The Bool Audio Blog

Jan 2023 — Where it all began

I've been obsessed with the Naim Aro for a long time. First made in 1987, it remains one of the finest tonearms ever produced — a unipivot design so elegant in its simplicity that decades of engineering progress have done little to improve on it. The bearing has virtually no resistance, giving the arm a fluidity of movement that more conventional designs simply can't match. And the ability to remove the arm wand from the pivot in seconds — swapping between a mono and a stereo cartridge, for instance — is a practical luxury once you've lived with it. 

My obsession started about six years ago when I picked up a Lenco L75 transcription deck on eBay and decided the obvious thing to do was make a tonearm for it. An Aro-inspired unipivot, built on an old Tom Senior milling machine and an Axminster lathe, with my dad helping along the way. The catch: neither of us had ever actually seen a real Aro in person. We worked entirely from forum posts, online articles, and photographs — reverse-engineering something we'd never touched. 

It worked. Not perfectly, but well enough to prove the concept and spend a very satisfying year listening to music on the L75 with a tonearm we'd made ourselves.

That should have been the end of it. But once you've made one, you start to see what you'd do differently. My dad — who spends his working life solving complex engineering problems for aerospace and medical companies — became as interested in improving the design as I was. We started drawing up something new. Something with a proper integral arm lift. Better cartridge alignment. A cleaner anti-skate solution.

And then reality hit. With only an old manual mill and lathe between us, there was no way to make parts to the precision a commercial product demands. The time involved alone made it economically impossible. Something had to change.

Keep an eye out for the next chapter of the story.