Why aren't Jazz basses wired Volume-Balance-Tone?

[MCS4]

The real answer is because that is how early Jazz basses were configured so it became the standard, and there's nothing wrong with it.

If we're making wish lists, I'd rather have a Jazz bass with one volume, one tone, and a three-way pickup switch.

 

[Passinwind]

Seems like a pain in the butt to try to sort a tone with the relative level of each pickup and set an overall volume at the same time.

Why not have them with a master volume and a balance pot instead? Wouldn't it be easier?

It cost more and Leo Fender preferred pocketing the cash, probably.

 

[KidAmnesia]

60-40 = 60%-40%. Sorry, but that isn't the same as 75-50.

Balance pots have 100%-100% at the center click and gradually decrease one of the pickups when you turn it either side, leaving the other one at full. So, if yoy turn it a 25% to the neck side you will have neck 100% - bridge 75%. If you then roll the master volume another 25% you end up with that 75-50.
Percentages are obviously theoretical, as the result will vary depending on the exact value and tapper of your pots, but you can achieve the same results with a VVT or a VBT.

 

[Passinwind]

Balance pots have 100%-100% at the center click and gradually decrease one of the pickups when you turn it either side, leaving the other one at full. So, if yoy turn it a 25% to the neck side you will have neck 100% - bridge 75%. If you then roll the master volume another 25% you end up with that 75-50.
Percentages are obviously theoretical, as the result will vary depending on the exact value and tapper of your pots, but you can achieve the same results with a VVT or a VBT.

Nope, not quite. It may be close enough though, or not.

 

[MonetBass]

Balance pots have 100%-100% at the center click and gradually decrease one of the pickups when you turn it either side, leaving the other one at full. So, if yoy turn it a 25% to the neck side you will have neck 100% - bridge 75%. If you then roll the master volume another 25% you end up with that 75-50.
Percentages are obviously theoretical, as the result will vary depending on the exact value and tapper of your pots, but you can achieve the same results with a VVT or a VBT.

That makes sense, but in order to achieve the 75-50 mix I proposed in this scenario, you have to sacrifice 25% of your overall volume. Not ideal.

 

[KidAmnesia]

That makes sense, but in order to achieve the 75-50 mix I proposed in this scenario, you have to sacrifice 25% of your overall volume. Not ideal.

In a 75-50 on a vvt configuration you are also sacrificing overall volume.

Nope, not quite. It may be close enough though, or not.

What am I missing?

 

[groooooove]

i recently had a conversation with a custom pickup maker. he insisted that v/v/t was superior. he used a lot of big works during our chat so he is obviously correct.

seriously though, i don't recall why, but there's a reason it's a "better" signal path according to some. i personally prefer it, though having one volume control is nice for swells and such, particularly on my 6 string basses where i play lots of melodies and chords.

 

[39-Bassist]

Shoot if you are going to do that you would be better off doing a V/V/T/T

 

[Passinwind]

26814510[/URL], member: 391432"]In a 75-50 on a vvt configuration you are also sacrificing overall volume.



What am I missing?

Take look at RobbieK’s video on passive tone controls, and how the tone and volume pots both roll off highs as they’re turned down. The math is complex and I’ve never tried to write out the whole equation, but it goes beyond just a resistive component and the very imperfect nature of pot tapers and varying oickup locations complicate things too. But “close enough” is often close enough, and there are many ways to skin felis catus.

 

[themickster]

Make sure the knobs are tone plastic to get the best out of the tone wood. Once you've nailed that, it won't matter which knob does what.

 

[lowfreqgeek]

V/V/T is not hard at all, unless you want to make it hard. It can achieve tones that V/B/T can't, and it doesn't put the additional load of an extra pot on the pickups like a V/B/T scheme does.

And, it's super easy to rewire if you really must have V/B/T instead of V/V/B, so I don't see the big deal.

 

[Chrisk-K]

The J has only three main tones: neck pup full and bridge pup off, neck pup off and bridge pup full, and both pups full. All the other micro variations can be heard only by the player. So, VVT or VBT doesn’t matter.

 

[KidAmnesia]

Take look at RobbieK’s video on passive tone controls, and how the tone and volume pots both roll off highs as they’re turned down. The math is complex and I’ve never tried to write out the whole equation, but it goes beyond just a resistive component and the very imperfect nature of pot tapers and varying oickup locations complicate things too. But “close enough” is often close enough, and there are many ways to skin felis catus.

Oh ok, yes. Close enough is pretty much all we get when we work with passive controls. Tapers and values are usually quite "unique". But if I'm not missing something too obvious, this "close enough" applies both to VVT and VBT.

 

[Altitude]

The J has only three main tones: neck pup full and bridge pup off, neck pup off and bridge pup full, and both pups full. All the other micro variations can be heard only by the player. So, VVT or VBT doesn’t matter.

This is what I think too. The math on 75-50 = 60-40 with a volume decrease is correct, but I'm just not a knob turner. I'm going to play my bass with one pickup or the other soloed or, more likely, at WOT for both. Anything in between is a science project. So I don't care which.

 

[Passinwind]

26814580[/URL], member: 391432"]Oh ok, yes. Close enough is pretty much all we get when we work with passive controls. Tapers and values are usually quite "unique". But if I'm not missing something too obvious, this "close enough" applies both to VVT and VBT.[/]

Yep, they both suck fairly equally in my book!

 

[Gilmourisgod]

My feeling exactly on most two-pup basses. I wire all my builds Master Volume/Blend/Master Tone. I suppose there are tradeoffs, but it sounds great to my ears, and its just simple, no change in tone as you dial in more volume. This is the Bourns Blend Pot I use, coincidentally, a Jazz bass installation, pretty much a start to finish tutorial.

 

[fhm555]

Seems like a pain in the butt to try to sort a tone with the relative level of each pickup and set an overall volume at the same time.

Why not have them with a master volume and a balance pot instead? Wouldn't it be easier?

BTDT, along with several other optional J bass control setups, and I'm back to 205K CTS pots with whatever the stock cap is in an MIM J bass. With a balance pot you can't run up your bridge and leave it while you add in some neck. As the neck increases the bridge decreases. I never look ay my knobs when dialing in, I just listen and adjust neck bridge and tone in that order. Each pickup having a dedicated volume gives me a lot more variety than does a balance or preset pot like a Tonestyler. Oddly enough, my active bass has a pair of double stacks, one is vol/bal and the other is bass/treb, and I love the range it provides. Oh and almost forgot, I pretty much use humbuckers in my j basses. I've got a couple of single coil examples but I play humbuckers most of the time.

 

[Tim Skaggs]

Don’t forget that early version of the jazz had two separate tone controls isolated by resistors. The volume, balance tone control configuration wouldn’t allow the subtle differences available with two separate tone controls. I still use two volumes and two tone controls on my jazz and the tone controls have different value capacitors. This allows some unique tone changes from adjusting a single knob. I can have my bridge pickup wide-open and the bridge pickup tone control wide-open with the neck pickup volume down a quarter turn and the neck pickup tone control rolled all the way off. The neck pickup tone won’t be affecting anything until the neck pickup volume is turned wide open. So, a wide open bright bridge pickup tone to a two-pickup rolled off tone can be achieved by just turning the neck pickup vol. from 75% to 100%. Other similar adjustments can take place in a reverse of this.

 

[J-Bass RMR]

The "volume" controls on a VVT wired bass don't really work like volume controls - as the pickups are reactive (their impedance varies with frequency), using potentiometers to turn two of those things up and down is something that, unless you put in an active circuit, really doesn't work well - they are as much tone controls as they are volume controls. The way VVT setups are done, the volume controls are wired backwards from what you see in a P bass. They "turn down" a pickup (this works very differently at high frequencies than it does at low frequencies) mostly by shunting it. What you get is, when you turn down a pickup, you turn down the high frequencies from that pickup by quite a bit, but the low frequencies don't get turned down much until the pot is close to zero - it's almost an on/off switch. If you use linear taper pots for the volume controls, all the same stuff happens, but the thing is even more of a switch - it exaggerates the major flaw in the scheme even more.

I always appreciate your explanation of things.
For many years, I never really gave it a 2nd thought; my '67 Jazz was my #1 for 30 + years (still is, in a sense), and the settings / quirks of a Jazz just become 2nd nature.
It wasn't until about 2 years ago when I got a dual-P with a VVT setup, which was much worse than a Jazz.
I switched to audio taper pots on that bass, and it was a major improvement - it allowed much better blending.
I do have a PJ set up with the (custom) Audere classic, which gives me the "stereo" front end (via blend) with a passive tone. It's a nice option...

 

[ToddB1963]

The "volume" controls on a VVT wired bass don't really work like volume controls - as the pickups are reactive (their impedance varies with frequency), using potentiometers to turn two of those things up and down is something that, unless you put in an active circuit, really doesn't work well - they are as much tone controls as they are volume controls. The way VVT setups are done, the volume controls are wired backwards from what you see in a P bass. They "turn down" a pickup (this works very differently at high frequencies than it does at low frequencies) mostly by shunting it. What you get is, when you turn down a pickup, you turn down the high frequencies from that pickup by quite a bit, but the low frequencies don't get turned down much until the pot is close to zero - it's almost an on/off switch. If you use linear taper pots for the volume controls, all the same stuff happens, but the thing is even more of a switch - it exaggerates the major flaw in the scheme even more.

This explains why I've never been able to achieve a 'blend' with jazz bass pickups when one is at 100% volume and the opposite is at any volume other than 100% - The tone simply reverts to the loudest pickup, i.e. 100% bridge and (for e.g.) 75% neck is actually all bridge; and 100% neck and (for e.g.) 75% bridge is actually all neck. I've never understood guys who say, for example, "favorite setting is 100% neck and 50% bridge", because for me it's never worked that way. 100% neck and 50% bridge is all neck.

That said, a slight amount of blending is noticeable when both pickups are at 100% and one volume knob is backed off just a tad to say 98% (about 2mm). There's a slight change in tone at that setting but if it's backed off any further, there's an immediate reversion to the dominant pickup.

I suppose some actual blending might be possible when neither pickup is at 100% but bass output at those settings is too low for my liking. I have two passive Yamaha BB PJs with the three way pickup selector switch and IMO that's a much more user-friendly set-up than the VVT on a jazz bass.