TRUE BLUE 520 Precision Mic Preamp

The CL-520 is a next-generation microphone preamp created through a collaboration between Cloud Microphones and True Systems, combining Cloud's relentless focus on high-quality, low-noise gain staging with True Systems' 20+ years in high-end studios, live sound, and post-production environments.

Designed for stunning musical accuracy, the TRUE BLUE 520 captures sound with exceptional depth, clarity, and dimension without relying on coloration or exaggerated character. The fully balanced topology provides outstanding low THD+N, wide bandwidth, and fast transient response, ensuring reliable signal integrity in any recording environment.

What you hear is what you capture. Focus on the performance, the mic placement, the source. The TRUE BLUE 520 delivers exactly what's in front of the microphone.

Performance Features:

- Extended 76 dB gain range
- Musically tuned variable high-pass filter
- Dedicated Dynamic and Ribbon Mode with optimized impedance and signal path for passive microphones
- Cloud Touch Interface (patent pending) activate high-grade telecom relays for precise, reliable signal switching
- The TRUE BLUE 520 is engineered to sound finished from the source: record-ready.

Capacitive Touch Controls:

+16: Adds +16dB of gain, extending the preamp's maximum gain from 60 dB to 76 dB for low-output microphones.

Phase: Inverts signal polarity by 180° to correct phase relationships when using multiple microphones.

HPF: Enables a variable 6 dB/octave high-pass filter adjustable from 25 Hz to 420 Hz.

48V / Dyn RIB: Engages 48V phantom power for condenser microphones. When disabled, Dynamic Ribbon Mode is automatically enabled, removing input capacitors and increasing input impedance from 5 kΩ to 10 kΩ for optimal dynamic and ribbon mic performance.

Gain Range
6 dB to 76 dB

Maximum Output Level
+26 dBu

Bandwidth
-3 dB: 6 Hz to 630 kHz
±0.25 dB: 10 Hz to 250 kHz

Phase Response
@ +26 dBu output
2.5°: 30 Hz to 20 kHz (40 dB gain)
2.5° @ 30 Hz, 3.3° @ 20 kHz (60 dB gain)

THD+N
< 0.0004% @ +28 dBu output

Intermodulation Distortion (IMD)
< 0.0005% (MOD) @ 40 dB gain

Equivalent Input Noise (EIN)
-133 dBu (unweighted, 20 Hz–20 kHz, Rs = 0 Ω)
-135 dBu (A-weighted, Rs = 0 Ω)

Slew Rate
54 V/µs

Common Mode Rejection Ratio (CMRR)
92 dB (30 Hz–20 kHz, +10 dBu CMV input)

Input Impedance
5 kΩ (phantom power engaged)
10 kΩ (Dynamic/Ribbon mode)

Next-generation precision mic preamp engineered by Cloud Microphones in collaboration with Tim Spencer of TRUE Systems

TRUE BLUE CL-520 Preamp is a precision 500-series mic preamp designed to deliver the highest possible level of sonic realism. It doesn’t color your sound - it reveals it with breathtaking clarity. Unlike traditional “transparent” preamps that can feel flat or lifeless, the TRUE BLUE 520 produces a stunning three-dimensional soundstage. Every nuance, transient, and harmonic is captured with remarkable resolution. You hear the microphone. You hear the talent. You hear the space - exactly as they truly are.

TRUE Legacy Reimagined - Built from a 25-year lineage with the TRUE Systems Precision 8 preamp with a proven history in live and studio performance (Kennedy Center, Warner Bros, Remote trucks at Coachella, Bonnaro, etc.), the TRUE BLUE preamps build upon the core of the TRUE designs utilizing modern innovation and technology to improve performance, reliability, and user experience.

Innovative patent-pending Cloud Touch Control System uses microprocessor controlled telecom-grade relays yielding 100x the reliability; expanding life cycle over conventional mechanical switching systems.

Illuminated interface is easy to see and intuitive to use, this is especially helpful in typical darker
studio environments

Ribbon/Dynamic Mode automatically removes front end phantom power circuitry, creating a capacitor-free front end, lowering distortion and raising the input impedance to 10kOhms.

Blink-Delay features prevent accidental engagement of Phantom Power and High Gain mode. The Phantom Power button must be held for 2 seconds, the LED will blink and go solid when it engages. This must be held to engage or disengage the +48v Phantom Power. This will prevent accidental damage to ribbon and tube mics, as well as unintentionally disengaging the phantom when being used.

High Gain mode provides an additional 16 dB of clean gain, bringing total available gain to 76 dB. The function is engaged by holding the button for three seconds, preventing unintended activation. The indicator will blink during engagement. High Gain can be disengaged instantly without delay, allowing immediate recovery if the added gain is excessive. This behavior helps protect monitors and speakers from sudden level changes while maintaining fast, intuitive control during use.

INSTRUMENT DI IN and THRU jacks act as a “split”, for simplified interconnections. The
instrument DI IN is routed to the preamp core while the THRU jack can pass the instrument
signal along to an external amp, or an additional DI signal path.

Powerful Focus with HPF control:
The continuously variable HPF provides precise control over low frequency content, making it especially effective for vocal applications where proximity effect can cause excessive low end buildup. With smooth adjustment from 25 Hz to 420 Hz, it allows targeted reduction of low and low mid frequencies that contribute to muddiness and plosives, without compromising the natural tone. This flexibility makes it easy to tailor the response to different microphone types and sources, helping maintain clarity across vocals, bass instruments, and other low frequency rich material.

Ultra-low noise floor throughout entire gain range, even when fully maxed

Three-dimensional high-resolution sound with stunning authenticity

Preserves true mic character with depth and musicality

Beautiful and Honest. Captures every detail as it truly sounds no hype, no smear

Cloud Touch Control System + relay architecture for high reliability

Capacitor-free, total DC signal path in Dynamic/Ribbon mode

Relays are placed exactly where signals switch, minimizing EMI

Blink-delay safety: prevents live pops and accidental dropouts

Illuminated interface for ease of visibility - studio and stage

TRUE Legacy with 25-year proven engineering lineage

“This preamp completely changed the way I think about transparency,” says Rodger Cloud, founder of Cloud Microphones. “It’s deeply authentic—like lifting a blanket off your sound. The preamp is designed to give you exactly what the microphone heard, what the talent produced, and what the acoustical environment allowed.

TRUE BLUE CL-520
Precision, Depth, and TRUE Reality.

Shipping

• Cost: Free standard shipping on all orders.
• Processing: 1–2 business days (excluding weekends/holidays).
• Transit: 3–5 business days via FedEx, UPS, or USPS.
• International: Customers are responsible for all customs, duties, and taxes.

Returns

• Policy: 30-day return window for unused items in original packaging (14 days for EU orders).
• Process: Contact support@cloudmicrophones.com for a free return shipping label.
• Fees: No restocking fees on approved returns.
• Refunds: Processed within 10 business days after inspection.