Active DI boxes and line-balancing problem solvers for stage and AV work. The sE Electronics DM3 is an inline pen-format active DI with a 10 megohm input impedance and Class-A circuitry, running on 48V phantom power; that very high impedance is what keeps the top end intact on instruments with passive pickups. The BSS AR-133 is the long-serving workhorse alternative, with a 0, -20 or -40dB input pad that lets it take instrument, line or amplifier-level signals, and power from either the console’s phantom supply or an internal 9V PP3 battery, switching to the battery automatically if phantom fails mid-show.

Interspace Industries covers the AV side. The passive PCBB4 Balance Box takes an unbalanced stereo feed on a captive 3.5mm mini jack lead and delivers it on two male XLRs with earth lift, output pad and a stereo/mono switch, needing no power at all, which is why one lives in most conference engineers’ workboxes as the quick fix for ground-loop hum. The USB-C BB3 goes a step further for laptops and playback machines: it takes a digital feed straight over USB-C, is powered by the same connection, and hands the desk a clean balanced left/right pair with ground lift, skipping the headphone-jack chain entirely.

Match the box to the source, and remember active DIs need power: confirm the console sends 48V phantom down the line you are using, or keep fresh PP3s in the workbox. DI boxes pair with our XLR cabling and stage box ranges when building festival or conference channel lists.