There's nothing like a real spring reverb. The BX-20 is the largest of the reverb tanks AKG introduced in the late 60's. Because of it's massive size, it sounds somewhere closer to a plate reverb than a traditional spring take a tenth of its size that we've grown accustomed to on guitar amps and effect units. You may recognize this unit from Universal Audio's UAD digital recreation of its famous tone. This unit is great for getting a stereo reverb back from a mono source (and just as a good with a stereo bus), and gives you depth and character that is hard to come by in other reverb units. A studio favorite for vocals, backup vocals, strings, and acoustic guitar.