AB763 Trem LDR 10M resistor wattage

[evancorylevine]

Is it alright to use a 1/4W for this resistor, or do I need a 1/2W?

[evancorylevine]

I have four 10M 1/4W resistors. If I hook them up in series parallel, would that effectively increase the power rating?

[sluckey]

The power rating is not an issue. But what is the voltage rating of your 1/4 watt resistor. I would want to use a 1/2 watt resistor because of the higher voltage rating.

Having said that, the reissue Super Reverb uses a 1/2w resistor just like the original AB763 amps. The reissue Twin Reverb uses a 1/4w but it's not wired exactly the same as the original AB763 TR.

You certainly don't need to use 4 resistors just to increase the power rating. Think about it. A 10M resistor with 400V across it only dissipates 0.016 watts.

[evancorylevine]

Thanks for the response!

So the short answer is that I need to source a 1/2W resistor?

[pompeiisneaks]

As Sluckey said, its going to dissipate only .016 watts, it's always good to double the expected dissipation to really give it room to handle overloads, and that's still .032 which is nowhere near .25w which is what a 1/4 watt resistor can handle, BUT as mentioned they're usually rated for 200V... the expected voltage may make it unsafe and therefore it would be smarter to source a 1/2 watt due to them being usually around 600 I believe.    If you know the power rating of the 10M you have and it exceeds what you'd see there, it's fine.

~Phil