Got my Hotplate today. I must say I'm really impressed. I had a Rivera, which had better features than the Hotplate (balanced line out, switchable impedance) but I think at low levels of attenuation the Hotplate is a bit more transparent. There also isn't a huge jump between attenuated and non attenuated volume levels. Full disclosure I've only tested it with my C5, but if anyone is interested, my findings were: At -4 db there was a slight volume reduction and no change in tone or feel. At -8 there was a noticeable loss of high end. Using the bright switch brought it back and brought the feel of the amp back to near non-attenuated response. The tone and feel remained pretty intact at -12 as long as the bright switch was used. At -16 to -infinity (fully adjustable control) the feel of the amp was greatly diminished. The deep switch really changed the tonality of the C5, but it actually made it sound like a much bigger amp. I couldn't hear a difference with the bulbs engaged or not. I'd say that this is a great tool to protect a speaker cabinet from a 100 watt amp or to bring a big amp down closer to club friendly volumes. It will not satisfy someone who wants to attenuate an amp down to a conversational level for something like late night practice.