Vintage Alps Japan 100KΩ Stereo Dual Linear Potentiometer

Dual-Ganged 100kΩ Linear Control with Loudness Taps | Vintage NOS

👨‍🛠️ Bench Verification & Technical Condition

Up for sale is a rare, premium New Old Stock (NOS) vintage Alps Made in Japan 100kΩ dual-ganged stereo potentiometer. Purchased in the late 1970s for premium audio servicing, this features the highly specialized 4th terminal per channel: an integrated physical Loudness Tap. This is a critical component required for period-correct restorations of classic Japanese silver-face stereo amplifiers and receivers. I have a second one of these listed separately and can manually combine postage if you want both.

Circuit Board Protection: Features an integrated mechanical anti-rotation / locating lug on the front body face to index cleanly into the front chassis panel, preventing torque from cracking delicate circuit board solder joints.
Pristine Track Health: Beautifully gradual, smooth linear resistance progression across both tracks, dropping down to a clean 1.9 Ω minimum floor when turned fully counter-clockwise.
Stereo Tracking Balance: Directly verified on the bench with a digital multimeter to confirm an authentic vintage Japanese BX2 Linear Curve matching the following precise channel values:

🔹 TOP POT (Channel 1):
• Total Resistance (Max): 98.40 kΩ (Minimum: 1.9 Ω)
• Loudness Tap (Pins 1 to 4 / Mid-Sweep): 48.82 kΩ

🔹 BOTTOM POT (Channel 2):
• Total Resistance (Max): 97.12 kΩ (Minimum: 1.9 Ω)
• Loudness Tap (Pins 1 to 4 / Mid-Sweep): 47.03 kΩ

📊 Verified Component Specifications

Brand / Manufacturer	Alps (Made in Japan)
Resistance Value (Nominal)	100 kΩ Nominal Stereo Pair
Top Pot Measured Total	98.40 kΩ
Bottom Pot Measured Total	97.12 kΩ
Casing Stamp / Markings	18-100KΩBX2
Architecture & Taper Curve	Dual Stereo Pair Carbon Track \| "B" Linear Taper Sweep
Loudness Taps (Pins 1 to 4)	Top: 48.82 kΩ \| Bottom: 47.03 kΩ (Integrated 4-Pin Array)
Mounting & Anti-Rotation	Threaded Collar (6mm Length) + Front Body Locating Pin Lug
Shaft Style & Material	Aluminium Split-Centre Knurled Spline (17mm Total \| 12mm Spline)
Terminal Architecture	Rigid, Untinned PCB Pins (Direct Main Board Mount)
Era & Origin / Condition	Late 1970s Stock \| Made in Japan \| New Old Stock (NOS)

🛠️ Premium Hi-Fi Restoration Focus

This rare tapped pot is highly targeted for high-end vintage audio restorations:

Classic Japanese Receivers & Amps: The required specific drop-in volume or tone replacement for 1970s and 80s gear (Pioneer, Sansui, Kenwood, Marantz, Luxman) running a dedicated loudness contour filter switch.
Period-Correct Loudness Curves: Bypassing this 4th pin with a modern standard 3-pin potentiometer completely deactivates the factory loudness circuit profile. This component fully preserves original factory performance.
Premium Custom Audio Projects: Excellent build choice for high-fidelity pre-amplifiers, valve line stages, or headphone setups utilizing low-volume bass-contouring circuits.

📮 Combined Shipping Policy

Clearing out multiple vintage assets from my workspace drawers? I will gladly combine shipping costs across all active component listings to save you money on postage. Please add all desired items to your cart and request a total prior to checkout so I can issue a manually adjusted invoice.

⚠️ Vintage Electronics Disclaimer

This item is a premium New Old Stock (NOS) component from an accumulation of classic workshop stock. While it has been cleanly bench-tested to confirm total resistance, tracking balance, and perfect loudness tap continuity, vintage components are sold as-is without extended modern operational warranties. Please review your unit's required shaft length and pin layout style closely before purchasing.