For your viewing pleasure....a Premier Md. Super 88 circa 1960. Yes, it does ‘Rumble’ exactly when on depresses only the high frequency tone selector...the white tab on the far right... and use the tremolo! There are many other sounds available there, as well. 2 x 6560s cathode biased. It came to me dead after being found in a farm shed. Magnificent amp, 8mho....