Tung-Sol 6550 1957

Vintage Tung-Sol 6550 Blackplate Vacuum Tube - Metal Collar - 1957 Date Code (Untested)

Brand: Tung-Sol Model: 6550 Blackplate (Solid Plate, Metal Collar Base) Year: 1957 Condition: Very Good (Cosmetic condition of glass, base, and pins)

Description

Offered by The Guitar Armory

Up for sale is a holy-grail piece of American audio history: an original vintage Tung-Sol 6550 Blackplate power tube, manufactured during the absolute golden era of US tube production.

This is the highly coveted, early-production variant featuring the rugged nickel/steel wrap-around base collar and solid, smooth carbonized matte-black plates—lacking the later three-hole grey-plate design. This specific tube was pulled from a meticulously kept private estate collection.

Authenticity & Date Code:

• Manufacturer Code: 322 (Authentic Tung-Sol USA)
• Date Code: 5721 (Manufactured the 21st week of 1957—late May)
• Full Stamped Code: 3225721-3

Physical Condition:

• Glass envelope is structurally sound with no cracks.
• The original top getter flashing is bright, highly reflective, and completely intact (no milky white air leakage).
• The center plastic octal alignment pin is intact.
• Internal plate structures and support rods are straight and secure.

Testing & Shop Policy: Because this tube came directly out of a large collection and we do not currently have a calibrated mutual conductance tube tester on-site at the shop, this tube is being sold As-Is / Untested. Returns will be permitted up to 7 days from delivery. Tube collection acquired from vintage pro audio service center for MacIntosh amps. Buy with confidence.

Thanks for looking! This won’t last. Make it yours!