[sdiy] Power supplies and effects - was: Death of DIY?

[Tim Daugard]

From: "Roy J. Tellason" <rtellason at blazenet.net>

: On Monday 18 July 2005 10:54 pm, harrybissell wrote:
: > I see no difference between guitar modules and synth
modules other
: > than packaging, and usually a unipolar 9V power supply.
Bring it on.
:
: Though I have no special interest in 9v supplies,  I think
unipolar is of some
: interest -- would that tend to use fewer op amps?  More
discrete transistor

: I like simpler power supply design and distribution,  too.

I looked at several of the designs and settled on a unipolar
power supply.  All the power connections only require two
pin connectors. These are less expensive and smaller than
three pin. I was going to use 15V, but the transformer that
fit my form factor couldn't provide enough headroom for a
fifteen volt regulator.

I went with 12 volt as the system standard. This provides a
reasonable signal level. Someone can do the math . . . I
think the difference between 12V and +/- 12 V would be only
about 3db (6db?) in signal to noise. WIth three wires and
two regulator you increase the possibity of supply noise
anyway.

Most effects units will run on 12V without a problem. THis
means If I want to integrat a commercial effect into my
rack, all I have to do is put it in a case.

: DIYer and not a mfr, the idea of making boards is more of
a hassle for one
: unit rather than lots of them (though stuffing perfboard
does have its tedium
: as well),  and all those mult-pin connectors add up quick.

I can stuff a perfboard in much less time than it takes to
layout and etch a PC board. I've had better luck with my
perboard point to point wiring holding up than my etched
circuit boards. I live in an area where there is lots of
moisture and salt in the area (especially when the
hurricanes kick up the seas) and my boards and even some of
the commercial stuff I've bought develop corrosion. I
decided that point to point wiring on a perfboard is good
enough for my 1 - 3 offs of any module.

: Sure seems like a bunch of the folks in here have lots
more to spend on this
: hobby than I do!

don't it though. ;-(

I put my lifetime by of through hole parts together and was
real unhappy when it was over $400. I've tried to keep my
module costs to less than $5 each. The good news was that
some parts I though had disappeared for ever turned up again
at Mouser.

Tim Daugard
AG4GZ 30.4078N 86.6227W Alt: 12 feet above MSL
http://home.sprintmail.com/~daugard/synth.htm

avoiding picking up downed tree branches from Dennis. I hope
the people of Mexico survive Emily ok.