A Helmholtz coil would require a current source rather than voltage source. The output voltage of the audio amplifier is proportional to the signal input voltage.

What you would need is an amplifier whom output current is proportional to the input voltage - voltage controlled current source. This can be done with an operational amplifier, but you should know more datails about the project setup - coil:

• max current
• inductance of the coil
• coil resistance
• do you want DC or AC coupling. DC would give you maximally flat response, but it needs a dual power supply.

A Helmholtz coil would require a current source rather than voltage source. The output voltage of the audio amplifier is proportional to the signal input voltage.

What you would need is an amplifier whom output current is proportional to the input voltage - voltage controlled current source. This can be done with an operational amplifier, but you should know more datails about the project setup - coil:

• max current
• inductance of the coil
• coil resistance
• do you want DC or AC coupling. DC would give you maximally flat response, but it needs a dual power supply.

A Helmholtz setup is usually used for "focusing" and analyzing the object's magnetic field density with its uniform magnetic field, feed by DC constant current. What is the goal of using AC filed in a Helmholtz setup?

It will probably need a high voltage operational amplifier to drive a high inductance coil, so I doubt the insulation could sustain it.