I believe the ARC design team feels fuses on output power tubes cause an unacceptable loss of sound quality in their amps. They prefer to sacrifice a resistor (or more) to protect the rest of the amp rather than sacrifice the loss in sq they have found fuses to cause in their amps. It is up to the consumer to decide if they want to own and maintain an amp so designed. There are, after all, other real good sounding power amps which DO have fused output tubes, not requiring repair every time a power tube fails!