So ipman you are sayig that dB coulndt be measurest since there is no Button A sellection for it?
You can read decibels using the Volts ranges in the ~ (AC) mode. Refer to the table shown on the back to learn how you should adjust the reading.
Example, if you use the "1V" range, you should substract 10dB from the value read from the "dB" scale.
(And you can obviously
read the manual or find on the internet a lot of info of how to use an analog multimeter, but I digress)
However, my personal opinion is that the dB scale is rarely useful in this case since the AC rectifying is done using diodes. Thus, any low voltage AC readings are not significant, which is where dB readings are actually useful.
My personal opinion is that this multimeter is useful for DC voltage, current and 50Hz AC (> a few volts). Forget about other things.
My advice is to keep this one and buy an inexpensive, but good quality digital multimeter. If you are serious about the electronic hobby/profession, you will re-discover this analog one in a few years and you will appreciate the low microamps scale and the coolness of the analog indicator.
Cheers,
Dan