I have an Alesis Studio 32 mixer that makes a "seashore" noise in the
right outputs of both subgroups and in the main output. The source of
the noise in channel-11, and it's there regardless of the position of
the mute and pan controls for that channel.

To further describe the "seashore" noise, its a hissy, static-y (like AM
radios during a thunderstorm) sound with occasional deeper rumbles.

Although the problem has also surfaced on channel-6, it's most
reproducable in channel-11. It will start a few minutes after the mixer
is turned on, then will quiet down for hours at a time before
re-occuring. No signal needs to be present on any channel for this
problem to manifest.

Before I open this thing (or send it out for repair), I'd like to have
some idea of what components are the likely culprits.

Any ideas?