Especially the TAD Premium Selected 5751 low-noise tube is recommended for best clean tone with big bottom, warm midrange and silky top end. Performs great for HiFi too! Replaces any 12AX7A/WA, ECC83, 7025 etc. The TAD Selected 5751 is the first choice for vastly improving the clarity, smoothness, and vintage tone character of most guitar amps! They still have plenty of gain so if you have a high-gain preamp that does not have that classic crunch characteristic, the 5751 tube will do wonders. In hifi preamps and CD players, the TAD Selected 5751 will lower noise floor and sound smoother and clearer in place of many 12AX7 tubes. SRV used a 5751 to improve his clean tone with vintage Fender amps producing that thick and three-dimensional bold tone.