Ampeg SVT Classic Mid control
So I've owned a vintage SVT for many years and one day the midrange control stopped working. No midrange, no difference no matter where the dial was. I tried having it fixed more than once and the problem just came back. I still have the amp but haven't used it for a while because of that problem.
Anyways, to the point. We rented an Ampeg SVT Classic for a backline of a little music fest yesterday and this new model has exactly the same problem. No matter what you do to the midrange control, even changing the frequency range, it does nothing to the sound. It's probably the main reason for using that amp, the mid range honk, but it's not there. Is this common or is it a coincidence. The rental amp has the same problem as my old vintage SVT? I also have an old V4-B and it's midrange control does exactly what I expect it to.
So, any thoughts, experiences?