Purchased new on May 10, 2024. I had EVA Electronics modify the input to low impedance, so impedance matching can be achieved if there is a buffer in the preceding stage. With impedance matching, the sound won't become thin, and the signal can be delivered to the amplifier without losing the low frequencies. ※It seems that 99% of effectors have high impedance INPUT, which is the cause of sound thinning. Please check the EVA Electronics website for details. Compared to compact effectors, the sound quality will be a compromise, but I've decided to use a multi-effector for everything, so I'm selling this one, even though I like it. Non-smoker, no pets, only used in my room, in beautiful condition. Thank you for your consideration. [Excerpt from another website] When the boost is OFF, it functions as a normal stabilizer. For guitars, Middle/Treble boost modes can also be selected individually (both function when the booster is ON). It may be slightly different from the image of what is called a booster that is overflowing in the market, and it may not be suitable for those who are looking for a dramatic change or distortion on its own. However, it may be a savior for those who are wondering if they need a little more gain or a little more essence to their current sound. It draws a beautiful boost curve without compromising the individuality of your amplifier or effector. Also, turning the knob counterclockwise from the 11 o'clock position, which is the boost zero point, will decrease the gain. This creates an unexpected way of using it, maintaining the sound's fullness and richness while lowering the volume of a tube amplifier. Simply turn up the volume of the tube amplifier sufficiently and gradually increase the booster knob from zero. CONTROL TONE SW, LEVEL, ON/OFF SW Terminals: IN, OUT Impedance: IN_LOz, OUT_LOz Power Supply: Ext DC 9 to 18V Size: 83(W), 115(D), 34(H) Notes: Size does not include protrusions