![](https://www.radialeng.com/wp-content/uploads/2018/03/j48-input-768x612.jpg)
15dB Pad
reduces the input sensitivity for active basses and high output keyboards.
48V Check
flashes once when the 80Hz filter is depressed to confirm 48V phantom power is present.
Merge
changes the input and thru-put to two LR inputs and mixes the output to mono at the XLR.
Input
instrument input connection to the J48.
Thru
throughput from the J48 to the amp. Hi impedance will not load instrument down.
![](https://www.radialeng.com/wp-content/uploads/2018/03/j48-output-768x612.jpg)
XLR Output
balanced 600Ω mic level output, use to feed mixer or mic preamp.
180°
polarity reverse use to correct the phase on old gear and reduce feedback on stage.
Low Cut
80Hz high pass filter cleans up bottom end and reduces resonant feedback.
Lift
ground lift switch disconnects the ground from the audio signal path and help eliminate hum and buzz caused by ground loops.
![](https://www.radialeng.com/wp-content/uploads/2018/03/j48-top-inside-768x546.jpg)
Glass-Filled
nylon XLR connector with extra large nickel-silver pin contacts. Tougher than steel!
Active Circuit
combination discrete & IC circuitry for exceptional signal handling & low noise.
Internal Switching Supply
increases rail voltage for more headroom and lower distortion.
Ground Lift
located inside the J48 circuitry (not at the XLR) to ensure phantom power isn’t dropped when the switch is engaged.