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Old 21st March 2021, 10:36 PM   #101
RussellKinder is offline RussellKinder  United States
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Hey, Eddie,
Do you ever use SMT resistor chips? Do you have a preference?
--Russell
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Old 21st March 2021, 10:47 PM   #102
cowanaudio is offline cowanaudio  Australia
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Quote:
Originally Posted by Fast Eddie D View Post
I'm telling you, the resistors I use make an audible difference.
I'd love to see measurements that show a difference that is significant enough to be audible. I am always sceptical of unsubstantiated claims.
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Old 21st March 2021, 10:55 PM   #103
RussellKinder is offline RussellKinder  United States
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Different resistors have different voltage and temperature coefficients.

I have always assumed that most 1% metal film resistors are about the same. It could be that when seeking distortion below 0.001% that resistors are a limiting factor. I'm sure someone has done a study on this somewhere. I'll have to hunt that down.
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Old 21st March 2021, 11:53 PM   #104
ticknpop is offline ticknpop  Canada
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I hear the difference between resistors, but there isn’t a test yet that describes the difference. Just because we can’t measure it with current instruments doesn’t mean it doesn’t exist, how do you describe the Mona Lisa,- as a picture of a sitting woman? If you can’t or don’t want to hear a difference save your money and buy Xicon metal films.

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Old 22nd March 2021, 05:09 AM   #105
cowanaudio is offline cowanaudio  Australia
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Quote:
Originally Posted by RussellKinder View Post
Different resistors have different voltage and temperature coefficients.

I have always assumed that most 1% metal film resistors are about the same. It could be that when seeking distortion below 0.001% that resistors are a limiting factor.
I completely agree with everything you have said here. In some situations in analogue audio resisters do make a measurable difference. The feedback loop divider of a power amplifier is likely the most extreme situation you could find. You are in the ballpark with the magnitude of the problem too. A 10c additional spend on some low TC thin film resistors in those two locations could likely be justified on engineering grounds alone, however don't think a reduction in THD from 0.001% to 0.0005% will actually be audible.

I object to the statements by Eddie and ticknpop that resistors make an audible difference. There is no study with any level of scientific rigour that will support that premise.
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Old 22nd March 2021, 05:15 AM   #106
dotneck335 is offline dotneck335  United States
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Quote:
Originally Posted by ticknpop View Post
I hear the difference between resistors.....
Do you also hear a difference in power cords?
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Old 22nd March 2021, 06:12 AM   #107
RussellKinder is offline RussellKinder  United States
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Quote:
Originally Posted by ticknpop View Post
I hear the difference between resistors, but there isnít a test yet that describes the difference. Just because we canít measure it with current instruments doesnít mean it doesnít exist
If there's a difference, there's a test for it. You just have to ask the right questions. Resistors are pretty simple. Send current through it and a voltage proportionally appears across it.

Deviation from proportionality is easy to measure and techniques certainly exist for quantifying that. Distortion can be calculated from the resulting transfer function, depending on the application. Modern instruments are certainly good enough.
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Old 22nd March 2021, 06:20 AM   #108
RussellKinder is offline RussellKinder  United States
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Quote:
Originally Posted by cowanaudio View Post
I completely agree with everything you have said here. In some situations in analogue audio resisters do make a measurable difference. The feedback loop divider of a power amplifier is likely the most extreme situation you could find. You are in the ballpark with the magnitude of the problem too. A 10c additional spend on some low TC thin film resistors in those two locations could likely be justified on engineering grounds alone, however don't think a reduction in THD from 0.001% to 0.0005% will actually be audible.
I've been out of the discrete component audio game for awhile. Twenty-five years ago, when I was designing amps professionally, 0.01% distortion was considered plenty good, especially if the harmonics were low order. Any 1% metal film was good enough to deliver this performance.

Now, with modern output transistors (well, newer than 1996), and some high bandwidth drivers and pre-drivers, I can get distortion well below 0.001%. Layout parasitics and feedback resistors may be the limiting factors in how low distortion can get. To me, it's not really a question of audibility. My amplifiers with 0.02% THD sounded great. It's really just an engineering exercise of building an amp that no one can possibly blame it for the sound coming out of their speakers.
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Last edited by RussellKinder; 22nd March 2021 at 06:25 AM.
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Old 22nd March 2021, 06:28 AM   #109
Fast Eddie D is offline Fast Eddie D  United States
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Quote:
Originally Posted by cowanaudio View Post
I'd love to see measurements that show a difference that is significant enough to be audible. I am always sceptical of unsubstantiated claims.


Of course. These resistors are very low noise, which is probably what's audible. They're very stable with regards to temperature. I buy them in batches, and they always match way better than their rated 1%.



I hope we don't have to discuss the audibility of potentiometers. Tracking is quite audible. The Blue Velvet tracks better than other potentiometers I've used and I've never had any scratchiness out of one. All of this is audible. There's cheaper volume controls, there's better volume controls, there's switched resistor arrays....I'll stick to shat I know. And I didn't do any fancy tests but I've had good luck with these resistors. They're probably overkill.

If you have a recommendation for resistors for audio circuits then I'd appreciate it. The CMF series is kind of expensive.
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Old 22nd March 2021, 10:17 AM   #110
jan.didden is offline jan.didden  Europe
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This will give you a perspective.

Also, don't forget that not all 1% resistors are the same. TC for instance ranges from 5ppm to 200ppm. Whether it makes an audible difference is debatable.
The feedback R in a power amp is in a class of its own - very high voltage across it (amp output voltage) and directly in the feedback loop.
Most other resistors are very uncritical, and a statement that any high-Q resistor in any position makes an audible difference is unconvincing.
And all resistors generate noise - there is no such thing as a noiseless resistor. The noise is a function of R and T. You want lower noise: lower the R and/or lower the T.
Some resistors have excess noise, like carbon resistors, but nobody uses them anymore for a long time (except in guitar amps but there they contribute to the typical non-HiFi sound).

Jan
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