I bought this Variac to run alongside my Marshal Plexi and since I'm selling my Marshall, it's time to see this guy go too. If you're looking this up, then you are among those who know that this is an ingredient to get that spongy brown sound. This thing is very fun and it does change the way your amplifier responds. It's very interesting. Please Note: For some reason, the measurements on the top do not match the actual voltage reading and so I had to write some out by hand and it's never been a problem. Thanks for checking this out!