Gain control to correct improper signal levels - Loop through input for daisy-chaining With a frequency response of DC to 120 MHz, the LTVB/VDA is suitable for even the highest resolution applications using one volt peak to peak composite video. The LTVB/VDA provides a loop-through input and gain control. The loop-through feature effectively gives you another output unaffected by the gain control. The gain control lets you compensate for improper signal levels over a -2.5 dB to +9.5 dB range.