In a software EQ market awash with innovative modern designs of all shapes and sizes, there remain many ageless hardware emulations that will forever stand the test of time. Here are seven of our favourites.

Universal Audio Pultec Passive EQ Collection

Running on UAD-2 and Apollo DSP systems, and now natively with no other hardware required, UA’s second-generation trio of classic Pultec emulations comprises the EQP-1A, MEQ-5 and HLF-3C, all three of which are passive designs, meaning that – in the original hardware – they don’t use any powered components in their filters.

Launched way back in 1951, the EQP-1A is one of the most sought-after EQs ever made, coveted for its smooth, musical response, and the ability to cut and boost low frequencies simultaneously. This last enables a technique known as the ‘low end trick’, which has a uniquely beneficial effect on kick drums and bass guitars, adding instant weight and punch; and UA’s version replicates it beautifully. It’s a one-stop bottom improver.

The MEQ-5 was built as a partner to the EQP-1A and offers three mid-range peaking bands, the outer two boosting, the middle one cutting and with a frequency range overlapping the boosting bands at either end. The HLF-3C, meanwhile, combines 12dB/octave high- and low-pass filters in a single unit.

Although the three plugins in Pultec Passive EQ Collection come together nicely, and share that wonderful Pultec musicality and ease of application, the main event is certainly the EQP-1A, which is arguably worth the price of entry on its own

Mäag Audio EQ4

The headline features of Mäag’s stunning plugin – which brings their own revered six-band lunchbox-format EQ to the software domain – are the amazing Air shelving (boost only) band, which corners at up to 40kHz in order to apply almost invariably enhancing ultra-high-end sheen, and the 10Hz Sub bell band, which pulls off similar audible-limit-pushing trickery at the bottom of the spectrum. There’s more to EQ4 than just that, though: this is a superb ‘musical’ equaliser in every sense, with three bell filters at 40, 160 and 650Hz, and a regular shelf at 2.5kHz, all perfectly calibrated for quick and easy smoothing and sweetening; and the plugin-exclusive ability to bypass individual bands and adjust the global gain proving useful additions to the original hardware spec. An absolute winner for non-surgical shaping of pretty much any signal, but especially effective on vocals, drums and the mix bus.

Three Body Technology Kirchhoff EQ

This one differs from the others in our list in that it doesn’t attempt to emulate a specific historic equaliser, but instead lets you design your perfect processor for any given task by loading a combination of vintage models (of which there are 32) and regular EQ filters (15) into up to 32 independent bands. The former draw inspiration from nine Neve, SSL, Pultec and Sontec hardware EQs – albeit without their characterful harmonic non-linearities, which is a bit of a shame – while the non-vintage types span the gamut from the staple low-pass, high-pass, band-pass, notch, bell and shelves, to tilt, brickwall high/low-pass, all-pass and more. All in all, it’s an embarrassment of frequency-sculpting riches if ever we saw one.

Every band can also be switched to Dynamic mode, and the control panel in which this is set this up is bristling with clever features, including separate Above/Below Range and Ratio controls for dialling in compression/expansion, and the unique and ingenious Detect/Relative Envelope Detection circuit, which we don’t have space to explain here! There’s also much talk of Psychoacoustic Adaptive Filter Topologies and switchable 117-bit processing, all of which plays into the incredible quality of the sound across the board, and perhaps most notably in those vintage models, which are fantastic.

It would obviously be fair to say that Kirchhoff EQ is heavily influenced by FabFilter’s hugely popular Pro-Q 3 when it comes to its core concept and GUI, which is certainly no bad thing; but in fact, what we have here amounts to quite a lot more in terms of sheer volume of features for those that need it and are prepared to get to grips with its potentially intimidating depth and complexity, and endless customisation options.

Mind-bogglingly versatile and pushing the technological envelope in many areas, Kirchhoff EQ is a powerhouse of signal shaping. Feast your eyes and ears on Luke Goddard’s review.

Sonimus Burnley 73

There are quite a few 1073 emulation plugins out there, but Sonimus’ take on Neve’s legendary console EQ sets itself apart with its exceptional sonic authenticity and hugely attractive price tag. Just like the hardware, Burnley 73 gives you low and high shelving bands, a semi-parametric mid band and a high-pass filter, each one switchable through a fixed range of frequencies, with up to 16dB of cut or boost. And as the mid band gain is increased, its Q factor narrows, bringing a vaguely surgical angle to this otherwise primarily ‘musical’ EQ.

The EQ itself isn’t the only story here, though, as Burnley 73 also models the line and microphone input circuitry of the real thing, serving up two distinct styles of distortion via the gain-compensated Saturation knob. Indeed, you can dedicate the plugin to use as a colouration effect by bypassing the EQ section entirely – great for imbuing any clean signal with a little analogue mojo.

IK Multimedia EQ-81

The follow-up to the 1073, the Neve 1081 doubled the number of semi-parametric mid bands to two and added a Hi-Q mode to both for sharper peaking response, expanded the the high and low shelving bands with a peaking mode option, and partnered the high-pass filter with a low-pass equivalent. Available within their T-RackS mastering suite and, of course, as an individual plugin, IK Multimedia’s EQ-81 nails the sound and feel of the hardware, including preamp distortion, and bolsters the specification with mid-side processing and optional stereo/MS channel linking/de-linking.

Like Burnley 73, EQ-81 is all about comparatively broad-strokes ‘character’ equalisation, and while the 73 is obviously the easier of the two to get to grips with for straightforward frequency-shaping jobs, the extra parameters of its bigger sibling can make all the difference when it comes to sculpting more complex signals.

Softube Tube-Tech Equalizer Collection

For the non-UAD/Apollo-equipped producer seeking top notch Pultec emulations, Softube’s officially endorsed virtual versions of Tube-Tech’s superb EQP-1A and MEQ-5 remakes – the PE 1C and ME 1B – tick all the right boxes.

Despite the name, the two members of Tube-Tech Equalizer Collection are actually rolled into a single plugin, with PE 1C first in the chain, followed by ME 1B. This makes total sense, given their complementary intent, and you can bypass each independently should you only need one of them.

Beyond that, everything is as you’d expect, with Softube’s sublime analogue modelling impressing at every turn, the PE 1C making a fine fist of the all-important ‘low end trick’, and the whole caboodle amounting to a fabulous solution for passive track and bus equalisation.

Waves API 550

Another revered console EQ that’s played a major role in literally shaping the sound of music since the ’60s, the API 550 has been emulated by numerous developers, chief among them the prolific Waves. You get two plugins for your money here: one modelling the three-band 550A, the second its four-band successor, the 550B. Every band of each plugin switches between five (550A) or seven (550B) fixed frequencies, with five steps of cut or boost (up to +/-12dB) on tap, and proportional Q narrowing the filter bandwidth as the gain increases. The high and low bands of both plugins can be individually set to peaking or shelving modes, too, and the Analog switch introduces preamp colouration when activated.

What’s always been remarkable about the 550s is the perfect selection and calibration of those centre frequencies, which never leave you wishing for greater precision, and the useful way in which they overlap in the 550B. Waves’ virtual versions get all of that just right, and sound fantastic doing it.

Tell us about your favourite vintage EQ plugins in the comments.