#1
My amps been acting up so i opened it up and resistors r10 and r18 were cooked. The value on both is 10R. Do they use "R" instead of the ohm symbol or does it mean something different. Any help would be appreciated as i obviously dont want to put in 10 ohm resistors when it should have been something else. Heres the link to the schematic if it helps at all. http://www.drtube.com/schematics/marshall/v230-61-02.pdf
#3
Yea they are called r10 and r18 but the value on them says 10r each. They cannot be read by colour code because they are too burnt.
#5
Typically the ohm symbol is replaced with an "R" because often times the Ω gets confused with a zero. Especially if there's a copy machine involved.

But yeah, both resistors are indeed 10 Ohms according to the schematic.
In the Oven:

18 Watt!