Trainwreck Rocket 10 Watt or 25 Watt Bias Resistor???

[TimDude]

I'm building a Trainwreck Rocket. The schematic and the layout call for a 50 Ohm 25 Watt biasing resistor. However, I noticed that Ceriatone only uses a 10 Watt resistor. In my inventory, I only have a 10 watt resistor. Is there a reason I would need the 25 Watt resistor? I'm referring to R27 on this layout from the files here on the Amp Garage.

[sluckey]

10 watts should handle the power OK. But that 25W chassis mount resistor looks so good and provides a nice mounting point for the bypass cap.

[martin manning]

With the cathode voltage shown in the Rocket documents, it's only dissipating about 1.3W at idle. Note that if it is the same aluminum cased type shown in the layout, it has to be attached to a heat sink (the chassis, e.g.) to achieve its full rating.

[TimDude]

With the cathode voltage shown in the Rocket documents, it's only dissipating about 1.3W at idle. Note that if it is the same aluminum cased type shown in the layout, it has to be attached to a heat sink (the chassis, e.g.) to achieve its full rating.

Thanks! What is the best way to attach it to the chassis? Super glue? Hot glue gun? Something else?

[martin manning]

It should be bolted to the chassis.

[TimDude]

10 watts should handle the power OK. But that 25W chassis mount resistor looks so good and provides a nice mounting point for the bypass cap.

Thanks, I agree, it looks awesome! Reading your post prompted me to ordered one, I couldn't resist. Hahaha! I'll start with the 10W for now, and I'll upgrade to the 25W when it arrives.

[TimDude]

It should be bolted to the chassis.

"DUUHHHH" Hahaha, thanks! That should have been super obvious to me.

[Koolaide]

Just a quick question? Should thermal transfer paste be used?

[sluckey]

no

[Mark]

Thermal paste is normally used in these sorts of applications where there is a lot of heat. It is messy stuff though.