@Chrisedge: Thank you for this thread, it's similar what I am looking for right now
And it's for the A10 as well.
After I followed the Minidisc Forum Link (See first post -> Sonyinsider.com) I build one up yesterday and it seams to work.
Capacitors are 10uf - 16V
Resistors: Metalfoil - 6,8kohm
I am using them with Roland Wearpro Binuaral mics (Omnis) and selfmade Mics.
I also realized I can use 9V (9V cell) with the selfmade ones and only 6V (4x AAA) with the Roland Mics.
the Trouble: I build the BatteryBox just for one purpose, because the MicIn of the Sony A10 and the Roland Mics are both very sensitiv and I thought about using the Line IN Mode to record a concert. If running directly into the A10 I need to set it to Reclevel 01 and even that is often to high.
Now after a quick test with the new BatteryBox, it works in LineIn, hurray! But also it seams, that the LineIn Mode on the A10 is just as sensitiv as the MicIn Mode is
. So I need to add something like -20db attenuator after the BatteryBox now.