[sdiy] Linear PSU options .. 7815/7915 vs LM317/LM337 vs 723 etc

[Jay Schwichtenberg]

Yes,

I wouldn't put 7XXX stuff in audio circuits. They are noisier than the
LM317/LM337. Linear Tech makes some even better ones. Might also look into
some of the new LDO (Low Drop Out) regulators. One problem now days is that
they spend most of the development doing positive regulators and not
negative ones. Mainly for all the low power portable equipment that is being
made. Thye don't need good neg regs so they aren't working to hard in that
area.

Check out the 4th bullet down:
<http://waltjung.org/Regs.html>

Happy soldering and to many more modules in our synths in 2006!
Jay S.

-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Seb Francis
Sent: Monday, January 09, 2006 7:55 AM
To: Synth DIY
Subject: Re: [sdiy] Linear PSU options .. 7815/7915 vs LM317/LM337 vs
723 etc


Someone just suggested the LM317/LM337 are supposed to be better than
the 7XXX series.  Has anyone ever done a comparison between these?

Seb


Seb Francis wrote:

> Hi,
>
> I'm almost getting to the stage where it's time to move my
> multi-compressor/gate/distortion project from the breadboard to PCB.
> The final piece to design is the PSU.
>
> The requirements are not too unusual .. +/-15V at probably 200mA max,
> and I want it to run from a standard AC wallwart (or maybe I'll stick
> a transformer in the box - I haven't decided yet).  My first thought
> is to use a 7815 & 7915, but I'm wondering is there some 'better' PSU
> design?  What are some other options, and what actually are the
> advantages in going for a more complex PSU?
>
> I've seen plenty of power supplies based on the 723, but I don't need
> variable voltage or current limiting and it doesn't have to be exactly
> +/-15V - near enough will do as long as it is a clean DC voltage!
> Would I expect to get less noise from a 723 based PSU compared to
> 7815/7915, or is this more a question of the smoothing, decoupling and
> board layout?  Are there any options which will make a better PSU than
> 7815/7915 but without the complexity of a 723 based PSU?
>
> Many questions, I hope some kind person can help me :)
>
> Seb
>
>
>
>