BURL AUDIO B1D 500 Series Microphone Preamp

Give your recordings the punch, weight and unmistakable character of transformer-driven analog sound. The BURL Audio B1D 500 Series microphone preamp with BX4 steel output transformer delivers powerful Class-A performance for recording engineers, producers and musicians seeking rich harmonic coloration and exceptional sonic detail. Built around BURL Audio's proprietary BX3 input transformer and all-iron BX4 output transformer, the B1D produces a bold, aggressive tonal character that adds depth to drums, presence to vocals and powerful definition to electric guitars. Its fully discrete, direct-coupled signal path eliminates capacitors from the audio circuit, preserving clarity while delivering the warmth and saturation associated with premium analog hardware. With up to 70dB of gain, independent Gain and Level controls, selectable input impedance and a front-panel 1/4" instrument input, the B1D provides versatile sound shaping for a wide range of recording applications. Designed in the API 500 Series format, the preamp integrates into compatible modular racks and complements BURL Audio's B2 Bomber ADC and B80 Mothership systems.

BX4 Steel Transformer and Discrete Class-A Circuitry Deliver Powerful Analog Tone

The B1D distinguishes itself from the standard B1 microphone preamp through its proprietary BX4 all-iron output transformer, which delivers a more aggressive, rock-oriented tonal character compared with the B1's BX2 nickel transformer. Paired with the high-definition BX3 input transformer, this design provides rich harmonic saturation, strong transient response and a full-bodied sound that complements drums, guitars, bass and vocals. Its fully discrete Class-A architecture uses a direct-coupled, capacitor-free signal path to preserve musical detail while introducing the distinctive weight and character of transformer-based analog processing. Independent stepped Gain and output Level controls allow engineers to shape the amount of coloration without relying solely on output volume. Increasing the input gain while reducing the output level produces more pronounced saturation, while lower gain settings and higher output levels support cleaner, more transparent recording. This flexible approach makes the B1D equally useful for capturing energetic performances and adding analog character to existing tracks or mixes.

Flexible Input Controls and 500 Series Compatibility Support Versatile Recording

Designed to accommodate a wide range of microphones and instruments, the B1D features selectable input impedance for optimizing performance with compatible dynamic, condenser and ribbon microphones. Its transformer-coupled impedance selection is particularly useful when working with low-impedance sources, while onboard phantom power supports compatible condenser microphones. A front-panel 1/4" DI input provides convenient connectivity for guitars, basses and other instrument or line-level sources, allowing musicians to record directly through the preamp's Class-A circuitry. A selectable 30dB pad accommodates high-output signals and balanced line-level sources through the rear microphone input, while phase reversal provides additional flexibility for multi-microphone recording setups. A tri-color level LED offers convenient visual feedback during gain staging, helping engineers monitor signal levels while dialing in the desired amount of analog coloration. Combining versatile input options, up to 70dB of gain and the distinctive sound of its BX4 steel transformer, the BURL Audio B1D provides a powerful recording tool for studios seeking authentic analog character in a compact 500 Series format.