Inverting buffer

[mookie]

I'm looking at building a version of the B Blender looper, but running at higher voltage and with a polarity inversion and high pass option on the loop. I'm having some difficulty getting a working inverting buffer. I've been experimenting and reading and currently have the following circuit on the breadboard.



I'm getting an output that is a clean inversion of the input but at 10% of the peak to peak voltage of the input.

Can anyone point me in the direction of the information I'm missing. All searches currently lead back to variations of the same circuit.

[mookie]

An additional point. I wired up the other side of the op amp, a TL072, as a simple non inverting buffer and the result is the same level of output. I'm wondering what I'm missing...

I've tried using lower values for the resistors from the input and feedback loop but that doesn't seem to effect the end result

Is it possibly a fault with the little battery powered signal generator I'm using and the loading of the op amp.

[anchovie]

Is it possibly a fault with the little battery powered signal generator I'm using and the loading of the op amp.

A sanity check for that would be to build a non-inverting buffer and see if you get a similar drop at the output. This would also verify the chip itself as there wouldn't be a direct passive connection in the result of it doing nothing.

[Gurner]

I'm looking at building a version of the B Blender looper, but running at higher voltage and with a polarity inversion and high pass option on the loop. I'm having some difficulty getting a working inverting buffer. I've been experimenting and reading and currently have the following circuit on the breadboard.



I'm getting an output that is a clean inversion of the input but at 10% of the peak to peak voltage of the input.

Can anyone point me in the direction of the information I'm missing. All searches currently lead back to variations of the same circuit.

I'd take that 560k off the +ve input pin (put it direct to ground)....re getting 10% output ....if I was a betting man, I'd say your resistors in situ aren't what you think you've used - double check them with a DVM.

As an aside, you're using dual supply (that takes me back "Everybody was King Fu fighting"), if you do ground the aforementioned +ve pin, the output will be 0V DC, so you can like lose the 10uf cap (almost certainly the follow on circuit will have a DC blocking cap anyway - not that there is any DC from this cct to block!)

[mookie]

It turns out I may just have been a bit sleepy. I always check resistors first as i don't trust myself to read the codes every time. What I didn't check was that both scope probes were set to x1. It was in fact working perfectly.
As were the three further circuits I built as sanity checks

Thanks for helping me in my moment of idiocy.