Multi-TT USB Interface
The DMK URIx devices are USB 1.1 sound cards. In order for USB 1.1 devices to talk to computers the data needs to be up converted using a Transaction Translator (TT) to USB 2.0. A Transaction Translator converts 1.1 packets to 2.0 packets in a serial queued fashion. Generally available USB 2.0 hubs contain 1 TT device, which for most applications is suitable as the latency induced when multiple devices attempt to talk at the same time goes unnoticeable. However, when translating audio packets, the latency induced when multiple audio devices are used at the same time can cause garbled audio.
We use a special USB hub called a Multi-TT USB Hub. This hub provides a dedicated TT to each port, meaning each audio interface has it's own dedicated translator from 1.1 to 2.0 giving much clearer audio when multiple repeaters are active at the same time.