Hi guys, I have looked but not very hard but here is my dilemma.

I have a randall 120D head and a 4x12 cabb with 2 chanels , 1 overdrive and one clean.

But I do not like very much my Overdrive chanel tone. I own a beta anvin Distortion pedal and when ever I turn it on I get this huge feedback when not playing.

I found a beta anvin NG-100 for just 50$. Is it necessary that I buy the pedal or there is anotherway to solve the problem.
Volume knob, or mute the strings. I'm assuming you have the volume cranked up. Noise gates can affect your tone which is why I don't use them.