Agree with Duke..I purchased rebuilt Quad 63 USA's from Kent at Electrostatic Solutions 2 years ago and was very pleased. He uses the best materials and techniques for perfect rebuilds of the panels and power supply EHT boards, spark arrestor and zener clamp protection circuitry and guarantees them 3 years I believe. I know he rebuilds the 63 and 63 USA as well as the 988/989..not sure about the newer 28/29 series. Contact Kent via email on his site and he'll give you all the info.