Hi everyone
I m haveing problem with the interaction between my ebs stanley clarke wah and my amp - roland db-500

.
Sometimes when i turn the wah on, there suddenly a huge volume drop + white noise. I checked it out with few guitars, few cables, few transformers - it happens every time. I sent the pedal to the store (it still has warranty). they said they checked it out any possible way and didnt find any problem. I got the pedal back, and ofcourse the same problem occured.
I plugged it into my other amp - trace elliot (why didnt i thought about it earier

), and it works perfectly.
Does anyone know what might be the problem? Do i need to fix the amp or the pedal? and What can i do to fix it? I should also mention i use the db-500 with many more pedals including envelope filter, and it works just fine.
thanks.