Subwoofer Connection: Speaker Level Amp to Line Level on Sub?

I often split the pre out to supply line level to both speaker amp and sub.

Your Prima has ’Tape Out’. That is the same as ’pre-out’, which is ’line-out’.

Your SUB has ONLY line-in/out (no alternate speaker wires in/out).

You can use the Prima Tape Out to go to the self-powered sub’s line-in. It has it’s own crossover so it ’ADDS’ ONLY low bass to your system as any sub is designed to do, job done!.
...........................................

Note: the Prima (40 wpc/8 ohms) will still amplify any source’s low bass (as well as everything else), and the Main Speakers will also try to produce all frequencies, therefore neither the amp or mains get a break from the low bass job.
...........................................

To give a low powered amp and smaller main speaker’s a break, (or because you are driving low sensitivity (efficiency) or low impedance mains perhaps) you need to get line level out, to a crossover (separate or in the sub) that takes the low bass. The crossover then sends all frequencies EXCEPT low bass via it’s line out back to the amp’s line level in (main-in, tape in, processor loop). Your Prima does NOT have tape-in, main-in, processor-in, so you cannot do this.

Raven says bass is 65% of power needs, which is why moving the job of low bass to the sub, and everything else BACK to the AMP is better than using speaker wires.

Line out/Line In (outsourcing the low bass job) is the best way to get more out of low powered amps, thus a great way to try tube amps.

Google is your friend.
speaker to line level output

Tape out is not the same as pre out. If you use tape out it will bypass the volume control on the EVO!

TAPE OUT or REC OUT take the signal before it's attenuated.  Tape recorders are built to handle this; not so much subs.  Which is why some preamps and some integrateds have more than one pair of PRE OUTs.