I got a new set of tubes for my Budda Superdrive 18. Except for the recto tube, I switched all out. I turned the amp on, sound came out but very quiet. I gave it a few minutes but still at the very low volume. Fiddle around with the volume and gain knob but still very quiet. I thought it was the tubes so I put the old tubes back in. Same problem. FYI v3 pretube's tube holder (metal thing) had a loose screw but the amp worked fine as is with the old tube. Nothing wrong with the socket but just the metal holder is loose (when I put the tube in, it stays in place though) What do you think is the problem?