I just picked up a used Aguilar Twin Filter used (not on TB). First, it's a really nice, clean sounding envelop filter. I love how fat and classic it sounds. I had an MXR M82 (a few years ago) which was great for dirty funk but I struggled to get a good clean sound out of it. With my cell phone on and within 3' of the Aguilar I'm getting clicking and distorted breakup of the Aguilar envelop. The distorted breakup isn't consistent; it comes and goes. Airplane modes stops the problem as does moving the phone around 3+ feet away. There is no problem when the pedal is off. No other pedals are influenced by my phone. I know cell phones can give problems with amps, but this is the first time I've had one interact with a specific pedal. I don't have many other pedals (MXR compressor and tuner) and am just getting back into having pedals. I don't know if there is a problem with the pedal, power block, or if this is just normal. The disruption in sound is bad enough that I'm concerned about playing out with it. Thoughts on the cause? I can return the pedal.