Op-amp voltage supply question

[JimmyM]

Does an Op-amp (if I'm going to power it with + & - supply) HAVE to be balanced? Does the V+ need to be almost exactly the same as the V- supply?

Can I use a +18V V+ and a -5V V-? I'll never need to the output to go below about -1V. But I'll need the output to go to around 15.5-16V. A pair of fixed regulators (LM7818 and LM7905) can supply the + and - rails.
The number of Op Amps to choose from is greater if I only have to use a V+ to V- diff of 22V versus 36V.

[Rerouter]

aslong as its within your minimum +- supply range, you will be fine, and if you dont have any reference to ground on the op amp, it doesnt have to be negative, unless you need a non rail to rail one to work to 0V

[ejeffrey]

Does an Op-amp (if I'm going to power it with + & - supply) HAVE to be balanced? Does the V+ need to be almost exactly the same as the V- supply?

No.  The supplies just have to be wide enough to support whatever input/output voltages you need, plus the appropriate margin for non rail-to-rail opamps.

[JimmyM]

Ehhhhxcelent.

Thanks, guys.