A Dual Channel ’73 For The Rest Of Us
If there’s one style of preamp that professional engineers would unanimously agree has defined the tone of pop/rock records for decades, it would most definitely be the venerable ’73-style of mic pre. ’73-style preamps have been massively used in recording and live applications for many years and are still considered to be the “Holy Grail” of preamp choices today. The Warm Audio “WA73 Family” consists of single and dual channel ’73-style preamps (with & w/out EQ), that each pay careful homage to British audio history.
When we at Warm Audio decided to release the WA273-EQ it was imperative that it met vintage expectation in both design and performance. The tone and sweet character that vintage ’73-style mic preamps impart is so unique and familiar, that we had only the pure desire to release sonically accurate reproductions. After years of R&D, careful reverse-engineering, and countless hours of auditioning, the WA273-EQ was born!
The WA273-EQ is a “Desert Island” boutique preamp, but it can also be classified as a studio and live work-horse. Classic ’73-style preamps are known for being versatile tools that work with all kinds of microphones from Condenser, to Dynamic, to Ribbon. The WA273-EQ equally shines on all types of microphones and sources including; vocals, acoustic/electric guitars, bass, drums, percussion, orchestras, keyboards, and even as a tone shaping tool to run partial or complete mixes through. With 80dB of gain and a fully discrete Carnhill Transformer balanced signal path, there’s no recording, mixing or engineering task that the WA273-EQ can’t handle.
UK Custom Carnhill Transformers
Enthusiasts unequivocally get excited about the components used in classic ’73-style British preamps. The signal transformers are a common topic of conversation. Vintage units used various versions of transformers throughout the years, but the most coveted were the earliest versions. These are regarded as the most desirable choice due to their fluid and forgiving nature. They saturate sweetly when pushed, and have been known to make engineers cry when they hear how beautiful their mixes sound through them!
Warm Audio worked closely with Carnhill Transformers of Cambridgeshire, UK, to design faithful reproductions of these most coveted, early version transformers. We at Warm Audio have not yet heard a modern day ’73-style preamp sound as sweet and musical as does our WA273-EQ with these beautiful custom Transformers.
Capacitors & Signal Path
An important part of these classic British circuits not often discussed is the different styles of capacitors and output transistor used. We found it important to maintain integrity to the original design by using tantalum and polystyrene capacitors in the signal path and an output transistor choice that is much smoother in the high gain settings than what is typically found in modern ’73-style reproductions.
UK Blore Edwards Switch-Pots
A great sounding ’73-style circuit should be just as reliable as it is great sounding. The complex dual concentric switch potentiometers in the EQ sections of the WA273-EQ are made in the UK by Blore Edwards who manufacture military spec switches and potentiometers. The use of Blore-Edwards components is no small inclusion for a ’73-style preamp-eq in this price range.
Hand Wired & Hand Assembled
Classic ’73-style preamps were often hand-wired and so is the WA273-EQ! Guru’s claim that a portion of the sought after classic British tone can be attributed to the hand-wired nature of the build. The WA273-EQ is hand-wired and hand assembled, including the pcb components that are all populated by hand.
- Handwired, hand-assembled 1073-style preamplifier/EQ
- 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
- 48V phantom power
- 4-position inductor-based highpass filters, selectable for Off, 50, 80, 160, or 300Hz
- Inductor-based 3-band equalization per-channel
- Low-band boost/cut at 35, 60, 110, or 220Hz
- Mid-band boost/cut at 360, 700, 1600, 3200, 4800, or 7200Hz
- High-band boost/cut at 10, 12, or 16kHz
- Additional high-band frequency EQ points added (compared to vintage 1073)
- 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
Thông số kỹ thuật
- Dual Channel, Class A, ’73-style British Microphone Preamp with EQ
- UK made Carnhill Transformers
- UK made – Blore Edwards EQ dual-concentric switch potentiometers
- Hand wired, hand assembled
- 80dB of gain – resistor stepped gain switch
- Fully discrete
- TONE button – Changes input transformer impedance for varying tone
- Polarity switch
- 48v phantom power
- Low Band Boost/Cut – 35, 60, 110, 220 Hz
- Mid Band Boost/Cut – 360, 700, 1600, 3200, 4800, 7200 Hz
- High Band Boost/Cut – 10, 12, 16 kHz
- Additional high band frequency EQ points added (compared to vintage 1073)
- 4 position inductor based hipass filter – 50, 80, 160, 300 Hz
- XLR mic inputs (front & back)
- Line level TRS input
- TS Send/Receive insert jacks
- XLR & TRS line level outputs
- Direct In, instrument input
- Output control
- Led level indication
- Freq response 20Hz – 20kHz +/-.5 dB
- 19″ rackmountable
- Internal IEC 115v/230v power inlet