Type: 6211A GE IBM. Model: 6211 GE 6211A IBM.
raytheon black plate triple micas are revered worldwide for their incredible detail, lush mid-range and soaring highsthe legendary carbide black plate coating radiates heat better, reduces plate temps faster, and enhances tonal characteristicsthe colorful harmonics, expansive sound stage, immersive bloom, and quality control all contribute to the collectibility and lore this regarded premium ecc81 12at7 upgrade is low-noise + more rugged w/ its premium metallurgy ~ see attached data sheets!all tubes also undergo a complimentary refurbish and deoxit process! one of a kind quality control ~ raytheon box included full mutual gm conductance test 92/91 % gm (65 % min good) + important life test pass (longetivity indicator) and all tubes undergo a leak short and gas checkour mutual gm output test applies real world 225vdc voltages w/ filtered dc! give several sessions or up to 100+ total hours w/ your specific amps voltage to fully break-inships well packed worldwide w/ free economy postage! ~ authentic vintage hifidelity audio / preamp / mic / power tube curation by caliacoustics ~see our official site for new arrivals + reserve/request options + true-nos sealed box rarities + limited-run special editions + pinched waist collectibles