[Hudson]

As above really.

I've built the basic version of the amp and I'm getting quite a bit noise.

At zero volume there's no noise but as I increase the volume pot (Rp on the original) so the noise becomes worse, untill I reach about 3 quarters volume, at which point it disappears!

Any ideas? I'm using a wallwart type supply which is a switch mode type, could that cause such a problem?

Cheers, Stu.

 

[fortney]

A switch mode supply can cause noise although my SEC 1223 does not.

A Jameco regulated linear wall supply is always nice, but get one with about 2x the amps that the amplifier draws to avoid over heating.

Be sure every thing that is to be grounded is grounded. Sometimes a star ground solves noise problems--simplest explanation is all grounds meet at the same point grounded to the chassis.

F

 

[Hudson]

Yeah cheers, I've got a linear supply that I'm half way through building which I'm hoping may help.

As for the grounding, I'm pretty sure it's all ok, it's in a sort of star configuration, all the grounds return to the negative leg of a capacitor I've added to try and reduce noise on the supply, near to where the supply comes into the chassis.

I'll keep moving things around, see what happens.

Cheers, Stu.