[Tim Farrant]

This is a very interesting topic, and one I have a very strong interest in. 0dbVU (on a standard VU meter) = +4dbu (or formerly known as +4dbm). This relates to a signal voltage level of 1.23V RMS. To obtain peak level of 0dbFS on the DAW requires that the analog driving stage will need to deliver +22dbu (as mentioned above). Here is where it gets important because in many caes, this +22dbu level will be at or close to clipping in many analog equipments.

In the old days of analog tape, you simply could not record these levels without undue distortion, with digital however, this is not the case. So analog electronics has to deliver more than ever greater levels, and quite simply, the analog electronics needs to be able to deliver this higher level and ultimately more power. Suddendly, op amps with +/- 15 volt rails seem inadequate for this task, because they are operating so close to maximum output and this is going to sound bad, believe me. This is why perhaps much low end gear still using +/-15V rails fall short and get a bad name, especially on percussive sounds like drums.

My advice, if you have a low cost mixer or outboard that runs on low power supply rails, use a higher dbFS setting like -12 or -14. This will put less stress on your analog, and therefore better overall sound.

Tim.