On Feb 4, 2012, at 8:20 AM, steve harley wrote: > on 2012-02-03 12:10 Collin Brendemuehl wrote >> "0 db" is not an output. It is the amount of attenuation (resistance) >> that the volume knob puts in the electron path. It is equivalent to >> "full volume" and means nothing else -- it has no reference to what >> that maximum output might be. > > sounds great except the knob goes to +15 ...
Yes, this means it has 15dB of gain available to compensate for low input signals. dB is all relative, it can be positive to indicate gain or negative to indicate attenuation. With preamplifiers 0dB simply means that the outgoing signal is at exactly the same level as the input. In an integrated amplifier the preamp is built into the same box as the power amplifier but the gain still refers to the preamp only, ie before the signal goes into the power amplifier which adds some extra gain to drive the speakers. FWIW my power amplifiers are about +24dB and +27 dB. I'm using active crossovers so I have to compensate for the different amplifier gains as well as the driver sensitivities, but that's getting a bit far off-topic. Because amplifiers tend to be quite sensitive, 0dB of input signal attenuation will usually send them well into clipping with most modern signal sources. So the actual dB figure is fairly meaningless and in a consumer environment I consider it nothing more than wankery. On a related note, a while ago I ended up attenuating my headphone amplifier to about -12 or -15dB because even 0dB gain (at the full volume setting) made the volume control too coarse for my headphones. It was a bit like Frank's friend with bleeding ears at 3/10. Now I have a comfortable listening level between about 10 and 12 o'clock depending on what I'm playing. One of these days I'll get around to making a nice stepped attenuator for it. Dave -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
