Colorsound wah issues - advise please

jlpman

I've owned a red Colorsound wah for about 10 years and it's been killer.  At some point I had it modded, so it could take a power supply rather than just battery.

I've noticed recently (since running all my pedals through a looper) that when you click on the wah there's a bit of a tone suck and a slight volume drop.  Also when it's fully forward you start to get some radio coming through.

Anyone got any ideas what could be the cause of this or what could resolve it?