Unbalanced input throught INA103 ?

[bent]

Hello,

I would like to use the INA103 ( Burr-Brown) for a blanced mic, but i would like to have a unbalanced input (instrument) that i can send in the INA103 so i could use the +60db gain fonction.... And i want to disable the balanced input mic when i connect the unbalanced input...

So can i connect the +(pin2) of the xlr on the tip of 1/4 stereo socket jack ( the dead side),
the tip of the 1/4 jack (active side) goes to the +input (pin 1 of the INA103,
and the -(pin3) of the xlr connected to the ring (dead side) of the 1/4 stereo socket jack ,
the ring ( active side) goes to the -input (pin 16 of the INA103),
the sleeve (active side) goes to ground.

That way, when unbalanced 1/4 jack is not connected:
The XLR pin 2 (+) goes to input + ( pin 1 ) of the INA103 , passing by the tip of the 1/4 jack,
The XLR pin 3 (-) goes to input - ( pin16) of the INA103 passing by the ring of the 1/4 jack,

When i plug the 1/4 instrument in the 1/4 jack:
the XLR pin2 (+) and XLR pin 3 (-) are  not connected , leaving floating
The tip of the 1/4 instrument goes in the + input (pin1) of the INA103,
The - input (pin16) of the INA103 is grounded by the 1/4 ring connected to the sleeve of the 1/4 jack....

Is it the right way to do it ?Ad will it work ( do i ground the -input (pin16) when unblanced? )  

http://focus.ti.com/lit/ds/symlink/ina103.pdf    

Thank's
Bent

[PRR]

You don't need or want 60dB gain on an unbalanced hi-Z source.

Hi-Z sources are made hi-Z so-that they have "high voltage" and don't need gobs of gain.

An unbalanced hi-Z line will suck a lot of hum and buzz out of the air (balanced lo-Z resists this).

Moreover, the 103's low noise is true only for low-Z sources. It has huge input hiss current, which is shunted by a lo-Z source, but will induce large hiss voltage in a hi-Z source.

A TL072 can easily give 40dB gain, which is probably all you could need; and it gives good hiss performce for hi-Z sources. Aint expensive.

[bent]

A TL072 can easily give 40dB gain, which is probably all you could need; and it gives good hiss performce for hi-Z sources. Aint expensive.

thank's, do you have a schematic to help me out ! that have a pot to control the gain (level) !

bent

[bent]

A TL072 can easily give 40dB gain, which is probably all you could need; and it gives good hiss performce for hi-Z sources. Aint expensive.

thank's, do you have a schematic to help me out ! that have a pot to control the gain (level) !

bent

repost in case someone have a schematic...   

bent