background noise on old ross flanger

[jessekates]

So I've got this super-awesome AC-powered ROSS flanger that I adore, but the thing's hissy as hell. I'm going to be recording soon, and I was wondering if there's anything I can do to reduce the background noise? Could this be an old cap problem?

[brad347]

More likely an old IC that's inherently noisy. It would probably be best to just live with the hiss as part of the personality of the pedal. But you may not be that type of person. :)

[jessekates]

More likely an old IC that's inherently noisy. It would probably be best to just live with the hiss as part of the personality of the pedal. But you may not be that type of person. :)

I don't mind too much. I just figured if it was something I could fix with a cap job or similar it would be worth looking into. The overall sound is very, very cool.

[BJF]

Hi,

Get Freezer spray, plug the unit in and listen and then freeze suspected caps and if noise changes you have it- yes this can be a problem.

However it's often the delay chip that is noisy and your only option then is to change the chip.

You can diagnose the chip by offsetting the bias trimmer so flanger sound disappears. If noise then drops dramatically the chip is a noisy part.

As a side note the other IC chips would generally have lower noise than the delaychip. There are a number of things including adjusting noise gain and optimizing impedances of the amplifiers that reduces background noise on the direct signal.

There might also be a compander in the circuit and if so the expander part can be set for higher expansion at lower levels and so noise will appear during played notes but may be silent during no input conditions.

Just a few thoughts

Have fun
BJ

Affiliations
www.mpamp.com
www.bjfelectronics.com