I have preamp circuit from an earlier project that is based on TL072 opamps. I have been using it with a 9 V (+-4.5 V) power supply, but now I have the chance to give it a +-9 V supply. The signal that goes through it is a small audio signal, probably never larger than 1 V. Does it make any sense to bother giving it a larger supply voltage? (I know that the minimum supply voltage for this IC is 7 V (+-3.5 V) by the datasheet.)
The datasheet I have for TI's TL07x series tells me that the minimum supply voltage is 10V(+-5V).
That, combined with the common-mode input range and max output swing, means that you're lucky your existing circuit works at all (and might not work if you drop in a different TL072 from a different production batch).
If you have 18V(+-9V) available I would definitely make use of it.