You will need a separate Phono Stage if you want to use any balance device with your existing Hegel, and then, TT, CD, Stream, you will need 3 Line Level inputs.
The Chase unit would work very nicely for that.
I wrote this seller, it behaves normally when plugged in, (flashing lights, power button stops flashing) I think seller is correct, it is new, best ’buy it now’ price for new I ever saw, if I didn’t have 3 already I would buy it
https://www.ebay.com/itm/267585317801?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=b866789a-1255-11f1-bfbd-313738333733
Or, use the Hegel for amp and it’s phono like now, but get a separate Headphone Amp, downstream from a balance control you add like the Chase.
The Chase has two identical line level outputs labled 'front' and 'rear', but they are identical, from the early quad idea, simply 4 speakers. You could use the Hegel's line out, fixed or variable to feed the headphone amp.