Why is solid state more popular when tubes are better?

do you have distortion measurements that you can share with us comparing your tube and class-D amplifiers?

In general our class D makes about 1/10th the distortion of our tube amps at full power. At lower power levels its much lower, since the distortion of our tube amps decreases linearly as power is decreased, whereas with our class D the distortion increases dramatically just before clipping.

The distortion spectra of our tube amps favors the 3rd harmonic with the 2nd slightly less- the better matched the tubes are the lower the 2nd becomes. In any event that distortion is plenty to mask the higher orders. Our tube amps are fully balanced and differential so the distortion spectra is based on a cubic non-linearity rather than the quadratic nonlinearity you see in an SET. Conventional tube amps that have a single-ended input and push-pull output have both non-linearities in the design so tend to feature a more prominent 5th harmonic (see Norman Crowhurst). SETs and fully differential push-pull amps like ours avoid this problem.

In our class D the 2nd harmonic is more prominent and in that respect the distortion spectra looks more like that of an SET. Again the lower orders are prominent enough that they mask the higher orders. But the distortion is essentially about an order of magnitude lower and most of that is the 2nd.

More important than the actual distortion values is the fact that in both kinds of amps we make, the distortion does not rise with frequency.

Pretty lame premise for a thread. Just trolling for vitriol, I see. 

I find myself convinced by much of what @atmasphere says.

I was lucky to be taught tube design at university (due to the non-retirement of an aged lecturer). In other labs I manufactured ICs!

Tubes have a lot of strengths and it’s quite possible to design reasonably accurate line-level amplifier stages using them. When it comes to power amplifiers, the need to use a transformer to effectively convert lots of volts to lots of current, creates many manufacture challenges, especially at very low frequencies. It’s also hard to avoid relatively high output impedances, in which cases, the sound can eb affected by the speaker’s impedance curve and every instance will sound different (but not, strictly, accurate).

The low cost and size of silicon and germanium devices means it’s economically possible to use 10 optimised devices for the equivalent of a singe tube - which can be compromised though having to do "too much". One approach is to use a 40+ tube amplifier, but even the most enthusiastic supporters find that a bit difficult to imagine :-)

@hilde45 and @mahgister go out on a parking lot and settle it. Oh and record it for TikTok and send us a link. 

This is a fair comment and I regret being partially responsible for the dialogue. My apologies to Mahgister and to forum members. People can read the substance of the exchange and form their own opinions but I agree it went over the line. I'll do better.

If on the fence, or not, do what I did…a big bold SS (vintage Crown DC 300 no less) with 5 foot tall 4 way vintage Infinity speakers in the BIG room (20 foot ceiling) for the big bold punchy party rock and roll and get the party started! Then when time to wind down, retreat to the smaller room, fire up the SET tubes into a pair of Klipsch and relax with low volume highly resolving jazz or singer songwriter vocals and chill till morning.

Different rooms, different systems, different music choices…best of both worlds.

Cheers!