[sdiy] EFM SBM Power supply problems (Again, Sigh....) Need alternate power source recommendations

[tomg@efm]

Do you remember the power supply discussion? The part about using a
center tapped transformer, full wave bridge and larger caps?

Tom




> Well, I've done some research trying to find the problem with my SBM
VCO's -
> they would not put out a single waveform, but rather had other harmonics
and
> strange sounds happening.....
>
> I have built two complete SBM boards and have this IDENTICAL problem on
> both.  I have used parts from Tom's SBM parts list with mouser numbers,
have
> verified each value and part number.
>
> At this point I am using two function generators (each set to opposite 12v
> DC voltages) instead, with original power supply disconnected, and WHOA
BOY
> does >everything else< work nice. (yes that is bitter sarcasm you smell).
>
> So the problem is in the power supply module, or its design, or in how it
> reacts to the load of modules.
>
> Question is: I need to build a +12DC/-12DC power supply module board,
> preferably using the same 12v AC wall warts I already have.  Can anyone
> recommend a schematic or link to one somewhere?
>
>
> Rob
>