AD2022 - Dual Mono Preamplifier

 

By Walt Szalva for Mix Magazine-All Rights Reserved 11/30/00

The folks at Avalon Design have made quite a name for themselves by designing high quality outboard gear that is as well known for its robust sound as it is for its very sexy look and feel. I've had the pleasure of accumulating several pieces of Avalon gear over the years, including the M5, their premiere one channel microphone pre amp/DI combo. So when Avalon released the AD2022, an updated two channel version of the M5, I was more than happy to take it through the testing process.

The AD2022 is a dual mono fully discrete Class A pre amp, combined with two Hi-Z instrument inputs. As is the case with the M5, the microphone input stage utilizes a low-ratio, balanced input transformer. Split low-ratio primary windings are combined within a custom mu-metal core for extended frequency response and low distortion. An obligatory variable high pass filter is built in for eliminating low frequency rumble at sub-sonic frequencies.

Improvements over the M5 include what is at first glance the most obvious - an output gain control, which belies the most drastic change in design. The AD2022 utilizes two signal amplifiers per channel, as opposed to one per channel in the M5 which, according to Avalon, "improves transient response and doubles the internal bandwidth" of the amplifiers. The output gain stage is controlled with an additional pot on the front of the unit.

Another improvement Avalon has incorporated is in putting the two hi-Z instrument inputs on the front of the unit (on the M5, they are on the back - terribly inconvenient). Additional improvements include selectable microphone source loading, an improved power supply, and doubled plated circuit boards for superior low level signal transfer.

Over the past several years, I've come to love using my M5 in a variety of situations, but one of my favorites has been for vocals. With that in mind, this was the first test I took the AD2022 through, and the female vocalist on this particular session was a real screamer. One thing about the M5 that is shared by the AD2022 is its ability to take an exceptionally high sound pressure level before distorting - definitely important with loud vocalists like our subject. As was expected, I found the AD2022 to have the same overall characteristics as the M5: smooth, with a well defined top end and tight low end, and very present, or as our vocalist called it, a "real in your face" sound.

The addition of the second amplifier and gain stage to the AD2022 allows you to control the color a bit more than the M5 by varying the ratio between the two amplifiers. Also, the addition of the "selectable microphone source loading" switch (50, 150, 600 Hz) adds even more control options - a definite plus over the M5.

Next I tried the AD2022 in a variety of situations using various microphones. These included drum overheads with a pair of U67s, a room mic using a U47, and a tenor sax using a Royer 121 ribbon mic. The AD2022 was exceptional in all of these situations, but I was especially pleased with the drum overheads within the context of the tune at hand - a roots-rock song with a lot of cymbal and hi hat activity. The drummer was as pleased as I was with the overall clarity of the kit and definition of the cymbals.

As far as the DI goes, the AD2022 is the same animal as the M5, which has always been my first DI choice when I'm looking for a colorization factor that is within the middle range of my various DI units. Synth pads, sampled drums and synth bass all benefit from the AD2022's fast transient response, and if you're looking for a clean but extremely ballsy bass guitar DI, this is one to put at the top of your list. With the instrument inputs being on the front of the unit, the hassle factor has been reduced substantially - extra kudos to Avalon for this improvement.

The bottom line on the AD2022: Avalon has improved on an already successful design without adding non-essential features. As is the case with the M5, the AD2022 is an exceptional piece of gear that would do well in a wide variety of situations, and it would surely get a lot of use in this engineer's studio.

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