Looking for information on building a Varitone switch

[Jim Bonnell]

I decided to build a couple of Varitone switches, how hard could it be right. Did I mention I know extremely little about electronics? I found quite a bit of information online. All was going well until I started to place my parts order. Oh my God, I had no idea there was so may types of capacitors. We have ceramic, coated ceramic, mylar, various polys of one type or another just to mention a few. Some are measured in uF some in mF and some in pF. Then we have a selection of voltages. And last but not least a number of manufactures. I'm lost. My plan was to build one using .1uF-.047uF-.039uF-.01uF-.0022-capacitors. For this one I planned to use ( here I'm going to really show my ignorance ) the little Chicklet looking capacitors (mylar I think ) . Who would have known there were so many types that looked like Chicklets. For the other I had planned to use .001mF-.01mF-.022mF-.047mF-.22mF ceramic capacitors. My plan was to compare the two and see which I preferred. I'm having trouble finding them all in the same voltage and I'm wondering if I can mix voltages. I didn't think this would be so over my head. If anyone has any suggestions on all this I would love to hear from you. Please keep it simple for a simple minds. Thanks for any help.

[Halgeir Wold]

These are known as engineering unit. Capacitance is measured in Farads, a unit way too large for practical use.
Thus 1 uF ( microfarad) = 1000 nF = 1.000.000 pF. 1 mF=1.000 uF, although older components were sometimes marked 1mF=1uF, for lack of a proper micro-sign....
For signal applications, polyester or mylar, polypropylene is OK, although polyprop usually are physically larger. Ceramics are usually not concidered suitable for tone or signal applications, mostly used for decoupling of noise signals in circuits ( although extensively used in RF signal circuits ).
For your applications I'd settle with mylar or polyester, - axial leads ( out of the end of a cylinder), rather than radials ( sticking perpendicularly out of the side ends). Rated voltage around 50-100V is more than enough. Larger voltage ratings makes larger sizes.........
And then there's the Component Tone Mojo..... of which I'm sure someone else will chime in.....

BTW - polarized electrolytics, from a few uF up to several thousands of uF, are for power supply filtering and coupling....

[Mark Wybierala]

The varitone is a simple circuit. You have a coil and a cap in series going from the pickup output to ground. A switch allows you to change the value of the cap. The voltage level of the signal coming out of a pickup is so small that you really don't need to have much of a concern with the voltage value. You can have any amount of switching positions but I believe that the original Gibson Varitone had six positions. One of those six was a non-connected position which removed the varitone from the circuit. I got an original schematic from Gibson a few years ago and it indicated that the inductor value was 1 Henry. I never found a 1 Henry coil but I had good luck using one side of a small audio transformer like you'd find in a little transistor radio. I made this schematic to show a Varitone in a typical guitar. I included a potentiometer that allows you to control the amount of influence the Varitone has on the signal. If you eliminate the switch and the coil, and use just one of the five caps, the Varitone circuit is incorporated in the same manner as a conventional tone control. On my Varitone circuits, I use a .005uf, .022uf, .047uf (or .050uf) and a .1uf. I use a five position switch and only four caps.

[Jedi Clampett]

guitarfetish. com has some varitone circuit boards that were destined for epiphone lucille guitars, but that they bought, I bought a couple of them.

[David King]

No to discourage the OP but I've always been curious... Does anyone use their Varitone? Seems like a lot of trouble to go to for limited return.

[Beate Ritzert]

I had installed one in my Epiphone EB-3 bass and removed it. Main reason was that the inductivity got into massive saturation (transformer with E14-Kernel - too small for a bass varitone), and i got a fuzz tone. I actually think of reinstalling it - it was quite funny.

Regarding the choice of capacitors: the values should increase from one value to another by a constant facto - this will lead to uniform changes in sound. The values chosen by Gibson were not optimal. BTW: 2 or 3 positions plus "off" should be sufficient, especially if You fine tune the capacitors to the sound of the guitar. Less is sometimes more (I had 3 steps in the bass, and the one with the largest capacity was the fuzz).

[Jamie Unden]

On one of my designs I haven't built yet I plan on making one using a Fender style 5-way switch. Four positions and off seems like it would be enough. If you are looking to buy a varitone, Big D Guitars sells them.

[Beate Ritzert]

This is one of the cases where i somewhat pity that links into other forums is against the policies of this community. Simply because there is a forum with very significant resources on pickup making (mybe the most significant resources...) with sufficient material on that topic.

[Mark Swanson]

Just tell us what to search for, using Google. That will get us there just the same.

[Jim McConkey]

Beate, and everyone else - our Forum rules are only meant to prohibit moving entire discussions to another board or venue and to prohibit using discussions here for the sole or primary purpose of promoting another web site, not to discourage informational links within a discussion here. If there is a relevant discussion on another specialty forum, feel free to post a link to it within the context of an ongoing discussion on this board. What we don't want to see is "I'm not discussing it here, go to this other site and discuss it there."

Happy New Year everyone!

[Jason Rodgers]

Thanks for the clarification, Jim. Link away, B!