"David Farber" wrote in message ...

Gareth Magennis wrote:
"William Sommerwerck" wrote in message
...
"David Farber" wrote in message ...
William Sommerwerck wrote:

The 1/4" phone jack is (supposedly) a balanced line-level input. If
you plug a mono plug into it, the plug's sleeve will short the jack's
ring to ground. This is normal; there's nothing inherently wrong with
this. It's one way unbalanced signals can be connected to balanced
inputs.
http://www.behringer.com/EN/Products/B215.aspx
I suspect you have a problem that isn't really a problem.

Hi William,

I think if you take an ohmmeter and connect it to a speaker input,
and it measures the lowest reading that it can display, that would be
cause for concern. The only time this happens is when the stereo plug
is inserted into the jack even when the plug isn't connected to
anything. How do you perceive that this isn't a problem?
-------------------------------------------------

As far as I can tell, this isn't a speaker input -- it's a balanced
amplifier
input. There is no reason why a mono plug or stereo plug should show a
short.

Your description of what's going on seems inconsistent and confused.





William, why do you keep doing this?

If you had bothered to do your research properly you will have
discovered that the Behringer B215 is a loudspeaker.
It has no internal amplifiers, the jack sockets are simply in
parallel with the Speakon sockets and do exactly the same job.

Clearly there is a problem with the replacement jack socket that
seems to provide a short with a mono jack plug inserted in it.


David, my usual technique where the original socket cannot easily be
replaced is to simply use a chassis mounted switched jack socket hard
wired to the PCB, if space allows it, after carefully working out
what connections to connect to where.



Gareth.

Hi Gareth,

There is lots of space to drill a new hole and mount another jack. Then it
doesn't have to fit the pc board directly. Why would it have to be a
switched jack? What would it be switching?

Thanks for your reply.
--
David Farber
Los Osos, CA


A switched jack will just cover all possibilities. You can use the
switching or ignore it, the cost is pretty much the same.

I can't see how a switched jack might be used in this unit, but nor can I
see how inserting a mono jack plug into the replacement socket can cause a
short, so something in the wiring is amiss.

You might not need to drill a new hole, you may be able to fit the chassis
mounting socket in the original hole, and just run wires from it to the PCB.
Hot melt glue or silicone sealant will secure and insulate it.


Gareth.