Just got a mint used Ampeg SVPCL and love it. It gives me my sound and I dont have to struggle to get it like I had to with my SWR IOD. But I just opened it up to have a look at the tubes. The Ampeg site states that this is supposed to have two 12AX7´s and two 12AU7´s but mine has four GT 12AX7C´s. How is this possible? Will it hurt or affect the preamp in any way? Or is there a misprint on Ampegs site?