I NEED a conversion box like that, because I have a mini-din connector out of the back of the arm (mine's above the deck). Thus I have to convert from mini-din to rca, then rca out to the rca Phono inputs. Note: ground connection also needed.
Yours, please clarify:
mini din OR larger standard size DIN connector within/out of the tonearm?
If standard size DIN, then you can skip the conversion box and use a DIN to RCA Phono Cable (with ground wire).
Verify if your tonearm connector is female or male, get opposite din connector on the cable.
Long enough to reach from the arm to your phono stage inputs with a bit of slack for convenience. Anticipate potential relocation when choosing length.
IF you already had an RCA to RCA phono cable you like, or want, you can continue to use the existing conversion box. That's one more connection, however if not noisy now, like mine, not a real issue.