Beyond the Ordinary
The CORE 12AU7 delivers everything you know and love about tube audio. With modern production and uncompromising selection processes ensuring reliability and consistency, the Ray Tubes CORE Collection is all you need for years of audio bliss.
Hand selected and tested, the Ray Tubes CORE 12AU7 vacuum tube is manufactured with modern production and selection processes for reliability and consistency. The CORE Collection leaves the uncertainty of the New Old Stock market behind and makes uneven performance and tube failures a thing of the past.
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.
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Sound Characteristics
The CORE 12AU7 provides a natural and clear sound, ideal for users who prioritize midrange performance, especially suited for systems that require warmth and smoothness in their audio reproduction.
- Bass Performance
Mild and balanced, with moderate quantity and good control. Well-suited for light music or medium-small dynamic audio, delivering clear rhythmic definition without overemphasizing the low end. - Midrange Performance
Clear and transparent, with a natural tone. Vocals exhibit good clarity and warmth, especially in female vocals, where it shines with a vibrant and elastic sound. - Treble Performance
Clear and non-fatiguing, with good detail but moderate extension. The overall high frequencies are smooth, making it easy to listen to for extended periods. - Dynamics and Soundstage
The dynamics are well-balanced, capturing small to medium dynamic details effectively. The soundstage is moderate, with clear imaging and well-defined instrument positioning, making it ideal for compact audio systems or near-field listening.
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
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.
I am sure there are NOS tubes out there with better sonic presentation but hunting for that elusive NOS tube is a rabbit hole you don't want to go into. For the price plus sound quality, you can't beat the Ray Tubes 12AU7 CORE tube. For now, my NOS tube-hunting is on hold.
Without question this is the biggest bang for the buck pair of tubes I've ever purchased.
The 12AU7 CORE Vacuum Tube has a resolution that is incomparable to the existing bundled vacuum tubes, a wider stage, and deeper harmonics.
Where to Buy
Local retailers are the heart of audiophile communities around the world, which is why we believe they’re best positioned to help you with your purchase. Ray Tubes are available from our retail partners worldwide—click the button below to find one in your region.
CORE → SELECT
Ready for an upgrade? 12AU7 is also available in the Ray Tubes SELECT Collection.Â
CORE is a perfect entry point for tube audio—SELECT is the ideal way to get more out of your existing system. With more involved production and stricter selection, SELECT is the best tube you’ll ever need. Take your amp to the next level and find out what bliss really sounds like.
SELECT 12AU7