Many modern guitar amplifiers have very effective master volume controls that allow you to play a high-wattage amplifier at lower volumes and still get great tone. But a fair number of vintage amps don’t have master volumes, and some amps that do have them don’t sound their best unless they’re cranked up. With an attenuator, such as the Rivera RockCrusher or Radial Headload, you can bring the volume of a loud amplifier way down, to conversation levels or even lower. Some amps even have built-in attenuators that work to tame the output from the power amp before it feeds to the speaker, allowing the onboard tubes to run full-out without issues with high volume from neighbors and loved ones.
An attenuator sits between your guitar amp head and your speaker, and serves as a post-power amplifier master volume. To use an attenuator, connect a speaker cable from one of your amp’s speaker outputs to the attenuator’s input, and then connect another speaker cable from the attenuator’s output or through jack to the speaker cabinet’s input jack. At this point, you can keep the volume of your amplifier as high as you want, and control the actual volume in the room by adjusting the output volume on the attenuator.
You may have heard some people say that attenuators burn out tubes faster. That’s not true, but here’s why people might think that: If you have your tube amp’s volume dimed, your amp will burn through tubes at the rate any amp turned up to “thermonuclear” would, even though the room volume is low thanks to the attenuator.
Also, in years past, some attenuators got a bad rap for “tone suck,” because the circuits of the attenuator changed the tone of the amp. These days, attenuators are generally high quality and they won’t adversely affect the tone. So if your guitar amp is too loud for your space and you need to bring the volume down, check out an attenuator.