Audio Technica's original 4033 cardioid condenser has been around for some years now (check out the review in the April 1992 issue of SOS) and has become something of a modern studio classic, but now the company has updated this mic by redesigning the internal electronics and changing the capsule suspension system to reduce handling and stand-borne noise still further. To indicate the differences, the redesigned 4033 has now gained a letter 'a' on the end of its name.
Part of the key to the original 4033's success was its affordability, and that in turn was made possible by using a fixed-pattern, cardioid back-electret capsule rather than a multi-pattern, dual-element capacitor capsule. In terms of performance, the back-electret capsule seems every bit as capable as a conventional capacitor capsule, and certainly hasn't adversely affected the mic's success -- over the years, the 4033's silky, detailed, warm sound has won it a lot of users.
Packaged in a similar way to other large-diaphragm mics, the AT4033a is transformerless and features a capsule built around a two-micron, gold-deposited diaphragm that has been processed to artificially age it, the idea being to ensure long-term performance stability. Even without the use of the 10db pad (see below), the capsule and preamp circuitry can handle levels up to a punishing 145dB without incurring more than 1% Total Harmonic Distortion (THD), and the new low-noise circuitry is fully symmetrical, providing very low distortion figures and a fast transient response. Not only does the circuitry have a low noise figure, it also provides a high output, making this a very sensitive microphone within its class: at just over 25mV/Pa, the mic is up to twice as sensitive as some ostensibly similar models, and the 17dB noise performance is creditable.
A high-pass, 80Hz, 12dB/octave filter can be activated with a recessed switch on the mic body, and there's also a 10dB pad which may be required to prevent console overload when operating at very high SPLs. The entire casework is finished in non-reflective black and the capsule is protected by a dual-layer grille. A thin layer of acoustic foam is positioned between the grille and the capsule.
Because of the large, open-basket construction, the off-axis response of this microphone is particularly impressive -- at 90 degrees off-axis, the frequency response is almost identical to that on-axis, but 6dB lower in level. The provided response plot shows the mic to be nominally flat from 30Hz to 20kHz, and though there are some slight undulations in the curve, there's no more than a couple of dBs of lift above 10kHz.
Two versions of the mic are available, but the only difference is in the mounting hardware provided -- the AT4033a/SC includes a basic stand clip, while the more costly AT4033a/SM comes with a heavy-duty shockmount system. The package comes in a practical, rigid vinyl carry case with foam lining.
Though the technical improvements to the original design may make a slight difference in marginal operating conditions, I don't think existing AT4033 owners need worry about selling their mics and trading up. Comparing the two models side by side, the mixer mic amp noise swamped any differences that might have been audible in the background noise level. I feel it's more important to confirm that in redesigning the electronics, Audio Technica haven't compromised the mellifluous tonality of the original -- so many so-called improvements seem to throw out the baby with the bath water. Fortunately, I couldn't detect any tonal change at all in a side-by-side comparison.
For those who haven't heard a 4033, both it and the newer 4033a produce a warm, flattering sound which somehow combines the solidarity of a really good dynamic mic with the transparency and detail of a top-end capacitor model. There's a flattering fullness to the sound, which goes some way towards emulating the sound of a tube mic, although it falls just short of the real thing -- tube mics often sound a little compressed, for some reason. However, if you make use of a tube mic preamp, or pass the signal through a channel with a tube processor in circuit, you can get very close indeed to vintage perfection.
All large-diaphragm mics have their own character, and the AT4033a is certainly no exception. Put it next to an accurate reference mic such as the Earthworks OM1 (reviewed elsewhere in this issue) or one of the Sennheiser MKH-series mics, and there's an obvious difference. It's always hard to describe mic characteristics in mere words, but the 4033a sounds both warm and intimate, yet there's plenty of space and air around the sound. It doesn't quite have the throatiness of a tube mic, but it certainly leans in that direction. Even though there are cheaper large-diaphragm cardioid condenser and back-electret mics, the 4033, and now the 4033a, remain my favourites within their price range. It's nice to see a company making genuine improvements to a best-seller without changing the fundamental character that made it so successful in the first place.
pros
Flattering on vocals and many acoustic instruments.
Sensibly priced.
Good technical spec including low noise, high sensitivity and tolerance to high SPLs.
cons
The shockmount is rather expensive.
summary
Audio Technica have made genuine technical improvements to this well-loved microphone without disturbing its fundamental tonal character.
£ AT4033a/SC (mic including stand clip) £651.95; AT4033a/SM (mic including shockmount) £694.95; AT8137 foam windshield £36.95; AT8446 pop shield £59.95. Prices include VAT.
A Audio Technica, Technica House, Royal London Industrial Estate, Old Lane, Leeds LS11 8AG.
T 0113 277 1441.
F 0113 270 4836.
Multi-pattern Condenser Microphone
Audio-Technica have added multiple polar patterns to one of their already successful designs, bringing increased versatility in the studio.
Audio Examples
Stereo Condenser Microphone

Theres more to this variation on Audio-Technicas flagship microphone than the simple addition of a second capsule...
Condenser Microphone
Paul White explores the capabilities of the understated-yet-powerful Studio Pro M2.
Microphone Preamp

Schoeps make some of the most revered mics on the planet, so when they release a commercial version of the mic preamp they use for testing, you have to take it seriously...
Test Measurements
The following charts, made using an Audio Precision Analyser, accompany our review of the Schoeps VSR5 microphone preamplifier.
Handheld Condenser Microphone
Designed as a hand-held live vocal mic, this mic has a cardioid pickup pattern, and seems very robustly engineered.
Mono Valve Equaliser

British 'boutique' outboard manufacturers seem to be rather thin on the ground these days, but if this Pultec clone is anything to go by, newcomers Cartec look set to make a big impression.
Dynamic Microphone
Prodipe say they wanted to offer a high-quality, live-sound, cardioid-pattern dynamic mic at a very affordable price.
Multi-pattern Condenser Microphone

Sontronics mics usually sound as distinctive as they look - and this one looks more distinctive than most!
Multi-pattern Valve Microphone

Hot on the heels of the impressive Genesis cardioid valve mic, MXL have unveiled their flagship multi-pattern model, the Revelation. Does it live up to its name?
MXL Revelation | Audio Examples
Multi-pattern Valve Microphone
These audio files accompany the SOS September 2010 review of the MXL Revelation microphone.
USB Microphone
Valve Microphone

Does AKGs Chinese-made Perception 820 maintain the Austrian companys impressive reputation?
Audio Examples
Hear for yourself how this mic performed during the SOS tests.
Audio-Technica AT4080 & AT4081
Ribbon Microphones
A-Ts brand-new transducer technology has produced a robust design intended to deliver high signal levels as well as that prized ribbon character...
Snare & Tom Condenser Microphones
Despite the ubiquity of the SM57 for use on snare, there are other options — and Earthworks aim to help you capture a more natural sound.
Cardioid Valve Microphone

We put MXLs Genesis through its paces alongside a much pricier model, to find out just how good a tube mic can be at this price.
Hear For Yourself
To accompany our July 2010 Genesis review, we recorded a series of standard tests with the review mic alongside a more established mic (in this case, the AKG C12 VR).