THD Hot Plate 4Ω This is a high-quality power attenuator and dummy load (load box). It allows you to reduce the output and volume of a tube amplifier without sacrificing its nuances, making it useful for creating saturated sounds when increasing gain and volume. While similar effects can be achieved with a volume pedal in the send/return loop, this device avoids the impression of high-frequency roll-off and blurred sound. If you don't need features like a cabinet simulator or spatial effects like reverb and delay, as found in the UNIVERSAL AUDIO OX, this device perfectly fulfills the role of simply reducing the volume while preserving the original sound's nuances as much as possible. I was very fond of it, but I've decided to sell it. Bulk purchases are welcome. Thank you.