The transformer is the beginning to great sound. It has to handle the requirements of a recording. If you think about it, why do different amplification from the same manufacturer sound different or handle music differently? Quick Silver just stopped making one of their amplifiers because they could not source the transformers any longer. We used to use Plitron transformers but they now require a minimum order of 100 pieces. Designs are not new so depending on what you are looking for, a design is important to the sound and cost. Power supply is the key to great sound. That needs to filter AC noise, handle dynamic swings, etc. Then capacitors and resistors have an impact. Tubes vs. SS is personal preference.
Happy Listening.