Unlock New Layers of Sound

The SELECT 12AU7 is the best 12AU7 vacuum tube you’ll ever need. It goes above and beyond the baseline with more involved production and stricter selection, all in pursuit of superior sound. The SELECT Collection brings out the best in all your favorites.

Hand selected and tested, the Ray Tubes SELECT 12AU7 features gold pins for corrosion resistance and improved conduction. The SELECT Collection is a substantial upgrade from both New Old Stock and other new production tubes. Fewer than 5% of production meets our standards.

Introduced in 1946, the 12AU7 was the world’s first noval (nine-pin) vacuum tube. The 12AU7 is a double triode, consisting of two 6C4 tubes in a single envelope. Before the advent of solid-state electronics, it was valued for its versatility and portability. Nowadays, it’s a common sight in the pre-amp phase of tube amplifiers, where it functions as a phase inverter or driver.

Sound Characteristics

SELECT 12AU7 delivers a well-balanced tonal signature with excellent resolution and dynamic sensitivity, providing a clear, transparent, and layered sound presentation.

1. Bass Performance
   Clean, tight, and well-controlled. Its focus on precision and clarity makes it well-suited for fast-paced music. Bass depth avoids excessive weight, ensuring a clean and well-defined low-frequency response.
2. Midrange Performance
   Clear and well-balanced, offering good transparency and resolution. Vocals sound natural with distinct layering and detail. Instrumental sounds are reproduced with accuracy and separation.
3. Treble Performance
   High frequencies extend smoothly with a sense of brightness and airiness. Treble detail is rich, adding liveliness and texture to the overall sound. Ideal for listeners who value purity and micro-dynamic expression in their music.
4. Dynamics and Soundstage
   Fast transient response makes the sound feel crisp and well-articulated. It excels in presenting music with strong rhythmic elements. Soundstage is precise with well-defined layering, enhancing the depth and immersion of the listening experience.

Technical Specifications

• Tube Type: 12AU7 / ECC82 / 6189 / CV4003
• Tube Socket: 9-pin
• Max Anode Dissipation Power: 2.75 W
• Max Screen Dissipation Power: N/A
• Output Power in Class A1 Amp (Single Tube): N/A
• Output Power in Class AB1 Amp: N/A
• Max Anode Voltage: 300 V
• Max Screen Voltage: N/A
• Max Grid Voltage: ~50 V
• Heater Voltage: 6.3 V
• Heater Current: 0.3 A
• Transconductance: 2.2 mA/V
• Amplification Factor: 17
• Internal Resistance: 7.7 kΩ

Package Contents

• Set of two, or single vacuum tube
• User handbook featuring burn-in guidelines
• Certificate of authenticity and warranty

Compatible Amps

Explore Ray Tubes' Tube Amp Compatibility List.

The Ray Tubes One Year Warranty

Most vacuum tubes are notoriously fickle. That’s why warranties are rare. But we trust our products and we’re proud to offer our One Year Warranty against manufacturing defects. For more details, check out our warranty page.