Hi,

Yes, remove the Sucker. Also, you can try other input valves with less gain, for example the 12AU7 (ECC81) would likely work okay and would lower the gain.

Another thing to try, you can replace C2/4/5 with Mundorf M-Cap Zn or Audyn KP-SN (both are tinfoil types). And re-try triode mode for the output stage.

Ciao T