The legendary 1073 wrote the book on characterful mic preamplification. This venerable circuit helped define the punchy sound of ’70s rock — and countless recordings and live concerts ever since. Today, this coveted tone can be yours for a song, with the Warm Audio WA273 mic/line/instrument preamp. In both design and performance, the 2-channel WA273 pays homage to the revered British console lineage that started it all. Throughout the audio industry, the 1073 is considered the holy grail of preamps, with a rich, sweet, and bold tonality that’s ideal for making audacious statements with your music. After years of R&D, painstaking reverse-engineering, and countless hours of listening, Warm Audio captured the sonic essence of this classic perfectly in their boutique WA273. With 80dB of gain and a fully discrete transformer-balanced signal path, the sound is a revelation: harmonically rich bottom end, focused midrange, and slightly resonant highs.

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, the WA273 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 are per-channel instrument jacks, polarity reverse, 48-volt phantom power, and switchable impedance for tonal variation and to optimally match a variety of microphones.

Optimize every source — and microphone

There is no source that doesn’t sound amazing through the Warm Audio WA273. With judicious mic selection and placement, drums are larger-than-life; DI bass and keyboards sound massive and synths become trance-inducing; electric guitars soar; vocals rule. Pianos and acoustic guitars are resplendent. Orchestral instruments — strings, woodwinds, brass, and percussion — achieve ineffable lushness and dimension. You can even use the WA273 as a tone-shaping tool to run stems or complete mixes through. Hear what the WA273 can do for your own recordings. It’s transformative.

UK Custom Carnhill transformers

The 1073-loving engineers at Sweetwater perk up when the conversation turns to the component history of these classic circuits, and signal transformers are a frequent topic of discussion. Vintage 1073s used different transformer variants throughout their production run, but the most coveted were the very first ones made by Marinair Radar due to their fluid and forgiving nature that saturates sweetly when pushed. They have been known to bring engineers to tears when they hear how gorgeous their mixes sound through them! Warm Audio turned to Carnhill Transformers of Cambridgeshire, UK, to design meticulous replicas of these most desirable early 1073 transformers. The results are stunning, and — to our ears — tantalizingly close to early vintage 1073s.

Warm left no stone unturned

A vital, yet not oft 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 and hit record.

Features:

• Handwired, hand-assembled 1073-style preamplifiers
• Fully discrete, Class A, transformer-balanced circuitry
• UK-made Carnhill Transformers
• 80dB of gain handles any type of microphone, including low-output ribbons
• Resistor-stepped rotary gain switches for easy recall
• Tone buttons change input transformer impedance for mic optimization and tonal shaping
• Polarity switches
• 48-volt phantom power
• 4-position inductor-based highpass filters, selectable for Off, 50Hz, 80Hz, 160Hz, or 300Hz
• XLR mic inputs
• Line-level TRS inputs
• TS Send/Receive insert jacks
• XLR and TRS line-level outputs
• DI instrument inputs
• Output level controls
• LED level indication meters
• Rugged 19″ rackmount chassis
• Ground lift switch
• Internal IEC 115V/230V power inlet

Specs

• Preamp Type:Class A Solid State
• Number of Channels:2
• Phantom Power:Yes
• Polarity Switch:Yes
• EQ:Highpass 50Hz, 80Hz, 160Hz, 300Hz
• Analog Inputs:2 x XLR (mic), 2 x 1/4″ (line), 2 x 1/4″ (Hi-Z)
• Analog Outputs:2 x XLR, 2 x 1/4″
• Channel Inserts:Yes
• Frequency Response:20Hz-20kHz (±0.5 dB)
• Rack Spaces:1U
• Power Source:Standard IEC AC cable