


Grace Design m303 - Active Direct Box
Availability:
Special Order ItemThis item is not stocked and needs to be ordered from the manufacturer. Please contact our sales team for more information.

Description
The Grace Design m303 is an active, galvanically isolated DI box, delivering next-generation audio performance for all stage and studio applications. Its 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, this thing is built.
Features:
- Phantom powered active DI with full galvanic isolation.
- Custom wound Lundahl transformer, magnetically shielded high nickel core
- Ultra-low distortion (below -100dB at 1kHz, below -80dB at 50Hz)
- Ultra-low noise (-118dBu, A weighting)
- Ultra-wide bandwidth 20-80kHz
- Wide dynamic range (124dB)
- Excellent low frequency headroom THD+N @50Hz -80dB (0.007%)
- 1M Ohm input impedance works with any line or pickup signal source
- Peak indicator LED – 3dB before clipping
- Power indicator LED
- Efficient design only draws 4mA of phantom power current
- Through signal connector
- Fully ESD and RFI protected
- Input pad (13dB) for high level signals
- High-quality gold contact toggle switches
- Very rugged 1/4″ wall extruded aluminum chassis, recessed connectors
- Backed by a 5 year warranty
- Made in the USA
On Stage
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.
In the Studio
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.
Lundahl Transformer
Grace Design knew they 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 their (very picky) standards for what was needed in the m303.
Gain | Pad Off, 13.6k Ohm load -6dB Pad On, 13.6k Ohm load -19dB |
Frequency Response | ± 0.2dB (50½ source, 13.6k load) 82Hz-27kHz ± 3dB (50½ source, 13.6k load) 20Hz-80kHz |
THD+N 20Hz-20kHz BW | -10dBu out, 1kHz -102.8dB (0.00072%) -10dBu out, 50Hz -83dB (0.0073%) -10dBu out, 25Hz (10Hz-20kHz BW) -72dB (0.023%) |
High Pass Filter | 2nd Order, Bessel -3dB 20Hz |
Intermodulation Distortion -10dBu Out | SMPTE/DIN 1:1 (50Hz, 7kHz) -106dB (0.0005%) SMPTE/DIN 4:1 (50Hz, 7kHz) -99dB (0.0010%) |
Noise Ð Output Level 20Hz-20kHz | Pad Off, 50½ source -116.2dBu Pad Off, Input disconnected (equivalent to 330pF source) -112.3dBu Pad On, 50½ source -113.1dBu Pad On, Input disconnected (equivalent to 330pF source) -113d.0Bu |
Noise Ð Output Level A-weighted | Pad Off, 50½ source -118.6dBu Pad Off, Input disconnected (equivalent to 330pF source) -114.9dBu Pad On, 50½ source -115.5dBu Pad On, Input disconnected (equivalent to 330pF source) -115.2dBu |
Maximum Input Level (0.1% THD+N) | 1kHz, Pad Off 14dBu 1kHz, Pad On |
Maximum Output Level (0.1% THD+N) | Balanced, 1kHz, 13.6k½ Load 8dBu Balanced, 1kHz, 3.65k½ Load |
Impedance | Input Pad Off 1M½ Input Pad On 115k½ |
Power Supply | 48V Phantom Power, IEC 61938 |
Dimensions | 5.30ÓL x 3.19ÓW x 1.73ÓH (134mmL x 81mmW x 44mmH) |
Weight | 1.05lb, (0.48kg) |
The Grace Design m303 is an active, galvanically isolated DI box, delivering next-generation audio performance for all stage and studio applications. Its 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, this thing is built.
Features:
- Phantom powered active DI with full galvanic isolation.
- Custom wound Lundahl transformer, magnetically shielded high nickel core
- Ultra-low distortion (below -100dB at 1kHz, below -80dB at 50Hz)
- Ultra-low noise (-118dBu, A weighting)
- Ultra-wide bandwidth 20-80kHz
- Wide dynamic range (124dB)
- Excellent low frequency headroom THD+N @50Hz -80dB (0.007%)
- 1M Ohm input impedance works with any line or pickup signal source
- Peak indicator LED – 3dB before clipping
- Power indicator LED
- Efficient design only draws 4mA of phantom power current
- Through signal connector
- Fully ESD and RFI protected
- Input pad (13dB) for high level signals
- High-quality gold contact toggle switches
- Very rugged 1/4″ wall extruded aluminum chassis, recessed connectors
- Backed by a 5 year warranty
- Made in the USA
On Stage
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.
In the Studio
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.
Lundahl Transformer
Grace Design knew they 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 their (very picky) standards for what was needed in the m303.
Gain | Pad Off, 13.6k Ohm load -6dB Pad On, 13.6k Ohm load -19dB |
Frequency Response | ± 0.2dB (50½ source, 13.6k load) 82Hz-27kHz ± 3dB (50½ source, 13.6k load) 20Hz-80kHz |
THD+N 20Hz-20kHz BW | -10dBu out, 1kHz -102.8dB (0.00072%) -10dBu out, 50Hz -83dB (0.0073%) -10dBu out, 25Hz (10Hz-20kHz BW) -72dB (0.023%) |
High Pass Filter | 2nd Order, Bessel -3dB 20Hz |
Intermodulation Distortion -10dBu Out | SMPTE/DIN 1:1 (50Hz, 7kHz) -106dB (0.0005%) SMPTE/DIN 4:1 (50Hz, 7kHz) -99dB (0.0010%) |
Noise Ð Output Level 20Hz-20kHz | Pad Off, 50½ source -116.2dBu Pad Off, Input disconnected (equivalent to 330pF source) -112.3dBu Pad On, 50½ source -113.1dBu Pad On, Input disconnected (equivalent to 330pF source) -113d.0Bu |
Noise Ð Output Level A-weighted | Pad Off, 50½ source -118.6dBu Pad Off, Input disconnected (equivalent to 330pF source) -114.9dBu Pad On, 50½ source -115.5dBu Pad On, Input disconnected (equivalent to 330pF source) -115.2dBu |
Maximum Input Level (0.1% THD+N) | 1kHz, Pad Off 14dBu 1kHz, Pad On |
Maximum Output Level (0.1% THD+N) | Balanced, 1kHz, 13.6k½ Load 8dBu Balanced, 1kHz, 3.65k½ Load |
Impedance | Input Pad Off 1M½ Input Pad On 115k½ |
Power Supply | 48V Phantom Power, IEC 61938 |
Dimensions | 5.30ÓL x 3.19ÓW x 1.73ÓH (134mmL x 81mmW x 44mmH) |
Weight | 1.05lb, (0.48kg) |
Your home for all things pro audio—backed by expertise and experience. Connect with us today.
Your home for all things pro audio—backed by expertise and experience. Connect with us today.