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Heritage Audio Motorcity EQualizer

Seven-band Inductor EQ By Neil Rogers
Published August 2022

Heritage Audio Motorcity EQualizer

We check out this painstaking recreation of the rare and coveted Motown equaliser.

You know how the saying goes: you wait years for a Motown equaliser to become available and then four come along at once! Heritage Audio were first to announce their take on this venerable EQ, with their 19‑inch rackmount Motorcity EQualizer, which is reviewed here. I’d only just got my hands on a pair of these units and started my tests when KIT Plugins launched an analogue‑modelling plug‑in based on original units (a review is in the pipeline), and Universal Audio quickly followed suit too. Then, at the recent NAMM show, I learned that Acme Audio had also announced a hardware reproduction.

Getting Into Gear

Why the popularity? Well, from the early 1960s to the mid‑’70s, Motown Records and their Hitsville, USA studio, run from a converted house in Detroit, Michigan, lay at the centre of a hugely significant musical subculture that achieved crossover success during a golden era of record making. Some of the key characteristics of the Motown sound which distinguished it from its peers included powerful bass and an expansive top end, and although the talented artists, engineers and producers were undoubtedly the biggest ingredients in their success, some pieces of studio gear also made a distinctive contribution.

As in many other prominent studios at this time, much of the Motown gear was designed or heavily modified by the studio’s in‑house engineers, and the Motown EQ, as it became known, is a great example. This was Hitsville in‑house engineer Mike McLean’s take on the passive, slider‑style equalisers of the day, which were designed by the likes of Cinema Engineering, Altec and Langevin primarily for the film industry. McLean adapted these designs to make them more suitable for use in a music studio context, and a key development was to isolate the EQ circuit and pair it with a separate makeup gain section. Importantly, this meant his EQs didn’t require a separate preamp to restore the level that’s inherently lost in such circuits.

Only eight of the original Motown EQs were built in‑house and a very small production run at a local facility followed, but they were never released as a commercial product.

Only eight of the original Motown EQs were built in‑house and a very small production run at a local facility followed, but they were never released as a commercial product. Consequently, original units are vanishingly rare, with fewer than 40 known to exist today, and as far as I’m aware there was no official schematic or component list/spec from which clones could easily be made. This, and the fact that several A‑list engineers have extolled their virtues over the years, has endowed them with an almost mythical reputation.

Based in Madrid, Spain, Heritage Audio have been best known to date as a high‑quality but competitively priced option for those wanting classic Neve‑style preamps, EQs and compressors. But owner Peter Rodriguez has long been fascinated by the Motown EQ and when celebrated mix engineer Michael Brauer sent his pair of original EQs to Black Lion Audio (BLA) for a routine service, BLA, having checked with Brauer, offered Peter the chance to examine the units in order that he could attempt to manufacture a faithful recreation. This was during the recent Covid lockdowns, so to do this Heritage had to work remotely in collaboration with Chicago‑based BLA — as lockdown projects go, a transatlantic collaboration to recreate this rare and coveted EQ is much more impressive than my attempts at baking sourdough bread or growing vegetables!

Discovering that many of the components were no longer available, Heritage developed new custom parts to replace the originals. Heritage describe the result as a ‘dead nut’ replication of Michael Bauer’s units, but with one deliberate exception: they chose to use a tried‑and‑trusted Carnhill transformer for the output stage rather than attempt to replicate the original’s op‑amp. Why? Largely because that op‑amp acquired a reputation for being unreliable and the Achilles’ heel of the original design!

Test Drive

In keeping with the original units, the Motorcity EQ is a no‑frills, minimal‑looking device: Heritage have chosen a raw steel faceplate as the backdrop for this unit’s vintage‑style controls. Like most engineers, I’ve never had the privilege of using one of the originals but, outwardly, these Motorcity devices seem well built, look great and feel inspiring to use. The EQ is powered by a bespoke external PSU and while this might look a bit ‘prosumer’ it does the important job of keeping mains AC power well away from the audio circuitry — Michael Brauer explained that he had this power modification done when he acquired his original units in the mid‑1990s, as he’d found that they would often produce unwanted hum.

Part of the beauty of this type of EQ, which inevitably dictates how you end up using it in the studio, lies in its operational simplicity. There are seven fixed‑frequency controls that allow broad cuts or boosts of up to 8dB, and the frequency ranges (which I’ll explore in more detail below) immediately spoke to me as having been chosen by people who’d regularly got their hands dirty making music. These cut/boost bands are each controlled by a large, custom‑made Bakelite knob, which switches in 1dB increments. The only other controls are a similarly styled output trim and a cool‑looking, three‑position lever switch which allows you to engage/bypass the EQ circuit or to power it off; a large red jewel light indicates whether the unit is powered on

.An external PSU, reminiscent of a mod to Michael Brauer’s units, is used to keep mains AC away from the audio circuitry.An external PSU, reminiscent of a mod to Michael Brauer’s units, is used to keep mains AC away from the audio circuitry.

It was a pleasant surprise be sent a pair of Motorcity EQs to review, since it meant I was able to use them on stereo material — Heritage obviously knew what they were doing because, in hindsight, I don’t think I’d have been able to fully appreciate what these units can bring to a project had I been unable to run a stereo drum bus or a whole mix through them. When these units arrived, I was in the later stages of an EP mixing project for an indie guitar band. Whilst I was happy enough with how my project was going, I was in that phase where I was looking for that little extra, indefinable ‘something’. So, just for fun, I thought I’d see how the Motorcity pair sounded across the whole mix — and what they did put a very big smile on my face.

Partly that’s a practical matter of the seven EQ bands correlating pretty much exactly with the frequency ranges in which I commonly end up massaging the balance of a mix. For the low end, there’s a 50Hz option for adding/cutting weight and a 130Hz option for boosting the more audible lows or clearing out what can be a very congested area in a mix. In the lower midrange, we have a 320Hz control — that’s so often where I end up cutting — and a band at 800Hz, which can be very useful for adding presence to a bass guitar or cutting a bit to ‘open up’ snare drums and toms. Another key area for removing nasty stuff is 2kHz, and we then get to the high‑mid 5kHz and high‑end 12kHz options, for adding brightness and presence. But there’s definitely more going on here than boosting and cutting at the specified frequencies.

On my indie guitar band mix project, I dived in with a quick ‘smiley face’ curve, which combined a generous boost at 50Hz with 3dB boosts at both 5 and 12 kHz. I’d rarely make such bold EQ moves at that stage of a mix with a software EQ, but it worked well: the track immediately felt more powerful and exciting. With a little more time spent, I also made small cuts at 320 and 800 Hz, and this final setting stayed in place for the rest of that project. It added weight to the kick drum and bass guitar, cleared out some low‑mid junk and added a lovely presence to cymbals and the top end of the snare, guitars and vocals.

On individual sources, I found that I could get even more heavy‑handed, and it’s easy now for me to understand why Michael Brauer uses his units almost exclusively for kick and snare drums. a great EQ can change the personality of something like a snare drum and the combination of adding weight, cutting out unpleasant low‑mids and dialling in more presence was hugely satisfying. Guitars, vocals and generally any source that I threw at it when tracking and mixing came back with either a subtle improvement or a completely new personality.

Motoring On

Regardless of the enticing back story, what really matters is how this EQ performs and what value it can add to your projects. I’ve been going through a period of streamlining the studio a bit, assessing which gear actually saves me time and/or makes a tangible difference to the finished product that leaves my studio, and I have to say these Motorcity EQs have thrown a cool‑sounding spanner into that process.

Just for fun, I thought I’d see how the Motorcity pair sounded across the whole mix — and what they did put a very big smile on my face.

The review units have been inspiring, enjoyable and useful, for recording and mixing jobs alike. Inductor‑based EQs like this one tend both to deliver a nice, characterful sound and to encourage you to work in a certain way, and both factors are important. The limited number of bands and control you have over them often leads you to making, quicker, broader moves. The EQ bands begin to overlap and interact, and this often produces surprisingly good results that you wouldn’t so easily achieve with a more surgical software EQ, or one with a frequency curve display. There’s also the wider sonic contribution that the electronics make, and these units deliver that almost undefinable, pleasing sense of subtle saturation when you engage the high‑mid band in particular. If you make dramatic boosts they might sound too much but they never really sound bad. So while the term ‘musical’ is probably overused when describing the sonic contribution of audio processors, it’s one that I feel is apt when describing the Motorcity EQ.

It often feels like I’m doing something more than a merely technical process. In particular, when using them across a whole mix, I found that I could use these EQs to do the heavy lifting in a way I found really difficult to recreate with plug‑ins. Speaking of which, I mentioned above that two well‑regarded companies have released analogue‑modelling plug‑in versions of the Motown EQs, and I was pleasantly surprised by how nice they sounded. While I didn’t find that they could do exactly the same thing as these hardware units, particularly on more complex program material such as full mixes, they can definitely give you a good taste of what these EQs sound like. If you can, though, I’d definitely recommend finding a way to audition this hardware. It really is a great‑sounding EQ. As professional tools go the price isn’t uncompetitive, although it’s obviously a more serious investment if you want a stereo pair!

Audio Examples

The MP3 audio files below provide a number of examples of how I ended up using a pair of these excellent-sounding EQs in my studio during the review period. For each before and after example, the Motorcity EQ was the only processing used.

Even better, download the 24-bit hi-res tracks in the ZIP file and audition them in your own DAW.

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The Motorcity EQs are replicas of mix engineer Michael Brauer’s original Motown units and he likes to use them almost exclusively on kick and snare. Here is a close kick drum mic channel before any EQ.


How the same kick drum sounded through the Motorcity EQ with the following settings: +4dB at 50Hz, +3dB at 130Hz, -8dB at 320Hz, -1dB at 800Hz, +2dB at 2kHz and +4dB at 5kHz.


A close snare drum mic channel with no EQ.


The snare channel with the following EQ settings: +4dB 130Hz, -1dB at 320Hz, -4dB at 800Hz, +2dB at 2kHz, +4dB 5kHz and +3dB at 12.5kHz.

05_Bass Guitar_RAW

I enjoyed using the Motorcity units on bass — this is a bass guitar part before EQ.

06_Bass Guitar_EQ

How the Bass sounded with +3dB at 50Hz, +1dB at 130Hz, -4dB at 320Hz, -4dB at 800Hz and a whopping +8dB at 2kHz!

07_Mix Bus_Raw

This was a rough instrumental mix of a track I was working on with no mix bus EQ.

08_Mix Bus_EQ

The same example but with the Motorcity units used across the whole mix. I'm pushing the high and low frequencies a touch more than I probably would but I wanted to show how heavy-handed you can get with these units before they sound 'bad'. I used the following EQ settings: +3dB at 50Hz, +3dB 130Hz, -2dB at 320Hz, -2dB at 800Hz, –1dB at 2kHz, +2dB at 5kHz and +3dB at 12.5kHz.


  • A deceptively versatile and powerful analogue equaliser.
  • Great in pairs for groups or a mix bus.
  • The fixed EQ bands help you focus quickly on what’s important.
  • An historic EQ design that has never been commercially available.
  • Build quality seems impressive.


  • You might need to budget for a pair!


Heritage Audio have boldly stepped away from the well‑trodden path of Neve‑style hardware with this hugely impressive recreation of a rare and storied EQ from the Motown era. The vintage, fixed‑band, inductor‑based design might strike you as limiting but the results are anything but.


£1649 including VAT.

Heritage Audio +34 (0)917 266 189.

$1999 each.

Heritage Audio +1 800 605 3127.