Grace Design m501 is a single-channel microphone preamp in the 500 Series format, the modular version of the respected m101 preamp. A balanced, transformerless design with a trans-impedance (current feedback) gain core delivers the same transparency and detail as the larger Grace Design preamps, in a format that fits any 500 Series rack.
Transparent capture of the source
Most 500 Series modules colour the signal, which with a good microphone and considered placement robs the recording of fidelity. The m501 is designed the opposite way: to reproduce the source with minimal coloration and distortion. The trans-impedance architecture maintains a nearly constant bandwidth across the entire gain range, improving dynamics without adding a metallic, solid-state character. 0.5% tolerance metal film resistors and a 12-position gold-plated rotary gain switch give precise, repeatable channel settings.
Ribbon mode and instrument input
An engineer recording with ribbon microphones risks damaging the delicate ribbon with phantom power. The m501 has an exclusive Ribbon mode activated with a single push: it raises the input impedance from 8.1 kΩ to 20 kΩ, bypasses the coupling capacitors and locks out 48 V, protecting the mic and also optimising dynamic mic performance. A Hi-Z 1/4" instrument input with 2.5 MΩ impedance lets you record guitar or bass directly, and a 75 Hz high-pass filter removes boom and rumble before the recording chain.
KEY FEATURES
- Single-channel microphone preamp in the 500 Series format
- Modular version of the m101 preamp
- Balanced, transformerless trans-impedance architecture
- 12-position gold-plated gain switch plus 0 to 10 dB trim
- Exclusive Ribbon mode with phantom lockout and raised impedance
- Hi-Z 1/4" instrument input on the front panel
- 75 Hz high-pass filter, 12 dB/octave
- 0.5% tolerance metal film resistors
- LED indicators for 48 V, Ribbon Mode and HPF
TECHNICAL SPECIFICATIONS
- Manufacturer: Grace Design
- Type: single-channel 500 Series microphone preamp
- Architecture: balanced, transformerless, trans-impedance
- Gain range: 10 dB to 75 dB (10-65 dB rotary in 5 dB steps plus 0-10 dB trim)
- Ribbon mode: impedance raised from 8.1 kΩ to 20 kΩ, 48 V lockout
- Hi-Z instrument input: 2.5 MΩ unbalanced / 5 MΩ balanced, gain -10 to +55 dB
- Filter: HPF 75 Hz, 12 dB/octave
- Phantom power: 48 V switchable
- Gain control: 12-position gold-plated rotary switch
- Components: 0.5% metal film resistors
- Output: balanced XLR (via 500 Series frame)
- Manufacturer warranty: 5 years
