Jazz bass vvt harness with 2 tone caps?

[MrRobert]

I recently received this vvt jazz bass wiring harness from another TB member and noticed it has 2 tone caps instead of the usual single tone cap. I am extremely deficient in electronics knowledge, so perhaps one of you experts can clue me in on the purpose of this dual cap setup? I have not installed it to any bass yet nor have I tested it, just to be clear.

 

[fig]

I recently received this vvt jazz bass wiring harness from another TB member and noticed it has 2 tone caps instead of the usual single tone cap.

Here's a wiring diagram and schematic of the Treble Tone Control.:

It will sound similar to a standard single cap treble tone control, meaning trebly when full clockwise (cw), bassy when full counter clockwise (ccw).

With the wiper (lug 2) full cw, lugs 2 & 3 are directly connected, short circuiting the .100uF cap (electrically removed from existence). Result is full treble (minus slight loading thru .020uF cap to ground).

Rotating the wiper ccw lessens the resistance between the two caps. Their values start to blend together toward a final resultant value of .017uF. Should be noticing a loss of treble as we'd expect with a standard treble tone control.

With wiper finally full ccw, lugs 2 & 1 are directly connected, fully combining both caps in series for a final value of .017uF and now tied directly to ground. Result is bassy, as we'd expect.

Wire it up and see how ya like it.

 

[Matt Liebenau]

Here's a wiring diagram and schematic of the Treble Tone Control.:

View attachment 7473248

It will sound similar to a standard single cap treble tone control, meaning trebly when full clockwise (cw), bassy when full counter clockwise (ccw).

With the wiper (lug 2) full cw, lugs 2 & 3 are directly connected, short circuiting the .100uF cap (electrically removed from existence). Result is full treble (minus slight loading thru .020uF cap to ground).

Rotating the wiper ccw lessens the resistance between the two caps. Their values start to blend together toward a final resultant value of .017uF. Should be noticing a loss of treble as we'd expect with a standard treble tone control.

With wiper finally full ccw, lugs 2 & 1 are directly connected, fully combining both caps in series for a final value of .017uF and now tied directly to ground. Result is bassy, as we'd expect.

Wire it up and see how ya like it.

Cool. I don’t think I’ve seen that one before. The post is bookmarked for future experimentation.

 

[fig]

I don’t think I’ve seen that one before.

Yeah, I don't remember seeing this one. Kept that drawing in my notes. But I've seen each cap position individually, just never combined like MrRobert's circuit. (I like that movie "Mr. Roberts" (1955)...but I digress LOL).

Matt, I know you've seen the following before, so this is for folk passing thru...

The .020uF cap in MrRobert's circuit is connected between the pot lug 1 and ground. This is similar to A and A+ in this drawing of the four common treble control configurations and their pop/scratch attenuator versions (the + drawings):

The .100uF cap in MrRobert's circuit is connected between pot lugs 2 & 3. This is similar to E in this drawing of a rarer treble control version I've seen on some factory basses.:

TB member @micguy was nice enough to run a Spice simulation on E and F. Very much the same as the 4 common connection types with a only a minor difference that probably isn't noticeable. Anyone interested can read the 2 page thread posted below. It also explains how the pop/scratch attenuator jumper works.:

Thread 'Weird (to me) P bass wiring'

Feb 20, 2024

Hi there,
I just removed the piguard of a bass I keep at my parents house. When I'm here, 2 or 3 times a year, I like to have a bass for playing, it's a super cheap 1987 Hondo-H83 Pbass that a friend gave me maybe 15 or more years ago.
I use it with a zoom b1 and headphones, the volme and tone pot have never worked with me (It's on or off). I wanted to check it out but I have never seen this kind of wiring. What should this solution bring compared to a standard Precision wiring?
Sorry for the poor and ugly digram I made.
Thanks

• maxmerx
• p bass wiring pickups and electronics precision wiring
• Replies: 38
• Forum: Pickups & Electronics [BG]

• 

Really curious about what MrRobert thinks of this new control when he hooks it up.

Unless...it creates an inter-dimensional portal and we never hear from him again...

EDIT: OK, I don't know *** happened with my link to the other thread and why it's showing so much of the first post of that thread. If someone could clue me in on what I did wrong, I'd appreciate it.

 

[Matt Liebenau]

Yeah, I don't remember seeing this one. Kept that drawing in my notes. But I've seen each cap position individually, just never combined like MrRobert's circuit. (I like that movie "Mr. Roberts" (1955)...but I digress LOL).

Matt, I know you've seen the following before, so this is for folk passing thru...

The .020uF cap in MrRobert's circuit is connected between the pot lug 1 and ground. This is similar to A and A+ in this drawing of the four common treble control configurations and their pop/scratch attenuator versions (the + drawings):
View attachment 7473592


The .100uF cap in MrRobert's circuit is connected between pot lugs 2 & 3. This is similar to E in this drawing of a rarer treble control version I've seen on some factory basses.:
View attachment 7473603

TB member @micguy was nice enough to run a Spice simulation on E and F. Very much the same as the 4 common connection types with a only a minor difference that probably isn't noticeable. Anyone interested can read the 2 page thread posted below. It also explains how the pop/scratch attenuator jumper works.:

Thread 'Weird (to me) P bass wiring'

Feb 20, 2024

Hi there,
I just removed the piguard of a bass I keep at my parents house. When I'm here, 2 or 3 times a year, I like to have a bass for playing, it's a super cheap 1987 Hondo-H83 Pbass that a friend gave me maybe 15 or more years ago.
I use it with a zoom b1 and headphones, the volme and tone pot have never worked with me (It's on or off). I wanted to check it out but I have never seen this kind of wiring. What should this solution bring compared to a standard Precision wiring?
Sorry for the poor and ugly digram I made.
Thanks

• maxmerx
• p bass wiring pickups and electronics precision wiring
• Replies: 38
• Forum: Pickups & Electronics [BG]

• 

Really curious about what MrRobert thinks of this new control when he hooks it up.

Unless...it creates an inter-dimensional portal and we never hear from him again...

EDIT: OK, I don't know *** happened with my link to the other thread and why it's showing so much of the first post of that thread. If someone could clue me in on what I did wrong, I'd appreciate it.

Not sure what happened with your link. I’ve had some post like that when I link to an entire thread. Probably another TB improvement.