Yep. Here is a direct quote from an email I received from Fender in response to this question:
"Bassman 500/800 and Rumble 200/500 amplifiers use class D + SMPS modules from ICEpower in Denmark. This is no trade secret, and many MI companies use the very same modules. These modules were designed for 230V operation and employ a (mains) voltage doubling configuration for 115V countries, a common technology for SMPS. At 115V (100-120V range) the mains voltage is doubled to 230V for the SMPS and the unit otherwise operates the same but at slightly lower efficiency. This requires a jumper setting on the module and when in 230V setting the voltage doubler is not active. However, to minimize cost as the voltage setting was assumed set by the factory, over voltage protection circuits were omitted in the event the voltage selector jumper is set to 115V but is connected to 230V AC mains - this will permanently damage the module. If set to 230V, the unit will not power up at 115V range mains with no risk of damage. The product markings reflect the factory setting and therefore the intended market (ie 100-120V or 220-240V). Opening the unit and changing the setting would void the warranty.
The general trend in class D + SMPS is universal mains operation (100-240V) without any need for user or factory set voltage selector switch. This is already present in some newer Fender products (Acoustic, Mustang GT, Rumble Stage/Studio) would be expected for future offerings."