Billy Zoom's Jet Set

Gretsch G6129BZ Pickups too noisy. Suggestions?

26

Home dimmers will generate hum too, but I'm talking about the big grey boxes is theaters and clubs. The old ones were extrememly noisy. In the 70's and 80's, when real sound systems were being installed in venues, people were aware of the problems and most were upgraded, but some of the older venues still have dimmer packs from the 40's and 50's. To make matters worse, it seems the information didn't get passed down to the younger engineers and many of the brand new systems are as noisy as the 1940's units. It's a big horrible noise with a wide bandwidth and it's tone changes as the lights change. I recently had a run in with it at the Crystal Ballroom in Portland, an otherwise nice venue, but they've never upgraded the lights. The venue's sound guys usually don't belive that's where all the noise comes from, and we frequently have to shut down the mains power to the dimmer pack to prove it to them. If we want the superior tone of a single coil pickup, this is a cross we have to bear.

27

SCR is a silicon controlled rectifier. It lowers the voltage to the light by rectifying the ac voltage and chopping it into squarish waves. The dimmer packs will transmit that waveform as a radio signal for a radius of about 50 to 60 feet. Single pickup coils act as antennae and feed the hash signal to the amplifier along with the string vibrations. The noise is often the louder of the two. When you have a dimmer pack with an SCR circuit for each light bank or color, the noise signals all combine into a big roar. The lower the lights are dimmed, the more the ac voltage is chopped and the louder the noise gets. The only way to stop it is to turn off the power to the dimmer pack which leaves the stage dark. This is why we actually carry extra mic stands and clip lights in case of a dimmer emergency on the road. AFAIK, the all time worst offender is a tie between Bogarts in Cincinnati and First Avenue in Minneapolis.

28

BTW, the dimmer pack at First Avenue is directly under my side of the stage. It was built in the late 1940's.

29

The dimmer pack at Bogarts is directly behind my side of the stage.

30

There is a system with an antenna loop you place in the guitar. It is a rudimentary noise canceller but I don't know if it really works.

31

I've tried that. It works with regular hum, but not broadband dimmer noise.


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