Rolls RA170 70-Volt Power Amplifier, 70 Watts, Transformerless, 1U

Rolls RA170: 70 Watts of Clean 70-Volt Line Amplification in 1U

The Rolls RA170 is a mono 70-volt power amplifier that delivers 70 watts into a 70V distributed speaker line from a compact single-rack-space chassis. It exists for the most common commercial-audio task there is: driving many ceiling or wall speakers spread across a store, office, or paging system from one amplifier. A 70-volt line lets you run long cable to dozens of speakers with minimal loss and simple tap-based volume setting, which is why it is the backbone of distributed audio. The RA170 does this transformerless, saving weight and preserving low-end response that an output transformer can rob. For an installer who needs a small, dependable 70V amp for a single zone, this is a purpose-built workhorse.

Transformerless 70-Volt Output

The RA170 produces its 70-volt line directly, without the bulky output transformer most constant-voltage amplifiers rely on. A traditional 70V transformer adds weight, cost, and low-frequency distortion; eliminating it keeps the amp light at just 5.5 pounds and cleaner in the bass. The result is a full 70 watts available to the speaker line for background music and paging alike. Because the design is transformerless, the RA170 stays compact enough to fit a 1U space where a transformer-equipped amp would need more room. For a distributed system where every rack unit and every pound counts, that transformerless output stage is a real engineering advantage.

Spring-Loaded Terminals and Simple Hookup

Speaker connections are spring-loaded terminals, so wiring a 70V line is a fast push-and-click job with no soldering or spade lugs required. RCA and 1/4-inch unbalanced inputs accept a mixer, paging source, or media player without adapters. This straightforward I/O is deliberate: a paging or background-music amp gets installed once by a busy contractor, and quick terminals shave real time off the job. A front-panel volume control sets the overall line level, while a Power LED confirms the unit is live. For an installer wiring a ceiling-speaker run in a retail space, the spring terminals and simple inputs mean the RA170 goes in and works without fuss.

Clip Indicators and Protection Circuitry

Dual front-panel Clip LEDs warn when the signal is pushing the amplifier into distortion, and a protective circuit guards against momentary shorts and overload. The Clip indicators let an installer set the level just below distortion by eye, which keeps paging intelligible and music clean at the far speakers. The protection circuit matters in the real world of install wiring, where a pinched cable or a shorted speaker tap could otherwise damage the output stage. Front-panel heat sinking keeps the amp cool in a closed rack without a noisy fan. For an unattended system running all day in a store or office, those safeguards are what let the RA170 run reliably without babysitting.

Strong Audio Specs for Commercial Audio

The RA170 specifies 40 dB of gain, a 114 dB signal-to-noise ratio at full 70 watts, and a 70 Hz to 20 kHz frequency response suited to voice and music paging. That high signal-to-noise figure means the amp stays quiet between announcements, so there is no hiss over the speakers when the room is silent. The frequency response covers the range that matters for clear speech and pleasant background music in a commercial space. A 47k ohm input impedance sits comfortably behind any mixer or source without loading it down. For a paging or background-music system where clarity and quiet both matter, those numbers back up the RA170's real-world performance.

Built for Stores, Offices, and Paging Systems

The RA170 is made for single-zone 70-volt jobs in stores, offices, warehouses, and paging systems where rack space is tight and reliability is everything. A retail shop uses it to drive a run of ceiling speakers for background music and occasional announcements, while an office feeds a paging line from a single compact amp. Because it is only 1U and 5.5 pounds, it fits small racks and equipment closets that cannot house a large amplifier. Its spring terminals, clip metering, and protection make it approachable for a contractor and dependable once installed. For a compact commercial install that needs clean 70V power and nothing more, the RA170 is exactly the right size.