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An integrated tuner for a Bassurgery custom bass.

My mate Kim called me up one day and told me he had started building custom bass guitars. Now if Kim is going to build a guitar you know it is going to be something special. He asked me to help him build an electronic tuner into the guitar so that you could just switch to 'tune' and look at the indication built into the guitar to tune it and switch back and you're ready to play.

In the final design each of the four strings - E A D G - is indicated by a backlit colour coded indicator and a row of cool blue LEDs indicate whether the note is low or high. The result is shown above - this is the story of its development...


This is the bass that was to have the tuner fitted. Kim's guitars are beautifully light because of the sculpted body, but this meant that space was going to be tight.	The bass uses the Lightwave optical pickup. Because there is a fair amount of electronics to support this Lightwave provide a rechargeable battery pack. This was a good start because it meant we could use this to power the tuner when required.	Rather than design a tuner from scratch, we decided that we should choose one of the most accurate tuners on the market and modify it so it could be integrated into the bass. This is the electronics PCB for the standard tuner.	The display from the standard tuner was carefully separated from the rest of the PCB and wired up so that it could be tested in its separated form. The red LEDs on the tuner were changed to blue LEDs. As these have a higher forward voltage drop than the red type I had to do a special PSU circuit to keep the tuner circuitry happy.

The standard tuner has the notes printed next to the LEDs but we realised that it would be difficult to see any printed text when on stage. So we decided to use colour coded LEDs to back-light the notes corresponding to the open strings. Kim made up this display assembly so it could be let into the guitar neck.	This new display module was quite a bit smaller than the original PCB version and as we did not want to make a one-off PCB Kim decided to wire the LED's by hand. I gave him the circuit schematic and he then took it back to the workshop to spend a few hours painstakingly wiring it up. A few days later he brought it over to test, but when we switched it on the LEDs came on in the wrong order - I'd made a mistake in reverse-engineering the LED wiring! I corrected the circuit and the poor chap had to undo all the wiring and re-wire it. Luckily it then worked perfectly.	All that remained to be done was to wire up the PSU and tuner to the multiway switch and fit this electronics into the recess in the body alongside the Lightwave electronics. Here's the bass (and Kim) along with three other of his basses at the guitar show.

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An integrated tuner for a Bassurgery custom bass.

This is the bass that was to have the tuner fitted. Kim's guitars are beautifully light because of the sculpted body, but this meant that space was going to be tight.

The bass uses the Lightwave optical pickup. Because there is a fair amount of electronics to support this Lightwave provide a rechargeable battery pack. This was a good start because it meant we could use this to power the tuner when required.

Rather than design a tuner from scratch, we decided that we should choose one of the most accurate tuners on the market and modify it so it could be integrated into the bass. This is the electronics PCB for the standard tuner.

All that remained to be done was to wire up the PSU and tuner to the multiway switch and fit this electronics into the recess in the body alongside the Lightwave electronics.

Here's the bass (and Kim) along with three other of his basses at the guitar show.