Royer Labs DB20 dBooster

Royer Labs dBooster (R-DB20) is a phantom-powered in-line microphone signal booster designed for use with passive ribbon and dynamic microphones of low sensitivity. The device performs two functions simultaneously: it amplifies the signal level by a switchable 12 or 20 dB, and it acts as an impedance buffer — a high input impedance (3.6 kOhm) minimizes loading (damping) on the transducer, while a low output impedance (300 ohms) allows the device to drive difficult loads such as microphone splitters, vintage-style preamps, and audio interfaces without level loss, increased distortion, or reduced headroom. The Class A input stage delivers gain without coloration or self-distortion. Built in the USA at Royer's Burbank facility.

Two gain settings and high input impedance

The problem with passive ribbon microphones in typical signal chains is not only insufficient preamp gain — equally common is impedance mismatch. Most preamps present input impedances below 1.5 kOhm, which for a passive ribbon means excessive damping, loss of low end, reduced sensitivity, and overall tonal degradation. The dBooster's 3.6 kOhm input presents the optimal load to the ribbon element, while its low-impedance output (300 ohms at the 20 dB setting) buffers the microphone from any downstream impedance variations at the preamp, splitter, or interface. The 20 dB setting is intended for quiet sources and ambient recording with low-sensitivity ribbons such as the R-121, R-10, or SF-12; the 12 dB setting handles louder sources (electric guitar, vocals) where an additional 20 dB risks overloading the preamp input. Switching gain settings produces a pop — change at reduced signal level. The low-impedance output also drives long cable runs and difficult loads without signal degradation.

Electrical isolation and phantom power operation

The dBooster provides complete electrical isolation between its input and output stages — protecting the ribbon element from phantom power present in the downstream signal chain and eliminating damage risk from miswired cables. Power comes exclusively from 48V phantom on the output side (console, preamp, interface); the microphone input side remains free of voltage. The device is equally effective with high-output-impedance, low-sensitivity dynamic microphones (SM7, RE20, and similar), passive DI boxes with piezoelectric transducers, and in setups requiring long cable runs on the output side. Self-noise is below 11 dBa at the 20 dB setting and below 15 dBa at the 12 dB setting, referenced to -48 dB re. 1V/Pa. THD+N is 0.0015% at 20 dB and 0.001% at 12 dB.

KEY FEATURES

• In-line microphone signal booster and impedance buffer, phantom 48V powered
• Switchable gain: 12 dB or 20 dB (front panel switch)
• Class A input stage — gain without coloration or self-distortion
• High input impedance: 3.6 kOhm — minimizes transducer loading and damping
• Low output impedance: 300 ohms — drives splitters, vintage preamps, audio interfaces
• Full electrical isolation — protects ribbon element from downstream phantom power
• Headroom: 127 dB (20 dB gain) / 120 dB (12 dB gain) — ref. -48 dB re. 1V/Pa and 4 mV/Pa
• Self-noise: below 11 dBa (20 dB) / below 15 dBa (12 dB)
• THD+N: 0.0015% (20 dB) / 0.001% (12 dB)
• IM Distortion: below 0.002% @ 800 mV output (20 dB) / below 0.005% @ 2.6V output (12 dB)
• Frequency response: 20 Hz – 20 kHz +/- 0.25 dB
• Output can drive an audio interface or mic preamp directly
• Works with: Royer R-121, R-10, SF-12, and other passive ribbons; SM7, RE20, and other dynamics; passive DI with piezo transducers
• Built in the USA (Burbank, California)

TECHNICAL SPECIFICATIONS

• Type: in-line microphone signal booster / impedance buffer
• Gain: 12 dB or 20 dB (switchable)
• Input stage: Class A
• Input impedance: 3.6 kOhm
• Output impedance: 300 ohms (20 dB setting)
• THD+N: 0.0015% @ 20 dB (-25 dBu input, 1.3 Vp-p output) / 0.001% @ 12 dB (-6 dBu input, 3.66 Vp-p output)
• IM Distortion: below 0.002% @ 800 mV output (20 dB) / below 0.005% @ 2.6V output (12 dB)
• Self-noise: below 11 dBa (20 dB) / below 15 dBa (12 dB) — ref. -48 dB re. 1V/Pa
• Headroom: 127 dB (20 dB gain) / 120 dB (12 dB gain) — ref. -48 dB re. 1V/Pa and 4 mV/Pa
• Frequency response: 20 Hz – 20 kHz +/- 0.25 dB
• Connections: balanced XLR (Pin 1 Ground, Pin 2 Signal Hot, Pin 3 Signal Cold)
• Power: 48V phantom
• Current draw: approximately 5 mA (zero signal) / 7.5 mA (full output)
• Dimensions: 92 mm (L) x 51 mm (W) x 41 mm (H)
• Weight: 170 g (6 oz)
• Warranty: 1 year