This Instructable is to show how i fitted a Varitone mod to my vintage Cruzer Stratocaster clone. I felt this was worthwhile as the guitar plays well and has a nice acton and i wanted to see if i could improve the tone.
**THIS IS NOT MY DESIGN! THERE ARE A NUMBER OF WEBSITES THAT SHOW THIS MOD> THIS IS JUST MY INSTRUCTABLE TO MAKE IT CLEARER**
Step 1: Components
For this mod I used four orange drop capacitors (.047, .033,.022,.01) which we bought from ebay for about £2.50 each.
I also used a genuine fender no-load 250k potentiometer which was about £5.50 and a 5-position rotary switch which I bought from ebay (via china) for about £2.60.
I decided to upgrade the wiring as some of it was quite thin so I bought some red white and black braid covered 22 gauge wire from ebay which came to about £6.
Step 2: Overview
In case anyone doesnt know how a tone control works on a guitar, basically there is a wire from each pickup to a selector switch position and a wire from the selector switch through the volume pot and then to the jack socket and on to the amp. The volume control works by leaking the signal to ground instead of to the jack socket so the more signal leaked to ground the less gets thro to the amp.
The tone controls work on the same principle except that the signal goes thro a capacitor fitted beween the pot and ground. The size of this cap determines which frequency is bled off, the larger the cap the more treble is taken out . This guitar had a wire from the neck and middle pickups on the switch, to two separate tone control pots. Note that the signal doesn't pass through these tone pots to the jack, it goes through the main wire from the selector switch and vol pot. The tone pots merely bleed off some of the signal to ground.
This guitar was unusual in that it had two 500k tone pots which i think are normally used with humbucker pickups not single coils.
The new system fits 4 different capacitors to the rotary switch, which goes in place of one of the tone pots. It's fed to the fender no load pot (fitted in place of the second tone pot) which allows you to vary the amount of bleed off. The no load pot differs from a standard pot only in as far as it has a detent position at which point it is taken completely out of the system. The fifth position of the rotary switch i left unconnected as a cut off.
Step 3: Fitting the Rotary Switch
there is a tab on the rotary switch which should go through a hole in the scratch plate to stop it turning. This switch is bigger than the original so the tab was in the wrong place. I didnt feel confident to drill the scratchplate without a drill press so i bent the tab down flat. The switch works fine so far.
**Please note that this guitar had an import style 5 way pickup selector switch, if you have the standard fender style switch the positions will be different. Check them with a multimeter to determine the correct tabs.**
Step 4: Soldering the Caps
This shows the capacitors soldered to the rotary switch and the new upgraded signal cable from the selector switch to the rotary switch. I was going to run the caps to the neck and middle pick ups only and this pic shows the forst of thos cab;es run to the rotary switch. I eventually decided though to run all the pups through the varitone system so i took the cable off the shown position on the selector switch, and soldered it to the the same selector switch tab as the main signal wire that goes to the volume pot.
Step 5: Capacitors Completed
This shows the caps connected together with an offcut from the one of the cut legs of a capacitor, and the new cable to the middle tab of the no load fender pot.
This shows the completed mod with the new cable from the left hand tab of the no load pot to the main body of the pot (all the pot bodies are connected together and go to the ground of the jack socket).
I also took the opportunity to upgrade the main wire from the selector switch to the volume pot, and the signal and ground wires from the volume pot to the jack socket (not shown here) as i read somewhere that better wire helps to improve tone.
Step 7: Conclusion
After putting the guitar back together and testing, I am very pleased with the results. The overall tone of has definitely improved, maybe due to better quality components, but there is definitely much more control over the type of tone. Dialling in the 047 cap drops the treble quite low so gives a warm tone, whilst the smaller caps give increasingly more top end. Taking the caps out completely with the fifth position on the rotary switch gives a raw signal which can be useful for some work. also, the no load position on the tone pot drops the caps out completely so its not really necessary, but i may just use the last position on the rotary switch to try a paper in oil capacitor for a comparison, in which case the no load position on the tone pot will be invaluable.
The next job on this baby is to decide on some new pickups and strings. I fancy trying the dimarzio heavy blues and blue velvet pickups if i can get some at a reasonable price. String wise I liked the sound of the last set of original Fender strings i fitted. Hope this helps someone thinking of doing the same. Please note, I am not a guitar tech so if i've made a mistake somewhere please be helpful and feel free to insert a comment.