I am wonder whats the differences in the sound we get from various types of SMD resistors.
Eg, I was told that foil resistors are the best, but they are also most expensive. We also have wire wound, thin and thick film resistors.
So, I am wondering if we are able to hear any differences in these resistors. Will a foil resistor sound very different from a thin film one??
Eg, I was told that foil resistors are the best, but they are also most expensive. We also have wire wound, thin and thick film resistors.
So, I am wondering if we are able to hear any differences in these resistors. Will a foil resistor sound very different from a thin film one??
There are no sonic differences. It's audiophile mythology.
Certain types of resistors will have specific applications depending upon material composition and physical properties. For example foil resistors are required where you need precision and temperature stability.
This is why manufacturers produce data sheets.
Certain types of resistors will have specific applications depending upon material composition and physical properties. For example foil resistors are required where you need precision and temperature stability.
This is why manufacturers produce data sheets.
Ok thanks!
Yes, I do understand foil resistors have the best tolerance (0.01%) and best temp coefficient (0.2ppm/c)
But thinking about the tolerance... 0.01% at small values Eg. 10ohm resistor, 0.01% is 0.001 ohm. I am just wondering if it matters at in audio. Because we already get differences larger than that in many other components esp. power transistors and op amps. I doubt we can match these components to 0.01%
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I choose my resistors based on what the datasheet says about their noise and generally try for something in the 50-100ppm range. This is the one area where choosing a different resistor may make an audible (noise floor) difference IMO.
Recently I discovered Vishay MELF resistors https://au.mouser.com/Vishay/Passive-Components/Resistors/MELF-Resistors/_/N-agsk8?P=1z0zls5 They tick all the right boxes (including being audiophile approved) except maybe price, but they are around the same price as the through hole Vishay CMF and RN series resistors I normally use.
As an added bonus they look cool
Tony.
Recently I discovered Vishay MELF resistors https://au.mouser.com/Vishay/Passive-Components/Resistors/MELF-Resistors/_/N-agsk8?P=1z0zls5 They tick all the right boxes (including being audiophile approved) except maybe price, but they are around the same price as the through hole Vishay CMF and RN series resistors I normally use.
As an added bonus they look cool
Tony.
Again trying to stir the pond with subjective opinion questions?
I wonder how long will this thread last until it turns into a mess.
Those who are sucked into this black hole, be warned 🙄
The sonic difference between different SMD resistors comes down the the sizzle they make when you overload them. 😉 Size appropriately.
But to answer your question honestly -- if you don't have a specific need where you know exactly why you're choosing a type of resistor composition, you'd do well to stick with metal films. (until at least you exceed their power range) I like susumu rg's.
But to answer your question honestly -- if you don't have a specific need where you know exactly why you're choosing a type of resistor composition, you'd do well to stick with metal films. (until at least you exceed their power range) I like susumu rg's.
Hard to say as there are too little data points so far. To my embarrassment i still have not conducted any listening tests of smd resistors. It seems most of the better products use Melf, so those would be first on my list to compare to familiar tht resistors.
The uncertainty is generally discouraging me from using smd resistors, even though the absence of leads and caps seems like a good thing.
I like Vishay Melfs for cartridge loading in phono stages the nichrome parts used by goldpoint in the switched pots are also good.
Largely speaking though with smd parts theres no bad uns, unlike with through hole parts where all manner of noisy and none linear resistive elements exist.
Largely speaking though with smd parts theres no bad uns, unlike with through hole parts where all manner of noisy and none linear resistive elements exist.
I am actually not in disfavor of possible variances due to types of resistors. The smaller they get, the more their tempcos will start to effect their actual resistance, since the voltage levels mostly stay the same in audio. The current density also can get to a point where excess noise starts to be a factor. But at those voltage swings the music should be so loud that the excess noise only a tiny speck in the mix, totally inaudible.
I do find the subject interesting tho if only to have the possible option of getting a dB or so better NF or distortion, but not so much because I think I can hear it.
Rather not, then yes. Thin film resistors have good enough properties to they were 'non audible' in audio circuits if they were right chosen (rated power with good enough margin etc).
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I don't know about sonic differences but thick film resistors can have a larger voltage coefficient than thin film. They can also have more excess noise. Or not. You have to look at data sheets and possibly measure. Derating resistors can reduce those factors.
^ bootstrapping on the TC and voltage coefficient issues, here's a link (from Bonsai's site!) to an article by Bruce Hofer, of Audio Precision, on these issues. It dovetails into what I said earlier about this being a topic that the details matter after plenty of electronics experience, not the beginner.
http://hifisonix.com/wordpress/wp-content/uploads/2017/11/Designing_for_Ultra-Low_THD_N-1.pdf
http://hifisonix.com/wordpress/wp-content/uploads/2017/11/Designing_for_Ultra-Low_THD_N-1.pdf
Here are some measurements of distortion between a normal 1206 smd resistor and a MELF resistor in the feedback path, whilst there will be no audible differences it will be important from an engineering perspective if for example you were designing a low distortion signal generator to used as test equipment.
Even order distortion in symmetrical amp
Even order distortion in symmetrical amp
Not quite true I'm afraid, its very possible to measure the difference between the various sorts and even sizes of SMT resistor with good equipment. Its rare for datasheets for SMT resistors to include the data you need to predict the audio performance - i.e. voltage coefficient and various excess noise parameters.
Thick film are metal oxide (ruthenium oxide in glass typically), and perform distinctly less well w.r.t. distortion and noise than thin-film (which are metal film by another name). Typical voltage coefficients for thick film are 30--100ppm,
versus ~1ppm for thin-film. If you want < 0.01% distortion metal oxide are to be avoided.
Larger sized SMT resistors tend to have less excess noise and less distortion as voltage coefficient depends on electric field strength - so larger thin-film (1206, 1210 or more) are needed to compete against standard 1/4W through-hole metal film, (although this is likely beyond audibility and most measurement equipment!)
Basically for the performance-defining components (filter components, feedback
networks) you need thin-film to assure metal-film levels of performance, and for high-voltage swings the larger package sizes are advised to match through-hole performance levels.
Doug Self goes into a lot of detail of resistor performance in Chapter 2 of "Small Signal Audio Design".
