Video
Story
The Nine Series Overdrive Pro+ takes Maxon’s classic OD-9 circuit and serves it up with two side orders of Whoop-Ass in the form of 9/18 volt operation and a Mid Boost switch.
In 9-volt setting the Pro+ sounds and functions like the standard OD-9 with the added option of a healthy +3 dB of midrange boost at approximately 800 Hz (actual frequency is dependent on Control settings) – great for cutting through a band during solos.
TECH TALK
The OD-9 Pro+ starts with a jFET buffer which simultaneously offers high input impedance and low impedance into the rest of the pedal – this helps to preserve high-end clarity in the signal.
The first tone stage is the Mid Boost feature: A switchable Op Amp with clipping diodes in the feedback loop. When this stage is not in the signal path the pedal behaves like a standard OD9. With this stage in the path it adds subtle gain and definition to the sound, similar to a cascading gain stage.
From here it’s on to the standard OD-9 circuitry: A clipping Op Amp with diodes in the feedback loop that clip the signal gradually as well as a high pass filter that keep the low frequencies from being distorted as much as high. Next there comes a passive LP filter and then an active tone stage. After the tone stage it’s through the Volume pot, an Op Amp boost stage which bumps the signal 3X and then sends it to the output.
The Pro+ also utilizes an NJM2374A voltage conversion chip that changes the 9V power input into 9V+ and 9V-, increasing the headroom of the Op Amps (9V to 18V swing) and giving a bigger, chunkier sound to the overdrive.
The OD-9 Pro+ features Mechanical True Bypass switching via a Fujisoku 4PDT switch - Input is switched to ground when bypassed.
Specifications
Input Impedance: 500K Ohms
Input Jack: 1/4 inch standard phone jack
Output Impedance: 10K Ohms or less
Output Jack: 1/4 inch standard phone jack
Outputs: 1
Equivalent Input Noise: -116 dB or less (input shorted IHF-A-weighted)
Maximum Gain: Normal 43 dB (at 1.5 KHz), Boost 46 dB (1 KHz)
Controls: Drive, Tone, Level, Boost/Normal switch, 9/18 volt operation switch
Switch: Normal/Effect (true bypass configuration)
Power Supply: 9V Manganese dry cell battery (6F22) or special AC adaptor
Power Voltage: DC9 V (Battery) / DC10 V (AC-adaptor)
Current Consumption
35 mA (9 V) / 32 mA (10 V) at 18 volt
27 mA (9 V) / 27 mA (10 V) at 9 volts
Battery Life
Manganese Dry Battery approx. 3 hours
Alkaline Dry Battery approx. 8 hours
AC Adaptor: AC210N (option) Input: AC120V Output: DC9V/200 mA Center - / Sleeve +)
Dimensions (whole): 74 mm (W) x 124 mm (D) x 54 mm (H)
Manual
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