Universal Audio 710 Twin-Finity Single-Channel Tube & Solid State Mic Pre/DI The 710 Twin-Finity™ is a radically new UA pre-amp design which uniquely combines both the classic retro warmth of UA tube design and the transient bite of solid-state in a 2U, half-rack, all-metal chassis. The 710 was created specifically to add the tonal versatility and sonic inspiration missing from generic audio interface preamps.