Update readme

README.md

 
 ![Inputs](/gui/img/audioshield_inputs.jpg)      ![Outputs](/gui/img/audioshield_outputs.jpg)
 
-[Teensy 3.1](http://www.pjrc.com/store/teensy31.html) 12 bit DAC
+Dual [Audio Adaptor Boards](http://www.pjrc.com/store/teensy3_audio.html) for quad channel 16 bit input and output.
+
+![](/gui/img/audioshield_quad_out.jpg)
+
+[Teensy 3.6](http://www.pjrc.com/store/teensy36.html), [Teensy 3.5](http://www.pjrc.com/store/teensy35.html), [Teensy 3.2](http://www.pjrc.com/store/teensy32.html), or [Teensy 3.1](http://www.pjrc.com/store/teensy31.html) 12 bit DAC Output (Mono)
 
 ![DAC Output](/gui/img/dacpin.jpg)
 
-[Teensy 3.1](http://www.pjrc.com/store/teensy31.html) or [3.0](http://www.pjrc.com/store/teensy3.html) ADC Input
+[Teensy 3.6](http://www.pjrc.com/store/teensy36.html), [Teensy 3.5](http://www.pjrc.com/store/teensy35.html), [Teensy 3.2](http://www.pjrc.com/store/teensy32.html), [Teensy 3.1](http://www.pjrc.com/store/teensy31.html) or [Teensy 3.0](http://www.pjrc.com/store/teensy3.html) ADC Input (Mono)
 
 ![ADC Input](/gui/img/adccircuit.png)
 
-[Teensy 3.1](http://www.pjrc.com/store/teensy31.html) or [3.0](http://www.pjrc.com/store/teensy3.html) PWM Output
+[Teensy 3.6](http://www.pjrc.com/store/teensy36.html), [Teensy 3.5](http://www.pjrc.com/store/teensy35.html), or [Teensy 3.2](http://www.pjrc.com/store/teensy32.html) ADC Input (Stereo)
+
+![ADC Input](/gui/img/adccircuit2.png)
+
+[Teensy 3.6](http://www.pjrc.com/store/teensy36.html) or [Teensy 3.5](http://www.pjrc.com/store/teensy35.html) 12 bit DAC Output (Stereo)
+
+![DAC Output](/gui/img/dacpins.jpg)
+
+[Teensy 3.6](http://www.pjrc.com/store/teensy36.html), [Teensy 3.5](http://www.pjrc.com/store/teensy35.html), [Teensy 3.2](http://www.pjrc.com/store/teensy32.html), [Teensy 3.1](http://www.pjrc.com/store/teensy31.html) or [Teensy 3.0](http://www.pjrc.com/store/teensy3.html) PWM Output (Mono)
 
 ![PWM Output](/gui/img/pwmdualcircuit.jpg)
 
+USB Audio: Bi-Directional Stereo Streaming to a PC
+
+![Inputs](/gui/img/usbtype_audio_in.png)      ![Outputs](/gui/img/usbtype_audio_out.png)
+
+