Building a circuit into the control plate of my Telecaster

Started by Indoor Fireworks, December 18, 2006, 12:47:52 PM

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Indoor Fireworks

You'll have to excuse me for not being very intelligent when it comes to explaining electronics. If you think I have no idea what I'm talking about, you're probably right.

I have a Fender Tele and I absolutely love the custom shop 52 tele pickups I installed. The only disadvantage is that the bridge pickup is almost twice as loud as the neck pickup. I was thinking of building a circuit into the control plate of my Tele that would even out the difference in volume. Rather than building a signal booster for the neck pickup, I was thinking of building a switch controlled circuit that would actually decrease the volume of the bridge pickup. When the switch is engaged, the volume would drop. But at the flick of the switch, the volume would go back to normal. Does this make sense? I have a push-pull volume potentiometer that also acts as a DPDT switch. Does anyone have any ideas about how I would go about building this into my guitar without compromising the tone? I'd love to hear anyone's input.

Jonathan

Mark Hammer

First off, the volume difference should not be THAT large, unless the pickups are adjusted very differently and are also very different in output to start with.  I suppose weirder things have happened, but if these are PUs from folks who assume they are going on the very same instrument, the PUs shouldn't be all that different in output level if everything is working right.

Having said that, the circuit may be one whole heckuva lot simpler than you imagine.

A volume pot reduces the output voltage, proportionally to the ratio of the two "legs", or halves, of the pot on each side of the variable contact, or "wiper".  Normally, the pot has a fixed overall value (e.g., 250k) and volume is a matter of how much of that 250k falls on one side or the other of the variable contact.

However...if the variable contact stayed put, and you added some resistance to one leg, then the ratio of the combined resistance of one side to the existing resistance of the other would change, wouldn't it?

So, let's imagine the wiper is at exactly halfway along the resistance of your existing volume pot; i.e., 125k or half of 250k.  Now suppose there was a 47k resistor between the hot lead from your bridge pickup, and the input of the volume pot, but your neck pickup was wired directly.  For the neck pickup, the 125k/125k divider would cut the oputput level to half of the input level.  For the bridge pickup, though, this would not be a 125/125 split, but rather 172k/125k, resulting in greater attenuation of the input signal for the bridge pickup than for the  neck pickup.

And there you go.  Solder a smallish-to-medium value fixed resistor (say, between 33k and maybe 100k) between the hot lead of the bridge pickup and the solder lug it currently goes to on the pickup switch.  Alternatively, a 100k trimpot that you can adjust to perfection, and glue in place will do.

Fleetdog

I think part of the concern may have been for the middle tele possition with both pups on.  I would suggest putting a trimpot in as a volume between the loud pickup and the pickup selector switch and use the push/pull to either activate this trimpot or bypass it. 

To wire this, you would connect the center lugs of the DPDT in the hot wire of the pickup headed to the selector switch.  Just put a jumper wire connecting one set of the outer lugs (this is your bypass option).  For the other pair of outer lugs, connect the one on the same side as the pickup to an outer leg of the trimpot; the other lug goes to the middle leg of the trimpot; and the final leg of the trimpot gets connected to ground. 

I hope that helps.  For more tele specific tips, I suggest checking out the forum at telemodders.com

Gus

I have two teles with 52 fender pickups not that much difference in volume..

Have you adjusted the pickups? maybe drop the bridge down a bit and angle the pickups side to side to balance the low E to high E

The Kinmann site had a good writeup for setting up pickups.  The distance and angle can be thought of as a tone control.

markm

Quote from: Gus on December 18, 2006, 03:10:46 PM
I have two teles with 52 fender pickups not that much difference in volume..

Have you adjusted the pickups? maybe drop the bridge down a bit and angle the pickups side to side to balance the low E to high E

The Kinmann site had a good writeup for setting up pickups.  The distance and angle can be thought of as a tone control.

What Gus says makes sense and would be a whole lot easier. Don't put your Tele under the knife...... :icon_neutral:

Indoor Fireworks

Thanks for all the helpful suggestions. I thought about adjusting the pickups so they're a little more similar in volume, but I also think it would be cool to have a switch that can make it shift from quiet to loud on the bridge pickup. It would be a good help for leads. I don't know. I'll experiment with a trim pot and if I don't like it I'll just adjust the pickups.

Thanks again for all your help!

Fleetdog

I'm all for modding the heck out of teles; however, I would very much suggest you reverse your plan and first adjust the pup heights then think about this mod.  I was assuming you already tried changing the heights and couldn't get what you wanted out of that.  Mods are cool, but the best mod is the simplest one that gives you the sounds you want. 

Mark Hammer

Quote from: Indoor Fireworks on December 18, 2006, 04:01:41 PM
Thanks for all the helpful suggestions. I thought about adjusting the pickups so they're a little more similar in volume, but I also think it would be cool to have a switch that can make it shift from quiet to loud on the bridge pickup. It would be a good help for leads. I don't know. I'll experiment with a trim pot and if I don't like it I'll just adjust the pickups.

Thanks again for all your help!
1) You really *should* see first if the volume balance thing can be effectively addressed by height adjustment before screwing around with the elctronics.  In theory, it ought to be.

2) Alternatively, why NOT have the best of all possible worlds and use a 5-way switch o effect.  In principle, you ought to be able to do things like have your stock 3 settings, plus one where the neck pickup is auto-muted (like the earliest Teles) and one where the bridge pickup is autoboosted - the so-called "blower" switch found on some Danelectros, where tone and volume settings are bypassed.


Gilles C

I bought a Tele copy last week, and am working on it again this week, so I'm listening...

And I had to readjust the neck pickup because it was too far from the string and was having the same problem. That fixed it. I also replaced the pickups by genuine Fender pickups I already had.

But I began checking for the different adjustements and setting for a Tele (being a Strat guy first...) and was wondering about the Esquire wiring with the resistor and cap that are not used in the normal Tele.

http://www.tdpri.com/wiringESQUIRE.htm

Is there still a use for that?

Ok, found it... no neck pickup...

http://www.fender.com/support/diagrams/pdf_temp1/telecaster/0131502A/SD0131502APg4.pdf

I also have a 5 way switch to replace the original 3 way. That's why I am interested in the thread. Keep writing guys  ;)

Indoor Fireworks

Despite people's suggestions to adjust the pickup height first, I went ahead and put in the switch because I'm just too stubborn. Actually, I could not be happier with the way it sounds. I replaced the 250K volume pot with a 500K pot/push-pull DPDT switch and it sounds amazing. I don't know if it is because there is a different value for the volume pot but my guitar now sounds indescribably good. I put a small 100K trim pot like Mark Hammer suggested, wired it all together according to Fleetdogs instructions and now my pickups are at an even volume. Of course, if I need a little extra volume for my bridge pickup, all I have to do is pull the volume knob. The only problem I ran into was an issue of adequate space for this rather large pot. I unfortunately had to switch the positions of the Tone knob and the Volume knob. I expected it to be difficult to get used to this, but I've been playing my Tele for the past hour and it already feels natural having the volume knob in a different place. Again, thanks eveyone for the help. Here is a picture of the two pots. I know it looks a bit sloppy, but I am very inexperienced.


Mark Hammer

a) Congrats!  The wiring appears to be a little space-consuming, but as you note that is likely a product oif inexperience.  I am confident that with a little time you will figure out how to reduce the bulkiness of what is packed in there.

b) The higher pot value has the effect of retaining more of the Tele's natural bite.  I know a lot of folks don't like them, but I'm a big fan of using higher-value volume pots (500k, 1meg), instead of the lower value pots intended to load down the pickup and tame what some feel is "brittle-sounding" treble.  The way I figure it, I can always take excessive treble away downstream, but I can't add treble that I never had in the first place, so I use volume pots that retain max treble, and do my filtering elsewhere.  Neither is "better", just closer to what a given musician likes.

c) One of the things I've becomepartial to is a bi-directional tone control.  I use a 1meg linear tone pot, with the wiper connected to the volume pot input, and the outside lugs of the tone pot each tied to ground through different-value caps, such as .015uf and .0033uf or .0047uf and .022uf.  At one extreme (lowest resistance to ground through the larger cap), you get the standard dull muted sound, and at the other extreme (lowest resistance to ground through the smaller cap) you get what one might call a "rounding off the edges" sound, that is closer to what a humbucker might sound like (though without as much bass).  Middle settings on the pot are the brightest with no discernible rolloff.  The neat thing about this arrangement, besides tonal flexibility, is that the entire range of adjustments is collapsed into half the rotation in each direction.  Since you don't have to rotate the knob quite as much to go from full rolloff to full brightness, that makes it easy to use your pinky to rotate the tone pot as an on-board wah.  Danny Gatton used to do this exquisitely.

markm

Quote from: Mark Hammer on December 19, 2006, 09:51:56 AM
c) One of the things I've becomepartial to is a bi-directional tone control.  I use a 1meg linear tone pot, with the wiper connected to the volume pot input, and the outside lugs of the tone pot each tied to ground through different-value caps, such as .015uf and .0033uf or .0047uf and .022uf.  At one extreme (lowest resistance to ground through the larger cap), you get the standard dull muted sound, and at the other extreme (lowest resistance to ground through the smaller cap) you get what one might call a "rounding off the edges" sound, that is closer to what a humbucker might sound like (though without as much bass).  Middle settings on the pot are the brightest with no discernible rolloff.  The neat thing about this arrangement, besides tonal flexibility, is that the entire range of adjustments is collapsed into half the rotation in each direction.  Since you don't have to rotate the knob quite as much to go from full rolloff to full brightness, that makes it easy to use your pinky to rotate the tone pot as an on-board wah.  Danny Gatton used to do this exquisitely.

Mark,
This is without a doubt one of the coolest Tele mods that I have heard of.
I may have to look into this one.
Thanks!!

Mark Hammer

There are a host of interesting but simple Tele electronic mods one can do.  I find this one delivers nicely, both in terms of the range of sounds attained and in terms of usability.  Just make sure that you use a 1meg (or at least a 500k) pot for tone since in the middle position you will essentially have two 500k (or worse, 250k) tone pots in parallel, resulting in signal bleed through two caps.  Remember that even if the overall pot has a resistance value of 500k, two 250k resistances going to ground in parallel are behaving sort of like 125k.  Hence the reason for wanting to use a 1meg pot.

Another strategy that I haven't personally used, but that has been discussed and merits trying out is to use a treble cut cap in one direction, and a cap/inductor combination for midscoop in the other.  A number of folks have adapted their Strats to provide midscoop via one Tone pot, and treble cut via the other.  In this instance, the one pot would do both.  If one chose to do this, just pay attention to which direction each effect is applied in.  I suspect most people would want to be able to "pinky-wah" the treble cut, but not the midscoop.  You'll probably want to have the pot wired such that "wah" is achieved by placing the outside of your pinky up against the "10" on the knob and pushing downward as you pick so that it rotates towards "5" to produce more treble.

Man that is tough to describe in words!! :icon_eek: :icon_lol:

I wish there were suitable pots with centre detentes so one could know when the midpoint was reached.  Alternatively, one could dab a wee bit of nail polish in the pidpoint to get the dead zone effect on the tone pot at the same time as having a point that felt a little different physically....sort of like a detente.