Hello. My name is Michael.
Typically, you would need a TAMB. I don't believe it is possible to just run a dry loop if that's what you mean.
If you are driving it directly from a fxs port or an extension port on an analog pbx, The tamb is an isolation device as well as impedance matching so its required. An alternate option you could hook this amp to a speaker out of a computer as long as you run it through a 8 to 600 ohm impedance matching transformer.