Tuesday, July 18, 2017

Taylor AB 1 stripped down to it's basic components for repair.

I know, risky business making repairs and modifications to such a beautiful instrument!

Luckily I know what I'm doing.

Lately a hum has developed in the Fishman electronics so I decided to install an earth from the bridge to the tail pin jack plug.

I've seen some rather clumsy looking modifications done to other Taylor basses (online) and decided to design my own earth network.

When stripping the Fishman preamp I noticed that the input cable from the Piezo pickup was loose  in its connector so this was a great opportunity to put this right. I you are having issues with this preamp as some folks have reported, then this is the first thing to check. The connection to the preamp board is made with a screw clamp which may need to be tightened.


This image shows how discreet the earth/string contact is.
I hammered a trough into 3mm x .3mm copper ribbon to accommodate the radius of each string in its pocket. I then soldered the 4 short lengths of this prepared ribbon on to a spine of the same material at the same spacing as the strings. 
I drilled down vertically with a 3.2mm drill bit into each of the string anchor cavities to make access through to the underside of the sound board.
The newly fitted copper saddle comb can be seen straddling the brace with the brown earth wire soldered to it. Each of the 4 prongs protrudes through the sound board  into the bridge string anchor slots. The earth wire is soldered to the 1/4" jack socket earth tab. The black wire is connected to the under saddle piezo pick up to the onboard Fishman pre amp.



 This image reveals the experimental, phenolic treated, wood saddle material I installed last year. It is by far the best saddle material I have used to date.I found a piece of this material in the workshop of a retired Navy boat builder. He told me it was the step tread material from a WW11, RNZN frigate. This material was once wood which has been pressure impregnated with formaldehyde resin. It is so heavy that it will not float. I have a 12" x 1" plank of this stuff 3' long which will last me a very long time.


Next job I wanted to do was to repair 2 cracks that had developed over time in the rib of the guitar body near the venetian cutaway. This is a problem area for these basses which may have been why Taylor decided to discontinue production in 2003. These guitars were built in El Cajon in California where the humidity is relatively low. My bass was exported to NZ in 1998 and encountered a very different environment. The humidity in Northland NZ runs to 100% at times and the climate is best described as sub tropical. The high humidity as put a great deal of stress into this guitar. Now that the guitar has reached 20 years of age it should have stabilised.

My solution was to unbolt the neck and drill down through the neck reinforcing block behind the crack (which ran vertically down the join in the rib panel, under the neck).

I then fitted a hard wood dowel of the same diameter and glued it into the hole with epoxy glue. The glue forced itself into the crack under the pressure of the close fit. Once set this connection is intensely strong. 

A secondary crack appeared in the rib from the neck pocket, out across the venetian cut away, parallel to the wood grain, in line with the sound board lining. 
Showing the repaired cracks in the rib.

I then sanded the outer surface to flush and then refinished the coating.

Last job: revisit my de-fretted neck. 
Steve Klien's ivoroid inlaid signature is clear to see.



The Taylor bass has a compound radius finger board so the sanding of the ebony surface requires a sanding beam (in my case, fine sandpaper double sided taped to the edge of my long spirit level.

I filled the old fret slots with Walnut veneer which gives me a visual reference when playing. I'm not so good that I can move from my Jazz electric to this bass without this visual aid for accurate intonation.


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