Buzz Audio REQ Dual Mono Resonance EQ 2.2

product review

Tape Op magazine by Larry DeVivo

I recently sold my beloved solid state Pultec EQP1A3 equalizers so I was in the market for a new unit to fill the empty void left in my mastering rig. Unlike my old Pultec program equalizers, this time I wanted something with more surgical precision to it. If at all possible, I wanted something with a bit of that Pultec "musical mojo" as well. Perusing the specs of the REQ 2.2 it looked like this unit might just be what I was looking for.

I contacted Buzz Audio's owner and designer of the REQ 2.2, Tim Farrant, to see what the chances were of getting a unit in for evaluation. Tim was in the process of building the first mastering REQ 2.2s and would be sending one of the units to Nathan Eldred at Atlas Pro Audio to send around. Unfortunately it was already committed to another mastering engineer David Greenberg of Sonopod Mastering. After a month of waiting, I finally got the unit in and it was well worth the wait.

Just looking at the unit, the Buzz Audio REQ 2.2 makes quite an impression . Not only is the build quality impeccable, but the blue colored knobs and two tone milled aluminum front panel makes the unit jump right out of the mastering console. With four equalization bands per side, 72 frequency points, bell and shelving switches on the hi and low bands, Elma (or Palazzo) precision stepped attenuators, separate high pass filter section and a unique set of switches called Saturation, the unit makes for one powerful equalizer.

Speaking of the Saturation control, this puts a steel transformer in the output signal path which changes the color of the EQ. Or should I say, it gives the EQ color. That's not to say that the standard signal path doesn't sound beautiful on its own, it does but in a very precise musical way. Not too clinical or boring... just "right". When engaged, the Saturation control adds that touch of vintage "musical mojo" I was looking for. I find this feature even more useful than the Pultec "transformer" trick ever was in that you can control the amount of saturation provided by the transformer. Where this feature really shines is on low end instruments like bass guitar or kick drum (just where one might use a Pultec). It tightens them up and gives them a much more solid feel while retaining a smooth top end on the rest of the program material. It's as if you boosted the low end on one of the equalizer bands and to a certain extent, looking at the graphs (provided in the exceptionally well written manual) you can in fact see that this is part of what is going on but with more of a 3D effect than just boosting an EQ point could do alone. In fact I just used this feature to great affect on over 50 comedy musical cues for an upcoming Hollywood movie that were composed using mainly sampled drums.

I have to say right here that trying to write about how an equalizer sounds or doesn't sound is very much like "dancing about architecture" as Frank Zappa once said. How do you describe the indescribable? My solution was to hear this mastering equalizer against as many other mastering equalizers as I could. Enter Dave McNair and his gracious offer to host a little listening session in his room at Masterdisk Studios.

I took the REQ 2.2 down to Masterdisk in NYC and we set the unit up in Dave's room. Dave has several well know mastering equalizers in his room and we set about testing the REQ 2.2 against them. Upon first listen, we were both impressed by how the EQ sounded. Throughout the time we were there, several of Masterdisk's other mastering engineers came into Dave's room to try the Buzz REQ 2.2. The one comment I heard over and over again from all the different mastering engineers was that the top end sounded just like the Sontec. A very high compliment indeed. Andy VanDette went as far to say that "many [other mastering equalizer manufacturers] say their EQ's sound just like a Sontec but this unit really nailed the top end." I'd have to agree. With most other mastering equalizers I've owned in the past, none of them could easily be used to great affect for raising the high end in shelf mode. They all seemed too heavy handed or unnatural sounding (the one exception being the Sontec). The REQ 2.2 is very natural sounding in doing this, never does the top end sound sharp or razor blade like... no "poke in the ear with a sharp stick" sound here. I find myself using shelf mode more often than ever before with exceptional results.

When I asked Tim why he chose to use resonant filters to do the actual equalization, his explanation was simple, direct and rather enlightening at the same time. "Why resonance? Well this pertains to the use of real chokes and capacitors as the filter elements. Filter circuits used in the GML or Sontec are "electronic" simulations of real inductors (or chokes) so you make a capacitor/resistor network look like a choke. These are easier to manipulate than real chokes. I wanted to make an EQ with the real thing!" Now it made perfect sense to me why the Buzz REQ 2.2 sounded better than most of the units I was shooting it out against. No op-amps here, instead the Buzz designed BE40 amplifier and real passive chokes. As stated on the Buzz Audio website "The passive resonant filters coupled with our True Class A BE40 amplifier technology yields a unique product with exemplary sonic performance and a new definition of tonality." I whole heartedly agree. However, implementing this kind of technology doesn't go without some minor negative trade-offs as well. When you engage the individual bands or the overall EQ, a slight delay (10 mS) is caused due to the internal relays. This basically means when you engage the EQ on, in the middle of dense program material being played a slight popping sound might happen. It also means when auditioning the EQ using the on/ off buttons you'll want to make sure you engage the buttons with the timing of the music being played. This becomes less of an issue when used in conjunction with a true mastering console and using the console's send and return section to put the equalizer in line.

Encouraged by the positive results at Masterdisk, I took the unit back to Silvertone for further "real world" evaluations in my own environment. After using the REQ 2.2 for over a month I find this unit has one of the best tactile layouts of any equalizer I've ever used. On/off buttons that light up for each channel, overload indicators for each side (this is really a nice touch and more useful than one might expect). Individual on / off buttons for each band. Separate switches for both the high pass filters and the saturation section (selectable over 6 different "presets" ) again with illuminated buttons. A nifty little feature found on the back of the unit is the "looping" input which allows you to daisy chain the REQ 2.2 with other audio devices. It also has two output connectors (paralleled) enabling you to feed two different separate devices. The high pass filter is very complete in the mastering version with frequency ranges at 20, 26, 34, 46, 58 & 70Hz. It should be noted here that these are different on the studio version as is the amount of cut and boost allowed; + or - 16 dB with continuously variable steps on the standard version while the mastering version is + or - 8 in half dB steps.

Using the high pass filter on this EQ seems more heavy handed than say the Weiss EQ but the overall effect is more pleasing to the ear. Very hard to describe but the REQ 2.2 seems to retain more of the musical sense of the low end while cutting than just about any other equalizer I've owned before. It takes out the low end muck without taking out the low end feel. I also found the precision I was looking for in an analog equalizer again. This thing rivals my Weiss digital EQ in many ways, however it conveys more of a smooth wide open sound and less of a clinical sterile feel that digital equalizers can sometimes convey. You really have to hear this and A/B it for yourself but whatever frequency I chose and then matched it on the Weiss, there was always a more open musical feel to what I was boosting or cutting on the REQ 2.2 with minimal phase shift around the chosen bands. Impressive to say the least.

With each source I tried the equalizer on, I came up with exceptional results prompting me to smile every time. In the end I figured with the amount of joy this unit gave me she was well worth the price of admission... so I bought the evaluation unit. I can't think of a higher compliment to end a review with.
[Silvertone Mastering July 2009].

specifications

Frequency Response measured with all eq bands on and set flat, Saturation and HPF off = 5Hz to 125kHz +0.2/-3dB
Harmonic Distortion at +10dBu signal level;
Saturation OFF; 100Hz 0.007%...1kHz 0.004%...10kHz 0.007%...100kHz 0.013%
Saturation ON POS-1; 20Hz 1.5%...100Hz 0.07%...1kHz and up 0.01%
Saturation ON POS-2; 20Hz 1.5%...100Hz 0.14%...1kHz and up 0.01%
Saturation ON POS-3; 20Hz 1.5%...100Hz 0.16%...1kHz and up 0.01%
Saturation ON POS-4; 20Hz 1.6%...100Hz 0.17%...1kHz and up 0.01%
Saturation ON POS-5; 20Hz 1.7%...100Hz 0.18%...1kHz and up 0.01%
Saturation ON POS-6; 20Hz 2.0%...100Hz 0.22%...1kHz and up 0.01%
Maximum Input Level; +25dBu
Input Impedance; approx 20k ohms
Maximum Output Level; +32dBu balanced
Output Impedance; approx 70 ohms
Input Common Mode Rejection; (ref 0dBu) 100Hz -65dB…1kHz -65dB…10kHz -60dB
Noise all bands ON set flat; -110dB below max output level (A weighted)
Power requirements 115V/230V selectable on rear panel
Dimensions 4U rack mount, 300mm deep

Specifications are typical of a production unit and are subject to change without notice. 0dBu reference = 0.775 volts RMS.