Originally Posted by alexh
AFAIK external scan doublers are exactly the same hardware as internal ones. The internal ones just get the signal before being routed to the 23-pin connector. It makes them more "aesthetically" pleasing for use in towers but are functionally the same.
i dont think, as you are connecting it to lisa, so dac BT101 is simply bypassed when you have internal SD.
external SD is digitalising signal again and there is really some ghosting etc.