This has been covered many times here and on the DIYAudio forum threads.
It's led's are powered by well regulated linear supply.
Many blind A/B comparisons have been done even with Li/Ion battery v the supplied linear power supply, and listeners could not reliably detect the difference, even Sam Tellig of Stereophile came to the same conclusions, with his own Lightspeed after getting a battery pack as well.
As ldr's themselves are self damping to "fine gained" changes as their reaction times to light changes are quite slow.
The only difference of power supplies that could be reliably detected was with SMP power supplies, and this was because of their switching noise infiltrating into the ground plane and into the output stage, not into the led's
Cheers George
