Low noise resistors

Archived from groups: rec.audio.tech (More info?)

Is it better to use over rated (higher wattage) resistors for low noise, or
just enough wattage capability to cover expected conditions plus a little
more for safty ?

My thinking is that over rating will result in cooler resistors, so therefore,
less noise, but, on the otherhand, more material for the signal to pass
through, therefore, more noise.
-Don
26 answers Last reply
More about noise resistors
  1. Archived from groups: rec.audio.tech (More info?)

    In article <uyxqc.74473$536.12094292@attbi_s03>,
    TAKE-OUTdobrien25@comcast.net (Don) wrote:

    > Is it better to use over rated (higher wattage) resistors for low noise, or
    > just enough wattage capability to cover expected conditions plus a little
    > more for safty ?
    >
    > My thinking is that over rating will result in cooler resistors, so
    > therefore,
    > less noise, but, on the otherhand, more material for the signal to pass
    > through, therefore, more noise.

    The noise is not due to heating, There are two sources of noise in
    resistors, thermal noise and "excess noise". Thermal noise is a function
    of temperature and resistance, and nothing you (or the manufacturer) can
    do will alter it.

    Excess noise is material and process dependent. If it matters ( and most
    times it does not), the proper solution is to select "low noise"
    resistors. In general, carbon resistors are worse than metal film, are
    worse than bulk metal.

    Isaac
  2. Archived from groups: rec.audio.tech (More info?)

    >Is it better to use over rated (higher wattage) resistors for low noise, or
    >just enough wattage capability to cover expected conditions plus a little
    >more for safty ?
    >
    >My thinking is that over rating will result in cooler resistors, so therefore,
    >less noise, but, on the otherhand, more material for the signal to pass
    >through, therefore, more noise.

    First thing would be to make sure that the resistors are adequately
    de-rated to survive properly! Years ago, one of the early-generation
    high-power transistor amps (the "Tigersaurus") developed a bad
    reputation for failing after some period of use. It turned out that
    the output stage used a "bias stack" of resistors, which were using
    relatively small parts (1/2 watt?) but actually were dissipating
    several times their rated amount of power. They cooked, and the amp
    had a tendency to suffer thermal runaway, oscillate, burst into flames
    (literally), or exhibit other forms of makes-the-owner-really-nervous
    misbehavior.

    So, I'd certainly recommend de-rating all resistors conservatively, to
    ensure long life. Running 'em at no more than 50% of rated
    dissipation would probably not be a bad thing.

    As to noise, though, I don't think it's a terribly big issue in any
    well-designed preamp. The primary noise source in a resistor is
    thermal or Johnson noise: the noise power is proportional to absolute
    temperature, and a matter of a few degrees of heating around room
    temperature isn't going to make a big difference. The noise voltage
    across the resistor is a function of the noise power and the
    resistance... the amount of material used to make up this resistance
    doesn't appear to enter into it. As long as you're using good-quality
    resistors (e.g. decent metal-film ones), a 1-watter ought to have the
    same amount of thermal noise as a 1/8-watter, at the same temperature.

    I don't know whether the size/rating of the resistor has any effect on
    the quantity of excess (non-thermal) noise, but this ought to be *way*
    down in the weeds if you're using good-quality film resistors.

    In short, I wouldn't worry about it.

    --
    Dave Platt <dplatt@radagast.org> AE6EO
    Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
    I do _not_ wish to receive unsolicited commercial email, and I will
    boycott any company which has the gall to send me such ads!
  3. Archived from groups: rec.audio.tech (More info?)

    "Isaac Wingfield" <isw@witzend.com> wrote in message
    news:isw-301A53.19580318052004@netnews.comcast.net...
    > The noise is not due to heating, There are two sources of noise in
    > resistors, thermal noise and "excess noise". Thermal noise is a function
    > of temperature and resistance, and nothing you (or the manufacturer) can
    > do will alter it.

    Saying thermal noise is not due to heating, is a bit of a misnomer. Sure
    there will always be thermal noise at any temperature above absolute zero,
    but heating will obviously increse the temperature and hence the noise

    TonyP.
  4. Archived from groups: rec.audio.tech (More info?)

    TonyP wrote:
    > "Isaac Wingfield" <isw@witzend.com> wrote in message
    > news:isw-301A53.19580318052004@netnews.comcast.net...
    >> The noise is not due to heating, There are two sources of noise in
    >> resistors, thermal noise and "excess noise". Thermal noise is a
    >> function of temperature and resistance, and nothing you (or the
    >> manufacturer) can do will alter it.
    >
    > Saying thermal noise is not due to heating, is a bit of a misnomer.
    > Sure there will always be thermal noise at any temperature above
    > absolute zero, but heating will obviously increse the temperature and
    > hence the noise

    Long ago I was building (tubed) RIAA preamps. I had a goodly collection of
    small precision wirewound resistors at my disposal, so I built a stereo
    preamp made up of them. The difference in noise levels, compared to carbon
    compostiion resistors, was negligable.

    Some time later I was building transistorized RIAA preamps, but this time
    the comparison was between carbon film resistors and deposited metal
    resistors. Similar results.
  5. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:7_mdnb24x5fb_jbdRVn-sQ@comcast.com...
    > TonyP wrote:
    > > Saying thermal noise is not due to heating, is a bit of a misnomer.
    > > Sure there will always be thermal noise at any temperature above
    > > absolute zero, but heating will obviously increse the temperature and
    > > hence the noise

    > Long ago I was building (tubed) RIAA preamps. I had a goodly collection of
    > small precision wirewound resistors at my disposal, so I built a stereo
    > preamp made up of them. The difference in noise levels, compared to carbon
    > compostiion resistors, was negligable.
    > Some time later I was building transistorized RIAA preamps, but this time
    > the comparison was between carbon film resistors and deposited metal
    > resistors. Similar results.

    Yes but has nothing to do with temperature. Not that I was suggesting large
    differences, just that physics dictates an increase.
    As for the reliability of carbon resistors, put your money on the metal :-)
    The carbon WILL become more noisy at some stage.

    TonyP.
  6. Archived from groups: rec.audio.tech (More info?)

    "TonyP" <TonyP@optus.net.com.au> wrote in message
    news:40ab893a$0$1588$afc38c87@news.optusnet.com.au...
    >
    > "Arny Krueger" <arnyk@hotpop.com> wrote in message
    > news:7_mdnb24x5fb_jbdRVn-sQ@comcast.com...
    > > TonyP wrote:
    > > > Saying thermal noise is not due to heating, is a bit of a
    misnomer.
    > > > Sure there will always be thermal noise at any temperature above
    > > > absolute zero, but heating will obviously increse the
    temperature and
    > > > hence the noise
    >
    > > Long ago I was building (tubed) RIAA preamps. I had a goodly
    collection of
    > > small precision wirewound resistors at my disposal, so I built a
    stereo
    > > preamp made up of them. The difference in noise levels, compared
    to carbon
    > > compostiion resistors, was negligable.
    > > Some time later I was building transistorized RIAA preamps, but
    this time
    > > the comparison was between carbon film resistors and deposited
    metal
    > > resistors. Similar results.
    >
    > Yes but has nothing to do with temperature. Not that I was
    suggesting large
    > differences, just that physics dictates an increase.
    > As for the reliability of carbon resistors, put your money on the
    metal :-)
    > The carbon WILL become more noisy at some stage.

    The thermal noise of all resistances is the same: kTB. The answer
    is in watts. If there is current flowing through the resistor, there
    will be additional noise, the amount and spectral charateristics of
    which are wildly different. I've found that bulk metal resistors have
    the least added noise, followed by metal film. The larger the
    resistor, the quieter it is wrt the excess noise.

    Norm Strong
  7. Archived from groups: rec.audio.tech (More info?)

    In article <40ab5fb3$0$1587$afc38c87@news.optusnet.com.au>,
    "TonyP" <TonyP@optus.net.com.au> wrote:

    > "Isaac Wingfield" <isw@witzend.com> wrote in message
    > news:isw-301A53.19580318052004@netnews.comcast.net...
    > > The noise is not due to heating, There are two sources of noise in
    > > resistors, thermal noise and "excess noise". Thermal noise is a function
    > > of temperature and resistance, and nothing you (or the manufacturer) can
    > > do will alter it.
    >
    > Saying thermal noise is not due to heating, is a bit of a misnomer. Sure
    > there will always be thermal noise at any temperature above absolute zero,
    > but heating will obviously increse the temperature and hence the noise

    I knew that, but I didn't say it very well, did I?

    What I *meant* was that in essentially NO application where a "low
    noise" resistor is called for, will there be enough electrical power
    dissipation in the resistor to cause it to become warm. In that sense,
    any resistor you put there will exhibit the same amount of thermal noise.

    Isaac
  8. Archived from groups: rec.audio.tech (More info?)

    In article <7_mdnb24x5fb_jbdRVn-sQ@comcast.com>,
    "Arny Krueger" <arnyk@hotpop.com> wrote:

    > TonyP wrote:
    > > "Isaac Wingfield" <isw@witzend.com> wrote in message
    > > news:isw-301A53.19580318052004@netnews.comcast.net...
    > >> The noise is not due to heating, There are two sources of noise in
    > >> resistors, thermal noise and "excess noise". Thermal noise is a
    > >> function of temperature and resistance, and nothing you (or the
    > >> manufacturer) can do will alter it.
    > >
    > > Saying thermal noise is not due to heating, is a bit of a misnomer.
    > > Sure there will always be thermal noise at any temperature above
    > > absolute zero, but heating will obviously increse the temperature and
    > > hence the noise
    >
    > Long ago I was building (tubed) RIAA preamps. I had a goodly collection of
    > small precision wirewound resistors at my disposal, so I built a stereo
    > preamp made up of them. The difference in noise levels, compared to carbon
    > compostiion resistors, was negligable.

    Wirewound resistors can be rather inductive, and that can make for
    "interesting" stability problems.

    > Some time later I was building transistorized RIAA preamps, but this time
    > the comparison was between carbon film resistors and deposited metal
    > resistors. Similar results.

    Compared to the groove noise, I don't think anything about the resistor
    matters 8^}.

    IMHO, the noise level when the stylus is not in the groove is of no
    concern as long as it's at least 10 dB below the in-groove value. It
    doesn't take *real* low-noise technique to achieve that.

    When I designed my own preamp, I selected the topology for lowest
    distortion instead of lowest noise -- that meant using a long-tailed
    diff pair for the front end. A single bipolar transistor running at
    microamp base currents shows considerable distortion due to Rbe
    modulation.

    Oddball piece of information: The Rbe of a transistor is not an actual
    resistance, and does not behave as one, noise-wise. This is a Good
    Thing, because at very low collector currents, Rbe can be interestingly
    large.

    Isaac
  9. Archived from groups: rec.audio.tech (More info?)

    Isaac Wingfield wrote:
    > In article <7_mdnb24x5fb_jbdRVn-sQ@comcast.com>,
    > "Arny Krueger" <arnyk@hotpop.com> wrote:
    >
    >> TonyP wrote:
    >>> "Isaac Wingfield" <isw@witzend.com> wrote in message
    >>> news:isw-301A53.19580318052004@netnews.comcast.net...
    >>>> The noise is not due to heating, There are two sources of noise in
    >>>> resistors, thermal noise and "excess noise". Thermal noise is a
    >>>> function of temperature and resistance, and nothing you (or the
    >>>> manufacturer) can do will alter it.
    >>>
    >>> Saying thermal noise is not due to heating, is a bit of a misnomer.
    >>> Sure there will always be thermal noise at any temperature above
    >>> absolute zero, but heating will obviously increse the temperature
    >>> and hence the noise
    >>
    >> Long ago I was building (tubed) RIAA preamps. I had a goodly
    >> collection of small precision wirewound resistors at my disposal, so
    >> I built a stereo preamp made up of them. The difference in noise
    >> levels, compared to carbon compostiion resistors, was negligable.
    >
    > Wirewound resistors can be rather inductive, and that can make for
    > "interesting" stability problems.

    I've heard that story, but even though it was a RIAA implemented via
    feedback, no problems with oscillation or ringing. Of course, in a RIAA
    network, there were big caps across the resistors in the feetback path. And,
    the feedback path pretty much controlled how the preamp worked.

    >> Some time later I was building transistorized RIAA preamps, but this
    >> time the comparison was between carbon film resistors and deposited
    >> metal resistors. Similar results.

    > Compared to the groove noise, I don't think anything about the
    > resistor matters 8^}.

    Agreed.

    , the noise level when the stylus is not in the groove is of no
    > concern as long as it's at least 10 dB below the in-groove value. It
    > doesn't take *real* low-noise technique to achieve that.

    Agreed.

    >I designed my own preamp, I selected the topology for lowest
    > distortion instead of lowest noise -- that meant using a long-tailed
    > diff pair for the front end. A single bipolar transistor running at
    > microamp base currents shows considerable distortion due to Rbe
    > modulation.

    These transistors didn't have a lot of beta, the collector current was
    several mA, so the base currents were probably dozens of microamps.

    > Oddball piece of information: The Rbe of a transistor is not an actual
    > resistance, and does not behave as one, noise-wise. This is a Good
    > Thing, because at very low collector currents, Rbe can be
    > interestingly large.

    Agreed.
  10. Archived from groups: rec.audio.tech (More info?)

    "Don" <TAKE-OUTdobrien25@comcast.net> wrote in message
    news:uyxqc.74473$536.12094292@attbi_s03...
    > Is it better to use over rated (higher wattage) resistors for low noise,
    or
    > just enough wattage capability to cover expected conditions plus a little
    > more for safty ?
    >
    > My thinking is that over rating will result in cooler resistors, so
    therefore,
    > less noise, but, on the otherhand, more material for the signal to pass
    > through, therefore, more noise.
    > -Don


    Check out Randall Aiken's website for an excellent technical paper on the
    subject of resistor types. There's actually 3 types of resistor noise.

    http://www.aikenamps.com/

    Click on Tech Info, then Technical Papers Advanced, then on "Resistor
    Types - Does it Matter?


    Mikey
  11. Archived from groups: rec.audio.tech (More info?)

    "Isaac Wingfield" <isw@witzend.com> wrote in message
    news:isw-5E2E1E.20221819052004@netnews.comcast.net...
    > Compared to the groove noise, I don't think anything about the resistor
    > matters 8^}.

    True.

    > IMHO, the noise level when the stylus is not in the groove is of no
    > concern as long as it's at least 10 dB below the in-groove value. It
    > doesn't take *real* low-noise technique to achieve that.

    Depends on the noise, but I would want a slightly better margin than that,
    and is very easy to achieve anyway.

    > When I designed my own preamp, I selected the topology for lowest
    > distortion instead of lowest noise -- that meant using a long-tailed
    > diff pair for the front end. A single bipolar transistor running at
    > microamp base currents shows considerable distortion due to Rbe
    > modulation.

    Since the distortion on any vinyl record is also high, you are reducing one
    non-problem, whilst claiming another is of no importance.

    TonyP.
  12. Archived from groups: rec.audio.tech (More info?)

    TonyP wrote:
    > "Isaac Wingfield" <isw@witzend.com> wrote in message
    > news:isw-5E2E1E.20221819052004@netnews.comcast.net...
    >> Compared to the groove noise, I don't think anything about the
    >> resistor matters 8^}.
    >
    > True.
    >
    >> IMHO, the noise level when the stylus is not in the groove is of no
    >> concern as long as it's at least 10 dB below the in-groove value. It
    >> doesn't take *real* low-noise technique to achieve that.
    >
    > Depends on the noise, but I would want a slightly better margin than
    > that, and is very easy to achieve anyway.

    Agreed. You have to consider not only the over-all amplitude of the noise,
    but also its spectum.

    >> When I designed my own preamp, I selected the topology for lowest
    >> distortion instead of lowest noise -- that meant using a long-tailed
    >> diff pair for the front end. A single bipolar transistor running at
    >> microamp base currents shows considerable distortion due to Rbe
    >> modulation.
    >
    > Since the distortion on any vinyl record is also high, you are
    > reducing one non-problem, whilst claiming another is of no importance.

    Same basic comment as noise. The spectral content of the nonlinear
    distortion have to be considered. However, it's trivial to build electronics
    with nonlinear distortion that is so much less than that of the LP, that
    there's not a lot to worry about.

    IME, the most common audible issues relating to phono preamps relate to
    frequency response, both that due to the RIAA demphasis network, and that
    due to cartridge loading.
  13. Archived from groups: rec.audio.tech (More info?)

    "MikeyMann" <mikeyamps@comcast.net> wrote in message
    news:TLCdna78AOMz_TDdRVn-uQ@comcast.com...
    > "Don" <TAKE-OUTdobrien25@comcast.net> wrote in message
    > news:uyxqc.74473$536.12094292@attbi_s03...
    > > Is it better to use over rated (higher wattage) resistors for low noise,
    > or
    > > just enough wattage capability to cover expected conditions plus a
    little
    > > more for safty ?
    > >
    > > My thinking is that over rating will result in cooler resistors, so
    > therefore,
    > > less noise, but, on the otherhand, more material for the signal to pass
    > > through, therefore, more noise.
    > > -Don
    >
    >
    > Check out Randall Aiken's website for an excellent technical paper on the
    > subject of resistor types. There's actually 3 types of resistor noise.
    >
    > http://www.aikenamps.com/
    >
    > Click on Tech Info, then Technical Papers Advanced, then on "Resistor
    > Types - Does it Matter?
    >
    >
    > Mikey


    Great page, Thanks
    Dale
  14. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:vYqdnXPMztw_ZTDd4p2dnA@comcast.com...
    > Same basic comment as noise. The spectral content of the nonlinear
    > distortion have to be considered. However, it's trivial to build
    electronics
    > with nonlinear distortion that is so much less than that of the LP, that
    > there's not a lot to worry about.

    Agreed.

    > IME, the most common audible issues relating to phono preamps relate to
    > frequency response, both that due to the RIAA demphasis network, and that
    > due to cartridge loading.

    Cartridge loading is usually easy to fix, and IME freq response errors are
    usually much less than the variation in the records themselves.
    Whilst it is good practice to set up a flat system using a good test record,
    the variation in response from supposedly identical records, but from
    different pressings, will usually be larger than any phono pre-amps
    variation from ideal RIAA response. Worrying about variations less than 1-2
    dB is a waste of time IMO.

    TonyP.
  15. Archived from groups: rec.audio.tech (More info?)

    TonyP wrote:
    > "Arny Krueger" <arnyk@hotpop.com> wrote in message
    > news:vYqdnXPMztw_ZTDd4p2dnA@comcast.com...
    >> Same basic comment as noise. The spectral content of the nonlinear
    >> distortion have to be considered. However, it's trivial to build
    >> electronics with nonlinear distortion that is so much less than that
    >> of the LP, that there's not a lot to worry about.
    >
    > Agreed.
    >
    >> IME, the most common audible issues relating to phono preamps relate
    >> to frequency response, both that due to the RIAA demphasis network,
    >> and that due to cartridge loading.

    > Cartridge loading is usually easy to fix,

    But IME rarely fixed.


    > and IME freq response
    > errors are usually much less than the variation in the records
    > themselves.

    However, that doesn't let them off the hook. If they are audible then they
    represented undesirable changes in sound quality.

    > Whilst it is good practice to set up a flat system using
    > a good test record, the variation in response from supposedly
    > identical records, but from different pressings, will usually be
    > larger than any phono pre-amps variation from ideal RIAA response.

    I'd be careful about *any*, particularly when it comes to legacy preamps
    from before the 1980s, that are still in use.

    > Worrying about variations less than 1-2 dB is a waste of time IMO.

    It very much depends where those 1-2 dB are.

    Take a listen to the differences from variation that size that you can hear
    in musical samples you can download from
    http://www.pcabx.com/technical/dips_pips_tips/index.htm , particularly the
    ones I call "tips".

    IME mastering is often about broad but shallow changes in frequency
    response.
  16. Archived from groups: rec.audio.tech (More info?)

    TAKE-OUTdobrien25@comcast.net (Don) wrote in message news:<uyxqc.74473$536.12094292@attbi_s03>...
    > Is it better to use over rated (higher wattage) resistors for low noise, or
    > just enough wattage capability to cover expected conditions plus a little
    > more for safty ?
    >
    > My thinking is that over rating will result in cooler resistors, so therefore,
    > less noise, but, on the otherhand, more material for the signal to pass
    > through, therefore, more noise.
    > -Don

    Purely for fun, I did a test today. My test setup is a x100 amplifier
    (with OPA2228 op amp) feeding the sound card on my PC, whereupon I
    have a crude FFT spectrum analyzer program. So I took two resistors as
    "signal sources" to compare their noise spectra. One was a 100k 1/4 W
    metal film, the other was a 100k 1/8 W carbon film. They were close
    enough in resistance on an ohmmeter to rule out resistance variation.

    The carbon film had 6 percent more voltage noise from essentially zero
    up to 20 kHz, give or take 1 percent. This is about 0.5 dB. Does
    anybody out there have a real "professional" spectrum analyzer or
    digital scope? This should be an easy measurement if you have the
    right equipment.

    I don't know if I would choose a metal film resistor in an audio
    circuit on this basis. If 0.5 dB makes a difference, then it may be a
    questionable design, since you can usually arrange matters so the
    front end op amp is the dominant noise source.

    Where I have seen it make a difference is in something like a
    transimpedance front end for optical detection, where the resistor is
    often the dominant noise source.
  17. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:tdWdnUrNUKgBDy3d4p2dnA@comcast.com...
    > > Cartridge loading is usually easy to fix,

    > But IME rarely fixed.

    Yes it's amazing how many people would rather buy a new pre-amp or
    cartridge, than a 10 cent capacitor :-)
    I buy cartridges based mainly on tracking performance (Shure V15VMR) then
    adjust loading to suit.

    > > and IME freq response
    > > errors are usually much less than the variation in the records
    > > themselves.

    > However, that doesn't let them off the hook. If they are audible then they
    > represented undesirable changes in sound quality.

    But how are they audible, only when doing a direct comparison with something
    else?
    Which then is the more accurate? How do you know? Does it matter if it
    sounds good to you?

    > > Worrying about variations less than 1-2 dB is a waste of time IMO.
    > It very much depends where those 1-2 dB are.

    Not at all, since the records frequency variation will be all over the
    place. Simply adjust tone controls to taste. That's what the mastering
    engineer does anyway!

    > Take a listen to the differences from variation that size that you can
    hear
    > in musical samples you can download from
    > http://www.pcabx.com/technical/dips_pips_tips/index.htm , particularly the
    > ones I call "tips".

    When listening to records I don't usually ABX them to the master tapes. So I
    have no idea which pressings are more accurate. Only which sound better to
    me at the time.

    > IME mastering is often about broad but shallow changes in frequency
    > response.

    As is the response variation in most pre-amps.
    IME the mixing/mastering, total EQ will be *MUCH* greater overall. And not
    flat to any reference whatsoever.

    TonyP.
  18. Archived from groups: rec.audio.tech (More info?)

    TonyP wrote:
    > "Arny Krueger" <arnyk@hotpop.com> wrote in message
    > news:tdWdnUrNUKgBDy3d4p2dnA@comcast.com...
    >>> Cartridge loading is usually easy to fix,
    >
    >> But IME rarely fixed.
    >
    > Yes it's amazing how many people would rather buy a new pre-amp or
    > cartridge, than a 10 cent capacitor :-)

    Exactly.

    > I buy cartridges based mainly on tracking performance (Shure V15VMR)
    > then adjust loading to suit.

    Exactly. Mistracking is a lot harder to fix downstream than FR problems.

    >>> and IME freq response
    >>> errors are usually much less than the variation in the records
    >>> themselves.

    >> However, that doesn't let them off the hook. If they are audible
    >> then they represented undesirable changes in sound quality.

    > But how are they audible, only when doing a direct comparison with
    > something else?

    It's often apparent without comparison.

    > Which then is the more accurate?

    The one you get when you get the FR of the playback equipment right.

    > How do you know? Does it matter if it sounds good to you?

    I find that if you get the FR of the playback equipment right, more
    different recordings sound good to me.

    >>> Worrying about variations less than 1-2 dB is a waste of time IMO.

    > > It very much depends where those 1-2 dB are.

    > Not at all, since the records frequency variation will be all over the
    place.

    Right, but I find that there is a natural centerline out there someplace.

    > Simply adjust tone controls to taste. That's what the mastering
    > engineer does anyway!

    It's nice to be able to play a stack of recordings without constantly
    fiddling with the gear.


    >> Take a listen to the differences from variation that size that you
    >> can
    > hear
    >> in musical samples you can download from
    >> http://www.pcabx.com/technical/dips_pips_tips/index.htm ,
    >> particularly the ones I call "tips".

    > When listening to records I don't usually ABX them to the master
    > tapes. So I have no idea which pressings are more accurate. Only
    > which sound better to me at the time.

    Yes, but if you can tune the playback system so that it is closer to the
    median without adjustments, it takes less individual adjustment to sound
    right with a variety of recordings.

    >> IME mastering is often about broad but shallow changes in frequency
    >> response.

    > As is the response variation in most pre-amps.

    Exactly.

    > IME the mixing/mastering, total EQ will be *MUCH* greater overall.

    Not necessarily. While I'm not shy about applying eq, I often make
    recordings where many tracks if not the whole mixdown has minimal or zero
    eq.

    > And not flat to any reference whatsoever.

    We all carry a reference around in our heads - it's the composite of
    everything we've ever heard.
  19. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:IP6dnSdQi_yD2C7d4p2dnA@comcast.com...
    > > But how are they audible, only when doing a direct comparison with
    > > something else?
    > It's often apparent without comparison.

    Not sure how you would know whether it's the equipment or the record?
    If they put test tones on every record you may have a shot.

    > > Which then is the more accurate?
    > The one you get when you get the FR of the playback equipment right.

    Not necessarily. If the record has say 3dB droop at HF compared to the
    master tape, then the cartridge/pre-amp with a 3dB rise will be more
    accurate for that record.

    > > How do you know? Does it matter if it sounds good to you?

    > I find that if you get the FR of the playback equipment right, more
    > different recordings sound good to me.

    I already stated that you should set the response flat using a good test
    record. Then you can ignore the 1-2 dB variations from RIAA that your
    cartridge/pre-amp might have, safe in the knowledge that the records you
    play will be far more than that anyway. Compensate with EQ as necessary.

    > > Not at all, since the records frequency variation will be all over the
    > place.
    > Right, but I find that there is a natural centerline out there someplace.

    I don't, but getting as flat as possible with a test record, is a good place
    to start anyway.

    > > Simply adjust tone controls to taste. That's what the mastering
    > > engineer does anyway!
    > It's nice to be able to play a stack of recordings without constantly
    > fiddling with the gear.

    Of course you can, but that doesn't mean they will all sound similar in
    tone, or similar to what the mixing or mastering engineers heard. You can't
    even expect that from CD's.

    > > When listening to records I don't usually ABX them to the master
    > > tapes. So I have no idea which pressings are more accurate. Only
    > > which sound better to me at the time.

    > Yes, but if you can tune the playback system so that it is closer to the
    > median without adjustments, it takes less individual adjustment to sound
    > right with a variety of recordings.

    Of course, but that was never the argument.

    > > IME the mixing/mastering, total EQ will be *MUCH* greater overall.
    >
    > Not necessarily. While I'm not shy about applying eq, I often make
    > recordings where many tracks if not the whole mixdown has minimal or zero
    > eq.

    Sure, but that would be the exception, not the rule.

    > > And not flat to any reference whatsoever.
    > We all carry a reference around in our heads - it's the composite of
    > everything we've ever heard.

    Yep, and everybody's is different. To be a reference, you need a common
    standard.

    TonyP.
  20. Archived from groups: rec.audio.tech (More info?)

    TonyP wrote:
    > "Arny Krueger" <arnyk@hotpop.com> wrote in message
    > news:IP6dnSdQi_yD2C7d4p2dnA@comcast.com...
    >>> But how are they audible, only when doing a direct comparison with
    >>> something else?
    >> It's often apparent without comparison.
    >
    > Not sure how you would know whether it's the equipment or the record?

    Keep the equipment properly tuned up.

    > If they put test tones on every record you may have a shot.

    I do have a number of test records, spanning decades.

    >>> Which then is the more accurate?

    >> The one you get when you get the FR of the playback equipment right.

    > Not necessarily. If the record has say 3dB droop at HF compared to the
    > master tape,

    That would be an artistic choice made by the mastering engineer.

    >then the cartridge/pre-amp with a 3dB rise will be more
    > accurate for that record.

    That would be a FR error I seek to eliminate.

    >>> How do you know? Does it matter if it sounds good to you?
    >
    >> I find that if you get the FR of the playback equipment right, more
    >> different recordings sound good to me.

    > I already stated that you should set the response flat using a good
    > test record. Then you can ignore the 1-2 dB variations from RIAA that
    > your cartridge/pre-amp might have, safe in the knowledge that the
    > records you play will be far more than that anyway. Compensate with
    > EQ as necessary.

    Works for me, but I want to minimize the need for added eq.

    >>> Not at all, since the records frequency variation will be all over the
    >> place.

    >> Right, but I find that there is a natural centerline out there
    >> someplace.

    > I don't, but getting as flat as possible with a test record, is a
    > good place to start anyway.

    We kinda-sorta agree.

    >>> Simply adjust tone controls to taste. That's what the mastering
    >>> engineer does anyway!

    >> It's nice to be able to play a stack of recordings without constantly
    >> fiddling with the gear.

    > Of course you can, but that doesn't mean they will all sound similar
    > in tone, or similar to what the mixing or mastering engineers heard.

    I can if I presume he set up his playback system competently, and I do the
    same.

    > You can't even expect that from CD's.

    I surely expect that from CDs.

    >>> I don't usually ABX them to the master
    >>> tapes. So I have no idea which pressings are more accurate. Only
    >>> which sound better to me at the time.

    >> Yes, but if you can tune the playback system so that it is closer to
    >> the median without adjustments, it takes less individual adjustment
    >> to sound right with a variety of recordings.

    > Of course, but that was never the argument.

    I'm happy to be in agreement. ;-)

    >>> IME the mixing/mastering, total EQ will be *MUCH* greater overall.

    >> Not necessarily. While I'm not shy about applying eq, I often make
    >> recordings where many tracks if not the whole mixdown has minimal or
    >> zero eq.

    > Sure, but that would be the exception, not the rule.

    As I tune up my recording setup, its getting to be more of the rule.

    >>> And not flat to any reference whatsoever.
    >> We all carry a reference around in our heads - it's the composite of
    >> everything we've ever heard.

    > Yep, and everybody's is different. To be a reference, you need a
    > common standard.

    Well yes, but common experiences can be the basis for an approximate ad-hoc
    standard.
  21. Archived from groups: rec.audio.tech (More info?)

    Detector195@yahoo.com (Detector195) writes:
    > [...]
    > Where I have seen it make a difference is in something like a
    > transimpedance front end for optical detection, where the resistor is
    > often the dominant noise source.

    What about a differential receiver or instrumentation amplifier where
    you're trying to establish a given input impedance?
    --
    % Randy Yates % "How's life on earth?
    %% Fuquay-Varina, NC % ... What is it worth?"
    %%% 919-577-9882 % 'Mission (A World Record)',
    %%%% <yates@ieee.org> % *A New World Record*, ELO
    http://home.earthlink.net/~yatescr
  22. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:IP6dnSdQi_yD2C7d4p2dnA@comcast.com...
    > > But how are they audible, only when doing a direct comparison with
    > > something else?
    > It's often apparent without comparison.

    Not sure how you would know whether it's the equipment or the record?
    If they put test tones on every record you may have a shot.

    > > Which then is the more accurate?
    > The one you get when you get the FR of the playback equipment right.

    Not necessarily. If the record has say 3dB droop at HF compared to the
    master tape, then the cartridge/pre-amp with a 3dB rise will be more
    accurate for that record.

    > > How do you know? Does it matter if it sounds good to you?

    > I find that if you get the FR of the playback equipment right, more
    > different recordings sound good to me.

    I already stated that you should set the response flat using a good test
    record. Then you can ignore the 1-2 dB variations from RIAA that your
    cartridge/pre-amp might have, safe in the knowledge that the records you
    play will be far more than that anyway. Compensate with EQ as necessary.

    > > Not at all, since the records frequency variation will be all over the
    > place.
    > Right, but I find that there is a natural centerline out there someplace.

    I don't, but getting as flat as possible with a test record, is a good place
    to start anyway.

    > > Simply adjust tone controls to taste. That's what the mastering
    > > engineer does anyway!
    > It's nice to be able to play a stack of recordings without constantly
    > fiddling with the gear.

    Of course you can, but that doesn't mean they will all sound similar in
    tone, or similar to what the mixing or mastering engineers heard. You can't
    even expect that from CD's.

    > > When listening to records I don't usually ABX them to the master
    > > tapes. So I have no idea which pressings are more accurate. Only
    > > which sound better to me at the time.

    > Yes, but if you can tune the playback system so that it is closer to the
    > median without adjustments, it takes less individual adjustment to sound
    > right with a variety of recordings.

    Of course, but that was never the argument.

    > > IME the mixing/mastering, total EQ will be *MUCH* greater overall.
    >
    > Not necessarily. While I'm not shy about applying eq, I often make
    > recordings where many tracks if not the whole mixdown has minimal or zero
    > eq.

    Sure, but that would be the exception, not the rule.

    > > And not flat to any reference whatsoever.
    > We all carry a reference around in our heads - it's the composite of
    > everything we've ever heard.

    Yep, and everybody's is different. To be a reference, you need a common
    standard.

    TonyP.
  23. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:euudnQSQo5FZ5y7dRVn-sA@comcast.com...
    > > Not sure how you would know whether it's the equipment or the record?
    > Keep the equipment properly tuned up.

    Sure, but proves nothing by itself, without a reference for each recording.
    How do you know if it's supposed to sound like that, or the cutter or
    stamper is worn out?

    > > If they put test tones on every record you may have a shot.
    > I do have a number of test records, spanning decades.

    So do I, but I prefer to listen to music myself.

    > > Not necessarily. If the record has say 3dB droop at HF compared to the
    > > master tape,
    > That would be an artistic choice made by the mastering engineer.

    Or a worn cutter, stamper, stylus. Lot's of possibilities.

    > >then the cartridge/pre-amp with a 3dB rise will be more
    > > accurate for that record.
    > That would be a FR error I seek to eliminate.

    Fair enough, I seek maximum listening enjoyment. Each to his own.

    > > I already stated that you should set the response flat using a good
    > > test record. Then you can ignore the 1-2 dB variations from RIAA that
    > > your cartridge/pre-amp might have, safe in the knowledge that the
    > > records you play will be far more than that anyway. Compensate with
    > > EQ as necessary.
    > Works for me, but I want to minimize the need for added eq.

    No argument there, but I just smile at the people who play vinyl with all
    controls flat, and think they have a sound the same as the original :-)

    > > Of course you can, but that doesn't mean they will all sound similar
    > > in tone, or similar to what the mixing or mastering engineers heard.
    > I can if I presume he set up his playback system competently, and I do the
    > same.

    Were talking about vinyl here right?
    (I'll ignore speakers for the sake of argument)

    > > You can't even expect that from CD's.
    > I surely expect that from CDs.

    I won't ignore speakers and listening rooms here though. CD just eliminates
    part of the corruption chain.

    > > Yep, and everybody's is different. To be a reference, you need a
    > > common standard.
    > Well yes, but common experiences can be the basis for an approximate
    ad-hoc
    > standard.

    Yes, well, sorta, maybe :-)

    TonyP.
  24. Archived from groups: rec.audio.tech (More info?)

    "Arny Krueger" <arnyk@hotpop.com> wrote in message
    news:euudnQSQo5FZ5y7dRVn-sA@comcast.com...
    > > Not sure how you would know whether it's the equipment or the record?
    > Keep the equipment properly tuned up.

    Sure, but proves nothing by itself, without a reference for each recording.
    How do you know if it's supposed to sound like that, or the cutter or
    stamper is worn out?

    > > If they put test tones on every record you may have a shot.
    > I do have a number of test records, spanning decades.

    So do I, but I prefer to listen to music myself.

    > > Not necessarily. If the record has say 3dB droop at HF compared to the
    > > master tape,
    > That would be an artistic choice made by the mastering engineer.

    Or a worn cutter, stamper, stylus. Lot's of possibilities.

    > >then the cartridge/pre-amp with a 3dB rise will be more
    > > accurate for that record.
    > That would be a FR error I seek to eliminate.

    Fair enough, I seek maximum listening enjoyment. Each to his own.

    > > I already stated that you should set the response flat using a good
    > > test record. Then you can ignore the 1-2 dB variations from RIAA that
    > > your cartridge/pre-amp might have, safe in the knowledge that the
    > > records you play will be far more than that anyway. Compensate with
    > > EQ as necessary.
    > Works for me, but I want to minimize the need for added eq.

    No argument there, but I just smile at the people who play vinyl with all
    controls flat, and think they have a sound the same as the original :-)

    > > Of course you can, but that doesn't mean they will all sound similar
    > > in tone, or similar to what the mixing or mastering engineers heard.
    > I can if I presume he set up his playback system competently, and I do the
    > same.

    Were talking about vinyl here right?
    (I'll ignore speakers for the sake of argument)

    > > You can't even expect that from CD's.
    > I surely expect that from CDs.

    I won't ignore speakers and listening rooms here though. CD just eliminates
    part of the corruption chain.

    > > Yep, and everybody's is different. To be a reference, you need a
    > > common standard.
    > Well yes, but common experiences can be the basis for an approximate
    ad-hoc
    > standard.

    Yes, well, sorta, maybe :-)

    TonyP.
  25. Archived from groups: rec.audio.tech (More info?)

    Randy Yates <yates@ieee.org> wrote in message news:<brkceybs.fsf@ieee.org>...
    > Detector195@yahoo.com (Detector195) writes:
    > > [...]
    > > Where I have seen it make a difference is in something like a
    > > transimpedance front end for optical detection, where the resistor is
    > > often the dominant noise source.
    >
    > What about a differential receiver or instrumentation amplifier where
    > you're trying to establish a given input impedance?

    Ah, I had not thought of that application. And I think there are
    actually low inductance wirewound resistors on the market, where they
    run half of the turns backwards on the coil form.
  26. Archived from groups: rec.audio.tech (More info?)

    I just saw this thread and noted, by the way, prompt accurate information
    from IsaacWingfield responding to the original question.

    "Detector195" in news:6213f73a.0405251734.5d5d23e0@posting.google.com...
    >
    > . . . I took two resistors as
    > "signal sources" to compare their noise spectra.
    > One was a 100k 1/4 W metal film, the other was
    > a 100k 1/8 W carbon film.

    (Careful -- two variables changed at once. An issue of possible distraction
    to some readers, more really than of misleading conclusions.)

    >
    > The carbon film had 6 percent more voltage noise from essentially
    > zero up to 20 kHz, give or take 1 percent. This is about 0.5 dB.
    > Does anybody out there have a real "professional" spectrum
    > analyzer or digital scope? This should be an easy measurement
    > if you have the right equipment.

    Those data sound reasonable to me. Without going into details, I have done
    many measurements as queried above. I use some very exquisite equipment for
    low-noise measurements, some of the best available in the last few decades;
    we have a lab full of it for such purposes. (By the way, you generally want
    analog, or at least good-analog-front-end, instruments to measure low-freq.
    noise spectra with low floors. And/or, build outboard low-noise preamps for
    the purpose and keep them in the same lab.) My end applications were not
    specifically audio, but I measured in the same frequency range. (I was
    concerned with "making" resistors in monolithic form, and possible sources
    of "excess" noise).

    The whole issue here is the "excess" noise that Isaac Wingfield already
    concisely explained. Typically it arises not in uniform resistive materials
    but in interfaces between different materials, or between different crystals
    or clusters of material. Commercial component resistors of metal or metal
    film, common and fairly cheap anyway, have the general reputation of the
    lowest excess noise, followed by carbon film. Carbon composition resistors
    (polycrystalline I think, and very common construction for wired reasistors
    when I was younger) have the worst reputation.

    Issues of the power rating of a resistor are only peripherally related to
    its noise sources. Self-heating capable of significantly raising a
    resistor's Kelvin temperature (which is what counts) from the usual 300-350
    found in operating electronic equipment would mean that the resistor is run
    at a high power level, which argues independently for a higher power-capable
    resistor, regardless of noise considerations. (Resistors, like people, are
    most reliable when not overheated.)

    I still think Isaac Wingfield said it more concisely. -- Max Hauser
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