I am involved in the design of the amplifying and clipping section of a guitar audio processor embedding your Ad528x digipots. For that a dual supply +-5V is necessary and we are currently exploiting (in the first working prototype) the LTC3260
The involved circuit has a very high gain, so, having the cleanest supply is mandatory.
What appears upping the gain is that the switching noise is somehow downconverted thus generating an audible tone which is unwelcome especially when the instrument is not playing.
The switching noise is present at both positive and negative rails.
Do you have any suggestion ? Maybe exploiting an lc filter with snubber?
Is there any additional solution with different PN that might fit our needs?
Thanks in advance for your support.