HO with split ground bus to solve Hum/Buzz issue. The bus was cut at the last gain stage before the Tone Stack and before the CF. The Mid ground was moved from the CF/PA/PSU side of the bus to the last pre gain stage side. A separate ground wire was run to the single ground point near the input jack. This helped quite a bit and Hum/buzz is now very minor/not noticeable. (This pic was photo-shopped to show the cut but the amp is just like it - HONEST! - just no camera available).