Not knowing what your tubes are definitively (did you actually confirm they’re JJ - you seemed uncertain…), nor the amp, speakers etc., this is not a realistic query for anyone to field.
More supporting input due from ya. 😉
Signal tube versus power tube, sound impact?
My mono block has eight KT 88 tubes(power tubes) and six smaller signal tubes. I'm using the stock tubes that came with each Mono. I think they are JJ tubes.
Rather than replace them all would it be best to change out the signal or the power tubes? Not sure how good the JJ tubes are but I hear they may not be the greatest.