I own a marshall amp midi programmable (30th anniversary) and a multi fx (boss se 50). With my midi foot controller (yamaha mfc05) i want to transmit progam change to either the amp and the multi fx via the midiman 2x2 merge (which have also midi thru capabilities), but it doesn't work. I tried different combinations, different midi cables, I tried to give external power (9V) to the box, but.. no way.... This little unit costed me 70 euro. Please help me !
