Let's face it: When it comes to overdrive, no one knows more than Maxon. Back in 1974 they invented the original "808" circuit, the staple overdrive design that has shown up in the rigs the world's greatest guitarists and has been copied, modified, and "upgraded" ad nauseum. Most boutique OD's are based on the 808 circuit, and there are more than a few self-proclaimed "fx-perts" out there who make their living developing mods for this legendary device and its successor, the OD-9.
Constantly ahead of these tweakers and unwilling to rest on their laurels, Maxon has been fine-tuning their overdrive units to meet with changing musical tastes and evolving technological trends for the past 30 years. The results of these efforts have included such highly sought after gems as the Super Tube, Sonic Distortion, and OD820 Overdrive Pro. So, who better to offer the definitive improvement on the classic 808 design than the company who put it at the feet of guitarists in the first place?
It's with great pride that Maxon introduces the OD-9 Pro+ Overdrive. At long last, an overdrive unit that meets and exceeds the demands of the market and deservedly takes its place beside the legendary 808. While developing the OD-9 Pro+, Maxon enlisted the help of several professional guitarists, including Scott Henderson, Lyle Workman (Sting), Borislav Mitic, Chris Traynor (Helmet, Bush), Phil Caivanno (Monster Magnet, Jackalope), and Joel Stroezel and Adam Dutkeiwicz (Killswitch Engage). All avid OD808 or OD-9 users, this "advisory board" offered us further insight into what features would be most useful in creating a new classic overdrive pedal.
Starting with the basic OD-9 circuit, Maxon improved the dynamic range of the OD-9 Pro+ by replacing the output stage transistor with a low-noise NEC uPC4570 OP-Amp. This substitution allows for less compression than the OD-9, providing a more balanced response from low to high ranges without emphasizing the mids like the OD-9 does. Output level is also +6dB higher than the OD9, so that the Pro+ effectively sounds twice as loud to your ears. In addition, this component change also offers a true undistorted signal when the Drive control is set at zero, allowing the Pro+ to be used as a clean booster as well as an overdrive.
New to the OD-9 Pro+ is the addition of a switchable Boost feature. Here's where the real fun begins. In Boost mode the midrange is goosed by +3dB, while high and low frequencies are reduced slightly. With 2 series distortion circuits, the overdrive level in Boost mode is also increased by +10dB, creating a thicker, more saturated overdrive tone. An NEC uPC4570 OP-Amp is used in the second distortion circuit, assuring low-noise operation. This new Boost mode provides a more compressed sound than Normal mode, and is perfect for searing lead passages that really jump out of the mix. Bright, Singing sustained notes and improved harmonic response are further benefits of this new feature. If you always felt that the OD-9 was a bit anemic, the Pro+ Boost Mode is just what the doctor ordered.
The biggest improvement to the OD-9 circuit comes with the addition of a stabilized DC-DC voltage converter in the power circuit of the Pro+. This voltage converter bumps 9 volts (plus and minus 4.5 volts) up to 18 volts (plus and minus 9 volts). A much wider dynamic range and increased head room are the benefits of this feature, allowing a fuller frequency response and the ability for the pedal to handle today's ultra high-gain pickups and active electronics. Best yet, the operating voltage is switchable between 9 and 18 via an internal DIP switch that is accessible through the unit's battery compartment, offering a choice between the classic OD-9 tone and this newer, full-frequency tone.
Like all Maxon Nine Series models, the OD-9 Pro+ features True Mechanical Bypass switching courtesy of a 4PDT switch. With the combination of these new features and circuitry, the Maxon OD-9 Pro+ effectively functions as a 4-voiced monster, offering everything from the classic, bluesy tones of the original 808 to the searing saturated chunk demanded by today's extreme metal music. Effective, functional, phenomenal - the Maxon OD-9 Pro+ is soon to become the reigning king of the stompbox world.