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'Heater noise or EMI ?'
Author:AZMike (registered user: 61 posts )
Date: Sat, Jun 16th, 2012 @ 15:02 ( . )

I have been fighting 120Hz noise for a while and believe it may be as good as it gets after balancing and elevating heaters to 40 volts. I have even tried running the AX7 tube heaters from a bench supply but with no significant audio results. The guitar pickups vary from 3k Ohms to 9k Ohms. I unplugged the input cable at the guitar end and placed a 10k resistor between the connector contacts. The noise fell dramatically, to acceptable levels.

The noise varies as I walk around the room with the guitar plugged in. Would this be expected if this was heater noise? The guitar is new therefore I expect no wiring issues. Two other guitars show the same results also. There is no noise with active pickups.

I suppose it is possible that the 120Hz noise is due to the guitar pickups being susceptible to radiated EMI from the amp?

As always any comments or suggestions are greatly appreciated.




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Replies:
--* Heater noise or EMI ?
6/16/2012 @ 15:31--stringbend
6/16/2012 @ 15:49----AZMike
6/16/2012 @ 16:09------stringbend
6/16/2012 @ 17:01--------AZMike
6/17/2012 @ 13:49--------mhelyar86
6/16/2012 @ 20:26--Celeste hall
6/17/2012 @ 16:17--Merlin
6/17/2012 @ 16:49----AZMike
6/23/2012 @ 10:32------AZMike

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