I am trying to convert the output of a photomultiplier tube module (Hamamatsu HC120) which ranges from 0 to 10V to +-10V in order to fit the full dynamic range of a ADC (MCC USB-205). To do so, I've implemented the circuit below using a TI TL074CN op-amp in order to substrat 5V with a gain of 2. The following values are used:
V1: signal 0-10V
R1: 1.5 kOhm
R2: 0.75 kOhm
R3: 1.5 kOhm
R4: 3 kOhm
U1 : 12V
U2 : -12V
Initially, the signal voltage was set from 0 to 10V using an ajustable DC power supply, the output gave the correct +-10V range. However, when connecting the PMT module, the output of the circuit will only range from -10V to 5.5V.
At this point I've kind of run out of ideas to what could cause this. Some hypothesis I have included grounding problem or some current limitation from the sensor that saturates the output. I however lack the theoretical electrical engineering background to properly assess the problem.
How can this problem be solved?
Here are the full connections schematics. As shown, I've grounded everything together. Could this be a source of the problem?