what type of noise does carbon film resistor make ? audio taper wireround??

[prorms]

what nosie will carbon film resistor ??
i know metal film are better will stop the problem

poteniometer audio taper and liner what the is the difference
will wireround effect the sound quality

[prorms]

what sound does carbon film make???

[QSerraTico_Tico]

Originally posted by prorms
what sound does carbon film make???

sssssssssssssssssssssssssssssshh
But only when with a voltage across it....
Sound is more mellow than metal films

[prorms]

heard that metal film will not make any sound

[SY]

All resistors show Johnson noise. Metal films show relatively low excess noise, but have the same Johnson noise as anything else in the universe with the same resistance.

One big secret- lower temperature means lower noise. Keep resistors in critical spots cool.

[gni]

Generally. . .the larger the power rating, the lower the noise also. .
because of the heat. Keeping resistors cool keeps the noise down
as stated earlier. A 1W metal film should exhibit less noise than
a 1/4W metal film.

[gni]

poteniometer audio taper and liner what the is the difference
will wireround effect the sound quality

A pot can be made is several ways; often carbon is used as the
resistive body; sometimes a long length of wire is used. If I remember
correctly: wirewound will withstand higher heat dissapation. Carbon
potentially can cause more noise since is it a very thin layer of carbon.

As for audio taper vs linear taper pots: Linear pots are just that. . .
if you set a 100k pot to 50% then it will be at 50k. An audio taper
responds more like our hearing. . .which is non-linear or logarithmic.

The following link explains it better than I could:

http://www.geofex.com/Article_Folder...s/potscret.htm

[djQUAN]

Originally posted by gni
Generally. . .the larger the power rating, the lower the noise also. .
because of the heat. Keeping resistors cool keeps the noise down
as stated earlier. A 1W metal film should exhibit less noise than
a 1/4W metal film.

I always thought that higher wattage resistors have more noise because there's more resistive material in them.

[AndrewT]

and metal wire as well as metal foil have lower noise than metal film.

[PigletsDad]

Originally posted by prorms
what nosie will carbon film resistor ??
i know metal film are better will stop the problem

poteniometer audio taper and liner what the is the difference
will wireround effect the sound quality

You have asked 3 questions. Taking them in order:

1) Carbon films show a lot of 1/f noise, in addition to the Johnson noise which all resistors have to show. Metal film resistors have much lower 1/f noise contribution. Note that in both cases, 1/f noise is predominantly resistance noise - the resulting noise signal is proportional to the applied voltage or current.

2) The taper of a potentiometer describes how the resistance varies with rotation angle. A linear taper gives resistance that is roughly proportional to angle. If used as a volume control, this is inconvenient, as the useful range is crammed in one corner. Audio taper attempts to give more nearly constant logarithmic attenuation as a function of angle.

3) Wirewound resistors can have significant inductance. It is hard to generalise, but this is very important in some circuits, but less so in others. There are so-called non-inductive wirewounds which do significantly better; they typically have wire that goes back and forth, rather than round and round the former.