Reverb pedal causing a "boom" sound from the amp speaker

[black_crow]

Hi everyone,
Got my TC Hall of fame 2 today, absolutely in love with the sound of it, great product!
connected it to my Marshall DSL-5 effects loop.

I'm experiencing a little troubling issue, when I hit the activation button there's a little
boom sound from the speaker, either when I'm activating or turning the pedal off.
happens even when the amp power is turned off.

Any idea why is it happening and what is a possible solution for it?

[black_crow]

Well the issue solved by changing the pedal configuration from true bypass to buffer mode.