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Just bump into something and cant really decipher the big difference on my own. Just wondering if someone can tell me the big benefit between carbon and metal filmed resistors. I understand I want the achieve low thermal noise and most from what I hear Metal film stands above carbon on the food chain. What are your opinions from your own experiences working with these resistors in condensed pedals?

If your want some scientific explanation, this will not be it. This is just one old fart's humble opinion.
Once upon a time there were carbon composition resistors. They were typically within 10% tolerance.
That's what there was, so everybody used them. Some time later carbon film resistors came along.
They were better, closer tolerance (typically 5%). They could be bought for $1.69 per hundred
for 1/4 watt and $1.79 per hundred for 1/2 watt. They were very nice. And everybody used them.
Later metal film came along. They were even nicer. They had tolerances of typically 1-2%. But they
were expensive. They were used primarily by the military, medical equipment, scientic equipment,
calibrating equipment, etc. Most people still used the carbon film resistors. As time went on and the
cost of the metal film resistors came closer to the cost of carbon film, they took over for many who could
afford the difference, but many still used the carbon film.

For the most part any of the three will suffice for a stompbox. The carbon composition resistors are
better now than they were a long time ago. They are built to better specs and better tolerances (5-10%
instead of 10-20%). But they are expensive. My advice is to use metal film exclusively. Use the carbon
film if you feel the need for more mojo.....just be aware that you will not notice any difference....at least
I can't. I'll put it that way. Save the carbon comps for those special stompboxes that you are trying to
recreate just for nostalgia reasons.

Speculation: If technology continued to advance at the same pace, but music and stompboxes had lagged
by 50 years......which resistors do you think would be in the fuzz face or the Big Muff if they were invented
today? I'll bet you it wouldn't be carbon comp!

Pokey pete,,, Has my vote

Arrh,,, someone with a common sense understanding ,,well explained.

Phil.

Phil, Pete

Some real sense on passive parts! Excellent!

Of course we're going to get the "golden-eared" Boutique Boobs trying to explain why their "mojo" parts actually make a sonic difference to their products, but you can take it from the three of us (Phil, Pete and me) that if the box is closed, nobody can tell the difference!

My recent "Fuzz Face" experiment was quite fun: I had a 1969 germanium original and a 1969 wrecked germanium original (a rotted battery destroyed the board and most of the components). Apart from differing case colours, they looked identical. I built a SILICON one into the wrecked one's case, added my base-to-collector ceramic caps, and padded the silicon beast's values to get the same control swing and overall levels as the original germanium one. I've had a few dozen guitarists try them both out, and NONE of them could tell the difference.... This largely proves that most of the "mojo" theories are nonsense and most of the Boutique Boobs out there are clueless snake-oil salesmen!

The only place where CC can make a difference is in Tube amps, under high signals and high voltages.
And even in this case, the small level of even harmonics they can induce can be achieved with a more clever design and metal resistors.
The difference in noise floor on the contrary is most of the time HUGE (not in the PI of a tube amp where signal is huge too).
So, use metal or oxyde resistors is my advice, anyway, in pedals, CC have no interest at all, both because they do not induce even harmonics under low voltages, and because the low level signals pick up noises very easily.

Hey Guys,

Thanks for enlightening me on this subject. I am sold on the metal resistors only for their tolerance purposes. I will if feeling vintage play around with Carbon Composite (thanks pete) but I will definitely save my self the energy buying both just to see the difference. Thanks again everyone this site is awesome for its simplicity!

Nonetosuffer