X8_DC_PIN 15
+#define U8X8_RESET_PIN 14
+#endif 
+
 #define CONTROL_RATE_MS 50
 
 #define BACK_FROM_VOLUME_MS 1000
@@ -150,15 +162,25 @@
 //* HARDWARE SETTINGS
 //*************************************************************************************************
 
+#if defined(__IMXRT1062__) //Teensy-4.0
+#define TEENSY4
+#endif
+
 // Teensy Audio Shield:
 //#define SDCARD_CS_PIN    10
 //#define SDCARD_MOSI_PIN  7
 //#define SDCARD_SCK_PIN   14
 #define SGTL5000_LINEOUT_LEVEL 29
+#ifndef TEENSY4
 // Teensy 3.5 & 3.6 SD card
 #define SDCARD_CS_PIN    BUILTIN_SDCARD
 #define SDCARD_MOSI_PIN  11  // not actually used
 #define SDCARD_SCK_PIN   13  // not actually used
+#else
+#define SDCARD_CS_PIN    10
+#define SDCARD_MOSI_PIN  11  // not actually used
+#define SDCARD_SCK_PIN   13  // not actually used
+#endif
 
 // Encoder with button
 #define ENCODER_USE_INTERRUPTS
@@ -166,12 +188,15 @@
 #define ENC_L_PIN_A  3
 #define ENC_L_PIN_B  2
 #define BUT_L_PIN    4
+#ifndef TEENSY4
 #define ENC_R_PIN_A  28
 #define ENC_R_PIN_B  29
 #define BUT_R_PIN    30
-//#define ENC_R_PIN_A  6
-//#define ENC_R_PIN_B  5
-//#define BUT_R_PIN    8
+#else
+#define ENC_R_PIN_A  6
+#define ENC_R_PIN_B  5
+#define BUT_R_PIN    8
+#endif
 #define BUT_DEBOUNCE_MS 20
 #define LONG_BUTTON_PRESS 500