Warm Audio WA73-EQ

Single channel mic-pre with EQ

Warm Audio WA73-EQ

Review by Russell Cottier

Warm Audio was founded in 2011 by Bryce Young and has come a long way, now offering accessible incarnations of classic studio pieces at reasonable prices. What’s more, you won’t have to expect huge repair costs with these all new ‘vintage’ racks. The WA73 comes in a variety of flavours including the single channel WA73 and the WA73–EQ, a one channel microphone preamp and classic ’73 style EQ. There are also two channel versions of these models available in the form of the WA273 and WA273-EQ.

The front panel is a blue-grey affair, obviously very reminiscent of the Neve 1073 from which the WA73-EQ undoubtedly takes significant inspiration. Warm has also gone
 a very familiar route for colour scheme and knob type.

Warm Audio WA73-EQ

On the front panel we have a microphone XLR input and instrument input, with an additional rear-mounted microphone input. Six white plastic push switches allow selection of +48V, Polarity, Line input, Instrument input and Insert. Those of you who are regular users of 1073-style preamps, particularly with dynamic mics, will be well aware of the tonal change when you flip the impedance switch. This is achieved by a change in the input transformer coil selection and is labelled Tone on the WA73 family. The tonal change is very much like the original, subtle but useful. Warm Audio worked closely with Carnhill Transformers of Cambridge to design reproductions of early ‘73 transformers. Tantalum and polystyrene capacitors were used in the signal path, like the original, and an output transistor smoother at high gain than those typically employed in replicas.

To the right of this we have the typical layout of classic looking knobs. The gain control is a stepped resistor switch and offers -20 dB right through to 80 dB in five dB increments. As with the original there is an off position between the Line and Mic ranges. Blore Edwards Switch- Pots have been used, they are robust and a pleasure to use, it’s quite clear these are high grade components that will last many years. The Blue High-Pass Filter offers frequency selections at 50, 80, 160 and 300Hz. The inductor-based circuit is not too aggressive sounding in general use and the simplicity really makes this unit simple and quick to use.

The WA73-EQ has a 3 band parametric EQ with very familiar metal concentric rings, stepped for frequency selection and a grey plastic central knob for gain. Usefully, the High band offers a variable frequency selection for the shelf, something I often wish was present on the original 1073. Selectable from 10-16kHz it really helps add a specific sparkle to your sources. The other two bands offer the expected 35-220Hz and 360-7200Hz ranges, thankfully the pots and selectors on the unit are the opposite way round to the original, offering a more conventional experience.

Warm Audio WA73-EQ

A slight discrepancy in the feel of the three EQ gain controls of these bands was mildly annoying, but that could be due to the newness of the unit. The large knobs make precise control quick and easy and the EQ circuitry sounds just fantastic, especially for a unit of this budget. Sonically the WA73-EQ can stand up and surpass many other ’73 style clones that retail at a much higher price.

Warm Audio WA73-EQ

As one would expect the smaller output knob feels robust and smooth, and sits above a five LED level meter showing output peaking. The rear panel of the unit houses all the expected connectivity, though the insert and returns are unbalanced TS this didn’t really cause much concern.

Recording with the WA73-EQ

The classic technique of overdriving the input stage with gain control and then trimming back the output is easily achievable, and could add some much needed mojo to a modern project studio with an all-in-one preamp/interface. Likewise the WA73 is totally at home in a commercial recording studio context, and stood up well against the original hardware during back-to-back comparison.

Warm focuses on the hand-wired nature of the unit and hand placed components, though this is rather moot as both are normal practice in through-hole circuit manufacture. Perhaps we should focus more on the excellent sounding Carnhill transformers and the low noise-floor of the units. The input stages colour signals nicely, and in the heat of battle the WA73-EQ is a breeze to use. The simple layout and large controls are exactly why this kind of preamp feels so ergonomic. When using the original 1073 I tend to crank the gain, getting to the point where I hear distortion and then knock back one notch, this technique worked exactly the same on the WA73, giving those controlled transients and a fat signal without an obviously distorted sound.

In practice the sounds achieved through the units were impeccable giving a sheen to vocals through U67’s, U87’s and even dynamic mics like a 57 on snare. For sources with wild transients such as acoustic guitar recorded through a AKG 414 the WA73 can bring everything more in line, allowing for aggressive pop and rock productions. The Instrument input impedance is enough to allow passive single coil guitars to behave nicely and actually give a hefty rock sound.

As a great functional and usable component of a recording studio the WA73 cannot be faulted, especially at £580 or £790 for the WA73-EQ. Compared to many of the ’73 clones out there the lower price doesn’t mean a compromise on build quality, I certainly would have no worries about installing one of these in the commercial studio.