[sdiy] +/- 9v synth circuits

[The Peasant]

> Thanks for the ideas guys! (spec the part about
> headroom) How about this, two 9v's in series per rail
> into 7812's,that will give me the headroom for the
> regulators even if the bat's go a little flat correct?

Sure, but you will be wasting a lot of battery power in 
your regulators, as much as 50%. In this case a switching 
regulator may be your best choice, in spite of noise issues.

> The only reason I'm thinking about regs is for tuning
> stability. The wasp idea is a good one too, iirc
> someone was thinking about cloning one of these with
> midi as a commercial project. The main reason for
> using batterys is for my commute to school (no outlet
> on busses)and the fact that I hate wall warts. I am
> shooting to make this thing semi-modular (ala evenfall
> minimodular, I have one and it rocks). If the 4 9v's
> and regs can do it I may just build up the madmouse
> board ive had forever and save myself some dough.
> Two more questions, how can I figure the max current 2
> 9v batts in series can give me, and does anybody know
> how much current a madmouse (the non-midi one) draws
> per rail?

You may need to upgrade to a lead-acid or NiMH rechargeable 
battery for a modular system. A 12 volt battery with a low 
dropout regulator will do 9V OK.

Take care,
Doug

______________________
The Electronic Peasant

www.electronicpeasant.com