[sdiy] Starting a synth project

[Gene Stopp]

Harry speaks much wisdom. I remember learning synth modules by concentrating
on the modules themselves and taking the power supply for granted. After a
while you get a feel for things like when a 1/2 watt resistor should be used
instead of 1/4 watt, or when and where to place bypass caps, things like
that. Power supply design goes much better once you have "the feel".

And a quick glance at eBay shows, let's see... aha! TWO Power One +/-15 @ 5
amp supplies for $19.99 for both with no reserve and zero bids, one day to
go on a seven day auction. Not bad! Those are going to be big and heavy, but
at five amps per rail you could power about a hundred modules. And have a
spare.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=58288&item=3862129158
&rd=1


- Gene


-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of harrybissell
Sent: Monday, December 27, 2004 2:04 PM
To: tlax at hellfish.org
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Starting a synth project


Hello Tero...

to tell you the truth, a lot of people post "starting a synth project" and
many
times
they come to the same conclusion as you.  I would advise that your first
project
NOT be a power supply. In fact I'd recommend you BUY a small, commecial
linear
power supply such as a PowerOne, or one of the many other manufacturers.

Brand new they would cost about $45 (US) but surplus they could be as low as
$10.

You need to trust your power supply.  I use an 800mA +/-15 supply from
PowerOne on
the bench and have never fried it. They have pretty sophisticated
overcurrent
protection
and will survive a lot of mistakes.

For a first project, I'd recommend a simple VCO, or LFO... followed by a
VCF. This
way you
get to hear some results right away.

Power supplies are cheaper to buy than to build...and they are not much fun.
If your
power
supply does not work, or fails suddenly... it can trash all the rest of your
work !

H^) harry

tlax at hellfish.org wrote:

> Hi,
>
> I've been thinking of starting a synth project. I thought it might be
convenient
> to start from the power supply and surfed for them on the net. But one
thing was
> almost never answered, what kind of transformers do people use in these?
>
> I've been thinking of something like this:
> http://www.ori.org/~aaronc/synth/PowerSupply_V1.pdf
> but with the 120V -> 2x24V transformer changed to a one with the european
230V
> -> 2x24V, but with 13VA, 22VA or more or even less than 13VA? Farnell.com
has a
> lot of these to choose from. :P
>
> Or maybe a better power supply schematics are lying on the net, but I just
> haven't runned into them. Might even buy a commercial one if I find a good
one
> inside the europe and could move to the nice part of project like VCO. :)
>
> --
> Tero Laxström <tlax at hellfish.org>