Also... Was there a capacitor issue with the original duo? I mean, sure they started failing 20 years later.... But in the early 90s they should have been solid, no?
Exactly what I was thinking, first I heard of Duo capacitor problems was in the 2000s.
Also as far as I remember reading at the time the Duo-R was a cheaper replacement for original Duo. As in the Duo-R had cheaper components, so it retailed for cheaper. Just turned out 20 years later that the capacitors were actually better in the Duo-R. But this was not NEC's intention, they thought they were making a cheaper model. I only mention this as Ian says in the video the point of NEC releasing the Duo-R was to improve the capacitors, this was not the case.