Carbon Film resistors are somewhere between carbon comp- and metal film resistors if looked from data sheets. Many builders do not want to use metal film resistors since those are said to produce "cold" sound. True or not, but many great tube amps use carbon comp and carbon film resistors... # ½ watt - 350V working, 700V overload, 0.4" long by 0.14" dia. # High stability, low noise, moisture stable. # EIA color coded.
For tube amps min 1/2W resistors are recommended, for plates 1-2W is good.