WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
I you want to improve the sound of your amp may I suggest a matched quad of JJ Tesla EL84 to replace the Sovteks. I'm confident you will enjoy the improvement. It made a large difference to my EL84 Amp.