Another stupid bridge question

[Flamingo21]

I still don’t know if a string absolutely needs to be grounded to induce a current in a magnetic pickup winding.

No it doesn't. When it moves, it induces.

 

[wiscoaster]

.... I still don’t know if a string absolutely needs to be grounded to induce a current in a magnetic pickup winding. I’m thinking an ungrounded string WILL induce a current in the winding of a magnetic pickup, but the ungrounded bridge / string will definitely prevent the player from touching ground which usually reduces noise. ....

Hmmmm .... doing some more thinking about this, from the standpoint of a ham radio licensee 60 some years ago and an EE major in college 50 some years ago who's forgotten most of what he learned. Yes, metallic strings don't need to be grounded to induce a current in the magnetic pickups, but what are the consequences of ungrounded metallic strings? Ungrounded strings can also function as RF antennas and pick up ambient RF noise, but uncertain how much of that can transfer to the pickups. Ungrounded strings can also serve as conductors for static electricity the player picks up, but again uncertain how much of that can transfer to the pickups and internal electronics. They're pretty well insulated. There are plenty of guitars out there with ungrounded strings and non-metallic bridges, so I really don't think this is a problem, just a hypothetical question, and deserving only an intellectual curiosity pursuit, not a practical build solution.

 

[ardgedee]

Ungrounded strings can also function as RF antennas and pick up ambient RF noise, but uncertain how much of that can transfer to the pickups. Ungrounded strings can also serve as conductors for static electricity the player picks up, but again uncertain how much of that can transfer to the pickups and internal electronics.

I wonder whether there's a difference between instruments that have all the strings joined by conductive materials and those that don't. Examples of the former would be anything with a Fender bridge, a Gibson style two-piece bridge, or anything with a brass nut. Examples of the latter would be anything that has both bridge and anchor made of wood, or a bass with monorail bridges.

 

[Bruce Johnson]

I wonder whether there's a difference between instruments that have all the strings joined by conductive materials and those that don't. Examples of the former would be anything with a Fender bridge, a Gibson style two-piece bridge, or anything with a brass nut. Examples of the latter would be anything that has both bridge and anchor made of wood, or a bass with monorail bridges.

Almost all basses of reasonable quality are built to have all the strings grounded. Electric basses with wooden bridges and tailpieces will usually have a concealed metal plate or bar linking the ball ends together. Monorail bridges are installed with a thin brass strip or buried wire under them. Common Fender-style basses have the buried wire contacting the underside of the bridge. This is considered standard practice in building an electric bass.

About the only exception is when some of the EMG systems are installed. EMG recommends that the strings not be grounded. I'm not sure of the exact reason, but it has something to do with the ground interfering with the operation of their preamp circuits.

 

[wiscoaster]

.....but it has something to do with the ground interfering with the operation of their preamp circuits.

Yes, I had a situation something like that with a bass mod project where the pickups were shielded, and the shields were grounded, and the shields were in contact with the cavity shielding paint. When you have a common ground like that your pickups can only be wired in parallel, and I was foiled in my plans to install a series/parallel switch. So I would guess EMG is using a "floating" ground for their pickups and preamp and they don't want a common ground (through shielding or hardware or strings) because it would be a real pain to isolate and insulate their floating ground from the common ground. I'm just guessing .....

 

[ThudThudThud]

a modification/variation on a cello tailpiece and bridge might work.
Invalid Link Removed

 

[Mickey666]

a modification/variation on a cello tailpiece and bridge might work.
Invalid Link Removed

Now that's an interesting idea, gonna hafta look into that

 

[dlmarquez]

In my opinion the coolest bridge I have ever seen with integrated volume and tone controls! From the Rob Allen Solid 4