Hola Jacob. I am also a tube guy. The specs of the tube amps are more humble than the specs of the SS. Also, there are members here that they love the sound of a good SS over the tube amps. And I respect that.
Sound quality its a matter of liking. Like the food. And the taste of SS to my ears its not so bad, even knowing that their specs are better than any tube. Why is this? Its has to do the harmonic distortion. The distortion that the tube amp has, is even, and the distortion of the SS is odd. Our ears are made for even distortion, and the harmonic structure of the musical instruments, human voice, etc, that have a lot of different timbre is due to this even harmonic distortion and here is where we can agreed or not. The odd distortion, 3,5,7 is present in the SS and the tube harmonic distortion is 2,4,6, etc.
The warmth, and the sound produced by the tubes is more lay-back than the SS. Also, because the SS output impedance is so low, that there is no need for an output transformer, thing that its necessary with tubes. There are designs in tubes were there is not an output transformers. The transformer acts a impedance match from the high impedance of the output tubes (circa 4K Ohms) to the impedance of the speaker's (typically from 2 Ohms to 16 ohms). You will find usually at the tube amp, the tab at the speaker's terminal, to match this impedance better. But the quality of the transformer must be very good. On these days, the quality of this transformer is very, very good...and the frequency response of a good amp, goes beyond the 20KHz! (our ear's threshold limit).
Also, the sound that its produced by the SS in general way of speaking, is more "precise" at the overall stage presentation. On the other hand, the tubes wattage is different ( and here I know that I am going to be nailed ). How is this? A Watt its a measurement! Think of this, a pony horse its horse too, but you can not do a comparison if you put a big horse pulling a weight vs this pony. Its has to do with the Joules at the power supply. Usually the voltage applied to the plate of the output tubes its around 500 Volts, and the collector voltage of the SS is around 70 Volts. Here, you need a lot of huge capacitance at the power supply to have a lot of energy storage and to have a lot of headroom.
So, who is right? Let your ears always decide. Trust your ears, not in the specs. If you liked your Dyna ST-70, using the EL-34/6CA7 output tubes, and delivering only 35 Watts/channel to drive your ML speakers, that's OK.
The volume knob its just that. A knob where you can adjust the level that you want for a certain signal that its applied at the input of your preamp. No matter what, your amp will be with a total power of 35watts/channel. The knob acts like an accelerator in a car. You are able to change gears, and also to push more gas, the the size of the car's motor remains the same.
Again, trust your ears! They are the final judges. Remember that what I do like, not necessary must be your liking! Happy listening!
