I wouldn't rush on the sub. You can always see how it sounds without it and then decide.
I thought I was going to need one when I got my Cayin but now I honestly don't even feel like I'm missing all that much. I'd still like to try a really nice sub in my system one of these days but I can definitely live with what I have.
As far as connecting a sub goes there are a few ways. Some amps like my Cayin or most Antique Sound Labs models have RCA sub outs built into them (I believe the Jolida and Prima Lunas do not). If not you can just use speaker level inputs. You run an additional speaker line from the taps on your amplifier to the subwoofer's line level inputs (this doesn't affect your amp by drawing wattage or anything like that). A lot of quality subwoofers like REL or whatever have speaker level inputs so I don't think you should have any problems.
I thought I was going to need one when I got my Cayin but now I honestly don't even feel like I'm missing all that much. I'd still like to try a really nice sub in my system one of these days but I can definitely live with what I have.
As far as connecting a sub goes there are a few ways. Some amps like my Cayin or most Antique Sound Labs models have RCA sub outs built into them (I believe the Jolida and Prima Lunas do not). If not you can just use speaker level inputs. You run an additional speaker line from the taps on your amplifier to the subwoofer's line level inputs (this doesn't affect your amp by drawing wattage or anything like that). A lot of quality subwoofers like REL or whatever have speaker level inputs so I don't think you should have any problems.