Metal Film Voltage Rating VS Carbon Film

[sunnyevan]

Hi, I'm rather new to the forum and I'm going to be attempting one of my first projects which is to mod my 2203x reissue amp. Some of the mods involve installing resistors.
I'm well aware of the positive effects in regards to noise of Metal Film resistors vs Carbon; I've taken a read of the Aiken site.

My concern is the voltage is rating of Metal Film:

1) Is the voltage rating large enough in 1 watt Metal Film resistors for use in almost any spot in the amp? I've seen metal film used before, but I don't know if its only safe to install in certain locations of an amplifier. I know that some Metal film resistors I've seen are about 300V.

2) Also, do certain manufacturers have different voltage ratings associated with their own metal film resistors, or are the ratings essentially universal? I.e I can purchase any metal film resistor and plug it in no problem.

I'm interested in purchasing this Metal Film resistor kit here: https://www.amazon.com/SIQUK-Resistors- ... 449&sr=8-7

Forgive my ignorance, as this is a new area I'm very interested in but know little about.

[pdf64]

Well done for being aware of this issue.
Every product line will have its own set of specs. You can’t imply a voltage rating from a power rating. The manufacturer’s product info for each line you’re thinking of buying should be checked.

[martin manning]

The assortment linked contains resistors rated at 1/4 Watt. There are some locations in tube amp circuits where that is enough, but generally, a minimum of 1/2 Watt parts are used, and the required power rating may be much higher in certain locations. The voltage any given component is exposed to and the power it is dissipating are a function of where it is used in the circuit, so you should calculate the requirements, or at least match the ratings of the parts you are replacing. An assortment of resistors is nice to have, but I would get 1/2 Watt for tube amp work. Be aware that these very cheap assortments are generally seconds, with (mostly) cosmetic defects. There is an 86 value 1/2 Watt assortment available under the brand “Joe Knows Electronics” which I have found to be of decent quality.

[thetragichero]

i have not enjoyed film resistors in any location where they may dissipate a significant amount of heat it looks cool as they glow bright orange right before smoking with i prefer metal oxide (for <5w) and cement (for >5w)
assortments seem like a good idea until you're left with a bunch of obscure values. if i could turn 51r resistors into 47k I'd be set
i ordering what I'll need (or think I'll need) and then ordering extras. besides not cluttering my parts bins this also forces me to figure out what I'm doing before i even plug in the iron, analyze the schematic, busy out my rc filter calculator, etc