does resistor wattage have any bearing on tone?

[Jimmybjj]

..does resitor wattage affact anything? other than the obvious size. could I (I don't want to, just an example) build an entire amp out of 10 watt resistors? would it sound any diffrent than 1/2 resistor?

[Hardtailed]

Given the same resistor type, a bigger wattage may mean lower background hiss.

However, if you say 10W, then they'd most likely be wirewound resistors which exhibit more inductance than you may want.

[loudthud]

With Carbon Composition resistors, lower wattage generally has more distortion but only when there is substantial voltage across the parts.

[R.G.]

Not in the sense you mean it, no.

Different types of resistors can affect sound, with the inductance of wirewounds and the excess noise of the carbon comps already mentioned being good examples. But no, changing from 1/2 W to 1, 2, 5, or 10W is not going to make a difference in making it sound "browner" or "more vintage" or whatever.

Side effects, yes. Tone, no.

[Mandopicker]

What would be some of the side effects not related to tone?

[DIY_Guy]

What would be some of the side effects not related to tone?

Lower 'hiss' from the resistor.

[Wilder Amplification]

What would be some of the side effects not related to tone?

The resistor doesn't go up in smoke.

[Mandopicker]

These are the obvious benefits IMHO...but are there any adverse side effects? Aside from them costing more and taking up more space.

Thanks in advance.

[R.G.]

These are the obvious benefits IMHO...but are there any adverse side effects? Aside from them costing more and taking up more space.

Lower hiss and better thermal stability are indeed useful. And you've put your finger on the costs - more money (although I've seen people trying to sell "NOS carbon comp" resistor for more than better-performance devices) and more space/weight. The question is how much do you pay for each succeeding increment of good-ness, and whether the good-ness per dollar paid remains constant as you increase the dollars.

Or, I guess, you could reverse the questions - how much money and space/weight would you pay to avoid some of the defects in other components? You're choosing a path between using the cheapest available components that will wear/burn out quickly and placing handmade platinum-film-on-ceramic resistors into a circuit board made of laminated $100 bills. There are probably good compromises in that range, points of high performance at affordable prices. The job is to find them.

Carbon comp resistors are somewhat unique. They are almost alone among the commercially available resistors in having excess noise over and above their inherent and unavoidable thermal noise.

They also have a high voltage coefficient of resistance, which causes a slight distortion when the signal component across the resistor is over 50-75V (see my article on CC resistor mojo at GEOFEX). The distortion is what has led to the "CC is better/warmer/more vintage/yada/yada stories in advertising and myth. But there are only about two positions in a tube amp where this can be used to advantage. In the other positions, you get lower noise, the same sound, and much lower drift with aging and better tolerance, which means your quieter amp will stay the same sound for much longer.

Then, too, a careful designer would look at what the actual power dissipated in each resistor and compute the temperature rise. Temperature rise is a major factor in aging and drift. If a resistor would dissipate 1/10th watt in a circuit, how much sense does it make to buy a 10W resistor for that position in the circuit? Would a 1/2W last longer than the owner's expected lifetime? What real change from the Intrinsic Failure Rate (IFR) would that cause? And how much money/time/space/weight do you pay for whatever incremental change in lifetime and performance?

The temperature/dissipation issues get settled by projecting the surface temperature of the resistors. Resistors are often rated for a power which causes surface temperatures to get to between 150C and 200C. For reference, 100C is the boiling temp of water, of course. That is dependent on the internal power dissipation, the external air temperature, and how much/little air flow is expected. For reference, the filament of a tungsten incandescent light bulb (now about to be outlawed worldwide) is about 3000C. This is the same temp reached in a 100W bulb and a 1/10W grain-of-wheat bulb. What matters is often how well the heat is emitted, not the internal dissipation. That set of factors has to go into the mix in choosing a resistor.

Then there's the secondary performance issues beyond lifetime - things like hiss, drift, IFR, pulse power capability parasitic inductance. Your job as a designer - and you have put yourself in the designer's seat by deciding what resistors to choose - is to pick the best compromise part in terms of performance (both primary and secondary) for the money and time expended.

What I'm trying to illustrate is that there's a lot to be learned here beyond whether carbon (or wirewound or metal film or metal oxide or...) is "best" and beyond whether 10W is better than 1W or 1/10W. The side effects exist, and they compete, reinforce, cancel, and/or don't matter, depending on what you're trying to do. There really isn't an alternative to either doing what's always been done, accepting advice in a relatively anonymous internet, picking at semi-random, or, the hardest thing, learning about it.

[Enzo]

When I laminate my $100 bills, I always make sure to use the NOS bills. The newer currency has those security strips running through them, and they degrade the tone.

[Mickthehat]

Higher wattage resistors MAY have benefits

I obtained a whole lot of 2 watt power resistors and made up my single-ended Champ-style amps using mainly these, some wire wounds and some 1 watt types. Might be overkill but the sparkle and chime are such that you almost seem to have reverb. I'm sure there's something to be said for components running cool well within their spec and hardly breaking sweat as opposed to struggling and getting overheated. I only use half-watt resistors in places in the signal chain where I know there is very little current.