Difference between metal film and carbon comp resistors?

[vanhansen]

Well, as far as metal film handling heat, look at any motherboard or controller board in a computer.  Pretty much every, if not all of the resistors will be metal film.  When I was working with a guy in CA for a new security product, we had to bake test the motherboard and controller boards to make sure they could withstand high temps since they'd be mounted in walls and such.  That meant putting them in the oven to see what the highest temp they could handle was before failure.  Circuits like that need such precise accuracy to be able to function properly.  Loose tolerances just don't cut it.  I don't think you'd see a carbon comp in any modern digital circuitry for that very reason.

[formerMember1]

Well, as far as metal film handling heat, look at any motherboard or controller board in a computer. Pretty much every, if not all of the resistors will be metal film. When I was working with a guy in CA for a new security product, we had to bake test the motherboard and controller boards to make sure they could withstand high temps since they'd be mounted in walls and such. That meant putting them in the oven to see what the highest temp they could handle was before failure. Circuits like that need such precise accuracy to be able to function properly. Loose tolerances just don't cut it. I don't think you'd see a carbon comp in any modern digital circuitry for that very reason.

thanks that is good to know

[stankyfish]

Mind you, there is 'dithering'..but let's not go there tonight....

I was thinking the same thing.  

Also, in digital voice applications, it's common to generate low background noise (comfort noise generation) instead of pure silence -- for whatever reason the continuity of the background noise is desirable compared to the stacatto nature of the audio on-audio off in a typical telephone conversation.

[Doug_H]

it is not like any big rock players are getting any tone to be proud of nowadays.  nothing compares to Hendrix's, Page's, early Van Halen's, The Who's etc... tone.

As far as the Who, some Hendrix, & post-'76 Page are concerned, I don't agree with this statement at all.

But that just shows that tone is completely subjective.

Doug

[stankyfish]

please respect my opinion, because it is not like any big rock players are getting any tone to be proud of nowadays.  nothing compares to Hendrix's, Page's, early Van Halen's, The Who's etc... tone.

I think Eric Johnson and Doyle Bramhall II would disagree.

[trjones1]

enclosures painted in tincture of wolfbane... simply sound better

Great idea R.G.  I'll have to try that!

[Doug_H]

Here is some personal opinion that should rile-up the masses, but speaking of MoJo, I was around back in the 70's when Electro Harmonix stuff was new, I remember clearly going to the music stores and trying out their stuff next to other effects of the day (Electric Mistress -vs- ADA, Small Stone -vs- MXR Phase 90, Muff Fuzz -vs- Fuzz Face) and my impression was they sounded cheap and very noisy, just full of HISS. I can't believe how now after 35 years gone by, everyone thinks EH stuff has MoJo, sheesh!

I was around back then too and remember that stuff. It was very cool when MXR came out with their pedals in the little die cast boxes, and you didn't have to worry about breaking a wire to change a battery.( :roll: ) The EH enclosures were (are? not familar with them now) total junk AFAIC.

I think there is a certain "garage creativity" attraction to the EH stuff. They went out on a limb quite a bit with weird, bizarre, and creative effects that no one else would attempt at the time with their product lines. But "back in the day" (heh-heh) they were viewed as '"junk" in many circles after companies like MXR came on the scene. I got a Bad Stone because I needed a phaser and could afford it. But if I had the $$ I would have taken a Phase 100 any day of the week over that (and probably still would).

Doug

[formerMember1]

hey Doug H,
Who do you think has great tone nowadays, that lives up to Jimi Hendrix, Page, Gilmour, of yesteryear?  Except for those who were out back then and continue to tour today.  Asfar as EJ, He could hear stuff some people here can't, including me!  

Just wondering your opinion, please respect mine. :wink:

What is wolfbane?  How would that affect tone?  I know thin skin finishes on strats sound better, but i never heard of painting a metal enclosure for sound.  Inless that was a paint that stopped the metal box from heating up in the sun, which would not make the temp raise in the box making the Germanium transistors suffer.  

oh yeah, neil young got some great tone on greendale, but he always had great tone too. :wink:

[Pedal love]

Let me pre-apologize for being so hard nosed on this one.  

R.G. please don't apologize, you are above reproach. Truth be known, I have and continue to use a lot of metal film resistors. I do so because I hate noise more than anything. But I do agree with you on the subject of humans adding sound mentally, I have seen some of the data. I still maintain that I could tell the difference in some pedals, but its just conjecture, until its actually tested in a reliable way.pl

[SonicVI]

I prefer the sound of blue guitars for some reason and I simply refuse to play a yellow guitar because they always sound horrible to me. If I were blindfolded I wouldn't care less.  It's like they say the color of a room can influence our mood. I'm sure it's true that the appearance of a resistor (even if you just know it's different inside the box where you can't see it) or color of guitar or color and style of your amp's cabinet can influence how they sound to at least many of us.

[Paul Perry (Frostwave)]

I can't believe how now after 35 years gone by, everyone thinks EH stuff has MoJo, sheesh!

A lot of the old EH stuff was badly built, from cheapo components. I know, I've got enough of them...
BUT!! Why do I have them? Because (unlike most fx) they actually did interesting things.
It's like, would you rather watch an INTERESTING movie on a 10 inch black & white TV or absolute crap in a 36 inch plasma with a 500W surround sound? (a rhetorical question, but history shows most people prefer the latter & the same goes for fx apparently).
Fortunately, the miracle of DIY means, we can have the best of all worlds, the tradition of EH but with quality parts.
BTW the CURRENT EH stuff is excellently manufactured, so far as I can see .

[Paul Perry (Frostwave)]

Composition resistors do have less 'parasitic' (built in inductance and capacitance). And, they are less prone to breakdown during temporary voltage overload.
The other thing, is that in the question of noise, there usually aren't many places in a circuit (certainly in an amp!) where resistor noise could be a problem.
I look on electronic design like building a house, or cooking a meal. Some parts are COMPLETELY essential to get right, some are a matter of taste, some dont matter much at all. Experience teaches which parts are which!

[petemoore]

Cool thread...
 Frostwave wrote:
 The other thing, is that in the question of noise, there usually aren't many places in a circuit (certainly in an amp!) where resistor noise could be a problem.
I look on electronic design like building a house, or cooking a meal. Some parts are COMPLETELY essential to get right, some are a matter of taste, some dont matter much at all. Experience teaches which parts are which
 This is the are that interests my curiousity.
 At the source is where I see any noise as being most problematic, before it's been multiplied. Large resistors around here would be the first I'd suspect as subject for noise introduction because they have a reputation for it I understand.
 Which brings me to the question...Are resistors In Signal path in a better position to introduce noise into the signal path?
 What other positions besides SP would make for good fodder for discussion.
I've seen testamonials about using high ended parts for a circuit such LPB, which can be 'noisy', 2n5089 being a low noise transistor in a small circuit ... maybe using higher spec peripheral components helps ITCase.
 Certain types of noise can be cool, but I'd might trade being able to get rid of it for use of all it's attributes.

[Doug_H]

hey Doug H,
Who do you think has great tone nowadays, that lives up to Jimi Hendrix, Page, Gilmour, of yesteryear?  Except for those who were out back then and continue to tour today.  Asfar as EJ, He could hear stuff some people here can't, including me!  

Too many to mention, but...

I think Joe Bonamassa and Warren Haynes have a good sound, for example. I saw Derek Trucks and he was getting a real good sound out of his Super.

If you like Hendrix-like sound, check out the Grooveyard people:

http://www.grooveyardrecords.com/mp3.html

A lot of those guys do the vibe-wah-fuzz thing "Hendrix-school" thing very well.

IMO Hendrix had a great live tone (I love BOG) but some of his studio sounds were kind of fizzy to my ears. But he was the first one to really go in that direction and he was experimenting a lot. The newer folks have had many many years to take his basic ideas and refine them.

But I have a difficult time distinguishing sound from music. If I love the music, chances are I'll love, or in the case of Neil Young  - tolerate the sound. But if I don't like the music I won't necessarily pay much attention to how it sounds.

Doug

[formerMember1]

Did anybody ever build a fuzzface or wah or any pedal, and build it first with metal film and record it, then swap resistors for CC and record again? Or are we going by what other people tell us?  Not that that is a bad thing though, cuz i listen to people on the forum and get great results from their help. :wink:

[formerMember1]

yeah doug h that is the same way i feel most of the time too.

Warren Haynes uses vintage equipment doesn't he? I think he used a 59 LP reissue hand selected, and a 100 watt plexi reissue, But for me, i like a 59 lespaul, who wouldn't, but i don't like the marshall reissue amps, I don't think they sound anything like the old ones, and many people agree too.  I am looking into those new handwired ones though, i want to hear one of em.  Sorry for rambling... :oops:

Derek trucks plays Allman bros songs doesn't he, i never had the chance to see him and Warren, i missed them when they came to my area.
I might check them out next time,...

[Doug_H]

Warren Haynes uses vintage equipment doesn't he?

When I saw him in a bar many years ago he was using an SLO. I'm not an SLO fan either but he had a real nice tone.

Doug

[Dai H.]

and SLOs have metal film...  :shock: resistors.

[Joe Hart]

SonicIV wrote:

I prefer the sound of blue guitars for some reason and I simply refuse to play a yellow guitar because they always sound horrible to me.


My guitars have to be in the red family of colors. That way I can play scorching riffs and runs! In a pinch a white or off-white will work, but then I need my rose colored glasses.
-Joe Hart

[R.G.]

Composition resistors do have less 'parasitic' (built in inductance and capacitance). And, they are less prone to breakdown during temporary voltage overload.

Quite true. However, the parasitics of carbon film and metal film are sufficiently small that it would be a very unusual circuit where the parasitics could cause a change in performance at audio.

In my experience, the primary effect that parasitics have in audio equipment is to allow the folks with an axe to grind or something to sell to have a grain of truth to build an argument around. The parasitics are measurable, and have a calculable effect. That calculation can be done and show the rolloffs of the parasitics are way beyond audio in almost all cases.

It's notable that **wires** have parasitic inductance and capacitance as well. Same argument.

I'm a little bit nutso on this topic - the tweakos and snake oil sellers (not you) love to use it to sell their wares. It's the basis they use for the Second Way to lie.

The other thing, is that in the question of noise, there usually aren't many places in a circuit (certainly in an amp!) where resistor noise could be a problem.

Quite true. As a rule, the more gain after a resistor, the more its noise matters. If you're hunting noise gremlins, start at the input first. Input stages dominate all noise calculations.

In really critical noise applications, like moving coil phono inputs (phono inputs? What are those?) where the signal is really small, you have to worry not only about the excess noise but also the basic thermal noise. That leads designers to use only low valued resistors to get the basic thermal noise down, and transformers, which have only their wire resistance for noise to step up the signal.

I look on electronic design like building a house, or cooking a meal. Some parts are COMPLETELY essential to get right, some are a matter of taste, some dont matter much at all. Experience teaches which parts are which!

Very true. However, a good grounding in *theory* also tells you where to look and some steps you don't even have to try.