The Marshall JCM800 is widely regarded as the foundation upon which most modern high-gain amps are built. This particular example has undergone a circuit board replacement due to damage to the original board. Fortunately, most of the original components were transferred over, with only a couple of modern carbon film resistors substituted in a few spots. The work looks clean and professionally done. Please see the circuit photos for further details.
The original Dagnall transformers still remain, along with the Drake choke. The filter caps have also been updated, giving the amp a nice, tight sound with ample low end. Some may even see the board replacement as making this a great candidate for further modifications, for those so inclined!