CDP voltage output...what does it mean to volume?

The formula to determine the differences in dB is
dB = 10* log10(power_ratio)

For voltage it is:
dB =20 * log10(voltage_ratio)

For the 2V system compare to the 6V

dB =20 *log10(2/6) = -9.54 dB

Every 10 dB is 1/10 the power (or about (1/3)**2 ) and will sound about 1/2 as loud. Hope this helps.

This link to Stereophile may help clarify things. On reading through the various posts, I can say that jcmcgrogan2 has got it right. There is something in Gregm's post that might confuse things more...but I'm not sure. I find myself turnig to Wikipedia more and more these days as it is peer review and continuously edited to fairly accurate on most issues...truly an amazing resource enabled by the internet.

cheers,

Here are a couple of more links to sort this out:

Crown amplifiers and dB

Relation ship between dB and perceived volume