Avalon U5 DI
The U5 high-voltage DI-preamp combines a unique passive tone selector with a variable gain preamp and filter. The high input impedance accepts a wide variety of signal levels and instruments from acoustic guitars to high-output active bass guitars and keyboards. The U5 direct box is loaded with sonic character and user features professionals demand.
Valvotronics TAD
Mains powered, custom built, classic valve DI, perfectly suited to bass. These classy DI’s were the input of choice for a number of sound designers internationally and have a unique warm sound. See the review below for more information.
“the Valvotronics DI is simply the best DI box that I have heard yet on bass…” - Larry Crane, tapeop.com
https://tapeop.com/reviews/gear/35/tube-amplified-direct-box/
A Designs REDDI
THE A designs REDDI Tube Direct Box is a unique unit. By "unique" we mean the effort placed into the REDDI to produce a sound and character all its own. That effort took A Designs Audio back to a place in time when the Ampeg B15 reigned supreme – making liberal use of tubes and transformers. The A Designs REDDI endeavors to not only rebuild that tone, but also bring that sound to pro audio. Plug a Bass into a REDDI and it's a step back in time. Thick, round, solid sounding Bass notes that sit perfectly in the mix. A Designs REDDI is also great for guitars, synths, and any other electronic instrument that requires a direct box for recording. In fact, some recording engineers have said that REDDI is the "best tube DI ever made.”
Radial Engineering
There’s a reason that System Sound has such a large collection of Radial products. These DI’s are robust, reliable and sound great. We have a variety spanning from active multi channel units to single passive DI’s.
Our range includes the JD6, RadialJDI, JDI Duplex, RadialPro RMP and RadialPZ-DI.