Presenting the m501, Grace Design's 500 series module version of the venerable m101 mic preamplifier. Now the signature transparency and detail of our circuit designs is available for your 500 series collection.
While the 500 series market has plenty of colored mic preamplifier options, the natural, musical clarity of the m501 makes it a welcome addition to the field. This circuit is for engineers confident with the quality of the source, mic section and placement, and wish to capture it with as little coloration or distortion as possible.
The m501 module is a balanced, transformerles design, with 48V phantom, a 75Hz HPF and a 1/4” HI-Z instrument input. Also standard is our exclusive ribbon mic mode, which raises the mic input impedance, bypasses the input decoupling capacitors and deactivates 48V phantom to protect delicate ribbon mics from damage.
Large diaphragm, vintage ribbon or trusty dynamic - the m501 brings out the very best in any microphone and takes the guesswork out of your input chain.
Features:
Fast and musical transimpedance architecture
Precision audio path with 0.5% precision metal film resistors
New 12 position gold plated rotary gain switch
High performance output line driver amplifier and HPF amplifier
New Ribbon mic mode (also great for dynamic mics) - Relay bypass of phantom power decoupling capacitors, increased input impedance, and 48V lockout
Wide 10-75dB gain range
Enhanced RFI interference suppression
Bombproof laser-etched black anodized frontpanel
Sealed gold contact relay for Hi-Z input switching
Led indicators for +48V, Ribbon mode, and HPF
20 year EON year warranty on parts and labor
Built in the USA
Specifications:
GAIN RANGE (5dB steps)
- Mic input 10-65dB
- Hi-Z input -10-45dB
Output trim control
THD+N 1kHz, 22Hz-22kHz BW
- @ 20dB Gain +20dBu out <0.00085%
- @ 40dB Gain +20dBu out <0.0010%
- @ 60dB Gain +20dBu out <0.0050%
INTERMODULATION DISTORTION
SMPTE/DIN 4:1 7kHz/50Hz
NOISE - REFERRED TO INPUT @ 60dB Gain
- 50Ω source <-130dB
- 150Ω source <-128dB
- 600Ω source <-124dB
CMRR, @60dB Gain, 3.5Vcm
- 100Hz >55dB
- 1kHz >75dB
- 10kHz >65dB
PHASE DEVIATION (HPF off)
- 50Hz-25kHz @40dB Gain <10
FREQUENCY RESPONSE
- Mic input @ 40dB Gain -3dB 3.8Hz-288kHz
- Mic input @ 40dB Gain -0.5dB 8.35Hz-135kHz
- Hi-Z input @ 20dB Gain -3dB 1.7Hz-180kHz
- Hi-Z input @ 20dB Gain -0.5dB 4Hz-72kHz
IMPEDANCE
- Mic input 8.1kΩ
- Mic input, Ribbon mode 20kΩ
Hi-Z input (unbalanced)
Hi-Z input (balanced)
Balanced Output
Unbalanced Output
PEAK LED METER
Green threshold
Red threshold
MAXIMUM OUTPUT LEVEL
- 100k Ohm load, 0.1% THD , 1kHz, API Lunchbox 27dBu
WEIGHT and DIMENSIONS
- 0.7 lb H5.25 x W1.5 x D6.6
- 316g H13.34cm x W3.81cm x D16.75cm
POWER CONSUMPTION
- Current required from +16V and -16V power supplies 120mA Max
