Are carbon films worth the trouble?

[dragonbat13]

I'm building a Marshall 2204 and am having a hard time finding the resistors I want to use. Particularly 2watt carbon film of a good known brand. I did find some TE Connectivity but don't know of anyone using those for plates.

And half of my head is telling me the whole thing isn't worth the hassle.

I've come to like the Vishay Drailect PRO series and can get them for just about the whole amp.

What do you all think? Just use metal film, wirewound on the screens, metal oxide on the droppers?

I plan on spending the extra coin on the Sozo coupling caps, if that matters.

If carbon film are that big of a deal then where is everyone getting them?

[sluckey]

I'm building a Marshall 2204 and am having a hard time finding the resistors I want to use. Particularly 2watt carbon film of a good known brand. I did find some TE Connectivity but don't know of anyone using those for plates.

1 watt is sufficient in most cases.

[mhuss]

Using CCs on anything except the plate resistors will just add noise and reduce reliability. Even as plate resistors, the amount of 'vintage' harmonic distortion they add is minimal, and that only at high voltages (>>100v). I'd certainly avoid CCs for things like the standard 1M input grid resistors, a point particularly susceptible to noise.

[dragonbat13]

Not wanting to use carbon comp at all. Carbon film if not metal film.

[Reeltarded]

I plan on spending the extra coin on the Sozo coupling caps, if that matters.

Tell you a secret.

Sozos aren't mustards. If you want anything particular, it's the look.. and you have to buy mustards.

Buy Mallory or orange drops. Use something fun looking like huge Solens or toidy $50 insanity, but Sozos aren't mustards.

Wimas. Use Wima! Get all Wimas.

[dragonbat13]

I hadnt expected for them to sound like mustards, whatever that sounds like. I don't like drops much, and figured if I were gonna spend premium on anything it would be those. I have read a lot of good about them. More than any other "vintage type" new cap.

[brewdude]

I have tried buying SoZo’s…
I have systematically replaced them chasing something I didn’t really dig…
Mostly with 6PS Orange Drops—I don’t like the 715’s. Only down side for the Orange drop to me is size.

I am most dissatisfied with the SoZo silver mica caps. I tried to like them, but ceramic discs sound better to me, and they are stupid expensive.

[mhuss]

Not wanting to use carbon comp at all. Carbon film if not metal film.

Sorry, my bad.

[bepone]

i have spent thousands on carbon films of all the manufacturers and sizes.. they are right parts to go with tube amps!

[WhopperPlate]

Xicon 1 watt work just fine with 1000s of hours getting slammed with a 475v HT in a Marshall super lead no problem . Personal xperience

As far as “worth the trouble”…

What’s technically better or less noisy … that’s not the concern if you are building a
Marshall… the added character of carbon films wherever Marshall used them is essential to the traditional vintage Marshall sound

And don’t get me started on carbon comp…uh oh too late… if you like that one special Marshall that was used on that one record by your favorite British wanker and you took a gut shot of that amp it more than likely had a few carbon comp in the power supply or on the plate loads…definitely carbon film

They used whatever. Sometimes you see a Cc on one half of the PI and CF on the other .

go and try to throw a bunch of modern bulletproof power 5 watt whatever’s in there because “I am going to build the most reliable amp ever” …and if you wonder why the amp feels stiffer than a new pair of boots, Or why anyone could like that 5000pf on the bright channel …not everything is an “upgrade “…it’s the sum of the parts as they say .

…unfortunately they don’t make iskra or piher anymore…

[bepone]

…unfortunately they don’t make iskra or piher anymore…

..but still there are billions of Iskra on stock..

[WhopperPlate]

…unfortunately they don’t make iskra or piher anymore…

..but still there are billions of Iskra on stock..

Easier to find in your neck of the woods I am sure… well you know where to look if you are trying to throw a bone

[R.G.]

I'm building a Marshall 2204 and am having a hard time finding the resistors I want to use. Particularly 2watt carbon film of a good known brand. I did find some TE Connectivity but don't know of anyone using those for plates.

And half of my head is telling me the whole thing isn't worth the hassle.
[...]
What do you all think? Just use metal film, wirewound on the screens, metal oxide on the droppers?
[...]

Use metal film, metal oxide, or wirewound. There is no screaming noise or "tone" advantage to carbon film. Some amp makers and users will violently object to this statement, but I have yet to hear a consistent argument backed up by facts that counters this advice. I do welcome the discussion on this issue, though. I'm always trying to learn more.

From the technical perspective; for audio frequencies, carbon comp is the worst choice for noise. Carbon film are lower noise, metal film and wirewound are lowest. This noise consideration only matters for the grid resistors on the input stages, and for the reverb return (which is a low signal input stage, too). For lowest noise, use metal film for input stage grid resistors.
For "tone" matters, carbon comp resistors do have an advantage, but only in ONE position in most amps. That position is the plate resistors of the phase inverter in nearly all cases. This is because carbon comp, in addition to having excess noise, have a high voltage coefficient of resistance, and for signal voltages across them of greater than 50 V can contribute some soft second harmonic distortion, which guitar players like a lot. This single fact is the only real basis for the idea that only carbon comps sound good. Realistically, in all other positions, use a carbon or metal film, or wirewound.
There is no screaming advantage or disadvantage to using carbon film over metal film in most positions. If you can't get the carbon films you like, use metal film, both of sufficient wattage and voltage rating for the position they're used. Wirewound works fine, again within their ratings.
The standard mythos-based criticism of film and wirewound is that the conductor is a spiral, and therefore contributes inductance, and therefore sucks tone. This myth-based wisdom would be a factor if we were amplifying radio frequencies. It's nearly always negligible in audio. And there are non-inductively wound wirewounds for high frequency use.
So the standard advice applies: use properly rated non-mythical parts that you can actually get and see how your amp sounds. If you then want to get a few mythically good parts that you procure at great expense from a supplier that found a treasured few parts under a mojo hand at the crossroads at midnight, go ahead and sub in the super-perfect mythical ones later.

[martin manning]

For "tone" matters, carbon comp resistors do have an advantage, but only in ONE position in most amps. That position is the plate resistors of the phase inverter in nearly all cases. This is because carbon comp, in addition to having excess noise, have a high voltage coefficient of resistance, and for signal voltages across them of greater than 50 V can contribute some soft second harmonic distortion, which guitar players like a lot.

I looked for this effect, but couldn't find it: https://ampgarage.com/forum/viewtopic.p ... 43#p444443

[bepone]

other than just a dry c/p internet theory about cc,cf, repeating the same "one guy opinion",
someone did 2 same boards , one with metal film other with carbon film, plug and replace and draw conclusions?