WARM AUDIO WA273-EQ DUAL CHANNEL STRIP

Does the Warm Audio 1073 clone sound like the original? We put it up against a pair of vintage Neves to find out.
Review: Mark Davie
Every time you see a review comparing a Neve clone to a vintage 1073, the reviewers typically give a similar disclaimer. It goes something along the lines of having used, hired, borrowed, or stolen a number of vintage 1073s over the years, and no two sounding the same.
To try and dodge that issue, we hired a pair of vintage 1073s from Kaj Dalstrom at Sing Sing. Sure, these two came from the same generation, but having survived almost 50 years, they undoubtedly have a completely different service history. 
Nonetheless, these were a pair of well-preserved, studio-bound, looked-after vintage 1073s. And they proved themselves to be fairly well matched.
In the other corner we had the Warm Audio WA273-EQ. It’s basically two channels of 1073 clone stacked into a 2U housing. 
HONING THE CLONE 
Warm Audio makes a lot of claims regarding the authenticity of its reproduction. Firstly, that it has commissioned custom transformers from Carnhill that are supposedly faithful reproductions of the early transformers (presumably the first Marinair 10468 input transformers). Your level of care probably depends on how much of the folklore surrounding these transformers you’ve engaged with and whether you believe Carnhill’s VTB9045 (the model number they moved to) continues to test the same as the originals. Some say not, including AMS Neve, which moved away from Carnhill some years ago, for its 1073.
It’s necessary for Warm (or any clone manufacturer for that matter) to claim exactness here, because in many people’s minds the transformers are where the magic happens. 
On the build side, these aren’t replicas of a 1073 down to the trace level. While they still use discrete components, unlike AMS’ newer surface-mount 1073DPX models, the boards are not copies of the originals.  
I asked Joe Malone — who has worked on countless Neves and makes his own JLM Audio Neve-like preamps — to take a cursory glance at the guts of the 273-EQ to tell me what he could see.
Joe was on the fence about the transformers; while his tests of the Carnhills have never lined up with the original Marinairs, he hadn’t had a go at these specific ones, so couldn’t give a verdict. Either way, they’d be a far cry closer than some of the Chinese transformers you can find some clones.
Speaking of Chinese, the units are hand wired, but likely in a Chinese factory; which is not necessarily a bad thing. Inside, there’s a bunch of PCBs interconnected by ribbon cabling. On the one hand, multiple boards does make serviceability easier, like the original. The downside is it’s easier to make wiring mistakes when you don’t have a full PCB, or when they don’t slot in like the pinned cards of the original. At the end of the day, if all functions test fine, it should be fine, but you have to know it’s desired behaviour in the first place.
Other than potential solder and connector issues, one future issue Joe did touch on was the small size of the heatsinks attached to the 24V regulator, and their potential for long-term failure. It would have been better for them to be bolted to the case. Other than that though, “not a bad attempt at a Neve channel,” he said.
WARMING IT UP
Over the last couple of months of use, the Warm Audio 273-EQ has been faultless. The internal power supply doesn’t induce any noticeable noise, and makes it simple to rack. All the buttons have a nice deep travel, and all the dual concentric switch pots are from Blore Edwards, a UK manufacturer that makes Neve-specific switches and pots. The switches all felt good, but the pots were inconsistent. Even over a small sample size of six EQ knobs, some had a quality feel with decent resistance, others felt a little elastic, while one was very loose. They were not a match for the original knobs. Likewise, the click of the main switches felt more clingy and the reissue Marconi knobs don’t feel like the real thing. Still, they do a good job at their function, it’s just hard to imagine them holding the same level of quality in 50 years time when they start out inferior.
One cost-cutting measure common to clones is to label the chassis instead of the face of the button. It’s understandable, but is a little problematic on the 273-EQ. There are six buttons for each channel, in two rows of three. For some reason Warm printed the legending for the top row above the buttons, and the rest below the second row. If you stick it in a rack, you have to bend right over below the buttons to read the bottom set of labels. If they’d simply printed the labels above both rows of buttons, it would be far less of an issue. 

Angus Legg is a super talented soulful, singer-songwriter; think Ed Sheeran, Jason Mark, John Mayer. He’s an absolute professional, and a privilege to work with. You can follow him most places @angusleggmusic

JUST ONE TRANSFORMER
Insofar as similarities go, the Warm Audio 273-EQ has every single feature of the original. 
The only major circuit difference is the inclusion of only one mic input transformer — not separate stages for mic and line, with separate transformers to match. Instead, the signal is simply padded by up to -20dB for line level inputs. It does alter the gain staging and switch labelling a bit. Traditionally, the line level section would travel from -20dB to +10dB. It then has an off switch, so you don’t get a thump when switching between the two sources. Likewise, there’s another off position above +50dB to stop another thump occurring when the third amplifier is switched into the path.
Like most clones, the Warm Audio saves a bit of dosh by ditching the separate line input stage and simply switching in a pad. In this case, a rotary pad that extends past the 0 setting on the switch.
I doubt most people looking at buying the 273 EQ are going to miss the separate stage. Especially considering everything else is there: A full 80dB of gain for mic inputs, high pass filter with four selectable frequencies, three band switchable EQ, and a phase flip.
FREQUENT FIXTURES
There are plenty of features you don’t get on a vintage 80 series 1073 module that you do on the Warm Audio 273-EQ.  On the 1073 EQ, the low band has switchable frequencies of 35, 60, 110 and 220Hz, while the mid band switches between 360 and 700Hz, and 1.6, 3.2, 4.8 and 7.2kHz. The high band is typically set at a fixed frequency of 12kHz. The Warm Audio EQ adds some extra choice up here, allowing you to switch between 10, 12 and 16kHz.
While the original only gave you buttons for phase flip and switching the EQ in and out of the circuit, the Warm Audio version also allows you to instantiate an insert, switch a DI into the circuit and change the turns ratio on the transformer, which adjusts the input impedance. This function is marked as Tone. With the switch out, microphones will see an impedance of 1200Ω, for a more natural open sound. Pressing in Tone changes that impedance to 300Ω, which can sound thicker and punchier with dynamic and ribbon mics. Condenser microphones could care less.
The DI is a great advantage. It makes the 273EQ a really well-rounded channel strip. Especially for those looking to make a leap in quality from the front end of their audio interface.
HOW DOES IT SOUND?
We set up both the Neve 1073s and the Warm 273-EQ in a side-by-side test, and asked talented singer-songwriter Angus Legg to come down and play a tune.
Preamp shootouts are always tough. Unlike converter tests, it’s incredibly hard to conduct them exactly. Split the signal and there’s always a tradeoff; transformers added, loss of level, or even frying an input with phantom power. Rather than trying to make it overly scientific, we like to test preamps by taking a song and layering a bunch of tracks up so the character of the gear starts to shine through.
We did this with Angus — recording his acoustic guitar and vocals, then layering a bunch of harmonies, shaker, and trying to play around the out-of-tune octaves of an upright piano to get a stereo track.
We had both channels of each preamp ready to go into the line inputs of an Antelope Audio interface. After each take, we’d simply swap the mic leads over and go again. The gain matching between both was pretty spot on with the Warm at full fader.

BE YOUR OWN JUDGE
You can listen to the unmixed 96k recordings on our Soundcloud account. There is just some mild compression on the mix bus to bring up the level of both recordings.
Go to: soundcloud.com/audiotechnology/sets/warm-audio-273-eq-vs-vintage-neve-1073 to compare.

COMPARE THE PAIRS
With everything tracked, Preshan did a rough mix and copied the processing between the tracks. He then did the rounds with a couple of unnamed stereo tracks to see what we all liked better. Unlike a high-end converter comparison, where the devil is in the infinitesimal, largely indistinguishable detail. The differences were darn obvious. It simply came down to a matter of, which would I choose?
On first listen, one was very forward. It had a lot more presence to it, and just generally sounded more punchy. The other undoubtedly felt more glued together, but the acoustic had a boominess I felt was distracting 
You can probably tell where this is going. After a couple of listens I went with the first one, which turned out to be the Warm Audio 273-EQ. Quelle horreur!
While I couldn’t get the acoustic boom out of my head, others were far more entranced by the glue of the Neve and picked that. 
Comparisons are not without perils, and mixing one side first was probably an unfair play. There’s just no way to mix one and translate it to the other. EQ to compensate for a lack of body in one, would only accentuate the boominess in another recording. 
Listening back to the original recordings, that acoustic boominess in the Neve mix translated to body that just wasn’t there in the Warm Audio tracks. In particular, when Angus occasionally plucked the lowest string on his guitar, it resonated satisfyingly deep and long in the Neve recording. On the Warm Audio recording, it didn’t have that resounding low end. The resonance of the low string matched the length of other strings, giving it a more compressed, controlled sound. In a mix, that can really help, but it also paints you into a bit more of a corner.
On the vocal side. It was hard to fault the solo vocal through the 273-EQ, which had more presence and air than the vintage Neve. It sounded pre-polished. However, when pushed, that presence could get a bit much and started to tax a little after layering three backing vocals. The Neve sounded more laid back on the solo vocal, and never felt overbearing when stacked.
RING TO IT
This is where the clone wars get interesting. Unlike the vintage Neve, the 273-EQ just sounds more modern. It was as if the harmonics were more obvious in the upper ranges than in the low end. Overall, it came across more modern mix ready, at the expense of extended low end and a darker tonality that can help to glue a track together.
Functionally, the 273-EQ far exceeds the vintage Neve. For one, you don’t have to carry it around in an 80 series rack. Everything you need for high quality stereo recording is in the one box. 
If you’re desperate for the Warm Audio 273-EQ to be a dead ringer for a vintage Neve… well, it’s not. That’s not a bad thing. It’s just different; it’s a very capable, great-sounding preamp, that’s well-built, has a gorgeous EQ on it, the convenience of a built-in DI and 80dB of clean gain. All for a very keen price. If you’re looking for a different, Neve-ish sound to add to your arsenal, then this is a solid bet.
If you’re low on quality channel strips and were looking around for a classic design to kick off your setup, then this is a great place to start.