www.megadrum.info

Hello friends.
I received allinone yesterday and i'm staring to solder all component, but one question is in my mind.
Can i use two power switch? one for USB and One for external power when i use midi out?
I ask this because maybe one day i will use Megadrum with an external expander, so i don't want open case to move jumper everytime i must change my sampler.
I think the only dangerous thing is to power-on both switches but i will try to be careful!
I'm newbie in eletronics and in english!
Regards from italy! bye bye!

You can use a single SPDT switch like this http://uk.farnell.com/multicomp/1ms1t1b ... dp/9473378 with the pole pin connected to Vcc, and one side pin connected to the pin 1 of USB_Power_switch and another side pin connected to the pin 1 of Ext_Power_Jumper.

OK i got. It's 3 or 2 position? (one for usb, one off, and one for Ext pow)

2 positions will be enough. When on USB power, Ext position will act as 'Off'. When on external power, USB position will act as 'Off'.

Perfect! thank you!

If I want to connect my external power, where do I connect the walwart's "-" side? Do I need to switch any jumpers as well?

dwetmaster wrote:If I want to connect my external power, where do I connect the walwart's "-" side? Do I need to switch any jumpers as well?

If not connected to a PC you can power you module via the USB socket with any +5V regulated power adapter. You don't need to switch any jumpers.

But I'd prefer to install a socket on my unit. I think it's cleaner. So my "+" will go to the power switch, and the "-" will be soldered on the USB's "4" pin?

Yes.