Audio Technica AT4060

Paul White tests a new valve mic that captures the essence of a good vintage design at a realistic price.

Valve mics are very much in fashion at the moment, with many of the more established companies trying to recreate their former glories at affordable prices, often by re‑engineering some parts of the design to reduce the build cost. Newer companies such as Rode and Groove Tubes have also made tube mics central to their product ranges, but Audio Technica, who are likewise relatively new in microphone terms, have until now left the valve market to others. Whether the AT4060 is a one‑off or the first of a new series remains to be seen, however.

Although the AT4060 looks like a stretch‑limo version of Audio Technica's popular AT4033 mic, it's actually very different — the 4033 is a back‑electret mic while the 4060 utilises a brand‑new, externally polarised, large‑diameter capsule. As with all the Audio Technica mics I've tried in the past, they've clearly paid a lot of attention both to engineering detail and to sound quality. Though it offers only a fixed cardioid pattern, the capsule has a dual‑diaphragm construction, ostensibly to improve the high SPL capacity of the mic without compromising its high‑frequency performance. I would have thought that once they'd gone to the expense of designing a dual‑diaphragm capsule, they'd have gone all the way and made the mic multi‑pattern, but perhaps they have that in mind for a future model based on this capsule?

As with the AT4033 and AT4050 capacitor capsules, the AT4060 employs gold‑coated diaphragms fabricated by a vapour‑depositing technique. The capsule is then artificially aged using a five‑stage process to give maximum stability over its operating life.

The mic housing follows similar lines to the 4030 and 4050, though the body is significantly longer to incorporate the tube amplifier. The valve, which is a miniature type, is hand‑selected and internal anti‑vibration mountings are employed for both the valve and the capsule to minimise tube microphony and handling noise. An AT8447 shockmount is included with the mic as standard, as is a protective case, though a basic screw‑thread mount is available as an optional accessory. The shockmount is nicely engineered with two inner rings supporting the microphone, these in turn being supported within a single outer ring by means of elastic loops. As with the other mics in the 40‑series, the AT4060 features a symmetrical, open‑basket structure, all‑metal construction and a matt black finish.

Unusually, there are no pad or rolloff switches on this mic — the literature claims that it can handle levels of up to 150dB without either the capsule or the preamp contributing significant levels of distortion. Power for the microphone comes from the included AT8560 1U, half‑width power supply (supplied with rackmount ears), which connects to the mic via the included 10 metre 6‑pin XLR cable. A regular XLR mic cable is needed to connect the PSU to the mic input of a mixing console or other device. The PSU is as straightforward as the mic — there are no controls other than a mains switch, a ground lift switch and a rear panel 120/230V selector.

Performance

In my view, the best‑sounding valve equipment is not usually designed with a view to creating a specific valve sound. When valve mics were first invented, nobody thought about the relative merits of 'the valve sound' because there was no other means of amplification. The engineers did their best to create circuits that added as little noise and distortion as possible, rather than bias the valves to deliver intentional distortion. I don't feel excessive levels of soft saturation are what the valve sound is really about, though subtle harmonic distortion does come into the picture, as it's inherent in the way valves and their matching transformers work. Indeed, the output transformer required to interface the high‑impedance world of the valve to the much lower impedance of a typical mixer mic input often adds as much to the sound as the valve does, so it's hard to pin down exactly where in the circuit the magic comes from. It's also worth remembering that you can design a bad‑sounding valve amplifier, just as you can design a bad‑sounding solid‑state amplifier — simply having a valve on board is not in itself any guarantee of sonic satisfaction.

The AT4060 certainly doesn't seem to have been designed to deliberately hype the sound — its distortion rises to around half a percent only at SPLs of over 130dB, and even at a massive 150dB SPL, the figure is still only around 1 percent. At normal operating levels, it's likely to be much lower. Similarly, the frequency response is notably free from the dramatic bass humps and presence peaks that go hand in hand with so many 'character' microphones. Other than a very gentle level rise below 200Hz and above 2kHz, the response is essentially flat up to 13kHz or so, after which it falls very gently to around 6dB down at 20kHz. This has the effect of lightening the mid‑range slightly, which tends to enhance the sense of detail and loudness, albeit very subtly. The AT4060 is also pretty quiet for a valve mic, with a quoted noise figure of just 19db SPL (signal‑to‑noise ratio of 75dB at 1Pa at 1kHz), while the sensitivity of ‑34dB for 1mV at 1Pa is fairly typical of other capacitor mics.

The Sound

So far then, the AT4060 comes over as a very nicely engineered microphone with a more than respectable paper specification, but what really matters is the subjective sound. In comparison with the 4033, the 4060 is similar in character but a little richer‑sounding in the lower‑mid and bass regions. The top end is both smooth and detailed as well as being very open‑sounding. It doesn't scream 'valve mic' at you right away, but that's no bad thing, as too much artificially created warmth can often make the sound seem a little congested. The performance is more like that of a pedigree valve mic — it flatters the sound, but not in an over‑obvious way. Vocals sound solid, natural and airy, while plucked stringed instruments come over with plenty of dynamics and life.

Summary

Though not the cheapest of the available valve mics, the AT4060 delivers a very classy sound at a sensible price (while comparisons also serve to show just what an exceptional performer the 4033 is). In these days when some readers are basing their entire studios around a computer costing less than this microphone, it's sometimes difficult to put the term 'affordable' into a proper context, but treated with care, this mic could still be giving you first‑class service in 20 years' time, which is a lot more than you can say for your computer! The fixed cardioid pattern is unlikely to be a problem for most users, as the majority of studio vocals seem to be done using a cardioid setting. Having no pad switch is unlikely to cause problems either as the mic has such a wide dynamic range, though a low‑cut switch might have been useful when working with a mixer that doesn't offer that facility.

In all, the 4060 is a nice‑sounding, beautifully made all‑rounder that has the courage to be a little different; most tube mics either mimic existing classic models or adopt a deliberately retro styling. I also appreciate the honest valve sound, rather having overblown distortion thrust upon me as a feature I can't turn off! The AT4060 is most definitely a worthwhile addition to the AT range that anyone interested in buying a quality valve mic would do well to try out.