Add a Chinese-made output transformer with some kind of pseudo-steel lamination materials and poor build quality. Then, add one cheap-as-possible speaker. Use 20dB of negative feedback to make the bass chunky and tight for muted power chords. Finally, 99% of all so-called "all tube" amps are NOT all tube, but have a row of cheesy 5 cent clipping diodes between the first and second gain stages to add distortion! It's like having a cheap Death Slasher Chainsaw Metal fuzz pedal built right in. Add the above ingredients and there you have it, a poor sounding amp with a buzzy, fuzzy, gritty, homogenized tone with plenty of sharp, metallic, cold, spikey overtones.

Mesa Boogie used to make a few good amps, but I don't know if they still do. The Double/Triple Rectifiers and all their newer models are very homogenized, flat, dead, and buzzy. They operate the power tubes at low current in order to increase high order distortion, and really crank up the negative feedback to tighten the sound, especially in light of the poor damping factor produced by the low current operation.

This is just my opinion, but neither Marshall hasn't made a good amp since the '80s, and Fender hasn't made one since the '60s.

Although expensive, a good boutique amp with carbon comp resistors, polypropylene (or paper in oil) signal caps, better quality electrolytics, a quality output transformer, no solid state clipping diodes, a "more normal" amount of negative feedback, and a good speaker like Weber VST or the upper-line Celestion of your choice will torch a mass-produced amp and eat if for breakfast.

If you can afford it, commission a custom amp builder to build you an amp exactly to your tonal requirements, with the correct circuit, tube types, transformers, speakers, cabinetry, component types, etc. It reap rich dividends in that you'll always feel inspired to practice and play BECAUSE OF your tone, instead of practicing and playing IN SPITE OF your tone.

Thermionic