Sonic Imagery Labs 994Enh-Ticha DUAL Discrete OpAmp Set of 2 dual op-amps These are high-end discrete op-amps, on par with Sparkos. I used them in a Burson Audio Soloist 3XGT. There are risks involved in replacing and handling op-amps, so please only purchase if you understand and accept the risks, and the item is non-returnable. Please consider purchasing. sparkos ss3602 SS2590 PRO Dual Burson Audio Soloist 3XGT burson Soloist Voyager burson Soloist 3XP fosi audio ZA3 V3 mono