ART CleanBox Pro Dual-Channel Level Converter

The ART CleanBox Pro is a dual-channel level converter that connects consumer audio gear to professional equipment in both directions, made for AV installers, live sound engineers, DJs, churches, schools and home studios that need to join RCA and 3.5 mm equipment to XLR-based systems without noise, weak signals or distortion.

Why level matching matters

Consumer equipment, such as phones, laptops, DVD players, DJ controllers and home stereo gear, works at a nominal level of -10 dBV on unbalanced RCA or 3.5 mm jacks. Professional equipment, such as mixers, power amplifiers and pro recorders, works at +4 dBu on balanced XLR connections. The difference is about 12 dB.

Plug consumer gear straight into pro gear and the signal is too weak, so you turn the gain up and the noise comes up with it. Go the other way and the pro signal overloads the consumer input and distorts. Unbalanced cables also pick up hum over long runs. The CleanBox Pro fixes all three problems by actively raising or lowering the level and converting between unbalanced and balanced connections.

Two converters in one box

The CleanBox Pro has two independent sections, and you can use both at once.

• Unbalanced to balanced (consumer to pro): RCA left and right inputs plus a stereo 1/8″ input, converted to two balanced XLR male outputs. Up to +21 dB of gain.
• Balanced to unbalanced (pro to consumer): two balanced XLR female inputs, converted to RCA left and right outputs plus a stereo 1/8″ output.

On the consumer side, the RCA and 1/8″ jacks are wired in parallel, so you can use whichever cable you have. Each section has its own stereo level control, so you can set the output for clean, strong signals at the receiving end.

Common uses

• Background music in venues: feed a phone, laptop or streamer into the XLR inputs of a PA mixer or zone system.
• Playback at events and churches: run a laptop’s audio over long balanced XLR cables to the front-of-house desk without hum.
• DJ gear into a pro PA: connect RCA booth or master outputs to a balanced system.
• Mixer to recorder or camera: send a balanced mixer output to a consumer recorder, camera or hi-fi with RCA or 3.5 mm inputs, at a level that won’t distort.
• Home studios: connect consumer playback devices or hi-fi gear to an audio interface or studio system.

There’s also a handy trick: loop one section’s output back into its input, and the CleanBox Pro becomes an inline level control for a balanced or unbalanced line.

Performance

ART specifies a frequency response of 20 Hz to 20 kHz (±1 dB), THD below 0.01% at 1 kHz and a signal-to-noise ratio above 90 dB. The balanced inputs have a common mode rejection ratio above 40 dB, which helps reject noise picked up along long cable runs. It handles up to +21 dBu at the input, and outputs up to +21 dBu balanced or +15 dBu unbalanced.

Build and power

The CleanBox Pro is housed in a rugged extruded aluminium case measuring 47 x 117 x 109 mm and weighing 0.5 kg. It’s an active unit, powered by the included external power supply (7.5 to 12 V AC/DC). A lit power switch and LED show at a glance that it’s on.

Who is the ART CleanBox Pro for?

• AV and installation work, where consumer sources need to feed professional systems.
• Live sound and events, for laptop and phone playback into the desk.
• DJs connecting RCA equipment to balanced PA systems.
• Video and content creators sending a mixer feed to a camera or consumer recorder.

It isn’t designed for microphones or instruments. To connect a guitar, bass or keyboard to a mic input, use a DI box. And it isn’t primarily a hum eliminator: if your problem is a ground loop between two devices already at the right level, a transformer isolator is the more direct fix.

CleanBox Pro vs CleanBOX II

The names are similar, but the two boxes do different jobs. The CleanBox Pro is an active level converter: it changes signal level and connector type, between -10 dBV unbalanced (RCA and 1/8″) and +4 dBu balanced (XLR), in both directions. The CleanBOX II is a passive hum eliminator with isolation transformers on 1/4″ jacks, designed to break ground loops while keeping the level the same. Choose the CleanBox Pro for connecting mismatched gear, and the CleanBOX II for removing hum. For more options, browse our signal splitters and isolation range.

Key features

• Bidirectional level converter: -10 dBV to +4 dBu and +4 dBu to -10 dBV
• 2 channels in each direction
• RCA and stereo 1/8″ consumer connections, wired in parallel
• Balanced XLR inputs and outputs
• Up to +21 dB gain from consumer to pro
• Separate stereo level control for each section
• 20 Hz to 20 kHz response, THD below 0.01%, SNR above 90 dB
• Extruded aluminium case
• Lit power switch and power LED
• External power supply included

Frequently asked questions

What does the ART CleanBox Pro do?

It converts consumer-level unbalanced audio (-10 dBV, RCA or 3.5 mm) into professional balanced audio (+4 dBu, XLR), and back again, so consumer and pro gear can work together at the right level.

Can I use both directions at the same time?

Yes. The two sections are independent, so you can send a laptop to a mixer and a mixer feed to a recorder simultaneously.

Can I connect my phone to a mixer with it?

Yes. Plug the phone into the 1/8″ input, then run XLR cables from the balanced outputs to two mixer channels.

Does it need power?

Yes. It’s an active converter and runs from the included external power supply.

Will it remove hum?

Running long cables balanced instead of unbalanced reduces noise pickup, and the balanced inputs reject common-mode noise. But for ground loop hum between two devices, a dedicated isolator such as the ART CleanBOX II is the right tool.

Can I use it with microphones?

No. It’s designed for line-level signals. Microphones need a preamp, and instruments need a DI box.