Advice about variable humbucker to single coil split?

[paw20051]

Hi Guy’s,
Thanks for this great Forum.
I have just become a member, and this is my first post!
I have been a “lurker” that has learned a lot through the generosity of the knowledge sharing of many members. I thank you for that!
I am building a guitar, “from scratch”, using 2 x 4 wire humbuckers (which I still have to wind). My question is, is it possible to use the Peavey T60 type wiring set up, whereby one can dial in variable single coil/ humbuckers settings. I want to use 2 x push pull switches/pots, instead of the 4 pots as used by Peavey. I believe the pots used by Peavey are different in some way. I did experiment on my test guitar, with the normal linear & analog pots (total 4), but the transition between single/humbuckers was not as smooth & regular, as I would like, and am not even sure whether it can be done. I am not that experienced in electronics or reading proper schematic drawings! If anyone has any ideas & simple drawings I would appreciate the advice! I want the guitar to be minimalist, ie max 3 knobs (pref. 2) & 1 x 3way switch.
I was previously a hobby knife maker, & have sold knives to the States, & the U.K.
Now have changed, as a beautiful guitar can make beautiful music!
It need not be stuck in a displace case somewhere!
Thanks in advance.
Cheers
Peter

[big_teee]

Hi Guy’s,
Thanks for this great Forum.
I have just become a member, and this is my first post!
I have been a “lurker” that has learned a lot through the generosity of the knowledge sharing of many members. I thank you for that!
I am building a guitar, “from scratch”, using 2 x 4 wire humbuckers (which I still have to wind). My question is, is it possible to use the Peavey T60 type wiring set up, whereby one can dial in variable single coil/ humbuckers settings. I want to use 2 x push pull switches/pots, instead of the 4 pots as used by Peavey. I believe the pots used by Peavey are different in some way. I did experiment on my test guitar, with the normal linear & analog pots (total 4), but the transition between single/humbuckers was not as smooth & regular, as I would like, and am not even sure whether it can be done. I am not that experienced in electronics or reading proper schematic drawings! If anyone has any ideas & simple drawings I would appreciate the advice! I want the guitar to be minimalist, ie max 3 knobs (pref. 2) & 1 x 3way switch.
I was previously a hobby knife maker, & have sold knives to the States, & the U.K.
Now have changed, as a beautiful guitar can make beautiful music!
It need not be stuck in a displace case somewhere!
Thanks in advance.
Cheers
Peter

Here is the Schematics for the T60.
Wiring Diagram - Schematic for the Peavey T-60 and T-40 -  The Largest Selection Of Peavey T Parts! 
I build Pickups and wire guitars all the time.
Not sure I understand why the centertap of the pickups go to the tone controls.
I recommend using a standard wiring layout when you get to that point.
I use the Seymour Duncan Guitar wiring layouts all the time with success.
Wiring Diagrams - Seymour Duncan
Go to the Humbucker drop down tab and pick the layout you want.
I prefer 4 knobs.
The reason, you have a separte tone for each pickup.
With a separate tone, you get to have a different value Cap for each Pickup.
Good Luck,
Terry

[rjb]

I am building a guitar, “from scratch”, using 2 x 4 wire humbuckers (which I still have to wind). My question is, is it possible to use the Peavey T60 type wiring set up, whereby one can dial in variable single coil/ humbuckers settings. I want to use 2 x push pull switches/pots, instead of the 4 pots as used by Peavey. I believe the pots used by Peavey are different in some way.

I have an old T-60 with a broken neck pickup. After I rewind the p'up some day, I'll probably replace the patented Peavey tone circuits with traditional tone circuits, using push-pull tone pots for coil cut. Personally, I never found the Peavey circuit particularly useful; it gives you the choice of noisy icepick single coil, muddy muted humbucker, or "something in between"*. I used to leave the tone controls at one setting: start at 10, then roll off just to the point where the hum is bearable.

OK- now that I've gotten that off my chest, let's try to answer your questions!

- Of course it is possible to use the T60 tone control circuit. Do you have a schematic? Many moons ago, Craig Anderton explained its operation in his GP column- but even if I could find my copy, I don't have a working scanner to convert it. The official T-60 wiring diagram and theory of operation can be found online, and I can upload copies if you need them.

- You are right- Peavey used 250K audio taper pots for volume (CTS 75065004) and 250K S taper pots for tone (CTS 75065005).

- I don't understand how you want to use the 2 push-pull pots. What functions do you want to control with each pot and its associated switch?

As an example, here are the original T-60 control functions:
DPDT ON-ON-ON Switch: Pickup selector
Audio taper pot #1: Neck Volume
Audio taper pot #2: Bridge Volume
S taper pot #1: Neck Tone/Coil Cut
S taper pot #2: Bridge Tone/Coil Cut
DPDT ON-ON Switch: Pickup phase switch

What do you want to do with Pot #1, P-P Switch #1, Pot #2, and P-P Switch #2?
If you can provide a clear description of what you want to do, I'm sure someone can point you to a schematic.


Later,
-rb

* The T60 tone circuit may have been useful in its day because push-pull pots were rare or non-existent; it removed 2 coil-tapping mini-toggles from the pickguard.

[big_teee]

I have an old T-60 with a broken neck pickup. After I rewind the p'up some day, I'll probably replace the patented Peavey tone circuits with traditional tone circuits, using push-pull tone pots for coil cut. Personally, I never found the Peavey circuit particularly useful; it gives you the choice of noisy icepick single coil, muddy muted humbucker, or "something in between"*. I used to leave the tone controls at one setting: start at 10, then roll off just to the point where the hum is bearable.

OK- now that I've gotten that off my chest, let's try to answer your questions!

- Of course it is possible to use the T60 tone control circuit. Do you have a schematic? Many moons ago, Craig Anderton explained its operation in his GP column- but even if I could find my copy, I don't have a working scanner to convert it. The official T-60 wiring diagram and theory of operation can be found online, and I can upload copies if you need them.

- You are right- Peavey used 250K audio taper pots for volume (CTS 75065004) and 250K S taper pots for tone (CTS 75065005).

- I don't understand how you want to use the 2 push-pull pots. What functions do you want to control with each pot and its associated switch?

As an example, here are the original T-60 control functions:
DPDT ON-ON-ON Switch: Pickup selector
Audio taper pot #1: Neck Volume
Audio taper pot #2: Bridge Volume
S taper pot #1: Neck Tone/Coil Cut
S taper pot #2: Bridge Tone/Coil Cut
DPDT ON-ON Switch: Pickup phase switch

What do you want to do with Pot #1, P-P Switch #1, Pot #2, and P-P Switch #2?
If you can provide a clear description of what you want to do, I'm sure someone can point you to a schematic.


Later,
-rb

* The T60 tone circuit may have been useful in its day because push-pull pots were rare or non-existent; it removed 2 coil-tapping mini-toggles from the pickguard.

The links to the schematics are in my other post!
T

[rjb]

The links to the schematics are in my other post!
T

Our posts "crossed in the mail" - you were submitting while I was still typing.

[Zipslack]

Also keep in mind the T-60 circuit was designed based on the impedance of their pickups. If you are using different impedances, you will want to "tweak" cap and pot values to get useful sounds. Otherwise, you may get tone controls that don't give much range or fall-off too quick and a small or non-existent region between SC and HB.

[rjb]

Here is the Schematics for the T60.
Wiring Diagram - Schematic for the Peavey T-60 and T-40 - *The Largest Selection Of Peavey T Parts!*

I just want to note an error in the Peavey schematic:
The arrows next to the tone pots point in the wrong direction; the pickup center taps are grounded when the pots are turned fully CLOCKWISE.

Also, the depicted phase switch wiring isn't quite right- but I don't think the OP intends to use a phase switch.

-rb

[52 Bill]

I just want to note an error in the Peavey schematic:
The arrows next to the tone pots point in the wrong direction; the pickup center taps are grounded when the pots are turned fully CLOCKWISE.

Also, the depicted phase switch wiring isn't quite right- but I don't think the OP intends to use a phase switch.

-rb

Yes, but both are correct in the pictorial layout.

And BigTeee, if you haven't looked this up already, the center tap of the pickups goes to the tone controls to single coil tap the pickups when the tone controls are off and to turn on the humbucker coil when the tone control is turned down. I think that Red Rhodes designed this circuit.

Gibson used a similar circuit on the GK-55 guitar, but it used a single shaft stacked pot, one element for the tone control and one for the coil tap.

[rjb]

Yes, but both are correct in the pictorial layout.

Yup. The pictorial and schematic disagree.

And BigTeee, if you haven't looked this up already, the center tap of the pickups goes to the tone controls to single coil tap the pickups when the tone controls are off and to turn on the humbucker coil when the tone control is turned down. I think that Red Rhodes designed this circuit.

Here's how Hartley told it. The hype starts in the right column of page 13; the explanation about half way down the left column of page 14.
http://www.peavey.com/support/techno.../chapter_5.pdf

-rb

[rjb]

...Otherwise, you may get tone controls that don't give much range or fall-off too quick and a small or non-existent region between SC and HB.

I never understood the usefulness of having "a region between SC and HB". Do people like to add "just the right amount of hum" to their sound, like spice to a soup?

-rb

[big_teee]

I never understood the usefulness of having "a region between SC and HB". Do people like to add "just the right amount of hum" to their sound, like spice to a soup?

-rb

I agree!
Also for a first time Pickup builder, I would recommend keeping everything real simple.
If it were me I wouldn't start with that complicated tone and split circuit.
I have wired many guitars with single coil split.
It seems to me to be a waste of effort.
Everyone ends up playing them in the Non Hum Mode.
I know, I do!
IMO the Seymour layouts usually can't be improved on!
Good Luck,
Peace, Tone, and Volume!
B_T

[rjb]

If anyone has any ideas & simple drawings I would appreciate the advice!
I want the guitar to be minimalist, ie max 3 knobs (pref. 2) & 1 x 3way switch.

Maybe this would fit the bill?
Master volume, master tone with coil tap switch, 3 way selector.
No "Peavey T60 in-between HB and SC".
http://support.fender.com/service_diagrams/telecaster/026-2000_520A_SISD.pdf

[paw20051]

Thanks to all. Really good advice. I am in the process (um ... a long one!) of building a guitar & have had various thoughts on which direction to go electronics-wise. Many years ago my son had a t60, & it seemed unique,... what I can remember of it, ... ("old timers disease" .. ;-)) ... hence the thought, but at least that one has been decided apon! As a matter of interest, the guitar will have some unique materials used, "hammered titanium" truss rod cover, knobs hand made, using African rosewood, topped with stabilized Mastodon tooth, Hippo tooth ivory nut, etc... BTW, I never killed the animals! Will post pics in the appropriate forum when done. Once again, thanks for the info & advice. Cheers , Peter

[rjb]

One thing I probably should mention: If you are going to use a coil-splitting wiring configuration, you may as well wind the pickups so that the two "active" coils form a humbucking pair.

I didn't say that very well, so let me give an example:

Assuming my notes are correct, in a T-60, each pickup comprises two coils which are wound CCW from start-to-finish; the coils are spliced Finish-to-Finish, and the coil-split wire is attached at the splice. When the pickups are in coil-split mode, the active bridge coil and the active neck coil are magnetically in phase. If you were to flip the magnet and swap the outer leads of one pickup, the two active coils would *still* be magnetically in phase- because both pickups would still have their coils split at a Finish-to-Finish juncture.

I attempted to rewire the neck pickup to attach each outer lead to a coil Finish and the the coil-split wire to both coil Starts. Even if I hadn't broken the coils while removing the epoxy potting*, the physical configuration of the bobbins would have posed a challenge. Some day, I'm going to rewind the bobbins CW- so they'll be magnetically out of phase with the bridge pickup.

Since you are going to build your own pickups, you can "do it right" from the start.

-rb

* Confession: I first joined this board looking for information to fix that TR60 pickup.

[Mark Hammer]

Funny you should ask.

I just finished wiring up the tone control for the neck pickup of a cheap dual humbucker guitar "T-60 style" yesterday. Since the pickups were installed as 2-conductor, rather than 3 or 4, I had to disassemble the pickup to get at the junction between the coils. Hence my reluctance to do both pickups.

I installed/modded the variable coil-cancelling tone control in conjunction with a compensated neck volume control. Normally, dual humbucker instruments tend not to use compensated volume pots in the manner that Fender type single-coil instruments do, simply because there isn't as much top end to lose when turning down. I went with a 1500pf compensating cap that has the featre of sounding like a bass-cut control until you turn down to around 5 or so. Cancelling one of the neck coils to lower the inductance and raise the resonant frequency, in tandem with a bass-cutting volume pot, gives a nice range of sounds, while still letting full-volume/full-tone sounds provide as much balls as the stock instrument always had.

The tonal variation available from the neck, now, when used in the N+B position, provides a much expanded palette of sounds, while providing all the traditional ones.

The punch-line here is that, although a FULL conversion of the instrument to T-60 wiring will yield a great many tones, simply converting one pickup in that manner, without phase reversal switching, can still serve up some pleasing variety, without demanding too much of your time and effort.