Originally Posted by 77PBass
Anyone know what the mod is or has a link that explains the mod?
Not sure what you exactly mean, but if its that lo output issue: try 12DW7 in place of the last tube (12AX7). Cant't remember did I change the cathode resistor, or other parts. But any how, the DW will help you to get more juice to low impedance inputs (like some power amps). If the last tube (cathode follower) is 12AX7, it seems not to deliver juice enough.