[sdiy] +/- 9v synth circuits

[Karl Dalen]

I build my things with +/-10V for bipolar in some cases other
wise i do most in +/-5V signal peak range, that is +/-7,5V for
bipolar or less for newer bipolar OPamp, and +5V for cmos logic
The current decrease is quite dramatic compared to +/-15v system 
with 10v swing. I have a complete 3 VCO VCF VCA ect board
all bipolar including controll logic sinking about 120mA at
full blast and that board uses Ovens for VCO and VCF.

I made a custom job once long time ago (body carried sound
machine) ,2VCO 2LFO, 2VCA 2ENV etc, modulating routings, 
pow amp,and some sound presetts body controlled, all in
CMOS ,that sinked ca 4,30mA, with full speaker blast
around 45-50mA depending on battery condition.

What i mean is that there is in no doubth a possibility to
do very low power designs, far lower what i have achieved!

Its all about proper design, as an tiny example, why use a buffer
that draws 3,42mA in front of the S/H switch when you can 
drive the switch directly from whatever sound source (eg noise gen)
as long as the source are within swing range of the switch.

There are millions of things you can actually do
to reduce power consumption in your designs!

Thanks.
KD  

--- harrybissell <harrybissell at prodigy.net> skrev: > Two 9V batteries
gives 18V... regulated to 12V thats 5V drop...
> you are going to eat batteries.
> 
> I'd say that a 9V is good for about 180mA/hrs... so a 180mA load kills
> the battery
> in one hour.  90mA = 2 hrs etc...   I probably would not want to use 9V
> batteries
> for more than maybe a 20-30mA load.
> 
> (some folks on the list suggested that the 180mA/hr figure is way low.
> I don't know
> whose right. Maybe they get better batteries than me :^)
> 
> I have to look at the madmouse again (carefully) but i'd say offhand it
> was not designed
> with battery operation in mind ...
> 
> You need to really pay attention to what you're doing in battery
> operated design.  Either
> use brute force (BIG batteries) or small circuits...
> 
> The minimodular indeed... rocks.  It has a +/-15V @ 400mA supply. Its a
> hungry puppy.
> 
> H^) harry
> 
> Ryan Guilfoyle wrote:
> 
> > 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?
> > 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?
> >
> > Once again I'm amazed at the mass of knowledge on this
> > list.
> >
> > __________________________________
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