Master Volume for Jazz Bass

[jlrush]

Topic: Master Volume for Jazz Bass???

jlrush

Member

Member # 45575

 

posted 09-26-2005 08:30 PM

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Does anyone know whether it is feasible to put a master volume knob on a Jazz bass? One for each pickup and one to boost the overall volume. It seems that it would provide a wider tonal range than just bass rolloff, and put all the control at your fingertips. Any input would be appreciated.

[dcr]

If I follow, the idea is to have volume for each pickup, plus volume control for the whole thing. The former controls the pickup blend, & the latter the overall volume. Yes?

 

In that case, it'd be simpler, I'd think, to install a master volume & a pan pot. That's two knobs, which is both simpler, and with a master tone knob will take up just the 3 holes on a J bass' control plate.

 

(If you mean by "boost" something to increase the on-board headroom, that's a whole different kettle of fish. Much more complicated & probably better handled on the outboard end. You could of course install an active preamp, like the J-Retro, which fits the control cavity as is.)

[davio]

"Kettle of fish" indeed. What dcr said.

[57pbass]

I have been told that this passive configuration -

 

master volume - pan - master tone

 

is not possible. Loss of high frequencies and other tech problems according to them

 

I wanted to do this to my Jo Osborn and the folks at Lakland gave me the bad news..

[...]

Originally posted by 57pbass:

I have been told that this passive configuration -

 

master volume - pan - master tone

 

is not possible. Loss of high frequencies and other tech problems according to them

 

I wanted to do this to my Jo Osborn and the folks at Lakland gave me the bad news..

Really? Huh.. that kinda sucks then, dunnit? I've thought about a master volume for my jazz basses for those times when it's necessary to do volume swell type stuff. But then I just remind myself that getting a volume pedal would be much easier and then I go on with my life.

[Davo-London]

Having moved from a P to a J, the 2 volume pots drive me nuts. I raised this debate previously search for: Control knobs - less is more?

 

I totally agree that master vol, PU blend and master tone is what we need but yeah we need to go active.

 

Davo

[getz out]

Dan,

 

Didn't Rick Turner used to do this modification all the time to J-Basses? I'd trust Mr. Turner over the folks at Lakland.

 

Maury

[jeremy c]

There are several ways you can go with this.

 

I'm with Maury, I think you could go volume-blend-tone with no trouble.

 

Now if it were me, the blend control would always be in the middle anyway and so there couldn't be any electrical problems.

 

A Jazz bass will always be noisy unless both pickups are at the same volume level. That's the nature of the beast.

 

You could go volume-3 way switch-tone for another option.

 

You could put in a J-retro preamp. That would be a killer solution to the problem, but it would cost almost as much as a Mexi-Jazz bass.

 

One of these days, I am going to take all the controls off my Jazz bass and just have an on-off switch.

[getz out]

http://static.zoovy.com/img/guitarelectronics/-/wduss2102

[getz out]

I thought the Lakland comment made no sense, but thinking more, it makes less than no sense.

 

How many of us have a bass with two passive pickups and a blend control? I do (my Fender Deluxe Jazz 5).

 

Where's the preamp? After the blend pot.

 

What does it matter if it is active or passive after the blend pot? It doesn't.

[wraub]

Yup. I'm with the getz-meister on this.

 

Peace,

 

wraub

[jlrush]

Wow! I had no idea I'd get so many replies. You guys ROCK!

Sorry that I didn't make myself as clear as I could have. As you know, with a two pickup (Jazz) configuration there are lots of possibilities for tone. One day it occured to me that I might be able to get the tone I wanted AND turn it up more from the bass by adding a master volume to what already was there. I would move the jack to the bottom of the bass, move everything else down a hole, and put the master vol where the neck vol is.

Wouldn't that give you more control than a pan knob? I just prefer to have that control from the bass. Besides, at my gig now, everything is run through the board and we use earphones and personal monitors.

Thanks for your interest guys! Jim

[jeremy c]

Jim,

 

You could very easily do what you want to.

 

A while back a made a little box for another forum member (ConnieZ from New Orleans who we haven't heard from in a while, but she did survive the hurricane without injury). The box was just a volume pot,a footswitch, and in and out jacks. This was so she could basically have a preset volume....just press the button and you have whatever level you set your pot at.

 

The only problem with the system is that when you turn down a pickup of course you are getting a weaker signal. Then if you put another volume pot in front of that you are weakening the signal even more.

 

You of course can raise the input level on the board butat the same time you are raising the noise floor.

 

There is also another factor. As you turn down your jazz bass pickups, you are not just losing volume, the tone is changing. The highs are rolling off and you are getting less presence in your sound.

 

That's why I always leave all pots all the way up on my passive basses.

 

For my whole life I have heard engineers in studios say, "please turn your controls all the way up." And I can always answer, "they are."

 

One reason for using a preamp is that the tone does not change when you turn it down...you aren't turning down the output of the pickups...you are turning down the preamp.

 

The nature of the humbucking design of a Jazz bass (two pickups wound opposite) almost ensures that there will be noise if the pickups are not at the same level.

 

If the noise doesn't bother you, then you don't have to worry about it.

 

I still think that a J-retro is the best, albeit most expensive, solution to the issue.

 

Welcome to the board, Jim.

 

You'll find a lot of nice people here and a few crusty old opinionated characters like me.

[davio]

http://home.jps.net/~jeremy/jeremy.jpg -> http://www.thesimpsons.stopklatka.pl/bohaterowie/img/miastowi_krusty.gif

[The Geoff]

Another solution, already mentioned above, would be a foot voulme pedal, but I find it works best for me if I put it in the Effects out/in loop.

 

G.

[jeremy c]

And the reason why it works better in the effects loop is because that way it is the volume level of the preamp that is being turned down, not the volume level of the bass.

[SteveC]

When I play my "jazz" equipped active bass, I use the blend knob more than the EQ section to change my tone. I know, it's a different thing.

 

When I had a jazz bass, I always had an active preamp, J-Retro or Sadowsky. I usually had the blend at the center click with those. I liked having a single volume control to make changes "on-the-fly."

 

I would like a passive jazz. Whenever I try those in the store, I always run both pickups full. I think most people do. It's not that big a deal to turn both knobs on and off, but it would be easier if it was just one knob.

 

I like the one knob thing - like the Timothy B. Schmidt Carvin.

 

http://www.carvin.com/products/guitar.php?ItemNumber=TBS4

[jlrush]

Several of you suggested vol, pan, and tone, and maybe that's the best way to go. Thanks Maury for the diagram, too.

In my other post I mentioned the Steve Baily system. So I guess I just need to decide if I want to put that much money (active pups and Bailey system) into this bass.

Anybody ever use LaBella Super Steps? I put a set in an MIM Jazz 5 I just bought. Best strings I've ever played. The inner wrap is all that crosses the bridge saddle and they have huge tone.

See ya, Jim

[wraub]

Here's a product that's pretty close, no?

 

Ebay item

 

 

Peace,

 

wraub

[Luke73]

You certainly can have Master Volume, blend pot and master tone on a Jazz. I've had it and it works fine.

 

My preference however is for a individual volume for each pickup, and a master tone. You don't need an additional master volume - if you want to turn the bass down, just turn down each pickup.

 

[jlrush]

Thanks wraub, for the link. Checked it out and it looks interesting. I saved it for reference in the future. It may be similar to what Luke 73 is saying.

I'm really "technically challenged" even though I've played for a long time. I've always liked a clean sound, and have just lately wanted to learn more about stomp boxes and such. But this thread is still about clean sound.

What I was thinking of when I originally posted was that the different settings on the volume pots can produce different tone, as much or more than the tone pot. So when I find tones within the volume settings, another master volume would be handy to have. This would require moving the jack to the bottom of the bass and having Master vol, neck vol, bridge vol, tone, on the plate. Does this make sense?

Thanks for taking the time to try and help an old fart figure things out!

Jim

[g.]

It is not uncommon to find J basses and J-like basses with one volume and a blend (I myself have one). I hope I don't have to read through this thread to find some wrinkle in what the subject actually is. And I'd guess there are wiring diagrams for this all over the net, including tips for running a low value cap inline to prevent any treble-bleed-off.

 

This isn't one of those trick threads is it? ; }

[Luke73]

jlrush,

 

Here's a link to standard Jazz bass wiring - One volume for each pot, and a master tone.

 

http://www.guitarelectronics.com/product/WDUSS2101

 

Here's the same bass, wired for a master volume, a blend pot and a master tone:

 

http://www.guitarelectronics.com/product/WDUSS2102

 

RE: your master volume, neck volume, bridge volume, tone idea - I'd be more inclined to go with the vol/blend/tone idea first. The blend pot does a good job, and you then have a master volume.

 

Having said that, I do prefer neck vol, bridge vol, tone (or indeed vol/vol/tone/tone) as I think it may give a touch more versatility. I guess you could add a master volume to that configuration also. The effect of too many volume pots may be that excess high frequencies are lost to ground though, as each pot will attenuate some of your high signal. If you're going to wire you bass in this manner, I'd certainly use 500k ohm or even 1meg ohm pots, as the higher pot value will attenuate less high frequency.

 

Cheers,

 

Luke.

 

 

EDIT: My apologies getz76, I just scrolled up and realised you posted the pic of the vol/blend/tone schematic earlier

[g.]

If I recall, using a higher value pot also makes a more exaggerated treble drop once the volume knob is USED, due to the larger change in capacitance. So actually using the knob really draws an attention to an increasingly duller tone. It's only when the knob is on full that the brightness of a higher value pot seems to be nice. There's a tonal reason too - as brightness is added it also begins to sound THINNER, why a lot of instruments have 250 or 300 K pots - they fit the characteritics of their pickups better.

 

A better solution which I mentioned above is to wire a cap in - I think a .001 mfd between lugs #2 and #3 is what does the trick. This shunts treble right past the pot so none is lost. It also makes the volume taper a little smoother.

[Luke73]

True Greenboy,

 

Here's a link to an article with a schematic, and small explanation of a high pass cap on the volume control.

 

If you find the treble bleeds off when the volume pot is used, it may be useful.

 

 

http://www.guitarnuts.com/wiring/volpass.php

 

As for a higher value pot making the bass sound thinner, I hadn't thought of it that way. As far as I'm aware, no low frequencies are lost (when all the way up), but moreso the high frequencies are retained. This may result in a brighter sound, and at times you might want to cut some treble with your tone knob or amp, but wouldn't it be simply a truer representation of what your bass produces, rather than the attenuated signal from a lower value pot? I'd think having the high frequency there in the first place is better, because you can easily cut it if you don't want it (perhaps in conjunction with a high pass volume cap is high frequencies are lost at low volume settings).

 

Or do I have it wrong, and the higher value pot loses some low end (when all the way up)?

 

Or, does the high pass volume cap circumvent the problem of high frequency attenuation whilst a lower value (250k) pot is all the way up. I had previously believed the high pass volume cap was only useful when a lack of high frequency was experienced at low volume levels.

[David King]

You guys have hashed this through pretty well. Maybe I'm missing the point but it seems like the beauty of having a 2 volume + tone passive bass is the variety of tones you can get from backing off the pots (and using really funky old cables).

Rather than master volume, blend and tone, why not a stacked volume a la '60-'62 Jazz bass. You can grab both together to turn up or down once you've set your balance.

 

Higher value pots simply put less drag on your pickups when they are all the way up. Cable capacitance is what kills your highs as your volumes go down.

[g.]

The problem with higher value pots from a player's perspective is that sometimes the player has become very used to the sound he's heard coming from his bass all those years. That type of player is not going to want to hear a bunch of treble that wasn't there before. It's not just brighter, its also creating the resonant peak at a higher freq, which in effect sounds thinner. Of course it is all interactive with the particular lead one uses to plug in with, the length and cable capacitance are also part of the passibe circuit...

 

From a technical standpoint, one should be aware that with higher value pots as one turns down their volume knob the lead going to the head/preamp becomes unloaded more, so this results in more noise and hum - almost like just breaking a wire in the lead.

 

It's all tradeoffs.

[Luke73]

Thanks,

 

It's an interesting subject.

 

Certainly lots of compromises in there. At the moment my bass is wired with two volume pots (neck+bridge) and a master tone, with a mini toggle switch for series/parallel configuration. I'm using 500k audio taper pots, and like this configuration.

 

It's pretty versatile for a passive configuration, and I'm able to achieve a range of useable tones.

 

It's all fun

[g.]

Yeah, my personal interest in this is actually not so high now, because about the only time I use my volume knob is maybe at the end of one song and just before the next one, the same with sets. Any tone or volume changes are from the hands or assigned to pedal on the V-Bass.

 

But I used to hotrod guitars for others as a sideline, and guitarists definitely should have good electronics if they want to control tube amp overdrive characteristics, tonal changes, etc. Bassists have less reason (in general) to actually use volume knobs heavily.

 

I haven't even bothered to look inside my Carvin to see what values they used for the passive volume/blend set because they have worked well with every pickup I've had in there, and with every outboard preamp/head. But I suspect if I were doing one for someone (withg the addition of passive tone knob too) I'd just make sure the volume knob wasn't compounding the high rolloffs of the stacked inverse pots of the blend by using the .001 mfd (or thereabouts after some tone checks) between the in and out legs of that pot.

[Luke73]

Quite true about the Volume pot. On my bass it's either all the way up when I'm playing, or all the way down between songs

 

Other than that, I control my volume at my amp.