Are carbon films worth the trouble?

[WhopperPlate]

If someone wants to double blind test me that’s going to be great fun! I just need to find someone competent enough to work with unless someone wants to do it themselves here lol. Anyways , glad to be part of science!

[R.G.]

Obviously I wouldn’t be testing myself , as you already indicated is pointless to any degree . What I would do is simply alligator clip in close tolerance resistors of different composition and brand within a single position and record them . Nothing fancy . What do you hear ? That’s it . I can tell you what I hear and feel and you can reference that against the limited data coming from the audio clip . Nothing designed to write your college thesis around, just something to give us all something to become more or less stubborn in our confirmation bias

Again, if that's the test, in my opinion you're wasting your time and the time of the others who decide to play.

Unless the question of whether you and/or anyone else who participates in it can first demonstrate the ability to tell by hearing alone
1- whether a change has happened or not
2- whether it's better or worse in their opinion if they think something changed, let alone whether #17 is better than #5
Edit: 2A - and whether #8 is better or worse or no change on unknown repeats of that part
3- with an accuracy much better than random guessing
then auditioning subbed-in parts doesn't tell you much, if anything. As you note, it only provides fuel for making people more entrenched.
We don't need to get into whether the same resistor sounds better swapped in one way versus the other, do we?

[WhopperPlate]

Cement resistors on the power tube screens are about the easiest easy for me to hear…next to f&t caps

What do you use instead that sounds less harsh. Not doubting you. I wanna hear for myself.

Honesrly , I don’t think they sound the harshest per se, but they sure feel zingy and accent pinch harmonic clarity ime . They can change the feel a lot .

Disregarding the particular circuit, I personally like ohmite ceramic wirewound. Nos welwyns are nice and woody to my ears . I also really like NOS CC . I like the Dralorics if I can find them . I like KOA CF 2 watters. I like whatever those 3 watt smaller resistors from CEDIST that look like koa, unsure obviously what they are . The only one I really don’t like at all ime is those blue xicons. They all work differently , and I think of them as colors suitable for different paintings .

Also, in this debate, can we really consider the results of different component types in hi-fi to the abusive conditions of a guitar amp? We are cranking gain up past a hi-fi level and I'm almost certain this could make audible differences.

You bring an another point that gets neglected often as negligible in the discussion , and that’s the relative volume and gain levels of guitar .

I have heard the argument of “how can you hear any difference at stage volumes? “ To be fair , yes the audience doesn’t notice such nuances when they are overwhelmed with 120 db of bass , but that’s exactly when I hear the nuances the most .

Things behave much differently once you start smacking them hard , especially something like a Marshall that spits and sags . That’s largely the trouble of replicating old amps is capturing the non linear imperfections that sound so good once the poweramp is pushed hard or overdriven .

[WhopperPlate]

Obviously I wouldn’t be testing myself , as you already indicated is pointless to any degree . What I would do is simply alligator clip in close tolerance resistors of different composition and brand within a single position and record them . Nothing fancy . What do you hear ? That’s it . I can tell you what I hear and feel and you can reference that against the limited data coming from the audio clip . Nothing designed to write your college thesis around, just something to give us all something to become more or less stubborn in our confirmation bias

Again, if that's the test, in my opinion you're wasting your time and the time of the others who decide to play.

Unless the question of whether you and/or anyone else who participates in it can first demonstrate the ability to tell by hearing alone
1- whether a change has happened or not
2- whether it's better or worse in their opinion if they think something changed, let alone whether #17 is better than #5
Edit: 2A - and whether #8 is better or worse or no change on unknown repeats of that part
3- with an accuracy much better than random guessing
then auditioning subbed-in parts doesn't tell you much, if anything. As you note, it only provides fuel for making people more entrenched.
We don't need to get into whether the same resistor sounds better swapped in one way versus the other, do we?

It would be blind to anyone listening and watching . I wouldn’t be providing any details essentially beyond the audio samples . Edit- I could even omit what I am testing for and people can guess literally anything they think without any potential for bias whatsoever lol. Doesn’t get any more basic than that . If it creates further debate and discussion, well that’s only a bad thing for those who don’t want to read and join the discussion , which is completely within their power to make that choice to participate or not .

I am not gonna make a video if no one wants to see though . How about a tally of nays and yays?

[dorrisant]

I say yes to this.

Thanks for the answer... I will experiment with those brands.

And I agree with the loud setting seems to reveal details. My favorite OD pedals (Klon and KOT) are magical when used in a band setting. Still good pedals at lower volume, practice by oneself, but not as magical as when the volume is at at least a moderate roar. And there are others that swear that a particular amp is best when dimed. I agree that sometimes that is the case.

[LOUDthud]

For those interested, I posted a THD graph of Carbon Comp vs Carbon Film on a 12AX7 here:

https://music-electronics-forum.com/for ... arbon-comp

You may have to be a member there to see the attachment. There was essentially no difference.

[bepone]

Obviously I wouldn’t be testing myself , as you already indicated is pointless to any degree . What I would do is simply alligator clip in close tolerance resistors of different composition and brand within a single position and record them . Nothing fancy . What do you hear ? That’s it . I can tell you what I hear and feel and you can reference that against the limited data coming from the audio clip . Nothing designed to write your college thesis around, just something to give us all something to become more or less stubborn in our confirmation bias

i'm doing often those tests when i'm searching the best resistor for anode stages, i took 8 different brands and composition and after quick test in a half of hour i know what are the canditates. There is a difference, sometimes i left metal oxide, sometimes carbon, sometimes metal film Dales..sometimes metal film Iskra depending of the result needed.
Allready i know from experience that metal film will be more agressive and fast, carbon film will be more mellow or in bad carbon film case muddy and boring (chicon)...those are differences which everybody can hear.

So if somebody is repeating the same story all the time, which is of course wrong this is a clear sign that the builder is still at the beginner level or lazy (to do some changes) or even not interested in this (also can be, build few amps and think that he has seen all and then quit)

[bepone]

Personally, components improving the tone within a particular component arrangement definitely is about 1 in 5 cases . I dislike most of what I have tried in any given context . An iskra or a piher magic unobtsnium part mixed in more often than not sounds bad to myself . It’s the sun if the parts

interesting part, i can add on it that i have built 15yrs ago one 18w mostly with pihers..and mustards..picture attached.
Despite being very expensive build, sound is not interesting at all, it is too dark! Amp was not used 10h in 15yrs because of that. Also i just left it how it is i was not even interested in tweaking. Spent money for nothing and also import PT+OT from US and pay all the taxes-.

Nowadays i'm seeing this build and i will just remove all anode resistors and pass from Piher to Koa speer 0.5W CF cheap from mouser.

I know the result, sound will became light and not dark at all. Did it many times.

How the people will explain this result to me if all sounds the same?

[dorrisant]

Bepone, what would you use in a JCM800 build? Same as above? I'd like to try your combination of parts if you have suggestions.

[bepone]

Bepone, what would you use in a JCM800 build? Same as above? 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

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
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
If you want few send me pm, but i will go with Sozo....

[martin manning]

For those interested, I posted a THD graph of Carbon Comp vs Carbon Film on a 12AX7 here:

https://music-electronics-forum.com/for ... arbon-comp

You may have to be a member there to see the attachment. There was essentially no difference.

Excellent! 10 years ago. Pity old internet myths die so hard.

[WhopperPlate]

For those interested, I posted a THD graph of Carbon Comp vs Carbon Film on a 12AX7 here:

https://music-electronics-forum.com/for ... arbon-comp

You may have to be a member there to see the attachment. There was essentially no difference.

Excellent! 10 years ago. Pity old internet myths die so hard.

I would love to see 475v across a CC within a ragingly overdriven amplifier …

[martin manning]

I would love to see 475v across a CC within a ragingly overdriven amplifier …

See the above link, where I put pulses up to 350V across CC and MF and they look exactly the same.

[WhopperPlate]

Bepone, what would you use in a JCM800 build? Same as above? I'd like to try your combination of parts if you have suggestions.

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
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
If you want few send me pm, but i will go with Sozo....

I guess I too am a believer lol mox are the grittiest to me , but they get smoother if you go bigger wattage. 2W xicon mox on the pi plates is a cool trick to bring the bass and balls into your sound . I see Victoria amps doing this a lot throughout their HP twins.

[martin manning]

MOX are noisy. I still wonder if this resistor mojo isn't just about noise.