Does the buzz happen in any location, or just in one. I was thinking some
kind of inductive or rf pick up in the particular location, after all, not
much to go wrong in this way is there?
Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Alan S." wrote in message
.145...
Is anyone here still using AKG C451 mics, or remembers using them?

I've had my 4 for some time but am becoming more and more aware of a low
level hum on the output. The hum gets worse the more of them that are
plugged in to the mixer. If only one is faded up, the hum gets worse as
others are plugged in. At first I thought the phantom power supply was
giving trouble but I have now tried them on two different mixers and a,
stereo, standalone mic pre-amp (M-Audio) with similar results. I wondered
if one of them was drawing too much current and dragging the PS down but
it
doesn't seem to matter which combination of mics I use. I think the hum is
100 hertz, which still suggests PS but on three differant i/ps?

Both mixers and the standalone are fine when used with dynamic mics.

The C451s are long in the tooth so are they prone to draw high current as
they age? Or am I barking up the wrong tree altogether?

Any suggestions, polite ones, would be appreciated.

Thanks.

Alan S.

"Brian Gaff" wrote in
m:

Does the buzz happen in any location, or just in one. I was thinking
some kind of inductive or rf pick up in the particular location, after
all, not much to go wrong in this way is there?
Brian


It has been apparent at two different locations in particular, both of them
CofE churches as it happens. It was, however, with the same mic cables. Can
I assume that the phantom power supply would not work if one leg or ground
is missing on the cable? They were each approximately 25metres.

Thanks for your thought, but to be pedantic, it is a hum, not a buzz. If it
was a buzz I'd be looking for things like lighting dimmer buzz etc.

Thanks again.

Alan S.

"Alan S." wrote in message
.145...
"Brian Gaff" wrote in
m:

Does the buzz happen in any location, or just in one. I was thinking
some kind of inductive or rf pick up in the particular location, after
all, not much to go wrong in this way is there?
Brian


It has been apparent at two different locations in particular, both of
them
CofE churches as it happens. It was, however, with the same mic cables.

Then I think the cables might well need looking at.

Can
I assume that the phantom power supply would not work if one leg or ground
is missing on the cable? They were each approximately 25metres.

If ground is missing the phantom power will not work. It will work if one
leg is missing, but you will get poor audio and added noise.


David.

"David Looser" wrote in
:

"Alan S." wrote in message
.145...
"Brian Gaff" wrote in
m:

Does the buzz happen in any location, or just in one. I was thinking
some kind of inductive or rf pick up in the particular location,
after all, not much to go wrong in this way is there?
Brian


It has been apparent at two different locations in particular, both
of them
CofE churches as it happens. It was, however, with the same mic
cables.

Then I think the cables might well need looking at.

Yes, it's looking that way. I'll bet there's a rogue somewhere! Now
where's my bright-eyes?



Can
I assume that the phantom power supply would not work if one leg or
ground is missing on the cable? They were each approximately
25metres.

If ground is missing the phantom power will not work. It will work if
one leg is missing, but you will get poor audio and added noise.


David.





Thanks again.

Alan S.

In article ,
Alan S. wrote:
It has been apparent at two different locations in particular, both of
them CofE churches as it happens. It was, however, with the same mic
cables. Can I assume that the phantom power supply would not work if
one leg or ground is missing on the cable? They were each approximately
25metres.

Seem to remember a one legged cable just results in a low output from a
451. Which may well give hum if you increase the gain for a distant mic.
Do you not have a 'bright eyes' phantom tester? Basically two leds built
into an XLR. If not contact me - I'm sure I've got a spare.

If you lose the screen you'll get no audio at all, IIRC.

--
*42.7% of statistics are made up. Sorry, that should read 47.2% *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...

Seem to remember a one legged cable just results in a low output from a
451. Which may well give hum if you increase the gain for a distant mic.


With a one-legged cable the audio must pass through the phantom power
supply, thus directly adding any hum or noise it creates to the audio. The
level will also be down.

If you lose the screen you'll get no audio at all, IIRC.

Because there will then be no phantom power at the microphone.

David.

"David Loser"


With a one-legged cable the audio must pass through the phantom power
supply,


** The OP is a ****wit TROLL

you ass.

Phil Allison wrote:
"David Loser"


With a one-legged cable the audio must pass through the phantom power
supply,


** The OP is a ****wit TROLL

you ass.


That is strange...how did you manage to climb out of my killfile ????

Ahh well, not to worry......plonk !

"Dave Plowman (News)" wrote in
:

In article ,
Alan S. wrote:
It has been apparent at two different locations in particular, both
of them CofE churches as it happens. It was, however, with the same
mic cables. Can I assume that the phantom power supply would not work
if one leg or ground is missing on the cable? They were each
approximately 25metres.

Seem to remember a one legged cable just results in a low output from
a 451. Which may well give hum if you increase the gain for a distant
mic. Do you not have a 'bright eyes' phantom tester? Basically two
leds built into an XLR. If not contact me - I'm sure I've got a spare.

If you lose the screen you'll get no audio at all, IIRC.


Thanks for the offer, Dave. I have got one somewhere, buried in the goodie
box. It's a long time since I used it - more than eight years since
retiring from TVC and Parkinson's means my days carting gear around are
probably numbered!

Now, where's the goodie box?

Thanks to all for your thoughts.

Alan S.

If you lose the screen you will probably get radio Moscow instead..grin.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Dave Plowman (News)" wrote in message
...
In article ,
Alan S. wrote:
It has been apparent at two different locations in particular, both of
them CofE churches as it happens. It was, however, with the same mic
cables. Can I assume that the phantom power supply would not work if
one leg or ground is missing on the cable? They were each approximately
25metres.

Seem to remember a one legged cable just results in a low output from a
451. Which may well give hum if you increase the gain for a distant mic.
Do you not have a 'bright eyes' phantom tester? Basically two leds built
into an XLR. If not contact me - I'm sure I've got a spare.

If you lose the screen you'll get no audio at all, IIRC.

--
*42.7% of statistics are made up. Sorry, that should read 47.2% *

Dave Plowman London SW
To e-mail, change noise into sound.