6680 = 12AU7A ECC82. MATCHED NOS PAIR RCA 6680. These are actually Labeled 6680 (see pics). Amplifier / Radio / Audio. Legendary CLEAR TOP. TESTED on HICKOK TV7. Side D Getter.
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HIFI C3850-S Single-ended Class A Preamplifier With 3 Way RCA input Reference Accuphase C-3850
Aliexpress UK
These are very special RCA D GETTER 12AU7 twin triodes. They are RCA tubes that were hand screen for low noise and low microphonics. Of all the tubes I have sold over the years RCA tubes are the finest for microphonics and noise, This is a nearly perfect example of one pair of the best sounding 12AU7's tubes ever made.
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Universal Auto Power Amplifier Compact RCA Output Interface Bass Subwoofer Universal Crossover Controller Car Accessories
Aliexpress UK
Triple Platinum Matched on Amplitrex AT1000. Amplitrex AT1000 Test Results 95%+ GM = Within NOS Specs 90%+ EM = Within NOS Specs. All tubes are tested with the Audiophile in mind for SHORTS, GAS, MUTUAL CONDUCTANCE and NOISE (large tube lots are not tested for noise).
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SMSL H400 Hi-Res Headphone Amplifier 16Ω/15W*2 32Ω/7.5W*2 Earphone AMP RCA XLR Balanced Input Hi-End Pre-Amp With Remote Control
Aliexpress UK
NOS tubes fall within the Gm characteristic range of an average tube, as published in the RCA RECEIVING TUBE MANUAL, which states "Individual tubes, like any manufactured product, may have characteristics that range above or below the values given.
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Juson Audio JTA100 RMS200W Integrated Stereo Hybrid Tube Amplifier BT5.0 USB RCA Opt Headphone for Turntables Audio Receiver
Aliexpress UK
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FiiO K7/K7BT HiFi Balanced DAC Headphone Amplifier AK4493S*2, XMOS XU208 PCM384kHz DSD256,USB/Optical/Coaxial/RCA Inputs Custom
Aliexpress UK
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HIFI PASS AM Pure Class A Power amplifier 10W+10W Support XLR/RCA Input
Aliexpress UK
RCA 12AU7A "CLEAR TOP" Tubes TESTS NOS. Triple Platinum Matched on Amplitrex AT1000. It's believed that the side getter contributes to the low microphonics of this tube. Wonderfully balanced airy highs, midrange warmth, and accurate bass.
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AIYIMA Audio T20 Tube Preamplifier Full Balanced XLR/RCA Output Stereo Preamp with DAC AMP 12V Trigger for Hifi Home Amplifier
Aliexpress UK
12AU7 = ECC82. serving as a desirable ECC82 = 12AU7 tube; representing the best of its kind. AUTHENTIC 1955 Amplitrex AT1000 TESTED RCA 12AU7 MATCHED PAIR TUBES. REAL 1955 N.O.S. RCA USA 12AU7. REAL NOS 1955 RCA BLACK-PLATE 12AU7 PAIR.
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PP400 Ultra-Compact Phono Preamp Preamplifier Home Mini Audio Amplifier with RCA Interface for Turntable Tube Amplifier Speaker
Aliexpress UK