Offer Details

I purchased this unit off a fellow reverb seller in 2025, the seller had indicated the serial # was 9-021226, since the paper serial on the outside of the unit is long gone the seller may have crossed referenced that "MR 45" factory inspector signature with production log records to pull the exact 9-021226 registration batch number. At any rate supposedly this unit was from 1978 based on the previous owners research.As far as the unit itself is concerned, it works really well, and I was quite surprised how good it sounds, I've used it for a few times on recordings but for the most part its been in my closet so time to let someone else enjoy it.Please note: “Enclosure interior contains typical black residue from the original factory foam disintegrating over time, but the circuit is completely unmodified and original."  I’m not making any attempts to clean or even blow air into the unit since its up for sale as someone may perfer this condition to validate its age and has not been messed with.About the unitThe 1978 MXR Six Band Graphic Equalizer (Model MX-109) is a legendary, analog tone-shaping tool. Released in the mid-1970s, it is housed in a distinct dark blue, cast-metal casing and operates entirely on a 9V battery.Key Specs & DesignFrequency Bands: ±18dB of cut or boost at 100 Hz, 200 Hz, 400 Hz, 800 Hz, 1.6 kHz, and 3.2 kHz.Controls: Six tactile sliders and no bypass footswitch—meaning it is always on when connected to the signal chain.Power & Build: Powered exclusively via a 9-volt battery. The cast metal enclosure is incredibly robust, measuring roughly 2 ¾" x 4 ¼" and weighing just under a pound. Tone Shaping & LegacyThe vintage MXR 6-Band is famous for its role in the signal chains of guitar legends like Eddie Van Halen and Dimebag Darrell. Players frequently use it to: Dial in the classic "scooped-mid" rhythm tone (a prominent V-shape on the sliders).Boost the 800 Hz frequency to create a searing, cutting lead tone.Tighten up muddy low-end in pickups and simulate a driving boost. Because of its analog circuitry, it offers incredible headroom and natural warmth. Today, vintage units are highly collectible and often range between $150–$300 on the used market.