Hum on hi gain/volume. Cause?

[Bigbizkit]

Hi made a bass preamp by Elliot Sound.
I am having problem eliminating the hum.
Everytime I turn the volume control up, the hum gets louder.
And when i increase the gain level, it produces a hissing sound.
But @ lower volume/gain, the preamp is working fine.
I am planning to put a voltage regulator using 7815,7915.
Wondering if it will work
Note: my wiring arrangement is messy,
Im thinking its one of the reasons why my project is noisy!humming.
Elp pls..
Bass Guitar Amp 1

[diydidi]

Yes, regulating the supplies will make a BIG difference. Also make sure the volume pot isn't too big.

[Tubis]

Try it inside a chassis to...

[Mick Bailey]

+1 on fitting it to a chassis. Your board is unscreened and will pick up any radiated hum. Fitting it to a grounded metal case will also ground the pot bodies and screen the tracks.

You have a lot of unscreened wiring too that you can tidy up when the project is cased. All of these are opportunities to pick up noise.

[tedmich]

shielded wire near the front end inputs can also help a great deal!

Rod Elliott is an excellent resource and answers most emails very promptly, especially if you've bought it from him, just follow his best practices:
Contacting ESP
which, like a lot of what he writes, are both sensible and funny.