The DSP-408 is excellent. I've been using four them for years in a 7.2.4 Dolby Atmos system. It's super quiet and completely audibly transparent to my ears. (I'm a retired broadcast TV production audio engineer.) Mine have been through the wars with lots of plugging and unplugging and one of the four units has developed jack issues due to all the abuse, so I just ordered a new DSP-408 to replace it. This is probably one of the best kept secrets in audio. I should send one in to Amir at Audio Science Review for a bench test. Highly recommended.
