Warm Audio WA273-EQ 2-channel Microphone Preamp

Handcrafted with top-quality parts

Boasting weapons-grade build quality with discrete, handwired Class A circuits and top-drawer parts such as UK-made Carnhill transformers and Blore Edwards mil-spec, dual-concentric switch pots, the Warm Audio WA273-EQ Microphone Preamp has 80dB of gain on tap so you can capture subdued sources with your favorite ribbon mic. Your ribbons and condensers will sound heavenly; you’ll even be gobsmacked when you hear how authoritative your dynamic mics sound. Cranking the input stage and backing off the output gain enhances your tracks with tasty vintage-style coloration. Topping off the feature set is per-channel instrument jacks, polarity reverse, 48V phantom power, and switchable impedance for tonal variation and to optimally match a variety of microphones.

The EQ sections of the WA273-EQ adhere to the classic 1073 circuit topology. The vintage 1073 is the holy grail of EQ, and the WA273-EQ nails its sonics and behavior (complete with its fabled harmonic distortion). It’s a three-band affair, with HF shelving at 10, 12, and 16kHz; midband peaking with selectable center frequencies at 360Hz, 700Hz, 1.6kHz, 3.2kHz, 4.8kHz, and 7.2kHz; and LF shelving, selectable at 35Hz, 60Hz, 110Hz, and 220Hz. A highpass filter, selectable at 50Hz, 80Hz, 160Hz, and 300Hz, lets you trim your signals of unwanted low end. If you’ve never worked with a 1073-style EQ before, all we can say is: you’re in for a serious treat. It’s worth noting that the original 1073 offered only a fixed 10kHz shelf, and the additional high-frequency flexibility afforded by the WA273-EQ is most welcome.

Warm left no stone unturned

A vital yet not-often-discussed component of these classic British circuits is the different types of capacitors and output transistors used. To maintain the integrity of the original circuits, Warm decided to use high-quality tantalum and polystyrene capacitors in the signal path and an output transistor choice that delivers smoother results at higher gain settings than what is commonly found in today’s 1073-style preamps. All considered, Warm Audio’s monumental effort to design a no-compromise product has paid off handsomely. You’ll appreciate this every time you plug into the WA273-EQ and hit record.