Flameproof/retardant resistors

[glebert]

Working on a Peavey Classic 50 amp with a blown preamp plate resistor (R60 on schematic link below). The original looks like it is probably flameproof/retardant (I'm sure these terms are completely different and I shouldn't use them carelessly, so feel free to educate me).and resistor was mounted up off the board on barrels. On other Peaveys they actually call out FP on the schematic but not on this one (https://www.thetubestore.com/lib/the...-Schematic.pdf).

So the question is does this need to be FP, and in general when should FP resistors be used?

TIA,
Greg

[The Dude]

R60 (10k/1W) on that schematic is actually a power supply node resistor- not plate resistor. IMO, there's no reason it needs to be FP, especially since it stands off the board and is unlikely to damage anything if it burns up.

[Enzo]

Usually when I buy 1 watt resistors, I get metal film anyway - flame proof.

But I agree with Dude, it is just a resistor.

[glebert]

Works for me, thanks!

[mozz]

Metal oxide are good power resistors also.

[Chuck H]

Metal oxide are good power resistors also.

Yup. Especially for tube type circuits because they usually have the right voltage rating. But then the voltage on those resistors is the differential from one end to the other and not the actual voltage of the power supply. Still, I try to use metal oxide for the rail. They usually do have a flame proof, retardant or resistant coating too. Though it's not needed here and I almost prefer plain enamel coating because it gives clear visible signs of an overheating situation.

JM2C

[Justin Thomas]

After having a few Carbon Comp resistors ignite on me wgen I made a wiring error, well, I tend to use anything but unless it's a museum-piece.

Geez. I forget to even think about voltage ratings half the time. But I tend towards overkill on wattage ratings anyway.

Justin

[Jazz P Bass]

Huh.
I never took note of how the B+ and the B++ nodes feed different halves of V1 & V2.