The new Grace Design m303 and m303s (stereo) are active, galvanically isolated DI boxes, delivering next-generation audio performance for all stage and studio applications. Our advanced power supply design provides incredible headroom and dynamic range, while the custom-wound Lundahl transformer outputs amazing low-end clarity and high frequency detail. All of this performance is packaged in beautiful and rugged ¼” extruded aluminum chassis. Don’t let the elegant exterior fool you, these things are built.

The m303’s sonic clarity and detail make it a FOH engineer’s best friend and keep large live productions sounding great. Any source on stage will benefit from the transparency and open musicality of the m303, from keys to passive bass to acoustic guitar. And the renowned Grace Design reliability will keep venues and stage crews happy for not having to throw another DI in the ‘dead’ bin. And now in Stereo!

For musicians, engineers and producers who want more flexibilty out of their DI recording duties, the m303 will make any direct instrument track sound detailed and alive, with robust low-end clarity. This allows for better downstream processing (saturation, compression, EQ), which results in better recordings and final mixes.

We knew we wanted the very best transformer in the m303. It had to be ultra-low noise and distortion and it had to sound great with killer low end. So the answer was clear: Lundahl. They are a world leading manufacturer of high performance transformers for pro audio applications and the very best choice for who could meet our (very picky) standards for what we needed in the m303.

• Mono and Stereo versions now available!
• Signature Grace Design transparent, musical audio performance
• Active design with true galvanic isolation
• World class Lundahl transformer
• Incredibly low distortion and noise with wide dynamic range
• Deep, rock-solid bass response
• 1M ohm input impedance, perfect for instruments with passive pickups
• Designed and built for years of reliability
• Backed by a 5 year warranty
• Made in the USA