If memory serves the Taboo is good power but low gain, hence the rec to combine it with the CSP. Might just have been a weak source more than low Taboo power.
Similarly I use the GS-X mk2 at low gain but since the PWD2 output is 5.6Vrms, 12 o'clock is tops for modern recordings. And frankly with replay gain, even older recordings and movies are fine too.
No doubt a DAC with a preamp function like the PWD2 or W4S DAC-2 will help, but it won't help others with a standard 2V source.