PEQ Tone Controls

i was wondering if anyone can comment on the PEQ Tone Control setup on the Thunder II guitars. do you find the controls useful and musical sounding? does the combination of separate tone controls on each pickup and the phase switching provide useful tone control?


there is a good hand-made drawing on the westone site of how the wiring is set-up for us DIY'rs to see.

http://www.westone.info/wiring/t2passive/index.html

one thing not indicated is the values for the pots. can anyone give a description of the pots used for this wiring scheme?

The pots are 500, obviously with centre detent. Like my drawing eh.
Funny enough, just received a load from Hong Kong for other projects.


These are the smaller one's but full size are available.

EH-urr - our survey says - the pots are, one half 500k log, the other half zero resistance over the first half of its travel, 500k linear over the second half, so a dual 500k pot wont work

I would have posted as link to the patent documents but apparently as a newbie I'm not allowed to...

fordetails. Dual 500k pots wont work. There is no commercial replacement available today according to the diagram for the rainbow II at
westone.info

In my poinion, the PEQ tone controls do not work as advertised. There is no smooth switch from series to parallel, there are dead spots between halfway up and all the way up. . I'd prefer to see separate series/paarallel switches for each pickup - perhaps pull switches with a full range tone control.

Have you physically tried them... Bob

i didn't know that the rainbow wiring was the same PEQ tone circuit.

so Westbone, yes i do like the drawing. thanks for taking the time to look inside and make us all something to work from. the phase switch seems like a good idea to add on to the setup used on the rainbow.

are those pots you picked up as described on the page for the Rainbow II wiring? what do you use them for?

Westbone wrote:Have you physically tried them

I've tried the originals - instant dislike for me, I only used them either as a normal tone control or full up to switch to parallel wiring, didn't find any useful sounds in between the extremes. I haven't tried any replacements, since i don't have any guitars that need them and I didn't like them anyway. The patent (Google for matsumoku tone control to find it) is very clear about the values of the pot and as far as I know there is nothing commercially available that matches the spec - a dual pot will definitely have a different response curve to the original ones, I couldn't even begin to guess at how it would affect the sound though, the only thing I can say for sure is that it could be used to switch from series to parallel at one extreme of it's travel, no idea what it would sound like anywhere else

It'd be a sad world if we all liked the same things...Bob

Agreed they do drop off at certain setting.
But I like the fact that you can have either pup at series/parallel and switch between them or have both pups on and use the neck volume to control your sound.

The Prestige 227 has pull/push switching. Phase/coiltap and agreed you could install pull/push pots in a Prestige 250/150
if you so desired.

By the way the link wire on the PEQ is the trick.

It was an interesting idea that, on paper, seems more useful than it really is. I'm not saying you won't like it. This is just my stupid opinion.

$0.02

It was an interesting idea that, on paper, seems more useful than it really is

I reckon that's probably right, too - Westone, under TP, were certainly not afraid to experiment ... no such thing as stupid opinions, colt.... I should know; I'm opinionated enough for a small country!!

well, when it coms to the almighty "TONE" it is all just opinions.

and that is what a forum is all about, and that's what i was asking for...so thanks for your $0.02. more donations welcome........

maybe there was no time or resource to find a pickup/pot/cap combination that would be more responsive to the gradual change from S -> P and vice versa. i wonder if it maybe it was one idea among many good ideas, and it just never got developed beyond one version. i guess, actually a second version might be the one with phase reverse also. perhaps that was an attempt to find more distinct changes or enhance changes in sound between S/P.

corsair wrote:no such thing as stupid opinions, colt.... I should know; I'm opinionated enough for a small country!!

IMO: in my opinion
IMHO: in my humble opinion
IMSO: in my stupid opinion

Imagine so.....................

okay then, dredging up an old thread here......


i have been working on a Paduak II that had the wiring mangled by the previous owner. they apparently couldn't get along with the PEQ circuit and ditched it. in the process they chopped the pickup wires short, "rewired" them (incorrectly) and used just a volume and a tone control. and they put a plug in the 3rd hole

i got some nice cable from stew-mac for new leads on each pickup

i unwrapped the pickups and soldered onto the coil wires, then re-wrapped the shielding tape

so i got the pickups all ready to go. i got some pots i thought were going to work to let me rewire the PEQ set-up, but it was not the right kind of double pot to make it work. so i got my pups ready to go but no PEQ just yet

i opened up my Thunder II to check out the pots on the PEQ circuit to verify exactly the setup on the pots and how they function electrically.


i disconnected the wires and checked the pots with a meter, then made a little sketch...
(i measured the rear pot at closer 650K end to end, terminals 4 - 6)

so it turns out that the stacked pots are not identical/mirror images of each other. the pot to the rear has the resistance element completely from one end to the other, with a center detent.
the front pot has the full resistive element on only half the sweep of the pot, and zero resistance the other half.
the replacement i got has 2 of the same kind as the front pot, just one reversed from the other. designed for a 'balance' kind of application. it doesn't have the right setup for the PEQ wiring circuit.
i guess i will continue to seek out the right pots, and the Paduak II will have to wait a little bit longer for restoration...

Just use what you have without the tone capacitor, who uses the tone much anyway.

Or switch to pull/push

What he said.

I find the tone controls on my T2 bewildering and not very useful.

Is this the same wiring as on the Trev Rabin Signature? Some kind of mid range control (adds or removes it..in a passive way)..
I find it good on my guitar..works well...I could see it not being to everyone's taste
but I like it..and its low noise and uses no batteries.
I have owned the emg Gilmore set and while its good and does some mid eq..it is noisy in some ways and uses batteries in a fast rate (for actives)..so I sold it and kept My Trev Rabin Signature.
GtrGeorge

GtrGeorge! wrote: Is this the same wiring as on the Trev Rabin Signature? Some kind of mid range control (adds or removes it..in a passive way)..

different system. the Rabin Signature uses the Mid Shape Control circuit.

the PEQ setup changes the humbuckers from series to parallel connection, and has the common capacitor tone circuit as well. with the tone cap full up is the 'bass' setting, the middle notch is common humbucker mode (series), and the other end is parallel connection of the humbucker coils. it uses rotary potentiometers but mostly functions like a switch, meaning not much of any middle ground settings. i find the rotary control kind of nice. many other westone models use mini switches or push pulls. i think the rotary control is good because it reduces all the fiddly bits into more compact control setup. all the controls for one pickup are on one knob and operate with the simplest motion.

the change of sound can be a bit subtle, but with a little bit of time it becomes more useful as familiarity develops. i like to tweek sounds while i play. like slight changes in your tone of voice during conversation, to accent certain points more precisely.

i think the PEQ series/parallel is better than the UBC split coils. the PEQ hookup still has some grunt, just a bit thinner, sharper sounding than humbucker mode, but not lightweight or weak sounding.

Thanks guys for the PEQ lesson. I never really got the real story on these puppies. I've heard many different explanations, but this definitely makes the most sense. I'm glad that over the years, no one got a 'wild hair' to experiment with other pots, chucking the PEQs. I like the tones and on my p150 the sonic contrast is significant and relatively useful. Thanks again!

The tone control on PEQ only works when the pickup is in series mode, centre detent and down.

You have no control for tone in parallel mode, full up.

Which would be more useful the other way around.

Both settings are full humbucker.

Personally I do like them.

for the totally wonky ones,
here is a link to the patent documents

i find the drawings helpful to understanding the whole thing.
fig. 3 shows a graph describing the resistance characteristics of the double-gang pots
the patent states that the goal is to provide tone control, and a smooth transition from series to parallel instead of using a switch, going from one extreme to the other (series/parallel). the logarithmic scale on the one pot is an attempt to make the transition between series and parallel, sound more gradual (a difficult task simply because of the physics of electron flow)

both settings use both coils, but only the series connection is a hum-bucker connection, the parallel connection does not have the noise canceling properties of paired coils in series.

Think you'll find it's hum cancelling in both settings at their extremes.

Not on halfway settings.

Try it in practice not in theory.

It would be a total waste of time having this circuit otherwise.

This is REALLY interesting.
This tone circuit and its ability to go GRADUALLY from single to humbucking (if I understood you correctly) is alot like an old arcane thing called the
"L Tone filter" by Bill Lawrence. It was some odd coil that yiu coild wire into your pots and smoothly go from SC to HB!!!
I liked it...but apparently the market didnt. It disapeared way back..like in 1985!
anybody remember that one?
GtrGeorge