Restoring my Telefunken Opus 7 - some pointers welcome

[majoco]

EL84's do run pretty warm, but it's strange that the pair are different temperatures especially as the one out in the clearer air is the one getting hot. Is it a push-pull output stage or bi-amped with one amp for each bass speaker. Check the value of the cathode resistor, the cooler running one may have gone high which will cause your distortion maybe....and yes, EL84's can and do suffer from grid emission when they get old - measure the voltage across the cathode resistors - they should be about equal and a reasonable value, say 6 volts or so IMHO.