Friday, March 25, 2011

Solidbodies, The 50 Year Guitar War - Video!

Nice Video on the development of the Solid Body Electric guitar. However, note that this video is a little dated already as we are above the 60 year mark. Therefore, this commercial video covers the 50 year history of electric guitars. This informative video features primarily Fender and Gibson guitars but there are others as well. I could pick out flaws but from a basic information point of view - this is worth watching if you are new to the instrument or buying and adding to your collection.
Enjoy learning about the history of an instrument that moved from the back of the bandstand to the forefront and thus dominating the air waves for years. The Video is available through Amazon at by clicking on this link!

Sunday, March 6, 2011

Guitar Shielding

Does your guitar hum? Got a noisy guitar? Shield it.

Do the following first:
  • Obtain a wiring schematic of your guitar.
  • No schematic?
  • Make a schematic or photograph all connects carefully
  • Check continuity to know which wire is connected to what (very simple terms here!)
  • Remove all old wires and components
  • Clean all components that will be reused
  • Shield the instrument (easier said than done - read a book about it!)
  • Solder all connections together using a decent soldering iron and solder (wire too)
  • Check continuity
  • Install components in the instrument (chronological sequence will vary with each instrument)
  • Double check continuity.
  • Button it up and enjoy.

This is a recent project of mine that wasn't nearly as simple as described because the PCB pre-amp was suspected of malfunction. I created a shielded test box to isolate problematic possibilities.

This was what the Factory sold to the public!

There was a lot of junk inside this cavity and I don't know what happened to the original battery clip but when I opened up this unit - The battery was wrapped in a napkin.

The Volume and Tone control cavity was grounded to the wire bridge in the main cavity - Still - the guitar had a troublesome hum. This hum was omni-present because this is a nylon string guitar with piezoelectric under-saddle pickup.

It is important to have secure wire connections. I used shrink tubing to insure a robust wire harness.

This is the shielding with the bad PCB Styrofoam insulation.

I ran many iterations to determine the source of 60 cycle hum. The pcb had some cold joints and bad components. I used my O-scope to pin-point the faulty component. Replace the component. Then I constructed a new insulation barrier for the pcb. The former PCB insulation was Styrofoam that was breaking down. The old insulation barrier was removed and I shielded EVERY CAVITY in the guitar.

This is what the shielded instrument looks like with the new wires, wire harness and components installed.

The guitar is now quiet as a mouse. Prior to this modification the guitar was annoying to play due to persistent hum noise. If I wished to use this guitar for a gig I had to adjust my all the amp settings to get barely passable tone. In addition, playing the guitar through a tube amp was not an option as the guitar would only work half decent on a solid state amp.

This guitar has a new life. Got hum - Try shielding! Scott \m/