+/-15V PSU vs MBCV/AOUT_LC

Design Concepts
1

Hi there,

perhaps some of you can help me out here.

since 90% of the synth projects i’ve been working so far on run on ±15V, i was wondering if it is feasible to use a second pair of regulators (any maybe some filter caps) in series, behind a 15V PSU, to trim the voltage to ±12V just for the AOUT_LC module i’m using? i currently run two separate PSU’s both based on the MFOS wall wart power supply. which feels kind of a waste actually.

i haven’t done any measurements but i would assume that the AOUT module does not draw an awful lot of current? o.k. i guess that depends on what i hook up to it… but in general?

i’m not sure though if additional regulators could have a bad effect on the stability of the remaining 15V circuitry. anybody?

it would be great to be able to go with a single combined PSU in a modular system, instead of using two separate PSU’s.

2

forget about additional caps, i realized that makes no sense when there is no more AC left to filter.

but 15V and 12V regulators in series? do-able?

thanks.

3

7812/7912s will happily run on ±15V.

4

As is see it, you don’t need regulators at all.

Take a look at the schematic of the LC. ±12V supplies the Op-amp(TL072), wich can also be powered by ±15V.

5

wouldn’t +/-15V upset my tuning ???

6

You’ll have to calibrate that thing anyway to get the tuning right.

You have two trimpots per channel, one for Gain and one for Offset. Gain is not affected by the supply-voltage.

The Offset-pot is wired as a voltagedivider. With ±15V on it’s outer pins, it can output voltages between -15V and +15V on it’s middle pin.

So You’ll have a wider range of voltage to chose from, compared to ±12V. In theory, that’s even a benefit. .

7

that sounds plausible. thanks!