Amplifiers are now made in batches. An amplifier will be announced, be offered for presale, and then built in numbers to satisfy presale orders.
Each batch will be a unique offering, rotating through different models. If a specific model is offered again in the future, it will have a new color scheme, new artwork, or something else to distinguish it from previous and subsequent batches.
The D₂O Amplifier is being discontinued but will continue to be offered while supplies last. There are parts to make a couple more.