CJ has been using relay / resistive ladder volume since the CT 6 maybe earlier. It is proven and in my opinion better than electronic volume controls like the ones CJ used when they built McCormack preamps. Those were a Burr Brown volume chip, I hated the volume control on my RLD 1 , in fact that was the shortest duration I have owned a preamp. I replaced it with a CJ Classic 2SE
My Zesto pre uses a motor that moves an analog volume pot. The IR circuitry has no effect on performance. I much prefer analog rotary volume knobs