Metallic vs Carbon

[HIWOOD]

Greetings,

1st post here!

Probably subject that's been beat to death but here it goes...

Just finished a DR103 clone. I did source some parts from Mojotone, but most of the resistors/capacitors I sourced from Digikey.

Anyhoo, I was going for the lowest noise, most precision components I could find so all of the preamp resistors on the turret board are metallic-film, 2w.

The amp works fine and is loud AF & clean, but a bit harsh sounding to me. Then again I'm not used to the HIWATT sound.

Been reading that some folks believe carbon resistors are the best to use where tone is concerned.

Thoughts on this please, also what parts of the pre-amp circuit would benefit the most from carbon vs metallic film resistors?

TIA

[alnight]

I've tried building an amp with all "big" resistors as well, and had similar results. I think it's something most of us do once. I suspect you will find that sprinkling in some 1/2w resistors in positions that do not need 2w of power handling will improve the sound.

Carbon film vs metal film is largely a matter of taste and application. My personal experience is that all metal film can impart a high end "hiss" that I find harsh and unpleasant. A few thoughtfully placed carbon films can help tame that.

I encourage you to experiment with different components and learn what you like. There are multiple paths to the destination.

[xtian]

Disagree. It's the nature of the amp.

[martin manning]

I was going for the lowest noise, most precision components I could find so all of the preamp resistors on the turret board are metallic-film, 2w.

Thin-film resistors are among the quietest. Metal foil and wirewound are a little better, carbon film are a little worse on average. Carbon composition are the noisiest.

Been reading that some folks believe carbon resistors are the best to use where tone is concerned.

Some people believe that, but I think that unless a little extra noise somehow produces a better "tone" there is nothing to it.

Thoughts on this please, also what parts of the pre-amp circuit would benefit the most from carbon vs metallic film resistors?

The earlier stages (where signal to noise is lowest), and positions where there is a DC current flowing through the resistor are places where low noise resistors will have the most benefit.

[HIWOOD]

I've tried building an amp with all "big" resistors as well, and had similar results. I think it's something most of us do once. I suspect you will find that sprinkling in some 1/2w resistors in positions that do not need 2w of power handling will improve the sound.

Carbon film vs metal film is largely a matter of taste and application. My personal experience is that all metal film can impart a high end "hiss" that I find harsh and unpleasant. A few thoughtfully placed carbon films can help tame that.

I encourage you to experiment with different components and learn what you like. There are multiple paths to the destination.

Thank you.

I'd be interested in knowing more about how resistor wattage influences tone.

[HIWOOD]

I was going for the lowest noise, most precision components I could find so all of the preamp resistors on the turret board are metallic-film, 2w.

Thin-film resistors are among the quietest. Metal foil and wirewound are a little better, carbon film are a little worse on average. Carbon composition are the noisiest.

Been reading that some folks believe carbon resistors are the best to use where tone is concerned.

Some people believe that, but I think that unless a little extra noise somehow produces a better "tone" there is nothing to it.

Thoughts on this please, also what parts of the pre-amp circuit would benefit the most from carbon vs metallic film resistors?

The earlier stages (where signal to noise is lowest), and positions where there is a DC current flowing through the resistor are places where low noise resistors will have the most benefit.

Thank you...

As a retired Navy Electronics Technician, I tend to lean towards robustness where possible.

Kinda bites me from time-to-time lolz....