Triad 9629 Filament Transformer 117V 60Hz Multi-Secondary GR.1 CL.A FAM.01

Triad 9629 Filament Transformer 117V 60Hz Multi-Secondary GR.1 CL.A FAM.01

The Triad 9629 is a multi-secondary filament transformer manufactured by Triad Transformer Corporation of Los Angeles, California. It accepts a 117V AC, 60 Hz primary input and provides multiple secondary windings, including center-tapped 6.3V filament outputs rated at 2.6A each, with a combined maximum secondary voltage of 357V across all windings. The transformer is housed in a potted steel enclosure with two top-mounted octal-style terminal boards (labeled A and B) that provide access to the full complement of secondary taps.

Specifications & What's Included

• Manufacturer: Triad Transformer Corporation, Los Angeles, CA, USA
• Model: 9629
• Type: Filament Transformer (multi-secondary)
• Group / Class / Family: GR.1 / CL.A / FAM.01
• Primary Voltage: 117V AC
• Primary Frequency: 60 Hz (60 CPS)
• Secondary Configuration: Multiple windings — includes 6.3V center-tapped (CT) filament windings
• Secondary Current (6.3V CT windings): 2.6A per winding
• Maximum Voltage Across All Windings: 357V
• Terminal Access: Two top-mounted octal-style terminal boards (Board A and Board B)
• Mounting: Corner bolt studs for chassis or panel mounting
• Enclosure: Steel potted box construction, gray paint
• Phase: Single phase
• Country of Manufacture: United States
• Included: Transformer only — no cables or mounting hardware

Applications

Filament transformers of this type are used to power the heater elements (filaments) in vacuum tubes — the thermionic valves that are the active components in vintage and classic audio amplifiers, radio transmitters, instrument preamplifiers, and test equipment. The 6.3V center-tapped winding is the standard filament supply voltage for a wide range of common receiving tubes, while the multi-secondary design allows a single transformer to simultaneously supply both filament voltage and a high-voltage B+ winding within the same chassis. Triad Transformer Corporation was a well-regarded American manufacturer of audio and power transformers from the mid-twentieth century, and their transformers were widely used in professional broadcast equipment, laboratory instruments, and high-fidelity audio electronics. The Triad 9629 is suitable for vintage equipment restoration, tube amplifier construction, and replacement applications where a compact, multi-secondary filament transformer at 117V/60Hz is needed.