[sdiy] AS3394E: Practical power supply?

[The SynthiMuse]

I think adjusting the voltage on a 7905 with diodes in a non-critical
supply is fine except it reminds me....

As a 23 year old junior tech (1981), I got a gentle 'bollocking' for
replacing a VCS3 -ve power regulator with a 7905 and a zener to bring it up
to the right voltage.
He told me that so much of the synth depended on good PSU regulation that
doing this wouldn't give a solid enough rail for stable operation as the
voltage could drift up and down with temperature.
I learned my psu lesson.

So, overall,  an LM337-type solution is the one I would go for.

Gerry


On Fri, 19 Nov 2021, 09:34 Gordonjcp, <gordonjcp at gjcp.net> wrote:

> On Thu, Nov 18, 2021 at 03:49:00PM +0000, Tom Bugs via Synth-diy wrote:
> > necessary not to compromise the VCO frequency resolution, which ranges
> from
> > -4 to +4 volts, in favor of a -5V
> > supply (this is because there needs to be 4 diode drops for the current
> > mirrors).Any one of the readily
> > available 3-terminal regulators may be used to supply the -6.5V negative
>
> So why not a cheap readily-available 7905 with two diodes in its ground
> leg?
>
> --
> Gordonjcp
>
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