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[DavidTurner]

I suspect this problem begins in the single coil pick-up on the steel guitar. Can someone point me to a forum that might help me find a better way to shield said pickup?

[Doug Fowler]

I suspect this problem begins in the single coil pick-up on the steel guitar. Can someone point me to a forum that might help me find a better way to shield said pickup?

Try the Guitars forum here:

http://acapella.harmony-central.com/

[DavidTurner]

Thanks!

[Ivan Beaver]

I have a band member who uses a vintage Fender Dual Showman for his steel guitar. On a number of occasions during last year's tour we had problems with induced hum. The problem seems to be venue specific, that is, some days, totally quiet - other days, wall to wall hum. Some days it would seem to be induced by the dimmers - relative to number of lights up and particularly noticeable when lighting scenes were cross faded.

Signal chain is: Steel guitar, volume pedal, EQ pedal, Delay pedal, 20' guitar cable, amplifier. Do any of you have any suggestions as to how we can better shield this set-up to prevent this induced hum?

Thanks

A couple of suggestions.

First-use the shortest possible cables.

Next use a directional cable.  NO NO not those expensive "Hi-Fi" cable, but rather a homemade one.

Get 2 good quality 1/4" plugs.  Next use a well shielded mic cable.

On the AMPLIFIER end hook the tip of the plug to the "hot" wire in the mic cable.  It can be whatever color you want-as long as you remember it.  Usually red or white.  Hook the other wire AND the shield to the ground of the 1/4" plug.

On the INSTRUMENT end hook the hot wire to the tip of the plug.  Hook the other wire to the ground of the plug.  DO NOT hook up the shield wire.  Make sure it is disconnected and cannot touchthe ground wire.

[DavidTurner]

In other words, telescoping shield...float the pedal board

A couple of suggestions.

First-use the shortest possible cables.

Next use a directional cable.  NO NO not those expensive "Hi-Fi" cable, but rather a homemade one.

Get 2 good quality 1/4" plugs.  Next use a well shielded mic cable.

On the AMPLIFIER end hook the tip of the plug to the "hot" wire in the mic cable.  It can be whatever color you want-as long as you remember it.  Usually red or white.  Hook the other wire AND the shield to the ground of the 1/4" plug.

On the INSTRUMENT end hook the hot wire to the tip of the plug.  Hook the other wire to the ground of the plug.  DO NOT hook up the shield wire.  Make sure it is disconnected and cannot touchthe ground wire.

. Thanks. That guitar forum wasn't much help.

[Bob Leonard]

David,
Before the amp is condemned please take the time to unplug the input cable at the amp and turn the amp up full. If you have no or very little hum the amp is not the culprit here. If you find no or little hum, and working from the amp back to the the steel guitar add cable and components one piece at a time until the offending culprit is found. If you want to find the source quickly do this under or near a flourescent light.
 
If you are not able to remove the source of the hum from the signal chain, and if the source can not be repaired or properly grounded, i.e., a single coil pickup, then the best device on earth for removing hum in cases such as this, and without killing the tone of the guitar, is made by Electro Harmonix;
 
http://www.ehx.com/products/hum-debugger
 
If it turns out that the source for the hum is the Showman then I suggest you start by adding a 100 ohm 1/2 watt resistor from each side of the front panel pilot light to ground (if not already there depending on year of make).
 
If that fails, or if those resistors already exist the problem could be lead dress or the need to replace power supply (B+) filter capacitors. Let me know what you find and have fun.
 
 

[DavidTurner]

Thanks Bob. Hum goes away when the guitar cable is unplugged from the amp. We have dicked with his pedal board and the power supply to the board, lifted grounds, tried every combination of ground lift - amp, pedal board, etc. Thanks for the tip about the florescent light as I was looking for a way to recreate the problem in a controlled environment and it has been intermittent throughout the tour. He is also using some rather cheesy vintage stomp boxes that may be contributing.

We are in a rehearsal hall for three days next week. It will give us time to try lots of stuff...

David,
Before the amp is condemned please take the time to unplug the input cable at the amp and turn the amp up full. If you have no or very little hum the amp is not the culprit here. If you find no or little hum, and working from the amp back to the the steel guitar add cable and components one piece at a time until the offending culprit is found. If you want to find the source quickly do this under or near a flourescent light.
 
If you are not able to remove the source of the hum from the signal chain, and if the source can not be repaired or properly grounded, i.e., a single coil pickup, then the best device on earth for removing hum in cases such as this, and without killing the tone of the guitar, is made by Electro Harmonix;
 
http://www.ehx.com/products/hum-debugger
 
If it turns out that the source for the hum is the Showman then I suggest you start by adding a 100 ohm 1/2 watt resistor from each side of the front panel pilot light to ground (if not already there depending on year of make).
 
If that fails, or if those resistors already exist the problem could be lead dress or the need to replace power supply (B+) filter capacitors. Let me know what you find and have fun.

[DavidTurner]

I have a correction: The guitar has a humbucking  pick up and the pedals are not cheesy (in a stompbox relative way) or vintage. The player thinks it might be his 9v supply. Going to try replacing that and doing the telescoping shield thing.

Thanks to all who have offered suggestions.

[Noah D Mitchell]

Are you getting the hum when the guitar is plugged straight into the amp (no pedalboard)? It may be worth sleuthing that out.


A custom guitar builder I know has the habit of shielding all the pickup holes in his pieces with sheets of copper that are all soldered (sealed around back) and wired to each other, don't know if that's just voodoo or if it actually helps, but may be a solution if the noise is coming from the guitar itself.


Jonathan

[DavidTurner]

Are you getting the hum when the guitar is plugged straight into the amp (no pedalboard)? It may be worth sleuthing that out.


A custom guitar builder I know has the habit of shielding all the pickup holes in his pieces with sheets of copper that are all soldered (sealed around back) and wired to each other, don't know if that's just voodoo or if it actually helps, but may be a solution if the noise is coming from the guitar itself.


Jonathan

Thanks for the suggestion. Seems like we may have tried that over the course of the last tour. Anyway, going to try everything at rehearsal.

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