The old condenser mics - do they need maintenance...?

[PenttiL]

The good quality condenser mics as Neumann 89 , -84. Do they need some
maintenance, or just simply using them tenth years until they go out of
order on some day? I have used some of them tenths years without any
problem, inside the studio. The phantom has been on most of the
daytimes, sometimes through the weeks all day and night long. Only some
dust have been clean outside the microphone cover. Do they at least need
some measuring to know are the mics still on the same class as they have
been when they was new? The sound of the mics I can hear through the
mics seems to been exactly the same it was years ago, if I remember
right and my ears are still on the same condition as they were many
years ago...;-)

Can I do some measures myself? I have a good quality analogic
oscilloscope, function generator, other mics, Yamaha DM 1000 concole and
some other measuring tools. What do I will need more?

-P

[William Sommerwerck]

"PenttiL" > wrote in message
...
> The good quality condenser mics as Neumann 89 , -84. Do they need some
> maintenance, or just simply using them tenth years until they go out of
> order on some day? I have used some of them tenths years without any
> problem, inside the studio. The phantom has been on most of the
> daytimes, sometimes through the weeks all day and night long. Only some
> dust have been clean outside the microphone cover. Do they at least need
> some measuring to know are the mics still on the same class as they have
> been when they was new? The sound of the mics I can hear through the
> mics seems to been exactly the same it was years ago, if I remember
> right and my ears are still on the same condition as they were many
> years ago...;-)

> Can I do some measures myself? I have a good quality analogic
> oscilloscope, function generator, other mics, Yamaha DM 1000 concole
> and some other measuring tools. What do I will need more?

By "tenth years", I assume you mean "decades".

The electronics in condenser mics can fail. I've had bad transistors and
capacitors. The element might become dirty and need a cleaning.

But other than keeping them clean and checking them occasionally to see if
they're working correctly, there is no required regular maintenance that I
am aware of.

[Paul Stamler]

"William Sommerwerck" > wrote in message
...
> > Can I do some measures myself? I have a good quality analogic
> > oscilloscope, function generator, other mics, Yamaha DM 1000 concole
> > and some other measuring tools. What do I will need more?
>
> By "tenth years", I assume you mean "decades".
>
> The electronics in condenser mics can fail. I've had bad transistors and
> capacitors. The element might become dirty and need a cleaning.
>
> But other than keeping them clean and checking them occasionally to see if
> they're working correctly, there is no required regular maintenance that I
> am aware of.

What William said is right. Meanwhile, doing microphone measurements is
actually pretty difficult if you want to get accurate, repeatable results;
you need things like calibrated sound sources and either time-domain
spectroscopy equipment or an anechoic chamber.

Luckily, you won't really need to do that. If you have matched pairs, you
could mount them right next to one another, set two preamps for identical
gain (you may need a tone generator for that), go to the other end of the
room and shout. If the output levels are the same, then the mics are still
matched; if not, they aren't.

Peace,
Paul

[Scott Dorsey]

PenttiL > wrote:
>The good quality condenser mics as Neumann 89 , -84. Do they need some
>maintenance, or just simply using them tenth years until they go out of
>order on some day? I have used some of them tenths years without any
>problem, inside the studio. The phantom has been on most of the
>daytimes, sometimes through the weeks all day and night long. Only some
>dust have been clean outside the microphone cover. Do they at least need
>some measuring to know are the mics still on the same class as they have
>been when they was new? The sound of the mics I can hear through the
>mics seems to been exactly the same it was years ago, if I remember
>right and my ears are still on the same condition as they were many
>years ago...;-)

They're probably fine. Maybe they could do with a cleaning, maybe not.

Used to be you could just send them back to Neumann and they'd do a quick
sweep test and noise level test on them for free. Ask your Neumann rep
if they still do.

>Can I do some measures myself? I have a good quality analogic
>oscilloscope, function generator, other mics, Yamaha DM 1000 concole and
>some other measuring tools. What do I will need more?

An anechoic chamber. That's the hard part.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Fletch]

On Dec 18, 7:40 am, (Scott Dorsey) wrote:
> PenttiL > wrote:
> >The good quality condenser mics as Neumann 89 , -84. Do they need some
> >maintenance, or just simply using them tenth years until they go out of
> >order on some day? I have used some of them tenths years without any
> >problem, inside the studio. The phantom has been on most of the
> >daytimes, sometimes through the weeks all day and night long. Only some
> >dust have been clean outside the microphone cover. Do they at least need
> >some measuring to know are the mics still on the same class as they have
> >been when they was new? The sound of the mics I can hear through the
> >mics seems to been exactly the same it was years ago, if I remember
> >right and my ears are still on the same condition as they were many
> >years ago...;-)
>
> They're probably fine. Maybe they could do with a cleaning, maybe not.
>
> Used to be you could just send them back to Neumann and they'd do a quick
> sweep test and noise level test on them for free. Ask your Neumann rep
> if they still do.
>
> >Can I do some measures myself? I have a good quality analogic
> >oscilloscope, function generator, other mics, Yamaha DM 1000 concole and
> >some other measuring tools. What do I will need more?
>
> An anechoic chamber. That's the hard part.
> --scott
> --
> "C'est un Nagra. C'est suisse, et tres, tres precis."

I always wanted to build one of those, but found it to be more work
than I was willing to invest. Still... it would be fun.

--Fletch

[David Satz]

> Used to be you could just send them back to Neumann and they'd do a quick
> sweep test and noise level test on them for free. *Ask your Neumann rep
> if they still do.

Neumann USA has no electroacoustic test facilities whatsoever.
However, that isn't ordinarily an issue since they don't repair
capsules anyway. They can test the electronics of any of their
microphones with the special measurement test heads which they produce
in-house; if an amplifier checks out OK but the microphone doesn't
sound right, or if it fails the breath test or any other go/no go type
of tests that they try, they simply replace the capsule.

Capsules for the KM 84 are still available from Neumann, and by
general agreement are as good as they ever were; the U 89 is still a
current model.