The minimum recommended supply voltage for a TL07x opamp is 7V so a 9V battery must be brand new.
Here is how an opamp with a dusl supply can be connected with a single supply:
I just saw your sticky. A couple of hours ago, I almost pointed out that if Audioguru ever loses that graphic, we're all screwed. You have saved us from that potential horrible fate!
Thanks a lot, I tried to make this configuration, but found it in another part of my circuit (reverb). It was there to supply TL072, so I will connect my 074 negative supply terminal to the same point. But I want to ask, is it save to load both 074 and 072 with the values in the attached configuration ?
The minimum recommended total supply voltage for the TL072 and TL074 is 7V. A 9V battery voltage quickly drops to 7V then drops slower to 6V when it is considered to be dead. It would be better to use two 9V batteries to give plus and minus 6V to 9V.