Headphone Amp. Where to hook it up??

I have an Audiomat Recital integrated. I just purchased a headphone amp to try out, never had one before. How should it be hooked up so I can use the volume control on the Recital? Thanks in advance for your help!

Use the tape output or other fixed-volume output. Headphone amps often have a pass-through so you can still use the tape out for taping.
If you want to use the volume control of your integrated, than you'll have to connect your headphone amp to the integrated's pre-out, if available.
If not, then you may connect it to the tape loop out and use the headphone amp's volume control.