sr555The SR554 is a low-noise, transformer-coupled preamplifier optimized for source impedances between 0.05 Ω and 1 kΩ. With an input noise of only 0.1 nV√Hz, the SR554 can be used in aSR555 Game, Medan, Indonesia. 49 likes. Cara Menang Bermain Slot Game & Sabung Ayam Taji Pisau Filipina Asli @autoJP