Ampeg SVT-2 pro blows tubes...

[CB Amp]

Hello,

I changed tubes on an Ampeg SVT-2 Pro about three months ago. I put some KT88 Gold Lion Reissue (and I biased them of course).
And the guy just came back, blown fuse, and there is also a blown tube...

I disassembled the amp and found a burned screen resistor. It uses 220 ohm 1/2W resistors. But on the original schematic, there is a 22 ohms in parallel with a 4007 diode (just as in the old black panel SVT's). The amp is stock, and there is no diode on the circuit.

I've got a moral dilemma... :
Do you think I should restore it to the schem specs or just change the 220 ohm resistors ?...
Thank you.

[ampdoc1]

If that's a St Louis Music amp, I'd rewire it. Years ago I got a new SLM Ampeg bass amp in my shop. A quick look at the schematic showed that two of the identical multipin connectors had been reversed. Can you say poor (no) quality control?