Hi again Tony. I don't think you'll need to dissipate anything like 80Watts.
In the 13E1 build, I tested the current sinks with them bolted to substantial heatsinks and they only got warm so to save space with the final build I dispensed with the heatsinks and bolted the MosFETs to the chassis top plate (they're right at the front, extreme left and right with a few slots either side to increase the surface area and air flow). The chassis top plate gets warm but I can easily keep my fingers on it where the MosFETs are mounted.
Anyway, this coming weekend I plan to finish the 6C33C SE-OTL build so I'll measure between the cathode and ground and let you know. B+ on my 6C33C is 130V and I'll set the current sinks to around 470mA. Incidentally, the 6C33C project will be using Maida regulators throughout, one per 6C33C and another for the input/driver stages.
In the 13E1 build, I tested the current sinks with them bolted to substantial heatsinks and they only got warm so to save space with the final build I dispensed with the heatsinks and bolted the MosFETs to the chassis top plate (they're right at the front, extreme left and right with a few slots either side to increase the surface area and air flow). The chassis top plate gets warm but I can easily keep my fingers on it where the MosFETs are mounted.
Anyway, this coming weekend I plan to finish the 6C33C SE-OTL build so I'll measure between the cathode and ground and let you know. B+ on my 6C33C is 130V and I'll set the current sinks to around 470mA. Incidentally, the 6C33C project will be using Maida regulators throughout, one per 6C33C and another for the input/driver stages.
