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Post by jelosno on Aug 29, 2006 17:53:12 GMT
another dumb question.... ;D what is the difference between these resistors? - Metal film resistor
- Carbon composition resistor
- Wirewound resistor
- Carbon film resistor
- Tantalum film resistor
- Concrete (?) resistor
Do they have any audiophyle differences or does it solely depend on WHERE they are used in an amp? Stefan
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rickcr42
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Post by rickcr42 on Aug 29, 2006 18:19:48 GMT
killin' me man first up,a mini-primer in generic resistors.remeber the word is the function here so a resistor "resists" and is used to set the parameters the operating ciruit needs to function properly I.E. as a voltage attenuating device www.interq.or.jp/japan/se-inoue/e_resistor.htmsince the part designation is already established as the descriptor of the function it gets to describing the types next and guess what ? Also totally descriptive any "film" resistor is just that,a spiralled film of whatever the resistive material is said to be so carbon film is depositied carbon on a film backing,metal film a metal spiral wrap film,tantalum a depositied tantalum film,etc The "composition" types are again exactly as described so a carbon composition resistor is a "paste" that is a composite of the carbon and whatever it is they use as the "glue" to suspend the carbon.Think baking cookies Wire wound.Yup.A wound wire as the resistive element,usually nichrome (which you can purchase in bulk spools BTW for making your own ) A "concrete" resistor is just a wirewound inside a "concrete" casing. ANYTHING that resists voltage can be considered a resistor including a simple loop of wire or even a light bulb element.The reasons for all the various methods of construction are the many various uses 1-tolerance (how far from the stated value the resistor varies) 2-environment (will it see moisture ? high humidity ? Extreme Heat ?) 3-size limits of the application (some methods of construction make a more efficient package) 4-surge current expected etc. Resistor sonics ? Whole different can of worms there dude and those worms have teeth !
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Aug 29, 2006 18:25:16 GMT
Yes.Along with the requirements of of the above listed environmental (how hot will it get ? Cold ?) and wattage it can expect to pass through.
I personally like to use hand selected carbon composition resistors when I can but use these next to a got tube or use in a portable device that will see hot/cold extremes and don't expect the originally measure value to be accurate.It WILL change and the change will be a rise in value,one that is unpredicatble without taking the part out and measuring it again.
Metal films are uable in limited wattages but to be honest are a cold sounding beast to me.Far better to use another precision tolerance type unless there is no choice
Wirewounds-anywhere the current is high this is the guy you want
The rest ? all about taste once you nail the requiremnts
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rickcr42
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Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Aug 29, 2006 19:16:32 GMT
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Aug 30, 2006 2:14:20 GMT
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Post by jelosno on Aug 30, 2006 13:18:50 GMT
Very good links again!
I did know what a resistor is and what it does (in general).
My question was directed to their differences in regard to the sound signal.
Also I did not know about the temperature and humidity related issues.
So, it must not be tantalum film all the time...
Stefan
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rickcr42
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Post by rickcr42 on Aug 30, 2006 16:11:14 GMT
no,in fact no single resistor "type" all the time or no matter the circuit you impart a sonic stamp of the resistor on it and in the case of tants (if used everywhere for all things) can make for a very uninvolving,sluggish/soft sounding signal path. a mix is always best with each selected depending on area of the amp. quicky example : On my Class-A high current follower/Headphone driver I played around with every manner of source load : Resistors,various CCS methods,an inductor as load and even a light bulb as the resistive element and all sounded different even though doing the same duty but in the end I found the source-resistor method to be the most natural sounding so once I identified the part "type" (resistor current source) it was time to try various part "brands" which was made easy by me using a barrier strip wited to the heat sink mounted mosfets so I could bolt in new ideas at will. I started out with the generic Radio Shack cement cased wire wound power resistors which sounded OK but a bit "gritty" in the mid-high area.Out it went and in went one of those fancy gold annodised power resistors with a built in heat sink,This looked great but, was an improvement over the Rat Shack resistors but they sucked the life out of the bass notes.the bass was there but to me had no "guts" surrounding notes so out they went. Next up were a couple of Audionote Tantalums but these were WAY WRONG for this application even though in other circuits were my first choice.The follower sounded sooooo limp it was as if someone hit the "eliminate all dynamics" button ! Tried various NOS carbons and the same thing.Dull and sluggish.Tried a Kiwame carbon which was betterby a bit over the NOS carbon comps but still not right.I had good luck using a Caddock TO-220 pack resistor as the IV stage of my heavily modded DITB (DAC In The Box ,now a DITB+ since all that remains of the original is the digital section ) but here in this application the sonics took on a solid state hardness that was totally unacceptable so I was ready to toss in the towel then tried a Mills MRA-5 in the 27 ohm size for the very expensive price of like $2 per ...and the Mills resistors are still there playing music This is a resistor I had used often in power supplies but never in the audio circuit section yet it was THE part in this case,at least to my ears. Smooth yet detailed,no gritty mids or highs and the bass had some "guts" restored so the notes sounded like actual music again. Is it just the IRF510/Mills MRA-5 combo that synergises ? Would this change with another brand of the same mosfet model ? Could be.All comes down to plugging in and listening over time and the above while sounding like it was an evening of plug-in,unplug,plug-in another,-was actually over a period of months before I got it right-for me ;D
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Sept 4, 2006 18:08:36 GMT
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