Wolff Audio FREQ

With pristine sound and four switchable bands, Paul Wolff’s 500‑series EQ design strikes a balance between versatility and intuitive control.

There are lot of 500‑series EQs, so a new one had better offer something a bit different from the crowd! That poses an awkward conundrum for the designer: given the space constraints, it’s not easy to add features to an EQ in this format without sacrificing something. But, in his FREQ, industry legend Paul Wolff has attempted to deliver a decent balance of sonics, features and practicality.

FREQ Scene

Described as a ‘four‑band, proportional‑Q, parametric EQ’, the FREQ is a single‑channel, single‑width 500‑series equaliser module. The output is balanced using a custom Cinemag nickel and steel output transformer, which Wolff says was selected for its transparency rather than for obvious coloration, and the amplifiers that drive this transformer are based around OPA2134 ICs, though reportedly the FREQ can be modified to use discrete op‑amp modules if desired. What colour this thing does impart is largely third‑harmonic distortion at the low end, which I generally perceived as a subtle enrichment of the bass. Higher up the spectrum, it really does sound as clean as a whistle, and there’s lots of headroom too, with clipping not occurring until +28dBu.

Each of the four EQ bands can function as a proportional‑Q bell type, with the bandwidth narrowing as you apply more boost/cut, making them suitable for gentle tone‑shifts or for tackling resonances. The gain control offers ±15dB in all cases. The top (HF) and bottom (LF) bands’ frequency pots range from 2‑20 kHz and 25‑700 Hz, respectively. The HM (high mid) band ranges from 350Hz to 10kHz and the LM (low mid) from 75Hz to 2.2kHz. So there’s plenty of overlap of adjacent bands.

The HF and LF bands each have a blue backlit button labelled Wide that, when lit, turns the band into a shelf. As with all the buttons on this module, they operate sealed relay switches, so should remain clean and crackle‑free for many years. The two central bands also each have a a button to change their function. In this case, the backlighting is yellow, and the button fixes the bandwidth at 1/3 octave. Being narrower, this essentially makes it possible to perform much more targeted cuts, such as to dip out some harshness in a vocal without too much collateral damage.

Between those two bands’ buttons is another, this time green‑backlit. This is an on/bypass button for the whole EQ, and is a hard‑wired bypass, but it’s also easy enough to bypass individual bands, since their gain knobs have detents at the unity gain position.

It’s a good, practical balance for a 500‑series module, that all feels very instinctive and immediate in use.

In Use

I used the FREQ on a range of sources in a mix, and since I had only one module I created a mono bus to see how it fared on drums. It served very well in all cases, being just as versatile as you’d hope a console‑style EQ would be. Yes, a true parametric EQ would allow greater control but it would also leave you with more to do, and in this diminutive format the additional knobs required can increase the risk of fingers catching and shifting adjacent controls. The FREQ’s bell band’s frequency and gain knobs take you a long way very swiftly, while the Width and 1/3 buttons allow you that bit more scope to bend a sound to your will. It all feels like a good, practical balance for a 500‑series module, and very instinctive and immediate in use.

In terms of sonics, cleanliness is the name of the game here, with very low noise and distortion. I detected just the tiniest hint of flattering colour at the bottom end, but elsewhere my ears were greeted with an appealing clarity. The top shelving band, for example, sounds effortlessly clean and classy. It was trivially easy to tame cymbals or to bring out the breathiness in a ribbon‑miked vocal, and when applying the maximum HF boost, as part of an attempt to rescue a dull‑sounding male vocal captured with an inappropriate dynamic mic, there was no trace of ‘grit’ or ‘scratchiness’; all I could hear was the beauty in the source being brought out. There’s headroom for days too, to the extent that I struggled to get a sound directly out of my audio interface that would clip it.

C’est Chic

In the 500-series, you can use dedicated modules to put any sort of colour you want into your signal chain at any point, so there’s arguably good sense in opting for elegant simplicity in your main EQ. The Wolff Audio FREQ ticks that box handsomely, while offering enough functionality to make it versatile. Of course, it’s jostling for position in a crowded marketplace, where you’ll find the likes of API, RND, Mäag and Undertone Audio, to name just a handful, but the FREQ is ample evidence that Mr Wolff knows how to make a high‑quality, great‑sounding circuit. With four switchable bands here, it’s a great all‑rounder, and if that’s what you’re after it would be well worth sticking on your audition list.