Can you explain the PTB circuit?

[RLB]

It's easier to grasp how the tone controls on the Legacy work by thinking of it this way:
Turn both controls fully "down" or "off" (fully counterclockwise, number "1" towards you from a playing position) & bring the volume up to a comfortable level. The tone will be very "bassy" & lack "highs".
As you turn the middle tone control clockwise (or "up") you will be cutting the bass & the guitar will become much "sharper" with the largest amount of "treble" reached at the fully clockwise ( number 10 visible from the playing position). This is as "sharp" as the guitar will go (in any pickup position).
I find it convenient to think of this middle tone control as the "Bass Cut" control as it eliminates bass as it is "turned up".
It has a large effect on tone as it utilizes a large value capacitor in its circuitry.
The other tone control (or "bottom one" when viewed from the playing position) will add "fullness" as it is "turned up", but because it uses a capacitor with a much smaller value it ADDS in a much smaller amount of bass (in all pickup positions) than does the "middle" tone control. I think of it as more of a "treble trim" control or, if you prefer, a treble cut control.
The PTB system gives you a much more flexible way of controlling your tone than does the "standard two tone control" approach, in my opinion.

[1946dodge]

Thanks RLB for that post. I agree that the PTB system is the best filter circuit I have seen or heard on an electric guitar. Would anyone happen to have a wiring diagram for it?
I have the schematics posted, but would like a nice easy wiring diagram. I have PTB on my Tribute Comanche and want to put it on my parts built legacy. Thanks.

[BillEvans1956]

It's easier to grasp how the tone controls on the Legacy work by thinking of it this way:
Turn both controls fully "down" or "off" (fully counterclockwise, number "1" towards you from a playing position) & bring the volume up to a comfortable level. The tone will be very "bassy" & lack "highs".
As you turn the middle tone control clockwise (or "up") you will be cutting the bass & the guitar will become much "sharper" with the largest amount of "treble" reached at the fully clockwise ( number 10 visible from the playing position). This is as "sharp" as the guitar will go (in any pickup position).
I find it convenient to think of this middle tone control as the "Bass Cut" control as it eliminates bass as it is "turned up".
It has a large effect on tone as it utilizes a large value capacitor in its circuitry.
The other tone control (or "bottom one" when viewed from the playing position) will add "fullness" as it is "turned up", but because it uses a capacitor with a much smaller value it ADDS in a much smaller amount of bass (in all pickup positions) than does the "middle" tone control. I think of it as more of a "treble trim" control or, if you prefer, a treble cut control.
The PTB system gives you a much more flexible way of controlling your tone than does the "standard two tone control" approach, in my opinion.

Very helpful explanation of the PTB system. Thanks RLB. I was beginning to wonder the same about my Legacy HB.

Bill

[BillEvans1956]

Is the 'PTB System' unique / proprietary to G&L? How do other similar guitars manage their tone control? Is there a wide variation of options?

Thanks.

Bill

[Craig]

Is the 'PTB System' unique / proprietary to G&L?

Yes.

From the back of the 1997 Retail Price List, we have in the Gallery:



Hope this helps.

[BillEvans1956]

Is the 'PTB System' unique / proprietary to G&L?

Yes.

From the back of the 1997 Retail Price List, we have in the Gallery:



Hope this helps.

Very helpful, as always, Craig. I'm glad I joined this forum. Always something new to be added to my G&L knowledge.

Thanks.

Bill

[Craig]

I recently found this post from BoogieBill while searching the old G&LDP Archives and thought it would
be a good addition to this thread: Legacy Pickups and PTB Secrets Revealed!!!!

Legacy Pickups and PTB Secrets Revealed!!!!
BoogieBill on December 29, 2006 at 22:19:16:
Legacy Pickups posted by anthony.rhoad@fbx.com on December 29, 2006 at 15:23:42:

: My Legacy pups semm very warm sounding compaired to most fender pups. I guess it's not a bad thing, just not much twang/quack out of them compaired to others.
: Are they designed to be this way?

I really like the pickups that G&L has used on the Legacy--both the CLF-100 that they use now, and the original Duncan SSL-2s are fine Strat pickups for authentic vintage Strat tone.

What you might find of use is a change in how you approach the PTB tone system on the Legacy. I am constantly using my PTB controls; and on the guitars with the hotter pickups (Legacy Special, S-500, Comanche), the PTB is even MORE effective. On a vintage Strat, the bridge pickup is almost unusable, since there's no tone control at all. The PTB works globally on all pickups, and it's a great improvement.

A lot of guys use the PTB controls either all the way up; or set to the mid-point on both controls. I find running the bass at ten all the time to be a little TOO bassy, and with the controls at T-5 B-5--it's a little wimpy.

Here's my secret: I usually set my controls with the Volume on 7-8; the Treble at 10; and the Bass at 5. Then I set my amp up so that I have good definition in position in #2 (B+M), and that just about gives me perfect Strat "bite" in in the #1 Bridge Only position.

Now, if I need a darker, Jazzier tone, I can simply roll back my PTB T control. If I want to add "punch" to a clean solo, I'll just add PTB bass. With high gain, I can actually dial in feedback harmonics using the T control. And of course, I can roll up the guitar's Volume for a lead boost, too.

I learned this method back in the late 1970's when I bought my first Music Man Sabre II. These guitars have a built-in active preamp and they can be really bright; but by using this system--I can go from Tele-style twang to Benson-esque jazz tones in one simple move.

With my Comanches, I will often "normal" my PTB controls at T-8, B-5--it may just depend on if a particular amp sounds shrill or edgy with the z-coils. Again, the PTB system offers tremendous versatility, once you get the hang of it.

Good luck.

Bill

Hope this helps.

[Craig]

Also, check out this recent post: Tone control confusion.

Hope this helps.

[Craig]

From a recent G&L Users Update email:

Tech Talk- P.T.B. System
In this Tech Talk episode Steve Araujo and Doug Osterkamp discuss the Leo Fender designed P.T.B (Passive Treble & Bass) System.
Guitars used in this video:
Fullerton Deluxe Doheny:
https://glguitars.com/product/fullerton-deluxe-doheny/
Tribute Series Legacy:
https://glguitars.com/product/legacy-2/

Video Link (click link and the video will be opened in a new tab):
Tech Talk-P.T.B. System