Nothing we tried had a hope of working. We lifted this from another article. We got eight answers that looked vaguely right. You'll destroy all the output buffers if you adjust R3 when the power is on. It's giving 2W out for 10W in and the output transistors are glowing red.
Performance is extremely good.
It worked for three hours and then died. Joe Smith completely rewrote the article at the last minute. The author's wish to thank Chris Hendrie for his comments about the manuscript. Chris gave us hell for using his dot-matrix printer so often. Ms. Scott finally got the circuit to work.