Rockboard | RPA 100 Power Amp Attenuator | 100W At Room Volume | w/ Cabinet Simulator, DI & Headphone Output

With the Rockboard RPA100 Power Attenuator you can set your amp to your favourite sound - including high-gain and power amp distortion - and then reduce the volume on the speaker to acceptable levels for stage or rehearsal room without affecting the sound of the amp. This is particularly useful if you play a tube amp. The Rockboard RPA 100 Power Attenuator can be used to “tame” amplifiers with a power output of up to 100 watts.

With a choice of 4, 8, and 16 ohm connections, your amp will always see the correct speaker impedance, regardless of the type of speakers actually connected to the attenuator. You can even use the amp without speakers and listen to the signal through headphones. In addition, the RPA 100 Power Attenuator gives you the option of routing the output from your power amp via DI OUT or LINE OUT to mixers or audio interface applications, or to practice with the amp’s original sound using the headphone output.

For a more realistic sound, cab simulations can be applied to these additional outputs. For practice, you can mix in backing tracks or drum tracks from external audio devices via the AUX IN connection

SPECIFICATIONS

Power attenuator, dummy load
Max. input power 100 watts
3 x separate inputs for 4/8/16 ohms
1 x 3.5 mm / 1/8“ AUX input
2 x 6.3 mm / 1/4“speaker output (parallel)
1 x 6.3 mm / 1/4“ line output
1 x 3.5 mm / 1/8“ headphones output
1 x XLR-DI output
1 x control for speaker level
1 x control for line out level
1 x switch for cab sim bypass
1 x switch for cabinet simulation 2 x 12” & 4 x 12”
1 x 9V DC, 2.1 x 5.5 mm barrel plug, polarity (-) center, input voltage for operation of phones/DI/line outputs
1 x fan
1 x overload LED
Dimensions (L x W x H): 180 x 160 x 125 mm (incl. feet & control knobs)
Weight: 1545 g

Please note: the main attenuator control knob may feel stiff or difficult to turn.

This is due to the fact that it’s not a standard potentiometer like you’d find on a typical amp or guitar. Instead, it uses a ceramic wire-wound rheostat. By design, this component feels gritty and produces a mechanical sound when turned. A rheostat is essential for this attenuator’s operation, as most standard pots can only handle about 2 watts before failing—whereas this design routes the full amplifier power through the control knob.

To withstand that load, a much more robust component is required. The rheostat used here is rated to handle 50 watts or more, depending on the model. While it may not have the smooth feel you’re used to, it does offer one benefit: once set, the high-friction nature of the rheostat ensures the knob stays in place and won’t drift during use.