At the other end of the expensive spectrum are the 'bargain shocks'. I bought my little aluminum Chinese headphone amp for $129 delivered. I was intrigued with the circuit, all discrete components: single ended JFET input (aka Boz-like Pass driver) driving dual MOSFET voltage gain, then push pull MOSFET current driver. The line stage is taken off from the JFET dual MOSFET voltage driver and bypasses the push pull MOSFET current driver.
I have six line stages, all the rest tube, ranging from very expensive (Allnic DHT preamp)(Manley Neo300b) to DIY (two 26 DHT, a WE417 transformer coupled Euridice). I rotate them in and out of my active crossover setup with amps, and use the line stages for gain equalization when needed.
So, using the little Chinese JFET/MOSFET as line stage? Sounds high end with no apologies, even compared to the others. Explicit, clean, kinna sweet, spacious with excellent tonality and intense internal detailing and very quick dynamics. Manley Neo300b opens things up with unfolding of imaging and that nice second harmonic stuff, but I could actually live with the little Chinese aluminum block. Do I prefer the costlier tubed units? Yes, ultimately, but not as much as I would expect, which is incredibly annoying.
Makes you wonder what the heck you actually need for sound quality vs. vanity purchase.