The JM47a is a high quality large diaphragm condenser microphone with Cardioid pattern. By using an FET device for the preamplifier circuit combined with a transformer-balanced output, we built a microphone that's destined to be an instant classic.
The capsule is made using a classic "center-electrode" design with dynamic feedback at the capacitor element. This insures that the JM47a will not exhibit low frequency "boominess" or distort as readily at high SPL. The diaphragm is manufactured from micro-fine Mylar, which is in turn gold sputtered. The body is machined from high-grade brass, with audio connection via a 3 pin XLR connector at the base. High Pass Filter and Pad switches increase the flexibility of this versatile microphone.
ThreeQ:
Built into a compact ½ rack chassis, we used the same Burr-Brown IC's for the Mic Pre that you'll find in our more expensive studio channels. We then added an extremely musical EQ section and an optical Compressor, for that signature "Meek" sound.
Features:
JM47A
Frequency response substantially flat 20Hz to 20KHz
Sensitivity approx. -36dBV
Output impedance 200 ohms transformer balanced
Recommended load impedance 2Kohm
Signal to noise ratio 74dB
Dynamic Range 126dB
ThreeQ
Input impedances: Mic: 1.2kohm; Line: 20kohm
Pre-amp overall gain: 0dB to 60dB
Common mode rejection: 70dB
Equivalent input noise: -128.5dBu (unweighted)
Distortion: 0.001% (below Compressor threshold)
Frequency response: 10Hz to 70kHz (-3dB)
Maximum input before clipping: Mic: +19.5dBu; Line: +44.5dBu
Headroom before clipping: +19.5dBu
Compressor threshold: +∞dBu to -20dBu (variable)
Compressor ratio: 5:1 (typical)
Compressor attack time: 1 msec to 100 msec (adaptive)
Compressor release time: 0.1 sec to 3 sec (adaptive)
EQ Boost and Cut: +/-15dB (zero phase-shift bell response)
LF Frequency: 80Hz (fixed)
MID Frequency: 300Hz to 5kHz variable
HF Frequency: 12kHz (fixed)
EQ “Q”: 0.9 (1.6 octaves)
Output Gain: -∞dBu to +16dBu (variable)
Nominal output levels: +4dBu/-10dBv (selectable)
Output impedance: 75ohm
Output Level switch: 12dB attenuation
Noise Floor: -85dBu (typical, with ~40dB mic gain)