No.
it would be 15 or 30 when the goal is to have an amp that starts to clip at 2V.
But here's the thing. I actually am a designer and would not give the amps 15x or 30x respectively but probably closer to 30x and 60x gain and I can assure you they would sell better and in subjective AB tests would win.
It's a bit like the L30 story... People saw huge output power numbers and expected the amp to reach this when using a standard 2V out DAC from the same brand. Almost everyone was universally disappointed the 'promised' output power was not available.
To make things worse most people wanted the extra power because they wanted to use it to boost lows using digital EQ and when they did they had to use negative pre-amp gain.
And there you had the volume control issue (volume control maxed out, highest gain, inefficient headphones) while they bought the L30 because of its variable gain, high output power, lowest noise and distortion.
So.. there you have it. When the design criteria would be 2V input voltage I would design design those amps 15x and 30x gain.
When I did not have this restriction I would either add a gain switch or an input voltage range control and would have a more usable amp.
Now... for another design... say DAC+amp combo that does not have line inputs. It would make sense to just reach max. output power at 0dBFS.
Almost the same issue arrises as the L30 story except there is no gain control and max. power can be reached. Great for the specs.
When using EQ the average max SPL will now not be so high. Yep, it won't distort or just touch clipping levels at max volume which is a good thing but means when playing at max volume the volume control would be at max. position.
No one likes that.
Just like any other it would have (semi)log volume control. One can even choose or manufacturer your own taper.
See explanation above.
It's why my amps have high gain.
Yes they will have higher distortion and worse S/N ratio than designs build to have best specs but no one bitches about not having enough power and you can even drive it from a phone/dongle with 1V or lower output and use digital EQ and get the promised output power without having to max out the volume control.
Downside is the bottom section of the volume control is problematic in channel balance. Thankfully there are various gain options.
But this is about the Sundara and am happy to report that the practical design of the amp in question can reach almost 2W into the Sundara.
Yes... there will be tube distortion so it will measure as utter crap and end up in the 'poor' SINAD section so I hope it is never reviewed here
(really)
With its max 20x gain (tube dependent) you can reach max. output power with 0.75V so you can drive it with just about any source you want and get full power out of it. Not really needed for Sundara but very handy for Susvara or HE6 (original), K1000 etc.