Atomic Analog Tonograf EQ

A vintage German console EQ gets a new lease of life in 500‑series format.

Vinny Wood is based in Iceland, and there, under the name Atomic Analog, he repairs high‑quality vintage analogue pro audio equipment and also makes his own. Back in SOS October 2024, Sam Inglis reviewed his debut release, a substantial RCA OP‑6‑based preamp called the Special OP‑6 and was impressed. Now, Atomic have released a 500‑series equaliser called the Tonograf EQ. It may be smaller than the OP‑6, but there’s ample evidence that Vinny has taken the same forensic approach to recreating another obscure but desirable bit of kit. Atomic kindly made available a pair of Tonografs for review, and that was great because it’s nice to have the option to use them on stereo sources when recording, and also I often enjoy running a stereo mix through analogue EQ.

Picking Up The TAB

The Tonograf EQ is billed as a part‑for‑part recreation of the TAB W95 equaliser module. Developed in the early 1960s, the W95 was a transistor‑based update of earlier valve‑based designs, and, like most such vintage studio technology, it commands high prices today — apparently with good reason. On first hearing it, Vinny says he was immediately taken by the sonic effect of the discrete germanium circuit, which contains both inductors and transformers. So much so, in fact, that it left him with a “blissful impression” even when no EQ boosts or cuts were applied.

The Tonograf has more features, yet is more compact than the W95C.The R&D involved in recreating this device was a challenge for a one‑man boutique company, not least because many of the original components are simply not available now. It involved detailed analysis of the components, in the case of the inductors so that custom recreations could be commissioned, and the swapping of ‘surrogate’ parts into his original TAB unit until Vinny was satisfied that they behaved exactly as the originals did. The resulting design features Lundahl input and output transformers, those custom‑made inductors and ‘name’ components such as Panasonic, AVX and Vishay capacitors and Vishay and Yageo resistors, chosen not only to match the characteristics of the original without compromise, but also to ensure this new product endures as long as the originals have.

Working within the tight confines of the 500‑series format, Vinny opted not to adhere to the aesthetics of the original units, but wanted to retain the ‘tactile’ feel of their detented controls and ensure that all the same simple EQ options were available. Accordingly, you can find controls for low and high shelving capacitive EQ bands in the bottom half of the control panel, and an inductor‑based proportional‑Q mid band in the upper half. There are some welcome additions to the original design, though. First, while the high shelf of the original TAB module was fixed at 10kHz, here you have the option of setting it to 7, 10, or 16 kHz, giving the user some useful flexibility. The low shelf remains set at 60Hz, and both shelves can cut or boost by up to 12dB. Second, the mid band on the original modules was a boost‑only affair, and in the Tonograf the design has been modified to allow the mid band controls to apply cuts too (±9dB), as well as adding another centre‑frequency option for good measure: you have 500 and 700 Hz, and 1, 1.4, 2 and 3 kHz to choose from.

The nominal operating level is +4dBu and you can find other specifications on the Atomic Audio website but, really, noise and distortion specs are almost an irrelevance for characterful vintage‑inspired designs such as this! The modules need a host capable of supplying each one with 180mA, which might be a little higher than the official VPR Alliance spec permits but it is within the capability of pretty much all modern 500‑series racks.

High‑quality components were used throughout, and considerable time and effort went into matching the performance of the original TAB W95 circuit — not least the mid band’s inductor, which had to be analysed and recreated.

On Test

Having installed them in my IGS Panzer rack, I decided to see what the Tonografs could offer on the project I was working on at the time, so patched them into the stereo mix bus for some quick rough mixes I needed to send to my client. I began playing with the low‑ and high‑shelf filters, and was immediately taken with the way a 16kHz boost seemed to open up this piano‑led track. I was also impressed at the extra weight that the low shelf was giving me.

I went on to use the Tonografs on other mixes, and have to say that I really liked them for mix‑bus EQ’ing. The two units seemed to be very well matched and suitably ‘stable’ when used on stereo sources, and the sweetening effect of these circuits — a subtle but pleasing sort of ‘sheen’, combined with that satisfying touch of fullness you get from transformer‑based designs — as well as the broad‑strokes EQ options should be very appealing to engineers as they approach the final stages of a mix or master.

My first proper tracking session with these units was on a piano session. It’s an instrument for which I’ve developed a few mic techniques over the years to make my studio’s somewhat dark‑sounding upright sound richer and, well, generally a bit more ‘grand’! The Tonografs’ low and high shelves helped a great deal, with both set to boost at just shy of the 3 o’clock position, but while the EQ curve was obviously helping, there was more to it. Switching the EQs in and out revealed just what a dramatic effect they were having, and my client remarked on how good the piano was sounding.

The rest of my time with these EQ modules coincided with a very busy period at my studio, during which I recorded a series of young guitar bands who were chasing a sound that was very familiar to a ’90s kid like me! The Tonografs sounded superb on drum close mics, and the 60Hz shelving filter in particular worked nicely for adding extra weight on kick drums; it was also great to be able to cut some boxy frequencies at 500Hz or add more presence if needed. When paired with the classic close snare mic option of an SM57, it was possible to get heavy‑handed with the midrange boost at 1.4 or 3 kHz, and I found myself pairing this with a high shelf boost set at 7kHz or a cut at one of the higher frequency options. In both these high‑SPL settings, I quickly developed more of a sense of the ‘colour’ being imparted by the electronics over and above the boosts and cuts; it was easy to hear how the subtle amount of saturation complemented the music. I had a similarly positive experience using these EQs on close‑miked guitar cabinets: they worked a treat in those in‑depth ‘tone‑chasing’ sessions, where you just want to be able to lean over and pull a little brightness up in the sound or add more weight.

Summing Up

As you can probably tell, I was rather taken with these EQs! They’re the kind of thing that you find yourself wanting to leave in your recording chain whenever possible, even if you’re not actually making any EQ moves. That’s precisely how I found myself using them on vocals, in fact — sitting there as a sweetener, they’re gently flattering all the time but, should you need it, they also offer simple tone‑shaping at the twist of a knob.

Of course, a diligent reviewer must also search for negatives. But while I did find a couple of points worth noting, it’s not a significant list in the grand scheme of things. For instance, I often had to get out of my chair to see what settings I’d dialled in, but this is a common issue for me with 500‑series modules. Also worth noting is that these units do get very hot when they’ve been on a while, and the manual rightly suggests you give some thought to where to place them in your 500‑series chassis.

...if you stuck two of these modules in a 19‑inch rackmount chassis for a similar price, they’d be competing with products that cost much more.

Finally, boutique tools such as these rarely come cheap, and certainly these are at the more expensive end of what’s available for the 500‑series format. Having said that, these are some of the nicest‑sounding 500‑series EQs that I’ve used, and if you stuck two of these modules in a 19‑inch rackmount chassis for a similar price, they’d be competing with products that cost much more. But of course these were originally console EQs, so I think it makes good sense to stick with a modular format — there are still mixers that can host 500‑series modules like this, after all.

The bottom line is that if you’re carefully assembling a high‑end recording and mixing setup, these would be a fantastic addition, and are well worth checking out.