* OP-AMP + SEPP(Diamond Buffer) [#b021d081] &ref(HPA.jpg); * Device [#sd3780e9] - uPC4557 (NJM4558DD, NJM4580DD, TL082, LM358) - 2SC1815 - 2SA1015 * Schematic [#g1ac42cd] ** AMP [#bdefd3e0] ** Protector [#u7968f50] * Listning [#hc1fdc84]