I was hoping someone here could clarify a question about the maximum possible supply voltage to an opamp in a single supply design.
Via an 18V wall wart brick, or two combined 9V supplies from a Voodoo Power Supply, can I safely supply +18V in a *single-supply* design to the power rails of a TL071 or TL072 op amp?
The application is any homemade distortion / boost / overdrive pedals that utilizes the above opamp. All the capacitors have at least a 35v tolerance, so this question is not about capacitors, but specifically about the op amp in the circuit.
The opamp datasheet gives the following specs, and I need to really understand how to interpret this data:
Supply voltage: Vcc+ = +18V / Vcc- = -18V
Differential Input voltage: +/- 30V
Input voltage: +/- 15V
So in my single-supply design, I would have 0v to 18V, with a Vref (or Vbias) of 9V. This setup is somewhat standard in stompboxes. Just to be clear, I am NOT using a dual (aka bipolar) supply which would spread the 18 volts with a + 9V above zero, and -9V below zero.
I can interpret the above listed specs in two ways. Depending on which is correct, one says I am totally safe, the other says I am near the danger point:
1) If the opamp can tolerate the range of +/- 18V (or 36V total swing), and does not care if that voltage swings between -18V and + 18V, or let's say 0V and 36V, then my running the pedal between 0V and 18V is not even near the limit and I can safely do what I want to;
2) If the opamp can tolerate the range of +/- 18V with its swing above and below zero, but cannot go above +18V because the +18V is an upper limit (above which damage would occur to it), then running my pedal 0 to 18V will be right at the border of damaging it.
I hope this is clearly stated and that someone can share some insights about interpreting the datasheet specs. Thanks.