John Sayers' Recording Studio Design Forum Archive

Am I starting too many threads here? Figured I'd try to keep new topics on different threads, easier for others to reference.

I have my lighting on a separate circuit from my power. Do I still need to use variac dimmers in this case? Seems like it shouldn't affect the power (therefore gear) on a different circuit.

-HB

Unfortunately SCR dimmers generate so much RFI that it will bleed into anything that's tied together anywhere in the building - worst case is when using dimmers at half power. Under those conditions, the SCR's stay turned off until the voltage is halfway thru its cycle - they then turn on right when the voltage is at its peak, which puts a really high frequency spike (caused by overshoot) into the circuit. This spike radiates high frequency spikes into everything around it, and does so at a 120 hZ rate - so you get tinny (high freq) hum (low freq) -

Few people (if any) have had success with even the more expensive SCR dimmers because of this. About the only other practical way (other than variacs) is to have multiple circuits; flourescent work lights behind the racks, and 2 or more circuits for incandescents - low wattage lamps in one circuit for "mood", and 1 or more higher wattage circuits for brighter illumination... Steve

ok, understood. Thanks!