This is a very basic low ripple power supply, perfect for audio use.

Change resistors to get different output voltage. (R1 & R2)

Some examples, with E12 (10%) resistors:

3.3V: 1k2 + 1k8 →→ 3% error

5V: 270 Ω + 820 Ω →→ 2% error

9V: 560 Ω + 3k3 →→ 2% error

12V: 390 Ω + 3k3 →→ less than 1% error

15V: 1k2 + 12k →→ 4% error

24V: 560 Ω + 10k →→ less than 1% error

(the first resistor is R1)

For comparison, with E96 (1%) resistors, all of the following have less than 1% error:

3.3V: 365 Ω + 590 Ω

5V: 1k02 + 2k94

9V: 71.5 Ω + 442 Ω

12V: 392 Ω + 3k32

15V: 590 Ω + 6k34

24V: 1k24 + 21k5

A nice resistor calculator can be found HERE for this circuit…

I will re do this board with a 5K pot for adjustable voltage regulation at some stage.

J1 is AC or DC In J2 is DC out.

IC1 = LM317

C1 is 1000uf 50v

C2 is 10uf 63v

C3 & C4 are 4700uf to 10000uf electrolytic

C5 & C6 can be generic green caps or mkt… anything really.

Diodes are 1N4004

Rectifier is KBP01

I have now cut the pcbs on the cnc router, just waiting for some parts to arrive so i can test the boards.

Etch at Home files HERE

Supply voltage should be 3v or so over the output voltage. A standard transformer will work… as well as DC input.