Could the fact that ne5534 is an audio amplifier be a source of the problem?
Wide Supply-Voltage Range ±3 V to ±20 V
Also, the NE5534 is rated for a minimum of +-3V, at least the On Semiconductor version is.
Large Supply Voltage Range: +-3.0 to +-20 V
Leaving very little overhead if running this from merely +-5V supplies.
Use a rail-to-rail opamp from 5V. How are you connecting the current transformer (that circuit appears to bea slice of a diagram for an electret condenser microphone amplifier).Does your CT have a built-in burden resistor? What value is it? You'll need to not load down thatburden resistor load significantly or you'll change the output level. Use a non-inverting opampcircuit to avoid loading the source perhaps?
Well you are not powering it correctly. The data sheet says:-So that means that 6V is the lowest voltage that it takes to drive correctly and you only have 5V.The Recommended Operating Conditions is a minimum of +5V and -5V, so you are way off that.
It will blow up your Arduino because the output will be over 5V. It needs to be reduced with a potential divider before feeding it into the Arduino.Why not just get a decent op-amp?