Originally Posted by Bill_Todd
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Pickle, (continuing from other thread)
I've just found this: mic transformer adapter from a UK based supplier.
It has a very useful 10:1/1:1 transformer that would be idle as the core part in a mic/line input for the Axim.
Can you find anything similar in Canada at your local suppliers?
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Hi Bill
Yes - this adapter is a standard connector in recording music.
It's main purpose is to convert the 3-pin balanced cable of a mic cable to a 2-pin unbalanced signal to plug into mixing boards or other equipment.
Most equipment these days just has a plug to receive the 3-pin mic cables, & so wouldn't need this. I have 2 of 'em & yes - they will be used to plug any mic into the axims input...
A 3-pin mic gives out a BALANCED signal:
one of the pins is the normal signal
One of the pins is the ground
3rd pin is the signal again, but INVERTED. It is a mirror image of the normal signal. (180' inverted)
the balanced & normal & ground lines are carried through a standard mic cable from one end to other, straight through to where it is plugged in to.
On the receiving device, (including the one you've found) the inverted signal is flipped again, (Re-inverted) to be the same as the normal signal. Now, as a the signal travels along a long mic cable, it will just "pick up" noises -ie interference, static, humm & whatever. Both the normal & inverted signals as they travel through the cable will pick up the same noise as they run alongside each other.
When you re-invert the inverted signal, now the mic's original signal is the same again, but all the noise on both lines are now inverted to each other.
When these two signals are combined back together, they will either add together to be a stronger signal -the stuff you WANT, as it is now in phase, or they will CANCEL each other out - the noise -since it is now equal & opposite phase -
The Result: nice clean mic signal that has travelled a long way along a mic cable to a mixing board or some other equipment. (Usually NEEDED if the cable is 50ft or more)
This adapter you've found is for doing exactly that. It inverts one side, puts the two signals back together & cancels any noise & gives me a mono connector from a 3-pin cable so I can plug it in to something EXACLY like the Axim's mic in, provided the levels are compatible. I just need to add an adapter to shring the pin size to 3.5mm .
I dont really know if the Axim can handle this kind of signal since a simple headset mic is what its made for...a real mic signal may be much higher than that kind if thing.
I'm interested in also using a Guitar signal which is different again.
I should make a connector that is switchable from Hi-Z to Lo-Z (impedance)
to do both of those things.....
I'm looking into the Transformer you've found
Thank you very much !!
P