Groove Tubes GT-EL84-RQ R5 Russian Quartet Power Tubes Once the most common low-power pentode power tube, the EL84 was popularized in early Vox amplifiers Developed by Phillips in 1953, the EL84 was originally used in tube radios before being adopted by Watkins and Vox amplifiers This Russian tube features quick, soft overdrive distortion, with slightly aggressive edge when pushed; It's especially great for recording applications with low-power amps Hand Tested & Matched in Quartets (a set of 4 tubes) Limited Warranty Included