Are carbon films worth the trouble?

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WhopperPlate
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 3:01 pm
WhopperPlate wrote: Mon Feb 20, 2023 2:57 pmI would love to see 475v across a CC within a ragingly overdriven amplifier …
See the above link, where I put pulses up to 400V across CC and MF and they look exactly the same.
I thought I just saw them up to 300v . Not trying to prove an unprovable theory or anything , I am obviously figuring the potential to see anything may exist at the highest voltages, which would be early in the B+ string . As I generally tout I like the effect these have generally in any amplifier , whether or not that’s added 2nd order Cc distortion or not lol
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 3:04 pm MOX are noisy. I still wonder if this resistor mojo isn't just about noise.
I remember someone here once posted an article discussing how resistor noise significantly contributes to the tonal nuances of each resistor . I can’t cite it or find it but I remember reading about it all
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Re: Are carbon films worth the trouble?

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bepone wrote: Mon Feb 20, 2023 8:43 am
dorrisant wrote: Mon Feb 20, 2023 8:18 am Bepone, what would you use in a JCM800 build? Same as above? :lol: I'd like to try your combination of parts if you have suggestions.
I tried many times, but metal films in this amp is no-way /for me/! You get more stiff bass but sound is very agressive and hysterical! There are people who want this sound of course. There is one builder in my country who is going only with cheap metal films and wima polypropilenes but those amps are highs and mid heavy . Excellent for cleans, but ear fatique when loud and overdriven. Good if you want to be main egocentric in the band, only your guitar will be heard from the mix :lol:

I have one good "marshall" at home, Metroamp JTM kit, i would try to follow that one, it is built mostly with CF and on several places 3W metal oxide! Why MOX if can pass also with CF. For mid grit i beleive, so i will do the same MOX-CF combination with SOZO caps, tone stack wih orig Mustards, ceramic cap.., with some good iron.

For first tube i will put non inductive Dales from mouser for low noise.. other use of metal films - maybe in grids for PI.. like a result i would expect mid grit, with use of CF i would expect nice highs not too shrill, with use of M6 iron i would expect good bass.. Using Iskra+Mustards all the way will be maybe too creamy :P
Sozo i like because they have unique character in the gain structure, like some "rolling chorus" in the note going forward and backward, when heavily overdriven. Good for Marshall tones.

I have factory box of Iskra 22nF 400V small white blocks MKT's like in the original JCM800, but they are for PCB mounting..they cannot be used in turret-eyelett construction -maybe with extended legs but this doesn't look good :lol:
If you want few send me pm, but i will go with Sozo....
I can attest this is a decent recipe . I have made similar concoctions with happy results
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martin manning
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Re: Are carbon films worth the trouble?

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WhopperPlate wrote: Mon Feb 20, 2023 3:07 pmI thought I just saw them up to 300v . Not trying to prove an unprovable theory or anything , I am obviously figuring the potential to see anything may exist at the highest voltages, which would be early in the B+ string . As I generally tout I like the effect these have generally in any amplifier , whether or not that’s added 2nd order Cc distortion or not lol
350V. I checked after posting and edited it within a minute or so. I'm convinced it isn't second harmonic distortion.

Re noise, see here: https://ampgarage.com/forum/viewtopic.p ... 05#p440105
WhopperPlate
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 3:16 pm
WhopperPlate wrote: Mon Feb 20, 2023 3:07 pmI thought I just saw them up to 300v . Not trying to prove an unprovable theory or anything , I am obviously figuring the potential to see anything may exist at the highest voltages, which would be early in the B+ string . As I generally tout I like the effect these have generally in any amplifier , whether or not that’s added 2nd order Cc distortion or not lol
350V. I checked after posting and edited it within a minute or so. I'm convinced it isn't second harmonic distortion.

See here: https://ampgarage.com/forum/viewtopic.p ... 05#p440105
I remember the first time I consciously heard an amplifier with CC resistors in the power supply . It was a Marshall demoed by Johan Borjesson on YouTube . They called the Salvation Army amp . 68’ 50watt super lead . In the clips the thing just churned and swirled with harmonics to my ears , and I was happily surprised to find out through some deductive reasoning that it had been documented on amparchive.com , and low and behold there were the CC in the dropping string . I actually cloned that amp as close as humanly possible (well close enough) , using all original parts and matching them to gut shots . I was committed to getting that sound.

When it was finished I was not disappointed. It was one of the purest tone amplifiers I had ever played . When it distorts it would ghost and spin out just how my ear likes to hear. How can some be creamy and crystal clear at the same time?

I have since applied this method consistently with happy results . So maybe not 2nd order harmonic distortion , but something nice happens .

Here’s a clip I made of the amp years back . Guitar-tube screamer (mostly off)-Echoplex1-amp1(50watt)-line out-evhoplex 2-amp2(100w)

https://youtu.be/jmtWQswUr7E

And here are some photo of the original amp for reference :
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Last edited by WhopperPlate on Mon Feb 20, 2023 4:01 pm, edited 8 times in total.
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martin manning
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Re: Are carbon films worth the trouble?

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How do you know it was the CC resistors that gave it the quality you liked? Seems like there are many other possibilities.
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 3:41 pm How do you know it was the CC resistors that gave it the quality you liked? Seems like there are many other possibilities.
I have since repeated this many a time with consistent results. Sometimes this effect is far too much. Replacing even one resistor with CC in the power supply is enough to temper an amp with some sweetness, whatever that means . It just sounds nicer overall to me. Like I have said previously, Screen resistors really noticeable to my ears
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martin manning
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Re: Are carbon films worth the trouble?

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WhopperPlate wrote: Mon Feb 20, 2023 3:43 pmReplacing even one resistor with CC in the power supply is enough to temper an amp with some sweetness, whatever that means . It just sounds nicer overall to me. Like I have said previously, Screen resistors really noticeable to my ears
Maybe Fender is hip to this too. These are screen and power supply dropping resistors in '65 DRRI. Or, maybe they just don't want any liability issues.
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 4:40 pm
WhopperPlate wrote: Mon Feb 20, 2023 3:43 pmReplacing even one resistor with CC in the power supply is enough to temper an amp with some sweetness, whatever that means . It just sounds nicer overall to me. Like I have said previously, Screen resistors really noticeable to my ears
Maybe Fender is hip to this too. These are screen and power supply dropping resistors in '65 DRRI. Or, maybe they just don't want any liability issues.
…mox and cement resistors help impart that heirloom potential …
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 3:04 pm MOX are noisy. I still wonder if this resistor mojo isn't just about noise.
Why mox would be noisy? Also you can put them in signal, cathode circuits, power supplies..
Which position do you have in mind?
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Reeltarded
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Re: Are carbon films worth the trouble?

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MOX sounds terribly cheap, like electric dust. I don't know why.

It would taste like a rice cake if you ate it. I am positive of this.

"Sure am hungry! Let me have a bite of this styrofoam lid!"

In my experience, distilled petroleum products might be good for washing rice cakes out of your throat.

Do not eat engineered obstructions. Don't drink petrol.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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Re: Are carbon films worth the trouble?

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WhopperPlate wrote: Mon Feb 20, 2023 3:09 pm
martin manning wrote: Mon Feb 20, 2023 3:04 pm MOX are noisy. I still wonder if this resistor mojo isn't just about noise.
I remember someone here once posted an article discussing how resistor noise significantly contributes to the tonal nuances of each resistor . I can’t cite it or find it but I remember reading about it all
Much ado on Metro about plates and it's most useful by context since the amps are generally simple circuits. I do recall a couple of challenges based on the original conversation with all metal film amps being assembled to prove that they can make a nice amp. That was not the point.

Carbon hiss is a little bit like dither to the ear. The difference is around the same as ceramic disk caps vs CD micas.

haha so glad I let this one develop before arguing. :lol:
Last edited by Reeltarded on Mon Feb 20, 2023 6:40 pm, edited 1 time in total.
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martin manning
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Re: Are carbon films worth the trouble?

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bepone wrote: Mon Feb 20, 2023 6:15 pm
martin manning wrote: Mon Feb 20, 2023 3:04 pm MOX are noisy. I still wonder if this resistor mojo isn't just about noise.
Why mox would be noisy? Also you can put them in signal, cathode circuits, power supplies..
Which position do you have in mind?
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Re: Are carbon films worth the trouble?

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martin manning wrote: Mon Feb 20, 2023 6:40 pm ..
:|
if i want to read a book i will take a book.
you said that MOX are noisy, on which position do you mean?
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Re: Are carbon films worth the trouble?

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Why does that matter?
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