Why no Carbon Comp in D-builds?

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Frostbite Slim
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Why no Carbon Comp in D-builds?

Post by Frostbite Slim »

Is Carbon Comp resistors undesirable in D-amps? I always see a mix of CF and MF, but rarely CC.

What gives?
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xtian
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Re: Why no Carbon Comp in D-builds?

Post by xtian »

CC are older technology, prone to drifting in value, decaying over time, and being noisy. CF and MF are more stable, more accurate, less noisy.

Why would you want to use CC? Nostalgia? Mystic Mojo?
I build and repair tube amps. http://amps.monkeymatic.com
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pompeiisneaks
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Re: Why no Carbon Comp in D-builds?

Post by pompeiisneaks »

yeah xtian is 100% on point here, they were common in the 40's through 60's due to being the least expensive ones, but nowadays most smart builders prefer Carbon Film or Metal Film as they're quieter, a LOT quieter.

Dumble likely knows this and avoids them like the plague.

~Phil
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Frostbite Slim
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Re: Why no Carbon Comp in D-builds?

Post by Frostbite Slim »

[quote=xtian post_id=378235 time=1507593147 user_id=8493]
CC are older technology, prone to drifting in value, decaying over time, and being noisy. CF and MF are more stable, more accurate, less noisy.

Why would you want to use CC? Nostalgia? Mystic Mojo?
[/quote]

Back when I worked on vintage Fenders, I gathered many AB Carbon comps. Was just thinking they were useable in a D build
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xtian
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Re: Why no Carbon Comp in D-builds?

Post by xtian »

Sure they're usable, with the above caveats.
I build and repair tube amps. http://amps.monkeymatic.com
Charlie Wilson
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Re: Why no Carbon Comp in D-builds?

Post by Charlie Wilson »

Dumble did use them in some places in earlier amps. Also, PAB hint. Dumble seems to favor carbon comp for the 22m resistors.
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talbany
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Re: Why no Carbon Comp in D-builds?

Post by talbany »

My impression of using CC's in these amps and in general
Yeah Dumble did use them sparingly in some of the earlier 1st and 2nd gen amps from some of the pics I've seen as well..The spots he used them were on grids (very rarely) and in the stack (usually to shunt signal to ground 22meg)as well as in the P.S since they are non inductive AFAIK..I will say he tends to keep them out of the main signal path on most amps..He does tend to keep them in many of the modded amps he converts (Ultra/High Gain Bassman's Explosions etc)..
My experience with CC is the difference in frequency response. MF's tend to extend it a bit on the top end ( some people tend to refer this as a ping on the notes when used on plates)..CC tend to do the opposite in the way of note separation/definition and less percussive attack (cork sniffer term)..To my ears CC's seem to accent the fundamental as well as 2nd order..IMO if you want to calm an overly strident amp down add in some CC's in the signal path..A few places I have used them for this is in my 2nd gen to calm the OD and thicken the tone was in the OD entrance network.Sometimes I use them on the grids as well but would stay away from the plates (shot noise)..The old Allen Bradley's are the ones you want (The new brown Xicons suck) and be sure to measure each one before you install :lol:

Have Fun!
Tony
" The psychics on my bench is the same as Dumble'"
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