This is another copy from http://www.nmr.mgh.harvard.edu/~reese/joelist/articles/articles_v01_4.html
JH
..........
I also changed the Radio Shack carbon films on the 5842 grid and cathode resistors
with half watt carbon comps and immediately noticed more tonal color and less bite.
I'm beginning to use more and more of them for what they can bring to the sound.
The only place I've had a problem with them is using them as plate resistors in the 5687
linestage. I had a pair make strange noises there, otherwise no problems and cheap
too (Mouser, 28 cents each). Those were NOS carbon comp resistors.
..........
JH
..........
I also changed the Radio Shack carbon films on the 5842 grid and cathode resistors
with half watt carbon comps and immediately noticed more tonal color and less bite.
I'm beginning to use more and more of them for what they can bring to the sound.
The only place I've had a problem with them is using them as plate resistors in the 5687
linestage. I had a pair make strange noises there, otherwise no problems and cheap
too (Mouser, 28 cents each). Those were NOS carbon comp resistors.
..........
Re: Technically, I think no tube amp really needs metal film
Fred, I have never heard you missioning for metal film. Also, Fred, sending me to sin bin just for expressing a view???
If I had built a tube amp today I had never consider to choose carbon resistors if there have been an alternative.
Fred since you are enlighted (previous actions), what is your opinion really? Sometimes it seems that you have opinions opposite of mine.
My opinion is that metal film is the best "normal" resistor type today for normal applications. They are also really cheap.
Fred Dieckmann said:
Fred, I have never heard you missioning for metal film. Also, Fred, sending me to sin bin just for expressing a view???
If I had built a tube amp today I had never consider to choose carbon resistors if there have been an alternative.
Fred since you are enlighted (previous actions), what is your opinion really? Sometimes it seems that you have opinions opposite of mine.
My opinion is that metal film is the best "normal" resistor type today for normal applications. They are also really cheap.
I usually try to avoid cheap metalfilm resistors at critical positions as I think they can make an amplifier sounding too bright. Some carbon film typs are much better.
But there are really good metalfilm types around. See the link http://www.borbelyaudio.com/index8.htm where Mr Borbely discuss the effects of different typs. His opinions are very much in the line what I have found.
Carl
But there are really good metalfilm types around. See the link http://www.borbelyaudio.com/index8.htm where Mr Borbely discuss the effects of different typs. His opinions are very much in the line what I have found.
Carl
Sometimes it seems that you have opinions opposite of mine.
Yes, and they are based on building, modifying, and listening to high end audio equipment for over 20 years. I try not to post opinions with which I do not have the personal experience with the subject at hand. I have plenty over expierience with tube amps and exotic resistors. I have no idea where your opinions come from.............. They often don't seem to be based on knowledge or experience, which leaves me to wonder where they do come from.
Yes, and they are based on building, modifying, and listening to high end audio equipment for over 20 years. I try not to post opinions with which I do not have the personal experience with the subject at hand. I have plenty over expierience with tube amps and exotic resistors. I have no idea where your opinions come from.............. They often don't seem to be based on knowledge or experience, which leaves me to wonder where they do come from.
Guys, I just wanted to have stable biasing on my tubes. I have always heard that carbon film has a warmer sound. This I can neither prove or disprove. I think that I am going to use the BC components 2 watt metal film(DigiKey section F) for biasing and carbon films for signal. I will let you know what I think. I'm still waiting for a choke that I ordered so it could be a couple of weeks before I have anything to write about. I will alternate between MF and CF and let you know my impressions.
G
G
Resistors
Hi ,
Please see Application Note 42 by Linear Technology, <B>Appendix A.</B>
It contains a overview of common resistor types: Carbon composition (also known as Allen Bradley), carbon film, metal film, and bulk metal film, wirewound etc.
http://www.linear.com/pdf/an42.pdf
Hi ,
Please see Application Note 42 by Linear Technology, <B>Appendix A.</B>
It contains a overview of common resistor types: Carbon composition (also known as Allen Bradley), carbon film, metal film, and bulk metal film, wirewound etc.
http://www.linear.com/pdf/an42.pdf
Re: Good advice:
I get all my resistors custom made now. They're made of the carbonized finger bones of red-tailed squirrel lemurs, from southeast asia. They cost me $800 each, but the high end is so silky and smooth. Nothing else can compare.
dhaen said:Mmm, I'll have to ask Joel which make "sound" better
I get all my resistors custom made now. They're made of the carbonized finger bones of red-tailed squirrel lemurs, from southeast asia. They cost me $800 each, but the high end is so silky and smooth. Nothing else can compare.
Hello G,
OK, in line with the riginal post, squirrels notwithstanding, here is my
worth.
Tubes after breaking in generally stay pretty much dead on, unless there is a defect in manufacture. I have always been able to measure the same voltage after a couple of years use. So...
I personally prefer the 2% metal film because of the two reasons: very low noise and accuracy. Tubes make enough noise, without the need to add to it with carbon resistors, especially in the input circuits (grid and cathode resistors) I make my amps (and kits I sell. OK, I am plugging ) dead on to the specs I desire by both picking the resistor values to as close to exact as possible (yup, I go through dozens. If I cannot find enough of the same values, I make sure that where they go in each channel is the same) and picking tubes that match closely enough on both channels. The values stay there for a long time, and the benefits are same sound all day every day (except for that middle of the night bloom), along with exact instrument placement, etc.
In fact, I find more variation in transistors than tubes.
As for the innacuracy of the old carbon... whatever... resistors, I have a few antique radios whose resistor values are dead on. I mean a 2K resistor (a red body with a red and brown dot. From 1934!) reads dead on 2K. It rivals the so called accuracy of the laser trimmed metal film resistor made a few months ago. So much for the poor old noisy crackly short lived resistors of yester-year! I am deeply impressed.
And as one other said, to base the choice of a resistor on how it sounds in the amp... yikes ! That is absurd! The amp design should not be affected by the resistor, the most linear component in there, but by the design itself.
However, I do believe that many amps benefit with good quality caps. But the difference between a ceramic cap (in some amps I listen to that use them they sound very darn good!) and poly, versus the copper foil in oil costing dozens of times more, I would stick with poly (or metal film caps, or whatever). But now this is a different subject. Point is I hear a difference between the poly and the much more expensive copper foil in oil, but not poly and ceramic. But it is not worth the cost, unless you don't care about price.
Thanks for reading,
Gabe
OK, in line with the riginal post, squirrels notwithstanding, here is my
worth.Tubes after breaking in generally stay pretty much dead on, unless there is a defect in manufacture. I have always been able to measure the same voltage after a couple of years use. So...
I personally prefer the 2% metal film because of the two reasons: very low noise and accuracy. Tubes make enough noise, without the need to add to it with carbon resistors, especially in the input circuits (grid and cathode resistors) I make my amps (and kits I sell. OK, I am plugging
) dead on to the specs I desire by both picking the resistor values to as close to exact as possible (yup, I go through dozens. If I cannot find enough of the same values, I make sure that where they go in each channel is the same) and picking tubes that match closely enough on both channels. The values stay there for a long time, and the benefits are same sound all day every day (except for that middle of the night bloom), along with exact instrument placement, etc.In fact, I find more variation in transistors than tubes.
As for the innacuracy of the old carbon... whatever... resistors, I have a few antique radios whose resistor values are dead on. I mean a 2K resistor (a red body with a red and brown dot. From 1934!) reads dead on 2K. It rivals the so called accuracy of the laser trimmed metal film resistor made a few months ago. So much for the poor old noisy crackly short lived resistors of yester-year! I am deeply impressed.
And as one other said, to base the choice of a resistor on how it sounds in the amp... yikes
! That is absurd! The amp design should not be affected by the resistor, the most linear component in there, but by the design itself.However, I do believe that many amps benefit with good quality caps. But the difference between a ceramic cap (in some amps I listen to that use them they sound very darn good!) and poly, versus the copper foil in oil costing dozens of times more, I would stick with poly (or metal film caps, or whatever). But now this is a different subject. Point is I hear a difference between the poly and the much more expensive copper foil in oil, but not poly and ceramic. But it is not worth the cost, unless you don't care about price.
Thanks for reading,
Gabe
I guess you need to define to me "limit value".
To me, if the markings say 2000 ohms, and my DVM says 2000 ohms, then it is 2000 ohms.
Limit implies range. The resistor does not change its value under non transient conditions... AKA room temperature. It shouldn't theoretically change value under conduction conditions either, but who measures a resistor when power is on??? Heat may change the value somewhat, but again I ask... who measures when powered on? And if THAT were the case, one would not be able to predict what the idle voltages would be, because none of the values would be reliable. Then nothing would work very well if at all because of the immense instability that would ensue.
So, what is your point? Or do you just like to wax philosophic? (Is that the correct phrase? It's been a long time since I heard or used it)
Gabe
Mojo
Guys,
This might help:at
http://www.geofex.com/
there is an article
"Using Carbon Comp Resistors for that Magic Mojo"
Keep smokin' those squirrels.............
Cheers,
Pete McK
Guys,
This might help:at
http://www.geofex.com/
there is an article
"Using Carbon Comp Resistors for that Magic Mojo"
Keep smokin' those squirrels.............
Cheers,
Pete McK
Hi Joel,
Don't want to pick a fight. But you can learn from the "voodoo" crowd. And vice versa..
I on the other hand want to barf when people talk about the low distortion of this or that.
Distortion tells you zip about the sound of something. Ofcourse 25% distortion is not good..but between 0,25% and 3% for arguments sake, what does it tell you?
I am only interested in the sound of my amp...Or should I say how it plays music.
One of the fundamental reasons a lot of people prefer tubes is for precisely that reason (2n harmonics). (Notice I said people prefer tubes and not tubes ARE better ;-)
So who are you or anyone else to tell us carbon comps belong in the wastebin..Apart from just giving your opinion. Rather gives us your opinion based on your own experience.
I have never used carbon comps so I have no opinion on them..My amps use a combination of carbon film and wirewounds..and I am happy as a pig in ****.
Cheers,
Bas
Don't want to pick a fight. But you can learn from the "voodoo" crowd. And vice versa..
I on the other hand want to barf when people talk about the low distortion of this or that.
Distortion tells you zip about the sound of something. Ofcourse 25% distortion is not good..but between 0,25% and 3% for arguments sake, what does it tell you?
I am only interested in the sound of my amp...Or should I say how it plays music.
One of the fundamental reasons a lot of people prefer tubes is for precisely that reason (2n harmonics). (Notice I said people prefer tubes and not tubes ARE better ;-)
So who are you or anyone else to tell us carbon comps belong in the wastebin..Apart from just giving your opinion. Rather gives us your opinion based on your own experience.
I have never used carbon comps so I have no opinion on them..My amps use a combination of carbon film and wirewounds..and I am happy as a pig in ****.
Cheers,
Bas
Joel, Bas,
Just an FYI:
The ear does by the nature of physics create its own "even order" distortions due to the fact of unequal pressure on either side of the eardrum. I do not know the "percentage" of this distortion, but the amplifier or speaker that produces a similar type of distortion (not so much quantity) will sound more pleasant ("The Science of Music").
IMHO, the imaging one gets from most tube amplifiers is from the even order distortion. This is why tube amplifiers also are perceived as "louder".
No, 25% distortion is never good. 1-4% OTOH can "sound" very nice. Odd order distortion is pretty much clipping, and one never wants to play their amps that loud ("drive them into clipping") anyway since these types of distortion can actually eventually damage the amp.
FWIW,
Gabe
Just an FYI:
The ear does by the nature of physics create its own "even order" distortions due to the fact of unequal pressure on either side of the eardrum. I do not know the "percentage" of this distortion, but the amplifier or speaker that produces a similar type of distortion (not so much quantity) will sound more pleasant ("The Science of Music").
IMHO, the imaging one gets from most tube amplifiers is from the even order distortion. This is why tube amplifiers also are perceived as "louder".
No, 25% distortion is never good. 1-4% OTOH can "sound" very nice. Odd order distortion is pretty much clipping, and one never wants to play their amps that loud ("drive them into clipping") anyway since these types of distortion can actually eventually damage the amp.
FWIW,
Gabe
Bas Horneman said:
Bas,
The only thing I've learned from the "voodoo crowd" is how NOT to build an amplifier. All the useful information I've acquired over the years has come from people who take the time to learn the science behind audio engineering.
It is based on my experience. I've only had to replace a part in any of my projects three times, and all three times it was a carbon comp resistor. One opened up, and two were fizzing like a can of soda.
Hi Joel,
Ok...thanks for clearing that up..(About your own experience).
I guess the only thing I'm trying to say is that..yes you can't do without engineers or scientist....(Without them no tubes or whatever) But someone who approaches this hobby with a certain philosophy or even ignorance might try something that is not considered good engineering practice and come up with something sounding brilliant.
Let's for instance say using a common mode choke on ac filament. When I said that to the guys at the electronics store they looked at me with a mix of astonishment and pity. But I don't care.. it appeals to me, but if it works why should I reject it on the basis that you can't measure the effect on a scope?
For instance..the simplicity of a SE amp appeals to my personality..so does the lack of feedback...There is no science behind any of my decisions...none. Building a tube amps is like lego to me.. take a tube run some current through it..does it sound good...yes..then its fine.. The only thing I use science for is to check if the tube is withing its ratings..
I'm not trying to convince you... I'm merely stating that one should use whatever you want if it makes you a happy.
And I have spotted you as someone with zero tolerance for what a lot of amateurs here are saying or doing. (If you think it has no technical merit. )..Correct me if I'm wrong.
To give an example..lifting the filament above ground to say 40 volts above zero. Your reply went something like..what do you want to do that for... Not attacking you here ..but this is something an engineer thought of.... but us poor sods that can't think it up for ourselves... pick up these things very fast..because..it might just work.... Some not all engineers think of SE as the "voodoo crowd" as well...and I just can't agree.
Ok...thanks for clearing that up..(About your own experience).
I guess the only thing I'm trying to say is that..yes you can't do without engineers or scientist....(Without them no tubes or whatever) But someone who approaches this hobby with a certain philosophy or even ignorance might try something that is not considered good engineering practice and come up with something sounding brilliant.
Let's for instance say using a common mode choke on ac filament. When I said that to the guys at the electronics store they looked at me with a mix of astonishment and pity. But I don't care.. it appeals to me, but if it works why should I reject it on the basis that you can't measure the effect on a scope?
For instance..the simplicity of a SE amp appeals to my personality..so does the lack of feedback...There is no science behind any of my decisions...none. Building a tube amps is like lego to me.. take a tube run some current through it..does it sound good...yes..then its fine.. The only thing I use science for is to check if the tube is withing its ratings..
I'm not trying to convince you... I'm merely stating that one should use whatever you want if it makes you a happy.
And I have spotted you as someone with zero tolerance for what a lot of amateurs here are saying or doing. (If you think it has no technical merit. )..Correct me if I'm wrong.
To give an example..lifting the filament above ground to say 40 volts above zero. Your reply went something like..what do you want to do that for... Not attacking you here ..but this is something an engineer thought of.... but us poor sods that can't think it up for ourselves... pick up these things very fast..because..it might just work.... Some not all engineers think of SE as the "voodoo crowd" as well...and I just can't agree.
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