Carbon comp resistors in Dirtbag deluxe

[marcfrom]

Is it a good way to build a Dirtbag deluxe with carbon resistors?

[jkokura]

Carbon Comp? No.

Carbon Film is fine.

Jacob

[madbean]

Metal film: ideal.

[marcfrom]

Ok,
What kind of resistors was used in "old" DMM, Carbon film or metal film ?

[nzCdog]

did you mean OLD DMM?



Looks like carbon film to me

[madbean]

Yeah, there is nothing wrong with using carbon film. That's what I used. I only meant if you do have metal this type of effect does benefit from lowering its noise floor as much as possible.

[marcfrom]

Thank you 

[marcfrom]

Yes i suppose the metal film will lower the noise, but i thinked maybe the carbon film provide something good and more authentic in the sound.

I used to build many vintage clone FX, Fuzz face, Treble boost, wah, with carbon comp resistors.
But if i understand well it seem's to be too noisy for DMM.

Marc

[Scruffie]

The originals used a combo of Metal Film, Carbon Film & Carbon Comp... the EHX way  A long with the majority of caps being Mylar with the odd paper 'n' oil & ceramic thrown in.

Any of them will be fine, your delay wont sound 'sterile' if you use all Metal Film resistors, it'd probably be a bit noisy with all Carbon Comps, but so would a 30 year old delay pedal with old electros and drifty resistors.

Basically... use whatever parts you can get your hands on in the right values, EHX were not a strict company regards components, there was always method, but they just used components that were cheap, available and would work happily IMO.

[madbean]

Personally, I tend to throw one or two mojo components in most builds strictly for the fun of it.

[Scruffie]

Personally, I tend to throw one or two mojo components in most builds strictly for the fun of it.

If you look at old EHX boxes it seems like they did exactly that, there's always one, usually in a normal value used all over the pedal 

I see no reason not to have a bit of mojo, as long as you don't go too crazy... so... Carbon Comp, Mullard Mustard Cap, Metal Can Op-Amp DMM!? 

[jkokura]

You have to consider the number o parts. The fuzz face has like 5 resistors. The Dirtbag has more than 50...

That's 10x the noise.

Jacob

[Scruffie]

You have to consider the number o parts. The fuzz face has like 5 resistors. The Dirtbag has more than 50...

That's 10x the noise.

Jacob

Noise doesn't add like that as far as i'm aware? Just as tollerance doesn't add? Or am I mistaken?

Not forgetting Gain adding to said noise though, the fuzz face being set up to produce gain and the DMM having a Compander to counteract noise.

Not saying it wont be noisey-er, just dunno if it quantifies like that.

[madbean]

That's an interesting point and I am admittedly kind of ignorant about it. How exactly does noise propagate through a circuit by virtue of component make-up? My gut feeling is that it is probably additive to a degree, IOW, if you use a lot of components prone to a higher noise floor, the resultant THD, or whatever, would be pretty close to a linear sum.

But, I'm no EE.

[jkokura]

You have to consider the number o parts. The fuzz face has like 5 resistors. The Dirtbag has more than 50...

That's 10x the noise.

Jacob

Noise doesn't add like that as far as i'm aware? Just as tollerance doesn't add? Or am I mistaken?

Not forgetting Gain adding to said noise though, the fuzz face being set up to produce gain and the DMM having a Compander to counteract noise.

Not saying it wont be noisey-er, just dunno if it quantifies like that.

Yeah, I was being somewhat silly in that comment.

I guess what I was saying was that in some cases the noise is fine. The bigger the circuit, the less noise tolerance there is/should be.

Jacob