Wadia S7i direct to amp

Paperw8: a 3dB reduction in voltage corresponds to a 6dB reduction in power.

Bombaywalla: wrong! a 3dB reduction in POWER corresponds to a 6dB reduction in VOLTAGE.

I haven't taken the time to read through most of this thread, but I'll just say with respect to the quoted comments that neither is correct.

A 3db reduction in power corresponds to a 3db reduction in voltage, for a given impedance. A 6db reduction in power corresponds to a 6db reduction in voltage, for a given impedance.

To see that, consider that a 3db reduction in voltage corresponds to the voltage being reduced by a factor of 0.707. Since, as I think we all agree, P = Esquared/R, that 3db reduction in voltage results in power being reduced by a factor of 0.707 x 0.707 = 0.5, which is also 3db.

Regards,
-- Al

Paperw8: If you look at power as a function of voltage and perform the power measurement AS A RATIO OF THE CORRESPONDING VOLTAGE LEVELS, then each halving of voltage level corresponds to a 6dB reduction in power level

Yes, absolutely. But note that each halving of voltage ALSO corresponds to a 6dB reduction in voltage level.

the voltage level is halved at each 3dB increment

I haven't taken the time to follow the parts of the thread that may be behind that statement, but an increment that results in voltage being halved is not in fact a 3db increment, regardless of the wording that may be used to refer to it. It is a 6db increment.

db = 20log(V1/V2) = 10log(P1/P2)

20log(0.5) = -6.02

Best regards,
-- Al