Wolff Audio RefPre – 500 Series Reference Microphone Preamplifier
The Wolff Audio RefPre is a high performance 500 series reference microphone preamplifier designed for engineers who require maximum transparency and precision. Featuring a transformerless signal path, stepped gain control from -10 dB to 60 dB, and a dedicated ribbon microphone mode with up to 70 dB of gain, the RefPre delivers exceptionally clean amplification for professional recording, sampling, and critical listening applications.
With advanced features such as a continuously variable output fader, switchable 80 Hz high pass filter, high impedance instrument input, polarity reversal, and protected 48 V phantom power, the RefPre provides flexible functionality while maintaining a highly accurate and uncoloured sound.
Ultra Transparent Transformerless Design
The Wolff Audio RefPre reference preamp is engineered to reproduce the sound of microphones and instruments with complete accuracy. Its transformerless design and carefully optimised signal path minimise distortion and coloration, ensuring that the original character of the source remains intact.
This makes the RefPre particularly well suited for high fidelity recording, acoustic instruments, classical sessions, sampling applications, and microphone modelling systems, where absolute signal integrity is essential.
The preamp provides up to 60 dB of clean gain, allowing it to work effectively with a wide variety of microphones while maintaining extremely low noise performance.
Dedicated Ribbon Microphone Mode
The RefPre includes a dedicated ribbon microphone circuit designed to optimise performance with passive ribbon microphones.
When ribbon mode is engaged:
Maximum gain increases to 70 dB
Input impedance is automatically optimised
Phantom power is automatically disabled to protect the microphone
This protection system ensures safe operation with delicate ribbon microphones while delivering the additional gain required for low output sources.
Precise Gain Control and Flexible Level Management
The Wolff Audio RefPre 500 series preamp uses a stepped rotary gain control with 10 dB increments, allowing engineers to recall settings easily and maintain consistent gain staging.
Additional level control features include:
±6 dB trim adjustment for fine gain control
Continuously variable output fader for precise signal level management
Switchable polarity for phase alignment
These controls provide detailed gain staging options, allowing engineers to optimise signal levels for different recording scenarios.
Exceptional Noise Performance and Headroom
The RefPre is designed for extremely low noise and high headroom operation.
Equivalent input noise of approximately -125 dBu
Distortion as low as 0.0005 percent at 60 dB gain
Maximum output level of +28 dBu
This performance ensures the preamp remains clean and stable even when working with high output microphones or demanding recording sources.
Wide Frequency Response and High Pass Filter
With a frequency response of ±0.5 dB from 10 Hz to 80 kHz, the RefPre captures the full detail of modern high resolution recording systems.
A switchable 80 Hz high pass filter with a 12 dB per octave slope helps reduce unwanted low frequency rumble, making it easier to maintain a clean and focused recording signal.
Flexible Connectivity for Microphones and Instruments
The Wolff Audio RefPre provides both front and rear microphone inputs, allowing easy integration into studio racks or portable recording setups.
The front panel also includes a high impedance instrument input with its own dedicated amplifier, making the unit suitable for direct recording of guitars, basses, and other instruments.
A mic or instrument selector switch allows users to quickly choose the active input.
Visual Signal Monitoring
A front panel signal indicator LED provides clear visual feedback during recording.
Green indicates an active signal
Red flashing at +18 dBu warns of approaching clipping
This simple metering system helps engineers maintain proper gain staging during sessions.
A True Reference Preamp for Modern Recording
The Wolff Audio RefPre 500 series microphone preamplifier is designed for engineers who need uncompromised transparency and precision. With its transformerless signal path, extremely low noise floor, high headroom, and dedicated ribbon microphone support, it delivers an accurate and reliable front end for professional recording systems.
Whether capturing the natural tone of high resolution microphones, recording acoustic instruments, or working with advanced microphone modelling systems, the RefPre provides the clarity and detail required for modern high fidelity production.
- Transformerless preamp with stepped gain adjustment from -10 dB to 60 dB.
- Ribbon mic mode adds 10 dB gain, auto impedance adjustment, and phantom lockout.
- ±6 dB trim control and continuously adjustable output fader.
- Wide frequency response (10 Hz – 80 kHz), ultra-low noise (-125 dBu EIN), and 0.0005% distortion.
- High headroom (+28 dBu) with switchable 80 Hz high-pass filter.
- Signal LED glows green on signal, flashes red at +18 dBu.
- Front/rear inputs for mics, Hi-Z instrument input, polarity reverse, and 48V phantom power.
