Hi,

I purchased a matched set of Earthworks SR 77's from eBay. When I tested
them I noticed one of the mics emits a buzzing sound when I touch the case.
If I touch the case with both hands the buzzing stops? Is there an
electrical problem with this mic? A bad ground perhaps?

Aside from that the mic seems to work ok and sound equal to the other one.

Please help...

Eric

Sounds to me like a ground issue at either the mic, or perhaps the cable, or
even at the mixer or preamp end. Try a different cable, then a different
input channel, and if the problem persists, check the XLR connector in the
mic itself and either fix it yourself or find an authorized repair center.
RON CHARLES

"Default User" wrote in message
...
Hi,

I purchased a matched set of Earthworks SR 77's from eBay. When I tested
them I noticed one of the mics emits a buzzing sound when I touch the
case.
If I touch the case with both hands the buzzing stops? Is there an
electrical problem with this mic? A bad ground perhaps?

Aside from that the mic seems to work ok and sound equal to the other one.

Please help...

Eric

Hi Ron,

Thanks for responding. I tried the mic on different channels and cables and
the problem was consistent. Its definitely the mic. I am going to call
Earthworks tomorrow to see what they suggest. I am really annoyed with
this....I've had great luck with eBay but I knew my time would come.

Eric

"Default User" wrote in message
...
Hi,

I purchased a matched set of Earthworks SR 77's from eBay. When I tested
them I noticed one of the mics emits a buzzing sound when I touch the
case.
If I touch the case with both hands the buzzing stops? Is there an
electrical problem with this mic? A bad ground perhaps?

Aside from that the mic seems to work ok and sound equal to the other one.

Have you tried switching the cables? The Earthworks may require pin 1 in the
XLR to be connected to the shield of the plug. (Some Neumanns do).
Otherwise, try measuring if there is connection between pin 1 and the case
of the microphone.

/Preben Friis

Default user wrote
Hi,

I purchased a matched set of Earthworks SR 77's from eBay. When I tested
them I noticed one of the mics emits a buzzing sound when I touch the
case.
If I touch the case with both hands the buzzing stops? Is there an
electrical problem with this mic? A bad ground perhaps?

Aside from that the mic seems to work ok and sound equal to the other one.

This sounds like a ground type thing. Is all your gear on the same power and
breaker? It's a good idea to install (or have instaled) a dedicated breaker for
all you audio gear.

Unfortunately I cannot get inside the case to repair it. The case appears to
be sealed shut. I tried calling Earthworks but all I got was voicemail. I
hope they return my call and/or email.

Eric

Default User wrote:

I purchased a matched set of Earthworks SR 77's from eBay. When I tested
them I noticed one of the mics emits a buzzing sound when I touch the case.
If I touch the case with both hands the buzzing stops? Is there an
electrical problem with this mic? A bad ground perhaps?

You SURE it isn't the cable?

Check with a meter and see if the case is connected to pin 1. Sounds like
it may not be. If not, you can use a cable with a jumper to do it (like
the Neumann mikes require).
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Default User" wrote in message
...
Hi,

I purchased a matched set of Earthworks SR 77's from eBay. When I tested
them I noticed one of the mics emits a buzzing sound when I touch the
case.
If I touch the case with both hands the buzzing stops? Is there an
electrical problem with this mic? A bad ground perhaps?

Aside from that the mic seems to work ok and sound equal to the other one.


Sounds like a ground isn't connecting to the mic body. This could be
because of your mic cable ( a screen connection not connected tp pin 1
maybe), or a fault in the mic, possibly a high resistance mechanical joint,
or a simple as a wire fallen off.

You could check with a meter both the pin1-pin1 on your cable, and pin1 to
case on the mic.


geoff

Default User wrote:
Hi guys,

I spoke with the tech at Earthworks (very nice folks there). Here is the
rundown:

With the tech on the phone giving instructions, I tested for continuity
between pin 1 (ground) and the screen on the capsule. The bad mic had NO
continuity and the good mic HAD continuity. The tech said the bad mic has
likely been dropped or received a significant impact which dislodged the
connection between the capsule and ground.

Since this an older model of the SR77, it is out of production and there are
no parts available for repair. The only option Earthworks offered was I send
the mics to them and they will replace them with a brand new pair for
$250.00.

Try using a cable with the shield tied to pin 1. If there is continuity
from the screen to the case, you'll be fine.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Default User" wrote in message ...
Unfortunately I cannot get inside the case to repair it. The case appears to
be sealed shut. I tried calling Earthworks but all I got was voicemail. I
hope they return my call and/or email.

You should try making an electrical connection between pin 1 and the
sheild/outside of your female XLR connector. No need to get inside the
microphone and thereby voiding your warranty.

Good luck.

Magnus Jansén

Scott Dorsey wrote:

Since this an older model of the SR77, it is out of production and there are
no parts available for repair. The only option Earthworks offered was I send
the mics to them and they will replace them with a brand new pair for
$250.00.

Try using a cable with the shield tied to pin 1. If there is continuity
from the screen to the case, you'll be fine.

Personally, since the mics are out of production and you got them
on Ebay (presumably for a good buy), I'd just dig into it if
at all possible. Grounding pin 1 to the case should be a very minor
repair. Any decent solder jock should be able to handle it.

Otherwise using a special cable that hooks pin 1 to the shell (which
then grounds the case) is the alternative if soldering mics makes you
paranoid.

Personally, if you like the mics, I'd make the repair. I can't see
how this would require any parts. Even if the mic used to be grounded
at the capsule and something broke off, it will work just as well
if you just ground pin 1 to the case some other way.

The only comment I'd make is that if the shock did something
such that the damaged mic doesn't sound like a matched pair
to the other one, THEN I'd send them back or get the new ones.

Benj

--
SPAM-Guard! Remove .users (if present) to email me!

In article writes:

Personally, since the mics are out of production and you got them
on Ebay (presumably for a good buy), I'd just dig into it if
at all possible. Grounding pin 1 to the case should be a very minor
repair. Any decent solder jock should be able to handle it.

Reading the reply from Earthworks, I understood that the problem was
that the capsule had lost its ground to the case. Since they suggested
that this was a result of physical damage or mishandling, I'm guessing
this isn't a soldered wire, but a mechanical fit which no longer fits.

I doubt that the seller will eat a $250 replacement cost, so I'd try
to return them and just be sure not to buy them again at another
auction. No doubt they'll show up for auction again if you're
successful in returning them and getting your money back.




--
I'm really Mike Rivers - )