Finally reached the shop today. What I needed wasn't the encoder-- that got replaced-- but the board that it attaches to. The tech hadn't heard anything and it hadn't arrived, so he called Tascam. The CS person became very apologetic when they found out he was asking about something from the "Model" series and said it would still take some time; after a little prodding they said that they're currently expecting the boards in October. So about 20 months from when the order was first placed.