Boss SG-1 Slow Gear 1979

Up for sale is a legendary and highly collectible BOSS SG-1 Slow Gear, Made in Japan.

This unit features the ultra-rare 4-digit stamped serial number "8300", dating its production to June 1979 (First year of production). It features the highly sought-after original Silver Screw and clear skeleton switch from the earliest era.

It is in 100% perfect working condition. This particular listing is an absolute museum-grade collector's dream, coming as a full set with rare original Japanese documentation!

[ What's Included ]
◾️ BOSS SG-1 Slow Gear (Serial #8300, June 1979, Silver Screw)
◾️ Original Box (Matching vintage box from the era)
◾️ Original Japanese Manual (Instruction sheet)
◾️ Vintage Warranty Card (From the era, for historical display)
◾️ Original Vintage BOSS Sticker

[ Internal Details ]
◾️ Op-Amp (Integrated Circuit): Ultra-Rare Original Vintage NEC μPC741C
◾️ Op-Amp Lot Code: P9101E (Dating the chip manufacture exactly to early 1979!)
◾️ PCB (Circuit Board) Number: 052-471 (SG-1 471)
◾️ The circuit board is 100% original, untouched, and clean. No modifications, no repaired solder joints, and no component replacements. The internal wiring and pots are exactly as they left the Roland/BOSS factory in Japan back in 1979.

[ Recent Operation Test & Performance ]
◾️ Fully Tested & 100% Working: This unit has been recently tested and is confirmed to be in 100% perfect working condition.
◾️ No Scratchy Noise: There is absolutely no scratchy noise (scratchy pots/scratchy audio) mixed in. The controls work flawlessly and smoothly.
◾️ Experience the Real Vintage Swell: During our tests, we noticed a massive difference in performance depending on the voltage. When powered with the correct voltage, the automatic volume swell/violin effect becomes incredibly responsive and dramatically richer. To experience the true, breathtaking magic of this 1979 original sound, we highly recommend running it with the correct power supply setup as detailed below!

[ Important Note on Power Supply (ACA Spec) ]
Like all original SG-1 pedals, this vintage unit operates on the BOSS ACA 12V DC power specification (not the modern 9V PSA regulated spec).
◾️ To power it correctly via an AC adapter without hum/volume drops, you will need a vintage BOSS ACA-100 adapter, or power it using a multi-power supply with an unregulated 12V DC output.
◾️ It runs perfectly on a standard 9V battery as well (Highly recommended for testing the full brightness of the LED and max effect response!).
◾️ Please note: If you plug a modern 9V PSA adapter directly into it, the LED check light may be dim because the internal circuit drops the voltage.

Pro-Tip for modern 9V PSA Power Supplies (Daisy Chain Trick):
If you want to use a modern 9V PSA power supply, you can bypass the internal voltage-drop circuit by powering the SG-1 using a daisy-chain (split) power cable shared with any other standard 9V (PSA-spec) pedal, as long as they are also connected via patch cables. This shares the common ground, allowing the SG-1 to receive full 9V power, and the LED will light up at full brightness!

[ Note on Momentary Check LED (Factory Specification) ]
◾️ Like the earliest 1979 first-batch BOSS pedals (such as the early OD-1 and SP-1), this unit features the legendary Momentary "CHECK" LED circuit.
◾️ How it works: When you press the footswitch, the red LED illuminates for a brief split-second to "check" the battery life, and then turns off immediately when you release your foot. The effect itself remains ON. (To turn the effect OFF, simply press the footswitch again—the LED will flash for another split-second to acknowledge the switch).
◾️ Please rest assured that this is 100% the correct, normal, factory-original vintage specification for this ultra-early model, NOT a defect. Collectors highly covet this specific quirk as proof of its 1979 un-modified circuit!

[ Condition ]
◾️ Pedal Body (Cosmetics): Excellent, clean condition! This unit appears to have been stored in a very well-controlled environment for decades. There are no major visible damages, heavy scratches, or deep paint chips. It is incredibly well-preserved for a 1979 vintage pedal.
◾️ Internal Board (PCB): Superb and pristine. As seen in the photos, the internal circuit board and components are exceptionally clean with absolutely no dust, rust, or degradation.
◾️ Rubber Grommet (Guide Bush): Replaced with a brand new, genuine BOSS factory part! The original vintage rubber had degraded over time, so it has been freshly replaced with a brand new, authentic BOSS grommet. It fits perfectly, functions flawlessly, and protects the silver screw area for decades to come.
◾️ Accessories: The original box, manual, vintage warranty card, and sticker show honest vintage wear, aging, and scuffs appropriate for their age, but they remain perfectly intact.

[ International Buyers - Please Note ]

◾️ For US Buyers (DDP):
The shipping rate for the United States includes all necessary U.S. customs duties and administrative fees prepaid via Zonos (DDP). You will not be charged any additional customs fees or import taxes upon delivery. (State Sales Tax will be automatically calculated and collected by Reverb at checkout as required by law).

◾️ For Buyers in Other Countries (Canada, UK, Australia, Singapore, etc. / DDU):
Import duties, taxes, and customs clearance charges are not included in the item price or shipping cost. These charges are entirely the buyer's responsibility.
Please check with your country's customs office to determine what these additional costs will be prior to buying. We cannot undervalue items or mark them as "gifts" on customs forms, as it violates international shipping regulations.