So Sick of SEARCHING, help me find a good +/- 24v regulator PLEASE!

[ostripper]

very good suggestion, Bonsai, the 317/337 is much better than
the 78/79XX combo for ripple as well as the ability
to trim it to exact voltage.(10 turn trimmer)

With decoupling caps at ADJ and output less than 1mv
can be acheived at output.
As far as sound, I use these in preamp and sub EQ
op-amp circuits with the relay circuits added and can
see no glitch/ripple or hear no noise.

For the low current use no heatsink or a small clip-on
will save space.

[Destroyer OS.]

Sweet I must go that route, seems easy.

[Destroyer OS.]

I hate to be a total *** but I use a computer at the library and it has no calculator and my phone will do not calculations...

http://cache.national.com/ds/LM/LM137.pdf

Could some one help me out? I know I need 2 120ohm resistors, 2 10uf caps (think I will use 22uf so I can use FM's), and then I might just use 8 (4 per side) 33uf caps for low impedence on the ouput. I can not calculate R2 though without a calculator .

[wg_ski]

2184 ohms. Use 2.2k, and trim by putting high values in parallel until it comes out right.

You mean the computer doesn't even have Excel on it????? I know it's overkill, but it works.

[BobEllis]

Showing my age, but a pencil and paper work for simple calculations, too.

2K2 is close enough - The tolerance of the chip is further off than that. You can absorb a few millivolts difference in the rails.

[ostripper]

Good choice, Dest. OS, simple ..but will do the job
here is my preamp supply:



Notice D1/2.. D1 protects against reverse bias of device
and D2 makes it short circuit proof. Just reverse the diodes to
make the negative (lm337) half of your PS.

R2 I use a 5k 10 turn trimmer. easy to get >.01V at
output, A really foolproof power supply.

[Destroyer OS.]

I can just reverse the diodes to have the second do -24v correct?

At this rate I think I might go four transformers. I will have dual mono line amps. (why not I thought I was going to be spending way more money) This will also insure 1a worth to each line-amp.

Also I am going to use two extra diodes per 24v supply.

Parts list.

16 MUR860 Diodes (already have Cool (full bridge rectifying)
$1.16 x 8 = $9.28

4 Transformers (power in)
$2.88 x 4 = $11.52

4 LM317T
$2.25 x 4 = $9.00

4 120ohm Caddock MK123 resistors (needed in circuit)
$2.00 x 4 = $8.00

4 2.2kohm Caddock MK123 resistors (define value of 24v)
$2.00 x 4 = $8.00

4 10uf FC Panasonic capacitors (in circuit capacitors)
$.28 x 4 = $1.20

16 56uf FM Panasonic capacitors (output capacitors, four per output, should be super low impedence)
$.14 x 16 = $2.30

4 Panasonic X2 .01uf caps (for on each transformers, although I already got pretty sweet AC filtering)
$.91 x 4 = $3.64

1 Velleman ECS2 2 Hole Island Euro Card 3.9" x 6.3" ("bread board" but easier to deal with)
$8.76

Total = $58 for a pretty nice PSU, of course not nearly as nice as what it is going to drive but...

Anything else?

That makes my total for line-amp, with 4 JFETs $16, four Vishay resistors $7 a pop, $28, two RCA jack pairs $6.50 so $13.00, 4 feet jupiter copper $1.10 a foot $4.40, and two Sonicap platinum .01 teflon caps $18 a pop, $36

$97.41

$155 dollars for a only matched by other DIY buffers with slightly nicer stuff, no matter how much money you spend, and paid for by my good old pre-amp I had for phono! Sweet!

Thank you for your help everyone. Especially for helping me get the right resistor value. I forgot about Excel, yeah they have it, the new one that confuses me even more!

[Destroyer OS.]

I reduced it to two PSU's. It should still work nice.

[ostripper]

no no, D. OS... You must buy 2-LM317 (pos) AND 2-LM337 (neg)
build the same circuit as I posted with The 317 and
substitute 337 and flip diodes (D1-2). you are getting ripped
for price.. try newark.com or mcm electronics. I built circuit for 20$$.

I get 317T for 0.22c

[Destroyer OS.]

No no I listed for four circuits.

I do not have to invert diodes and use other regulator I found out. I can just use two different transformers, and connect the negative and positive to the opposites for one of them.