Sugden writes: "As Sugden amplifiers are class A, they require a certain size of heatsink to make sure the output transistors run at a controlled temperature. The Sugden Grande is 100 Watts per channel and requires much larger heatsinks than our 50 Watts per channel Masterclass SPA-4 power amplifier. A doubling in power doesn’t mean a doubling in heatsinks, it needs to be four times the size.

Our 100-watt class A power amplifier requires four time the heatsink of our 50 Watt class A power amplifier. It's just a fact we thought people might be interested in. It was to explain why the Grande was so much bigger that the Masterclass SPA-4."