Amazon.com: NE5532 OP-AMP HiFi Preamplifier Board 2.0, AC 12V-18V to DC 12V 20hz - 20khz Dual Port Preamp, Adjustable Treble - Mid - Bass Tone Volume, 2.54mm Interface Port/ 5.08mm Terminal (Assembled
Amazon.com: ATNEDCVH Mini Small Stereo Audio preamplifier, Headphone Amplifier, Gain 20dB Phono Turntable Phonograph preamp, Dual op amp NE5532 with RCA 3.5mm Input to RCA 3.5mm Output : Electronics