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The HAMMER nails it when it comes to stereo bus usage — "it adds punch, fullness and sparkle without adding any noise."

I’ve been a huge fan of A-Designs since reviewing their MP-2 tube mic pre after it debuted several years ago. I went on to review their Pacifica mic pre (which I bought) and their REDDI tube DI. In each instance, I was impressed with the sonic and physical quality of A-Designs’ product line.

Their latest device is the HM2EQ HAMMER, a dual mono-channel, three-band analog equalizer. The HAMMER has been engineered with a unique filtering system that allows the even harmonics to flow through its 12AT7 Philips tubes while filtering out unwanted noise. The result is a warm, musical sound with an open high end and amazing transparency for a tube device. The HAMMER provides a unique approach to equalization in comparison to other EQs; this quickly becomes apparent by looking over the filter-response graphs included in the owner’s manual. Each of the HAMMER’s three bell-curve filters span more than seven octaves at full boost or cut.


The 10-pound HAMMER is 10 inches deep and features beautifully milled aluminum knobs and a jet-black faceplate built into a 2U metal casing. The black faceplate is stunningly offset by the white titling, which makes for easy adjustment even in the dimmest control room.

Inside this hybrid vacuum-tube design piece is a toroid power transformer and a pair of 12AT7 tubes. The $2,695 box has a 30 kHz bandwidth and a -94 dBm noise floor. The frequency response -3 dB points are 5 Hz and 40 KHz. The unit is switchable between 120 and 230 VAC. The HAMMER’s inputs are passive and each channel has a single 12AT7 tube in its audio path. (The noise floor is specified to be -94 dBm across a 30 kHz bandwidth.) The outputs are driven by ICs and are transformerless.

The HAMMER’s front panel has identical controls for left and right channels. The equalizer includes independent frequency selectors and gain controls for its low, mid, and high-frequency bands. Also included are a hard-wired channel bypass and separate high-cut and lowcut filter switches per channel. The filters’ cut-off frequencies are fixed at 8 kHz and 84 Hz, respectively and their slope is 12 dB/octave. The low-frequency band is selectable between 30 Hz, 50 Hz, 100 Hz, 200 Hz, 300 Hz, and 400 Hz. The mid-frequency band is selectable between 250 Hz, 500 Hz, 1.2 kHz, 1.6 kHz and 2 kHz. And the high frequency is selectable between 2.5 kHz, 3.5 kHz, 5 kHz, 7.5 kHz, 10 kHz and 15 kHz. Each band’s boost/cut control provides ±13 dB continuously variable adjustment with no detents. The control knobs are large and demonstrate smooth, deliberate motion. There are no Q controls, floating Q or individual band bypass switches.

The HAMMER’s rear panel includes a pair of female XLR connectors for audio input and a pair of male XLR connectors for audio output.

In Use

I first put the HAMMER to use on kick and snare during a tracking session. I ran an AKG D112 through the Gordon mic pre then through the HAMMER on the kick and a Heil PR-20 thorough the Gordon pre then the HAMMER on the snare. I had good results in both instances, yet I occasionally missed the precision that I get when using an EQ with adjustable Q like the GML 8200. The bottom end sub-harmonic information I was able to pull out of the kick with the HAMMER was amazing. With a problematic snare drum I used the HAMMER to add some high-end sparkle and some punch with a single band of the GML set to a narrow Q to remove an annoying 800 Hz overtone.

During another tracking session I used the HAMMER on drum overheads, and again I had fantastic results. I used the Royer SF-12 through the A-Designs Pacifica mic pre and was able to get a beautiful sparkle and shimmer by boosting 10 kHz by 7.5 dB. In several instances (electric and acoustic guitar, violin, cello, and vocals), I found the HAMMER to be the perfect complement to ribbon microphones.

While recording a Baldwin grand piano, I ran a spaced pair of Audix SCX-25 mics through a pair of Hardy mic pres and the HAMMER EQ and had fantastic results by boosting 50 Hz by 2 dB, cutting 250 Hz by 2 dB and boosting 15 kHz by 3 dB.

My favorite use for the HAMMER is strapping it across the stereo bus. Anyone who has complained about the sonics of mixing in the box should give the HAMMER a try as I’ve found it to completely transform my mixes into an entirely different beast; it adds punch, fullness, and sparkle without adding any noise. I’ve been using the HAMMER this way for nearly a year now, and I’m continually impressed with its detail and precision. Rather than add it toward the end of a mix, I’ll add it early on before I start to insert a bunch of plug-ins on individual channels. This makes me rely less on plug-ins, which—when used overly aggressively—can often result in phase-correlation issues.

The thing that has continually amazed me about the HAMMER is that I can make drastic adjustments on individual instruments or on a stereo mix (boosting 10 kHz 9 dB, cutting 500 Hz 12 dB, or boosting 30 Hz 9 dB) and the audio remains smooth.

I wish that detented potentiometers on the band gain controls were optional; it would simplify recalls—but I’d be willing to pay more for this option. Additionally, I wish there was a way to bypass each of the three bands individually in addition to being able to bypass the entire EQ circuit.


The HAMMER is truly a new concept in equalization. This isn’t the equalizer to tweak a narrow frequency band or with a vintage tube sound. But if you are in need of a broad-stroking, smooth, and sweet sound, the magical HAMMER could be your salvation.

Review Setup: Apple Macintosh 2 GHz Dual Processor G5 w/2 GB RAM, Digidesign Pro Tools 7.4, Lynx Aurora Converters, Lucid Gen-X-96 Clock, PMC AML-1 monitors, Focal Twin6 Be monitors

Russ Long is an producer/engineer in Nashville and a regular contributor to Pro Audio Review.