Re: M-Audio Microtrack?


"David Satz" <DSatz@xxxxxxx> wrote...
Richard, the generalization at the end of your message is a bit too
broad; there are in fact 12 Volt phantom-powered microphones that can
be damaged by at least one version of "standard" 24 Volt phantom
powering. (I put "standard" in quotes because 24-Volt phantom powering
is being ushered out of the relevant documents--it was a good idea that
unfortunately came along many years too late.)

If these microphones are damaged by 24V, you'd better put on
your protective gear and stand back if you should accidentally
plug them into "standard" 48V phantom power. How can any
microphone be called "phantom powered" if it is endangered
by *half* the normal phantom voltage?

Also, microphones that "refuse to work" aren't necessarily the primary
issue. It would be a blessing if microphones would simply shut
themselves off when the wrong powering was applied. The real problem
here for working engineers isn't the risk of damage, but that if a
microphone delivers a signal when it is turned on at an ordinary sound
pressure level, most of us will assume that it's working OK. With
substandard powering, it may well have 15 - 20 dB less operating
headroom than normal, but we probably won't find that out until that
high an SPL occurs--perhaps just when the concert performance starts to
get really interesting.

Of course. But then anybody who goes into a critical live
situation without checking out their rig first has just invited
Murphy to the party.


And then you don't know whether the microphone or the input has
overloaded. Of course if it's a unique live recording, it's ruined
either way but you do need to know which problem is occurring if you're
going to solve it for future recordings.

Should each end user have to test each of their microphones
for maximum undistorted SPL each time they connect that
microphone to a new recording device?

If they have a microphone that is known to be particular
about its phantom supply, or they know they are using
equipment with <48V phantom power (the MT2496 is
most certainly not the first, or even latest equipment to
run at something lower than 48V) it would seem prudent
to test these things. Otherwise we are just dumb appliance
jockeys if we are not applying some level of inteligence
to the exercise.

Most people can't do that, or won't take the time and
trouble.

People like that can buy their music pre-recored down
at the CD store (or steal it off the internet).
This is still rec.audio.pro, isn't it?

Nor should we need to do that. Standards aren't statements of
some wishful, ideal conditions. They're minimum statements about the
conditions that are necessary in order to avoid specific problems in
practical, working situations.

And yet we can identify dozens of microphones, some
with excelent reputations which seem to do just fine at
a fraction of the traditional 48V. And mic preamp inputs
which supply <48V have also been with us for decades.
Can someone explain why everyone is so fired up about
the MT2496? I don't get it. (Unless it is latent disappoitment
or something?)

Transistors are nearly 60 years old. 48V is a standard
from the days of our grandparents' firebottle equipment.

.

Relevant Pages

  • Re: Quick questions about phantom powering units
    ... The standard allows a microphone to draw as much as 10 mA. ... Some 48-Volt phantom-powered microphones draw ... A phantom power supply that you find on the market, ...
    (rec.audio.pro)
  • Re: The decibel
    ... measure the loss of signal over distance. ... power loss in a standard telephone line over the distance of one mile, ... What is wrong with my interpretation of what the "Phantom" posted? ...
    (rec.audio.tubes)
  • Re: The decibel
    ... measure the loss of signal over distance. ... power loss in a standard telephone line over the distance of one mile, ... What is wrong with my interpretation of what the "Phantom" posted? ...
    (rec.audio.tubes)
  • Re: repairing an electret microphone
    ... Antenna amplifiers, satellite LNBs, cable ... references to the technique of phantom powering in these applications. ... Phantom powering was first used by the telephone industry long before TV ...
    (sci.electronics.repair)
  • Re: repairing an electret microphone
    ... If the cable TV industry - hardly a bastion of good ... "phantom powered" had some particular meaning, ... That is called line powering. ... Phantom power doesn't - only to those devices configured to ...
    (sci.electronics.repair)