קדם מגבר PreSonus BlueTube DP V2   2 input channels, each with:   High-headroom Class A XMAX mic preamplifier with 80 dB gain range 12AX7 vacuum tube gain stage Tube Drive tube-saturation control 48V phantom power 80 Hz high-pass filter -20 dB pad to reduce hot input levels Polarity-reverse switch Illuminated analog VU input-level meter   Input/Output   2 balanced combo mic/unbalanced instrument inputs 2 balanced XLR main (L/R) line outputs 2 unbalanced ¼” main (L/R) line outputs   Physical   Compact 1/2U chassis External 12 VDC, 1A power supply