All of these tubes came from Upscale Audio and are made by Mullard. I have• one matched pair of 12AU7/CV4003, less than 50 hours usage – asking $70 for the pair (new retail is $65 PER TUBE) • one matched pair of 12AX7/CV4004, used about 3 months – asking $125 for the pair (new retail is $160 PER TUBE) The above tubes are “Platinum grade” in the Upsacle grading system: “The best of the best. Lowest noise and microphony with the tightest triode balance we have available.” I bought them for use in a PrimaLuna preamp, tried them briefly to make sure that they worked, and then set them aside and returned to the stock tubes. I have sold the preamp, so the tubes are available. I also have:
• a single Mullard 12AU7/CV4003 in the “Special CJ test” grade, less than 50 hours usage, asking $40 (new retail is $70) In the Upsacle grading system, “Special CJ test” is “for guys with Conrad Johnson or Rogue preamps. The absolute tightest triode balance, with the lowest noise and microphony. Then we put these tubes through another special test to ensure they stay low in microphony.” I bought this tube for use in the center preamp position of a Rogue Cronus Magnum integrated, tried it briefly to make sure that it worked, and then set it aside and returned to the stock tube. I have sold the Rogue, so this tube is available. Prices do not include shipping, but I charge no extra fee for PayPal. US-48 sales only, please. Preference to experienced buyers with positive feedback on this or a similar website. I have a long record of 100% positive feedback on Audiogon. More info available at: http://www.upscaleaudio.com/Mullard-CV4003-12AU7-Vintage-New-Old-Stock_p_9.html http://www.upscaleaudio.com/Mullard-CV4004-12AX7-British-New-Old-Stock_p_21.html
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