From Cloud Microphones
The CL-520 Microphone Preamplifier / Instrument DI is engineered to deliver stunning musical accuracy, practical and innovative features, outstanding value, and long-term reliability. Every element of its design has been refined through extensive critical listening evaluations and comprehensive user feedback.
The CL-520 features an updated TRUE Systems preamplifier core design, providing ultra-high-resolution musicality and optimized performance with condenser microphones, dynamic microphones, ribbon microphones, and self-powered tube microphones. The original TRUE Systems preamplifier core has been trusted for over two decades in studio, live sound, post-production, and educational environments - supporting virtually every genre of voice and music production.
A unique illuminated Cloud Touch-ControlTM User Interface replaces conventional pushbutton and toggle switches. This advanced interface enables microprocessor-controlled, high-reliability telecom relays for signal and function switching, resulting in significantly shorter signal paths and reduced sensitivity to electromagnetic interference (EMI). The illuminated controls also enhance visibility of preamp status from a distance or in low-light environments.
To enhance operational safety, the CL-520 includes a Blink-Delay feature that helps prevent unintended activation or deactivation of Phantom Power and High-Gain modes.
When either function is selected, its status indicator briefly blinks as a visual warning before activation is engaged after a short delay.
The DI IN and THRU jacks function as a signal split for simplified system integration. The DI IN routes the instrument signal directly to the preamp core, while the THRU jack passes the signal to an amplifier, additional DI, or 500-series module without interruption.
The continuously variable High-Pass Filter (HPF) provides precise low-frequency attenuation across a range of 25 Hz to 420 Hz. This control allows fine adjustment to compensate for microphone proximity effect and is highly effective in reducing low-mid frequency buildup or “mud” in vocals, bass instruments, and other sources.
When the HPF is disengaged, the low-frequency response extends down to 6 Hz, ensuring full bandwidth performance.
Microphone Input
- Gain (MIC In)
-
- +6.5 to +60 dB (+16 high gain mode OFF)
- +22 to +76 dB (+16 high gain mode ON)
- Maximum Input Level @ min gain setting
-
- +21 dBu (60 dB range)
- +3 dBu (76 dB range)
- Input Impedance (MIC)
-
- 5.5 kΩ (+48V phantom power ON)
- 10 kΩ (+48V phantom power OFF — RIB/DYN mode)
- High Pass Filter (HPF)
-
- 25 Hz to 420 Hz, 6 dB/octave (HPF ON)
- 6 Hz (HPF OFF)
Direct Input (DI)
- Gain (DI In)
-
- 9 to +43 dB (+16 high gain mode OFF)
- +7.5 to +60 dB (+16 high gain mode ON)
- Maximum Input Level @ 20dB gain, +26dBu out
-
- +6 dBu in (THD+N = <0.0007%)
- Input Impedance (DI)
- 1 MΩ
Audio Performance & Distortion
- Frequency Response @ 40dB gain, +26dBu out
-
- 3dB BW: 6 Hz to 630 kHz
- Flatness: ±0.25 dB (10 Hz to 250 kHz)
- Maximum Output Level @ 40dB gain
-
- +28 dBu
- (THD+N = <0.0004%)
- CMRR @ 40dB gain, +26dBu out
-
- 92 dB
- (30 Hz to 20 kHz, +10dBu CMV in)
- Output Balance @ 40dB gain, +26dBu out
-
- 80 dB @ 1 kHz
- Phase Shift @ +26dBu
-
- 2.5° @ 30 Hz to 20 kHz (40 dB gain)
- 2.5° @ 30 Hz, 3.3° @ 20 kHz (60 dB gain)
- THD + N @ 40dB gain, +26dBu out
-
- <0.00036% @ 1 kHz, 20 Hz to 20 kHz (Note 1)
- THD @ 40dB gain, +26dBu out
-
- <0.0002% @ 1 kHz (Note 1)
- Intermodulation Distortion @ 40dB gain, +20dBu out
-
- <0.0005% MOD (u1–u9) (Notes 1, 2)
- <0.001% DIM 30 (Notes 1, 3)
- Noise Rs=0
-
- 133 dB unwtd (20 Hz to 20 kHz)
- 135 dB A-wtd
- Slew Rate
- 54 V/µS
Power & System
- Common Mode Output Offset @ max gain
-
- 40 mVDC
- Differential Output Offset @ max gain
-
- 5 mVDC
- Power Consumption +26dBu out
-
- +16VDC @ 80 mA, -16VDC @ 55 mA (10 kΩ load)
- +16V @ 90 mA, -16V @ 65 mA (1 kΩ load)
Free 3-Year Warranty
Sound Pure stands behind our products. Free three-year warranty on this item. Coverage exclusions live in Terms & Conditions, Section 27.
Level of support and expertise that simply isn't available at big-box megastores. Read the warranty →
Returns
Not eligible for Try Before You Buy or the 48-hour approval period. Standard return policy applies — see Terms & Conditions, Section 18 for details.
Sound Pure Studios · Durham, NC
Come hear it in our control rooms.
Sound Pure is a working studio in Durham, NC — a 1,000 sq ft live room and two pro control rooms. Book a session to audition gear in a world-class acoustic space before you buy.