GE 6SN7GTB NOS Matched Pair Side O-Getter 1950s Tested

Superior Sound Supply selling some seriously special stock. This listing is for a factory-matched pair of New Old Stock (NOS) General Electric 6SN7GTB vacuum tubes. These are the highly desirable mid-era construction featuring side O-getters and double mica spacers, representing a significant step up in build quality over the later, lighter top-getter versions. Preserved in their original GE boxes and testing exceptionally strong, these tubes are an ideal choice for high-fidelity preamplifiers, drivers, and headphone amplifiers requiring low noise and robust reliability.

Item Details & Technical Specifications

• Brand: General Electric (GE)
• Model: 6SN7GTB (High-voltage dual triode)
• Plate Structure: Grey ribbed plates (Gray plate)
• Getter Type: Side-mounted O-Getter
• Construction: Double Mica spacers (top and bottom) for reduced microphonics
• Base: Black octal base with clean, bright pins
• Heater: 6.3V / 0.6A
• Max Plate Voltage: 450V per section (GTB specification)
• Plate Dissipation: 5.0W per section
• Production Code: ST 188-5 (Owensboro, KY plant)

Condition & Testing

This GE 6SN7GTB side getter matched pair NOS set is in excellent physical and electrical condition. The glass is clear with distinct white "6SN7 GTB U.S.A." etching, and the bases feature the classic white GE logo. The "188-5" code identifies these as authentic productions from the renowned Owensboro, Kentucky plant. Unlike used pulls, these pins are straight and free of solder or heavy oxidation.

These tubes have been professionally tested on a calibrated tube tester. Both tubes pass all safety checks with No Shorts, No Opens, and No Leaks. They exhibit strong emissions well into the "Good" range, consistent with New Old Stock status.

• Tube 1: Tests strong at approx 90% / 88%
• Tube 2: Tests strong at approx 90% / 95% The triode sections are closely balanced, making them perfectly suited for stereo applications or phase inverter positions where symmetry is critical.

Historical Context & Applications

The 6SN7GTB is the final, most robust evolution of the classic 6SN7 lineage. Designed with a controlled heater warm-up time and higher plate voltage ratings than the earlier GT or GTA versions, the GTB is extremely reliable in modern circuits that push tubes harder. This specific "Side Getter" variation is favored by audiophiles over later production runs due to its heavier internal construction and double mica support, which helps mitigate mechanical noise in sensitive headphone amplifier 6SN7 circuits and vintage hi-fi preamp driver stages.

Superior Sound Supply Guarantee

Superior Sound Supply Quality Assurance: Transparency and accuracy are the cornerstones of our business. We ensure every component is vetted so you can buy with complete confidence. Along with Superior Supplies for all of your sounds, We stand on Superior Service, If your not satisfied with our supply we will make it right.

Shipping: Carefully packaged with consistent methods that are proven to protect your item and ensure safe delivery. We primarily use USPS, and FedEx for large or high-value items, and can arrange international shipping to anywhere in the world. Orders are processed and shipped within 1-3 business days of payment clearance. We do not ship on weekends or federal holidays. Orders placed after 2:00 PM CST Friday will ship the following Monday.

Returns:

• New Items: Returnable within 30 days of delivery.
• Used & Vintage Items: Returnable within 30 days of delivery.

General Terms: Items must be returned in original, as-shipped condition with all original packaging and no signs of use. Buyer assumes responsibility for all return shipping costs unless the item was not received as described. Make sure to check the return policy on each individual listing as some items may be sold "As-Described" and not eligible for a return. We want you to be completely satisfied with your purchase.