Here's a cool design that Lee Roitberg of Simplicity Audio brought to the recent Lone Star Bottlehead meeting. My copy is beginning to take shape as parts arrive. Nickel core output transformers - no caps in the signal path! See the link to pictures of Lee's prototype and the schematic in the caption above my picture. You can build this one for a bit over $100 - less if you use inexpensive or reclaimed parts.