Input is fed into a 2SC1815 emitter/follower transistor to optimize the signal’s impedance structure. From here it’s on to the first section of an NJM 4558D Op Amp – NJM is the company formerly known as the Japan Radio Corporation (JRC) – the legendary manufacturer that designed and built tons of these components in the late 70’s/early 80’s.

In this non-inverting Op Amp there are diodes in the feedback loop that clip the signal gradually as well as a High-Pass filter that keeps low frequencies from being distorted as much as high frequencies – the classic “808” configuration that creates the tone we all know and love.

After this is a passive LP filter and then an active tone stage that uses the other half of the Op Amp to create a HP filter that brings back frequencies cut by the inter-stage LP filter. After the tone stage it’s through the volume pot, another E/F 2SC1815 to provide a low impedance output and then the true bypass switch.

The OD-9 features Mechanical True Bypass switching via a Fujisoku 4PDT switch – input signal is sent to ground when bypassed.

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: -114 dB or less (input shorted IHF-A weighted)

Maximum Output Level: 0 dBm

Maximum Gain: +40 dB (at 1.5 KHz)

Controls: Drive, Tone, Level

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: 6 mA (9 V) / 7 mA (10 V)

Dimensions (whole): 74 mm (W) x 124 mm (D) x 54 mm (H)

Weight: 580 g

Accessories: 9V Manganese dry cell battery (S-006P) x 1

Warranty Card: x 1

User's Manual: x 1