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[Nick Enright]

You will hear the difference right away, in the form of noise. Lots of buzzes.

That's not the question, the question is now, why?

[Tim Perry]

Admittedly I know way more about linear supplies, but I just cant figure why audio devices would see a difference if the AC is a step function or a continuous one.

Nick, are you familiar with "dimmer buzz" issues? you would think maybe that all the power supply filtering would take care of that but sadly at times the audio system as a whole is affected.

If you have ever had a frantic time just before a show swapping cables, reconfiguring equipment, and adding inline transformers to eliminate or reduce hums buzzes and whines  you will understand why someone who has gone through it would make recommendations for 'true sine wave' power sources.

[Nick Enright]

Nick, are you familiar with "dimmer buzz" issues? you would think maybe that all the power supply filtering would take care of that but sadly at times the audio system as a whole is affected.

If you have ever had a frantic time just before a show swapping cables, reconfiguring equipment, and adding inline transformers to eliminate or reduce hums buzzes and whines  you will understand why someone who has gone through it would make recommendations for 'true sine wave' power sources.

Since I switched to all balanced audio connections, bring my own power, and use single point ground schemes, I haven't ever had a buzz, even when the dimmers were almost on top of the snake, and the DMX was running down channel 42.

Occasionally I'll get a light buzz from a DI'd instrument, but that can be fixed by the specific ground lift.

Maybe I'm just lucky?

[Chris Clark]

and the DMX was running down channel 42.

Not totally on point, but as long as all your snake lines are properly balanced and shielded, you shouldn't get any crosstalk from the dmx signals. Since DMX is basically a constant digital RS-485 signal at its roots, the active dimming of lights wouldn't change the signal being sent through the snake anyway. I too have done this before with no problem.

The typical problem with hum in a sound system from lighting dimmers tends to come more from the actual dimmers themselves - typically the construction of the dimmers will determine this, though anything that isn't properly wired/grounded could still cause backfeed into the sound system if they're on the same power source.

[ProSoundWeb Community]