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5 position pickup switch Jazz Bass


brensabre79
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I'm not sure if this has been done but interested to try...

I can't get on with blend controls, or vol/vol controls. Too much faffing around. In a gig i really like to be able to just dial a switch, knowing exactly what sound will come out and start playing (no noodling between songs whist adjusting the blend / volume control to get the right tone...)

Currently I have a 4 position rotary switch where the second volume knob should be: pos 1. Series :: 2. neck :: 3. both :: 4. bridge

...but I'd like to be able to have a little bit of bridge with the neck and vice-versa

So what I'd ideally like is a 5 position rotary switch as follows:

1. Neck only :: 2. Neck + 50% Bridge :: 3. 100%neck + 100% bridge :: 4. 100% bridge + 50% neck :: 5. Bridge only

Or better still, a 6 position that will do all of the above plus both in series.

I'm guessing that resistors could be used to half the volume of the pickups when switch to the right location. Essentially a preset where the volume of one pickup is at half or 3/4 (I'd have to play with resistor values to get the right balance I suppose).

Anyone got a wiring diagram...? or even a clue if this is possible?

Thanks
Bren

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I can see this being do-able but, really have to ask myself if this is a lot of hassle, for what I can see to be of maybe little benefit. May I ask why you found that the four-position switching wasn't enough?

Dingwall offer the 'super switch' which is essentially the same as your arrangement (both series - neck only - bridge only - both parallel), which I would see as possibly the most versatile - as Alex Claber pointed out in his build thread, everything else from there on in is technique i.e. right-hand playing position etc.

Another option could be to explore replacing the rotary switch with a centre-off switch that cuts either coil and leaves them in series in the centre (off) position, like the Gibson Les Paul toggle switch (neck/both/bridge)

HTH,
Ian

Edited by Bottle
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Thanks guys, the reason the switch I currently have (like the Dingwall you describe Bottle, but in a different order) isn't quite right is that I am having trouble with a drop in bass frequencies when I use the bridge pickup alone. I have tried replacing the bridge pickup and checked wiring etc. The bridge pickup sounds great, just no bass! Andy at Wizard has re-wound the pickup to make it fatter and it was suggested I roll in a bit of the neck pickup in to add bass. trouble is, with a switch i can't do this.

I guess what I'm looking for is a blend pot that has a centre detent as well as detents at 1/4 and 3/4 the way around.

The series mod is OK but to be honest the volume jumps so much I rarely use it these days (it was handy for a solo etc. before I had a boost pedal).

Thanks BassBunny, I'm not on finnbass but I will google it :)

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[quote name='brensabre79' timestamp='1327330171' post='1509382']
Thanks guys, the reason the switch I currently have (like the Dingwall you describe Bottle, but in a different order) isn't quite right is that I am having trouble with a drop in bass frequencies when I use the bridge pickup alone. I have tried replacing the bridge pickup and checked wiring etc. The bridge pickup sounds great, just no bass! Andy at Wizard has re-wound the pickup to make it fatter and it was suggested I roll in a bit of the neck pickup in to add bass. trouble is, with a switch i can't do this.

I guess what I'm looking for is a blend pot that has a centre detent as well as detents at 1/4 and 3/4 the way around.

The series mod is OK but to be honest the volume jumps so much I rarely use it these days (it was handy for a solo etc. before I had a boost pedal).
[/quote]
Mmmmmm this might sound like a bit of a suck-eggs moment, but have you considered that the [i]neck[/i] pickup may just be a little too hot? Have you tried maybe screwing it down a little, as that may help with the volume balance between neck and bridge pickups.

One other tip might be a set of matched pickups from Wizard if you let them know what you're trying to achieve, or a set of Duncans - Classic Stack in the neck position and a Hot Stack in the bridge position - this would have the additional benefit of being hum cancelling in all switch positions as they are inherently humbuckers.

Ian

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Well electronicaly it's do-able although I'd probably use some little presets instead of fixed value resistors.

The stumbling block for me would be that having a set of fixed tone settings would reduce the degree of tone control over the setup and essentially remove the option to compensate for string age and venue acoustics.

I'd be more inclined to identify the setting that was most problematic to set and use a switched pot to kick that preset in.
You might also make it easier for yourself by using centre detent pots and knobs with some sort of marking on them.

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Thanks Ian, yes have tried screwing it down - neck pickup is almost at scratchplate level, where the bridge is much higher. Measured the impedance etc.
They were originally a matched set of Wizard '74s - custom wound after a long conversation with Alan. When I changed to 70s spacing the problem became more so, I spoke to Alan again and he wound me a new bridge pickup that was fatter than the neck one to compensate. It has worked a bit but still not 100%. So I thought that by dialling in a bit of the neck I would get the boom back :)

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[quote name='brensabre79' timestamp='1327332629' post='1509448']
Thanks Ian, yes have tried screwing it down - neck pickup is almost at scratchplate level, where the bridge is much higher. Measured the impedance etc.
They were originally a matched set of Wizard '74s - custom wound after a long conversation with Alan. When I changed to 70s spacing the problem became more so, I spoke to Alan again and he wound me a new bridge pickup that was fatter than the neck one to compensate. It has worked a bit but still not 100%. So I thought that by dialling in a bit of the neck I would get the boom back :)
[/quote]
Crikey! Well, I'm glad we're both of like minds hehehehe sounds like you've tried just about everything else I would have suggested anyway :)

It seems to be an inherent 'problem' with Jazz basses (much as I love 'em), with the VVT or VBT arrangement - there's a big mid-scoop when both pickups are full- or half-on etc, and going to a series-only arrangement does work wonders, plus its hum-cancelling without any messing around.

I did see a schematic or something similar on the Duncan website for a three-position blade switch when hooked up to a humbucker, which had a parallel 3k3 bleed resistor when in 'single-coil' mode - just substitute the 'North' and 'South' coils for the neck and bridge pickups - this might be the route to bass happiness :P

Hope you get there fella :D

Ian

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Thanks Ian, yes it seems an eternal struggle to getting the right balance of range of sounds and simple controls.

Heres my best guess so far, anyone care to chip in and tell me why this won't work?
Not sure the resistor values are right, I'm basing this on the idea that the volume pots are currently 250k as the pickups are single coil...

[attachment=97996:wiring-v2.jpg]

This is based on a 6position, 2 pole switch I found at Stewmac - its the same they use for the Fender Varitone wiring.

Edited by brensabre79
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[quote name='brensabre79' timestamp='1327335425' post='1509513']
Thanks Ian, yes it seems an eternal struggle to getting the right balance of range of sounds and simple controls.

Heres my best guess so far, anyone care to chip in and tell me why this won't work?
Not sure the resistor values are right, I'm basing this on the idea that the volume pots are currently 250k as the pickups are single coil...

[attachment=97996:wiring-v2.jpg]

This is based on a 6position, 2 pole switch I found at Stewmac - its the same they use for the Fender Varitone wiring.
[/quote]

To get the resistor values I'd be inclined to set the existing pot to get the sound you wanted, disconnect one of the wires to said pot and use a DVM to measure the resistance between the wiper and the track connection (you need to disconnect the pot from the rest of the circuit or else you'll get a false reading).

Alternatively, if you replaced those resistors with some miniature 250KΩ vertical presets then, with a bit of inginuity, you should be able to mount them to the rear of the switch.
That'd give you the facility to get 'exactly' the sound you want instead of an approximation.

Something that just occured to me is that you might get an almighty clunk as you change settings - not tried it so I'm not 100% certain.

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[quote name='icastle' timestamp='1327336577' post='1509539']
To get the resistor values I'd be inclined to set the existing pot to get the sound you wanted, disconnect one of the wires to said pot and use a DVM to measure the resistance between the wiper and the track connection (you need to disconnect the pot from the rest of the circuit or else you'll get a false reading).

Alternatively, if you replaced those resistors with some miniature 250KΩ vertical presets then, with a bit of inginuity, you should be able to mount them to the rear of the switch.
That'd give you the facility to get 'exactly' the sound you want instead of an approximation.

Something that just occured to me is that you might get an almighty clunk as you change settings - not tried it so I'm not 100% certain.
[/quote]

Thanks icastle,

So if I use a 5 position switch and 2 tiny variable resistors (presets?) I can fine tune the resistance... Like this?

[attachment=97997:wiring-3.jpg]

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[quote name='brensabre79' timestamp='1327336945' post='1509547']
Thanks icastle,

So if I use a 5 position switch and 2 tiny variable resistors (presets?) I can fine tune the resistance... Like this?

[attachment=97997:wiring-3.jpg]
[/quote]

Not really.
Look at your first diagram and replace each of those resistors with a preset.

On the preset you just want to be using the centre connection and one of the outer ones.

Something like [url="http://www.maplin.co.uk/sub-miniature-fully-enclosedcarbon-preset-potentiometers-6499"]these[/url] would do the trick.
They're just tiny pots with a screw slot to adjust them instead of the shaft that you get on standard pots.
I reckon with some careful juggling you should be able to get the vertical ones to stand in a circle around the back of the switch - just make sure that the slot faces outwards. :)

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[quote name='brensabre79' timestamp='1327341472' post='1509636']
Thanks mate

So...
[attachment=98006:wiring-4.jpg]
won't this just short the pickups out anyway? if they are connected like this? Or am I missing something..?
[/quote]

I think I must have got my diagram references muddled up. :)

What you want is the diagram below, but replace each fixed resistor with a preset...
The idea is that instead of guessing what value resistors you need to use (and faffing about for hours trying to 'tweak' it afterwards using piles of odd value resistors), you have a mechanism to preset the values precisely as you want them.

Resistors come in preferred values - so if you wanted a 20KΩ resistance the nearest you can get is a a 22KΩ resistor (unless you use two 10KΩ resistors in series, but then it starts getting messy).

Presets are infinitely variable between 0Ω and whatever the value of the preset is.

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To simulate a 250k volume control being tapped at various preset points the resitors should add up to 250k. The resistors in the diagram above are all connected and form part of a voltage divider circuit. The resistors add up to 445k which is the same as a 445k pot with one end connected to the signal source, the other end to ground and the switch positions being the wiper. For example in NPU switch position 4, the pickup signal passes through a 250k resistor before being tapped off but part of the signal is also running to ground through the remaining 125k and 75k resistors. For a 250k total you could try resistor values of something like 125/65/60.

I'm playing around with something similar at the moment - a humbucker series/single-coil switch with a preset resistor in the series setting to bring the output down to a comparable level to the single-coil. The idea is be able to easily switch between the clarity/punch of single-ooil and the added girth/meat of series without the massive increase in volume.

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[quote name='brensabre79' timestamp='1327323609' post='1509239'] I'm not sure if this has been done but interested to try... I can't get on with blend controls, or vol/vol controls. Too much faffing around. In a gig i really like to be able to just dial a switch, knowing exactly what sound will come out and start playing (no noodling between songs whist adjusting the blend / volume control to get the right tone...) Currently I have a 4 position rotary switch where the second volume knob should be: pos 1. Series :: 2. neck :: 3. both :: 4. bridge ...but I'd like to be able to have a little bit of bridge with the neck and vice-versa So what I'd ideally like is a 5 position rotary switch as follows: 1. Neck only :: 2. Neck + 50% Bridge :: 3. 100%neck + 100% bridge :: 4. 100% bridge + 50% neck :: 5. Bridge only Or better still, a 6 position that will do all of the above plus both in series. I'm guessing that resistors could be used to half the volume of the pickups when switch to the right location. Essentially a preset where the volume of one pickup is at half or 3/4 (I'd have to play with resistor values to get the right balance I suppose). Anyone got a wiring diagram...? or even a clue if this is possible? Thanks Bren [/quote]

going back the the original problem... you can't get on with blend or v/v controls... but have an ACG eq in your gear list.... surely that is harder to use than a blend pot?

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OK fine tuned version. I think this will work... so pos. 4 gets a resisted signal from NPU and all of BPU etc. I can fine tune the VR presets to taste and then close it all up and leave it.
[quote name='LukeFRC' timestamp='1327357881' post='1510068']
going back the the original problem... you can't get on with blend or v/v controls... but have an ACG eq in your gear list.... surely that is harder to use than a blend pot?
[/quote]
:) Its a good point you make there, but that preamp is on my fretless bass. And in terms of pickup switching I tend to use one of two sounds, neck or bridge, thats it. The sound I use relies heavily on the ACGs parametric and flatwound strings to imitate a double bass - but I can set up my fretless before the gig starts and leave it.

What i need this for is my main gigging bass, so I can dial in a preset sound without needing to listen to it in between songs. I do need to change tones throughout the set without subjecting the audience to a one note bass solo while I sort it out. We like to have very short gaps in between songs, literally as the note decays fom the last song the clicks are coming in for the next one, (can be quite frantic at times!) so i just need to switch and go!

Cheers
Bren
[attachment=98065:wiring-5.jpg]

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Thanks Lawrence, an intersting suggestion, I could add the cap just before the Preset VR so I get just the bottom end of the neck with the top of the bridge right? I guess the standard .47uF would do this to some degree, but maybe i wouldn't even need the VR with a higher value one of these in position...
Any recommendations for the cap?
:hi:

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Hmm, it's not something I've played with myself and corner frequency will depend on the particular pickup inductance, but I'd guess a 0.1uF or even 0.2ish would be a good starting point (I'm assuming you meant 0.047uF?)
You'd probably still want to try the VR due to resonance making the neck pickup low-mids louder. Depends on the pickup and corner frequency really

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