Re: [Harp-L] XLR>1/4 inch IMT

["John F. Potts" <hvyj@xxxxxxx>]

GB,
	i have more experience as a musician than a technician,  and i have  
almost no experience w/ wireless units,  so I'd prefer to let others  
on the list with greater expertise  provide an explanation.  But it  
has  to do with ohms of the mic output and whether the signal is  
"balanced" or "unbalanced." The type of connector is NOT the  
controlling factor in determining whether you need an impedance  
matching transformer... and it's certainly NOT a dumb question.
	JP


On Sep 13, 2008, at 5:40 PM, gbuxman@xxxxxxxxx wrote:

> Ok, in the spirit of the old saying, "there's no such thing as a dumb
> question"...
>
> Why is impedence matching necessary?  What will happen if you don't  
> do it?
>
> I currently play through a Shaker dynamic mic, with a male XLR.  I
> specified this construction when ordering the Shaker because I wanted
> to use my Samson Airline wireless system with its female XLR
> transmitter.
>
> So I just use a cable that has a female XLR on one end, and a male
> 1/4" connector on the other. As far as I can tell it works fine.
>
> Thanks in advance.
>
> - GB
>
> On 9/13/08, John F. Potts <hvyj@xxxxxxx> wrote:
> > Rick.
> > 	As a long time devotee of non-bullet style mics for harmonica, I
> > have more than casual experience with XLR>1/4 inch impedance matching
> > transformers.  My cumulative wisdom on this subject  (for whatever it
> > may be be worth) is as follows:  The Radio Shack unit works fine, but
> > (like the Shure IMT) it is much longer than a standard 1/4 inch plug
> > as it protrudes from the input jack of your amp and is even more
> > lengthy with the output of the XLR cord connected to it.  This
> > creates  leverage that will put significant  pressure on the input
> > jack if the cord is pulled or the transformer  is bumped (as
> > inevitably happens) which  can and often will damage the jack on the
> > amp and/or bend the input plug on the transformer.  Accordingly, it
> > may be preferable he  to use a "pigtail" transformer on which the XLR
> > receptor is separated from the 1/4" jack with a short length of mic
> > cord, so only the 1/4 inch plug protrudes from the jack on the amp.
> > Peavey makes one and I am sure  other manufacturers do as well. I
> > also think they may be  easier to handle and carry around,.  But all
> > of the impedance matching transformers i have ever used sound fine
> > and about the same EXCEPT the pigtail transformer made by Audix.  The
> > one i tried produced a very weak signal that was significantly
> > diminished in volume and tone. I don't know if the particular Audix
> > transformer i tried was a defective unit or if they are all that
> > way.  The Audix transformer is a little pricey anyway, although
> > Audix does make some great mics. 	Hope this helps.
> > 	JP
> >
> > 	
> > _______________________________________________
> > Harp-L is sponsored by SPAH, http://www.spah.org
> > Harp-L@xxxxxxxxxx
> > http://harp-l.org/mailman/listinfo/harp-l