Hello all
Due to many enquiries over impedance issues and running several lasers off one input within the projector Dan and I have come up with a slight revision of MatIlda to serve this application.
This revision we have named Buffy, its a single MatIlda board with one set of buffers - six channels of diff buffering - 12 buffers in all, and is powered by an on board dc-dc convertor allowing Buffy to be powered from one of your 5V supplies in the projector. There are no external connectors and the holes for the Db-25s can be used as mounting holes with all connections being soldered to the pads on the pcb. We are keeping this the same price as all other versions for consistency and we will be making some over this weekend for them to appear on the MatIlda buy page (here http://danielbriggs.co.uk/laser/matilda/) on Monday.
Now to pre-empt the inevitable question about why dont we power all MatIldas off a nice n easy 5V supply - why do we use an ac supply instead - the answer is simple. MatIlda is designed to be modular and powering off a 2W dc-dc convertor would only allow one input and one output board as the upper limit - not very flexible! As MatIlda was intended to be an external device and requires a split rail supply for the op amps we thought a single ac supply was better to acheive this than 2x wall warts or having to add a more complicated internal psu which we didnt have space for.
I hope this helps people to eradicate some of them impedance blues. Long live Buffy!
Rob