Rod Elliot’s site, a wealth of information and projects relating largely to HiFi and Audio in general. I have built a couple of these and they are extremely good indeed.
A great resource with many good tips for just about anyone with an interest in electronics. well presented interesting and entertaining!
Check the forum from the link on the left. Much lively discussion on all matters relating to building if inertial electrostatic confinement fusion reactors. Be sure to search the forum before asking questions though, there is a LOT of information in the historical posts.