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Post by strabo on Aug 23, 2023 9:32:27 GMT -5
I found myself wondering the following. With a two pick-up guitar and a typical three-way pickup selector (a/a+b in parallel/b), could you install one of those blender pots (two pots on the same axis, as you turn one up, the other turns down, with a centre detente where both are on full power, the usual set-up) before the pickup selector (i.e. with the output from each pickup going to one or the other pot of the two blender pots, which would be wired as normal to send the signal to ground at the right time, and the hot output from each blender pot then going to the lug on the pickup selector where that pickup output would normally have gone directly)?
I suppose the answer is you could, most of our countries are free countries - but more importantly, having done that, would it then be possible to use that centre position as a kind of blend position (i.e. when the two pickups were selected in parallel in the centre position, would the blender work as a blender, fading out one pickup or the other, depending on which way you turned it, with the sound just being normal 'two pickups in parallel' if the pickup selector is in the centre positions and the blender is in the centre detente position)?
I can't think why it shouldn't, but I am not very good at electronic thought experiments.
And then I got to wondering how it would work with (for example) the complicated double wafer kind of Superswitches with fiddly wiring (such as the a/a+b in parallel/a+b in series/a+b in parallel and out of phase/b wiring I have discussed with proper electronics experts in previous threads). Could the blender work in such cases, or am I opening up a whole can of electronic worms here?
I know there are people who are much better than me at imagining such things and their consequences, and I throw myself upon their mercy, with thanks in advance!
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Post by Larry Madsen on Aug 23, 2023 10:53:02 GMT -5
My bass utilizes a blender knob for two pickups. Maybe there is a reason to use both a switch and the blender, but I'm not coming up with one quickly.  |
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pdf64
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Post by pdf64 on Aug 23, 2023 15:17:56 GMT -5
“ two pots on the same axis, as you turn one up, the other turns down, with a centre detente where both are on full power”
That doesn’t make sense.
At halfway (centre detente) the output from both pickups would be reduced.
A single track blend pot becomes much more doable with low impedance pickups / active electronics.
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Post by strabo on Aug 23, 2023 16:40:41 GMT -5
Perhaps I wasn't explaining it properly! As I understand blend pots, the output from each pickup is 100% at the centre detente position, and the pickups are in parallel. The carbon track on each pot is arranged such that the tail-off is between the centre and the end in one direction on one pot, and between the centre and the end in the other direction on the other pot, and the remaining halves of each track are 100% all the way along; so when you turn the knob in any one direction from the centre, you get 100% of one pickup in parallel with a decreasing percentage of the other pickup in parallel, until at the extremity you get just 100% of one pickup and 0% of the other. If you head back in the other direction, the situation reverses until you are at 100% of both in the centre, and then the other pickup tails off.
So given that, would the centre position of a three-way switch work in that way? I'm not asking if I should, just wondering if I could...
And the notional reason for having both a switch and a blend pot is that you have the workaday option of quickly flipping between the three positions on the switch, or a leisurely weekend-style opportunity to tailor a custom blend of two pickups in the middle position.
(and the question still obtains for the complicated double-wafer-wired switches, as this is what I am really interested in!)
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pdf64
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Post by pdf64 on Aug 23, 2023 18:10:48 GMT -5
Ah, right, I think I get your drift now.
To achieve 0 loss in the centre position, it would require a custom pot, the tapers you describe are non standard. But it should be doable, if you decide to order a batch.
Plus with regular high impedance pickups and passive electronics, the only way I can envisage it would change the tone of the pickup that was being turned down, becoming more muffled (due to loading).
With active electronics it becomes easy and a simple single track pot can be used, but then you’ve got to deal with powering the darn thing, and keeping hiss under control.
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Post by strabo on Aug 24, 2023 5:20:48 GMT -5
Ah, maybe I misunderstood. I found this: forum.bassbuzz.com/t/blend-pot-how-and-why/26497which seems to suggest that this kind of taper does exist, however. But I definitely take your point about the tone of the diminishing pickup darkening as the blender is turned (I suppose it is working just like a regular volume pot as far as the pickup being turned down is concerned, with an increasing amount of the signal being diverted to ground). Would a treble bleed on each side of the blender pot address this, do you think? And I'm also trying to get my head round the effect essentially of having two volume controls affecting the same pickup signal (one before the selector switch, and the master vol). |
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pdf64
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Post by pdf64 on Aug 24, 2023 12:58:38 GMT -5
“this kind of taper does exist” Haha, MN taper pots, I’ve learnt something new  “the tone of the diminishing pickup darkening as the blender is turned (I suppose it is working just like a regular volume pot as far as the pickup being turned down is concerned, with an increasing amount of the signal being diverted to ground)” No, it’s not working like a regular volume control (potential divider). Rather it reduces the pickup’s output by loading it down, eventually shorting it out at the extreme. That mechanism affects the tone first, damping down the high frequency resonance. A guitar pickup has a frequency response you might mistage for a wahwah. I don’t see how a resonance that’s been damped down can be reinstated with a treble bleed. See buildyourguitar.com/resources/lemme/Plus the way the blend pot is wired, a treble bleed that makes the attenuated pickup brighter will tend towards making the unattenuated pickup duller. “I'm also trying to get my head round the effect essentially of having two volume controls affecting the same pickup signal (one before the selector switch, and the master vol).” So you were envisioning a blend pot, pickup selector, then master volume and maybe tone? If so then I think the pickup selector would need to be a complex multi pole type, so that the blend pot was completely taken out of circuit. Because its setting might be hamstringing or completely muting one of the pickups. |
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Post by strabo on Aug 24, 2023 18:22:00 GMT -5
These are exactly the considerations that were likely to escape me; I had a pipe dream about a smoothly adjustable pickup position: *in the distance, sirens*....
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Post by funkykikuchiyo on Aug 24, 2023 19:06:45 GMT -5
I just replaced the switch in an old Silvertone that had some sort of odd "blender" circuit in it, but I forget how it did it.
I think the results/utility of such a circuit would be underwhelming. On a Jazz Bass, you have two volume controls wired such that you can fully turn one off without shorting both to ground. There are a few sweet spots of blending the two pickups that sound pretty cool (like neck around 8 and bridge full up - Jaco used this sort of growly sound a lot), but it isn't all that special. Guitars have been made with individual volume controls wired that way many times, and a Gibson can be modified to do this in the center position just by swapping a couple wires at the volume pots (the "out" needs to be on the side lug instead of the middle lug). I've never found anything all that interesting when I've experimented - like having full neck and a hint of bridge in there or something.
In any case, if I'm understanding your goals with this idea, you should be able to do the same thing with individual volume controls, if nothing else as a way to experiment and see if you like it. On a two pickup guitar if you leave one all the way up and adjust the other you'll effectively be doing the same panning thing it sounds like you're looking for, like the balance control on an old stereo.
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Post by strabo on Aug 25, 2023 3:13:35 GMT -5
Many thanks for thoughts! And yes, the panning thing was exactly what I was wondering about, and the reason I was considering a blender was the option of being able to vary pickup levels with one knob rather than the two involved with twin volume controls, and fine tune the balance when two pickups were selected, like a kind of trim pot.
What lies behind all of these enquiries is that I am helping a pal of mine who has a Fender bass with PJ pickups and active circuitry (it's a Fender Precision Lyte, apparently) and he wants to take out the active circuitry. There are 4 knobs and thus 4 holes in the front of the bass (the old controls are: master volume;blender;bass boost/cut;treble boost/cut) so it is a question of finding a use for each hole, if I can say that on the BBC. My thoughts ran to master volume; master tone;either a 3-way rotary switch or even that fancy 5-way rotary Superswitch with two wafers (you get a; a+b in parallel;a+b in series;a+b in parallel and out of phase; b), so there would be another hole left over - and that was what got me to wondering if a blender was even electronically possible in such a set-up, and if it might help with fine-tuning the pickup selector options where both pickups are involved.
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Post by Cal-Woody on Aug 26, 2023 11:12:27 GMT -5
Here is a thought, if both pickups are at full volume, couldn't you use the blender pot to taper off one pickup to get a more pleasing sound, instead of just having both pickups making an expected tone? In other words, you might want the treble pickup to be more present in the sound with the rhythm pickup giving you a little more fullness to the sound, or vice-versa, when in the center position using both pickups and adding a slight hint of the treble pickup to give you some more sparkle to an otherwise darker tone? It seems logical to me but both pickups would have to be at full volume as not to become muffled.
If my thinking is correct here, then that would be a really nice way to get a better balance of tones between the two pickups in a standard switching scenario. But the blender switch would have to be able to be 'out of circuit when you want the regular pickup selection.' So, in one position the blender switch is engaged and in the other position disengaged.
I think that would be exciting!
There has been so many times when I want to use the middle position and have more of one position than the other.
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Post by funkykikuchiyo on Aug 26, 2023 12:29:41 GMT -5
Many thanks for thoughts! And yes, the panning thing was exactly what I was wondering about, and the reason I was considering a blender was the option of being able to vary pickup levels with one knob rather than the two involved with twin volume controls, and fine tune the balance when two pickups were selected, like a kind of trim pot. What lies behind all of these enquiries is that I am helping a pal of mine who has a Fender bass with PJ pickups and active circuitry (it's a Fender Precision Lyte, apparently) and he wants to take out the active circuitry. There are 4 knobs and thus 4 holes in the front of the bass (the old controls are: master volume;blender;bass boost/cut;treble boost/cut) so it is a question of finding a use for each hole, if I can say that on the BBC. My thoughts ran to master volume; master tone;either a 3-way rotary switch or even that fancy 5-way rotary Superswitch with two wafers (you get a; a+b in parallel;a+b in series;a+b in parallel and out of phase; b), so there would be another hole left over - and that was what got me to wondering if a blender was even electronically possible in such a set-up, and if it might help with fine-tuning the pickup selector options where both pickups are involved. Well, I'd mention again that you (sort of) get the experimentation with just turning one knob with two volume controls. Sort of. Maybe. Kinda.
If you leave the neck up, you only adjust the bridge control to get an array of sounds, and if you leave the bridge up and adjust the neck volume control, you get an array of sounds. So, it isn't like you're fidgeting with two knobs at once (set one at 7, one at 3), you're just tweaking one (since one is always at 10). The style pan pot you've been talking about does the same thing, it just switches from one mode to another on either side of the detent.
If you can't source the correct blender pot, you could use a stacked volume pot that is only engaged for the middle pickup position. Same thing, two knobs instead of one.
For the extra hole, don't bother with an extra tone control. Electrons aren't smart enough to know whether you're adjusting for the neck or bridge pickup, so you'd just be wiring in two parallel tone controls for no reason.
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Post by Cal-Woody on Aug 26, 2023 12:56:09 GMT -5
One other thought: Can a blender switch be wired so that one way it is engaged and in the opposite position, be out of circuit?
If I could I would like to know if a blender pot could be wired to be able to use it as a blender switch and when disengaged, out of circuit, thus leaving the regular circuit (3 way switch) as normal and then engage the blender switch to use when I want it?
This brings about another question: if I did this, depending on the pickups used and the pots I like with those pickups, what ohms rating would you recommend?
Because, I like 300k with my P90's and some humbuckers and 500k with higher gain pickups, plus 250k with single coils.
I know a little about how different pot resistance affects the tone on my pickups but if I can use a blender switch, I don't want to alter how the pickups sound.
Let's say you are using 500k pots for a dual humbucker guitar and want to add the blender pot, would I just need to ohm match the installed pots as not to alter the tone when it is engaged? Or would it be a better choice to get a 1 Meg ohm blender pot as to keep any or all pickup choices more neutral when engaging the blender switch? I don't want to dampen the tone quality from the original wiring scheme and thought maybe an 1 Meg ohm blender switch would allow my preferred pot arrangement to sound and behave as expected.
I think this could be doable if I could find a 1 Meg ohm blender pot and wire it for this idea.
Also, if I used this idea, would the 1 Meg ohm blender pot load the circuit in a weird way, especially when the original circuit is being used?
All thoughts are appreciated, thanks Woody
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Post by funkykikuchiyo on Aug 26, 2023 21:15:59 GMT -5
I'm not fully tracking what you're seeking to do Cal-Woody, but the short answer is yes, but to have simpler wiring and not need 12-lug switches it would probably have to be simplified.
It does remind me of an idea I've had for a while but never executed, of just using high value pots in the guitar and adding a trim pot in the cavity in parallel to alter the load, so that you can dial in the "pot value". Got the idea playing around with hard wiring resistors into circuits with 500k pots that would sound better with lower values, and finding that small adjustments can be nice. No need to have it on the fly (hence putting it in a trim pot in the back), but an awfully nice thing to do when you set up the guitar and set the pickup heights.
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Post by Cal-Woody on Aug 26, 2023 23:53:00 GMT -5
My idea is to add a blender pot and be able to dial in the sounds I want when both pickups are engaged, thus, the blender pot could add the pickup that I want to hear more of when both pickups are being used. So in essence, I can add more of the treble pickup to the rhythm pickup to enhance the sound by adding some brightness to that sound. And the opposite when I want to add some fullness to the treble pickup.
Its a simple concept but need to: 1) know the blender pot value, (I'm thinking 1 Meg ohm), 2) can it be made to go out of the circuit when I want to use the 3 way switch, as per normal and be able to use that volume and tone controls as you normally would, 3) I know that to do this (using a blender pot) I would have to have both pickups at full volume as not to lose their tonal quality, and 4) is it possible to wire up a blender pot to switch between the regular wiring and the blended circuit?
I think it is a cool concept!
I guess I should just Google the blender pot circuit and see if this can be done...
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Post by Cal-Woody on Aug 27, 2023 10:17:32 GMT -5
Well, after some thought I learned that the blender pot is what it is: it blends! So I would have to add a switch that would take the regular circuit and reroute it to the blender pot. There are several ways to do this but for now I'll just write it down and work up a schematic for it and see if it would be practical to do and use.
Thanks for entertaining the idea with me. Woody
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Post by funkykikuchiyo on Aug 30, 2023 10:49:41 GMT -5
Well, after some thought I learned that the blender pot is what it is: it blends! So I would have to add a switch that would take the regular circuit and reroute it to the blender pot. There are several ways to do this but for now I'll just write it down and work up a schematic for it and see if it would be practical to do and use. Thanks for entertaining the idea with me. Woody Yeah, PDF goes over this up above, but maybe goes too fast.
They're really just two volume controls working in opposite directions, which is why I think having two volume controls, at least in a "will this be useful?" phase makes the most sense. A blender pot may have virtues for on-stage quick adjustment, but other than that it won't provide added value.
I tend to be a pessimist with a lot of wiring ideas on here, but some of it is that I've seen all kinds of variations come across the bench, and so few seem useful. I was obsessed with the idea of 7-way switching on G&Ls where you can have all three or just neck & bridge in addition to 5-way until I tried one, and realized it isn't that useful. Coil splits are useful for some people, but tend to be utilitarian - need a quick clean song for a certain passage, or whatever. I never understood why out-of-phase would be appealing except if you're playing X song off of X album where X artist famously used an out-of-phase sound.
I do think there are some ideas left out there worth trying - there are some vintage circuits that do cool things that are along the lines of a varitone or the Jazzmaster rhythm circuit that popped up randomly in '60s guitars, but I can't remember what they did. They may have only worked because they were using cool old DeArmond pickups (or similar from Japan) which lent themselves better to this.
Mostly, what works best for guitarists is giving on-guitar controls that give them the most control for a usable, balanced sound and let pedalboards and amps do the tweaking to explore new sounds. But, this is turning into a rant, so I'll stop there.
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Post by strabo on Aug 31, 2023 3:06:41 GMT -5
I am delighted and extremely grateful to see such lively debate - and please accept my apologies for my silence over this week; I went Denmark last Friday and have been stranded in Germany every since by air traffic control disruptions, only making it back to the UK last night. I shall catch up on this thread with all speed!!
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sirWheat
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Post by sirWheat on Aug 31, 2023 6:55:25 GMT -5
I don't know if this relates or will help any but I have a Yamaha SGV700 (I think it's cool) that partly incorporates what you're talking about, though in a three pickup situation. Uses a three-way switch with a blender that allows you to adjust the level of the "bridge" and "middle" pickups from either of the first two switch position.  |
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Post by Cal-Woody on Aug 31, 2023 13:29:32 GMT -5
On my P/J bass I have 2 volume controls and 1 tone control with a blender pot. I like this set up but it isn't always practical to have to use the blender pot to switch between 2 pickups and sometimes think a 3 way switch would be more useful. But you can dial in some very good tones using the blender pot and get a good solid bass tone! Without adding an additional switch to toggle between the pickup selector or the blender pot, I think the extra effort is not worth it. For a studio application that might be ideal but to use it as a piece of performance gear, I like the blender pot best.
I do have an active preamp that I could put in my bass which has the option to switch between 2 pickups or lift one of the volume controls to use the blender pot. This is made by Feul electronics. It is an aftermarket unit and gives passive pickups great sound! I installed one in my friends 5 string Schecter bass and it really great string definition. Not sure if they are still around but it might be worth the search to try and find one. That might address the original posters issue if they still want to go with passive pickups and have a great preamp to boot! It is a 9 volt system and was an easy swap because it was designed for that bass. They had quite a few configurations back when I was installing it but haven't looked into it for quite a few years.
Oh, I now use this with my Seymour Duncan Quarter Pounders in my Fender Jazz bass with great results! And I forgot to mention that it can be switched to change over to passive with the tone control lifted.
Best regards always, Woody
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Post by strabo on Aug 31, 2023 13:44:12 GMT -5
Funky, I take your point about the separate volume controls; but what I meant with using two controls rather than one is best instanced by a Jazz bass - if you want to switch from just one pickup to just the other, you have to turn one all the way down with one knob and the other all the way up with the other = using two pots. With the blender described above, you could effect that swap with one knob, passing through all the blends en route. The bit I couldn't get my head around was what would flow to ground from which position (is it the case, for example, that with the complicated double-wafer selector switch positions, both pickups in series, say, if the blender pot is turned one way or another, the signal from both pickups would flow to ground equally down whichever side of the blender had least resistance, whichever direction you chose?).
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Post by Cal-Woody on Sept 1, 2023 15:48:02 GMT -5
My best understanding is: a blender pot is always On, just like the way a single pickup is wired to its own volume and tone control, but now you are routing the signal to the blender pot instead of a pickup selector. So, it doesn't matter what you have the volume controls set to, you are now just blending the pickups, instead of switching them back and forth. All of your volume and tone controls are wired as you normally would, but you will be using the blender pot to select which one you want to hear or tapering the pickup you want to add to the sound you want to develop.
So, No More pickup switch, just a blender pot to switch between the pickups.
The pickup wiring is as Normal and will behave just like when they would have been wired to a selector switch.
When you leave the volume controls up full, there will be less tonal difference when blending between the two, but if you turn down the volume of a pickup without a treble bleed circuit, the pickup will become duller in its sound and so that is why I suggest with passive pickups, it is always best to use a treble bleed circuit and not have the duller tones when using a blender pot and using the volume controls at different levels when blending.
So, a blender pot takes the place of a selector switch and is wired as you would normally.
Best regards always, Woody
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Post by strabo on Dec 12, 2023 12:44:36 GMT -5
An update on this - after much consideration and consultation of the excellent advice here (both specific - addressing the mechanics of how this might be achieved - and philosophical - whether it would be worth it!), I installed a rotary three-way switch, a blender and a push-push switch to series/parallel switch the two halves of the Precision pickup, along with a master volume and a master tone (the potentiometer half of the push-push switch).
I wired it all up, plugged the bass in, and it was completely dead.
Some experimentation (and choice language) later, I discovered that a few bits and pieces had been shorting out on the conductive paint inside the cavity. A little light insulation followed , and the thing suddenly worked like a dream. The differences in tone were subtle, but not at all outlandish, and some of the combinations were quite interesting - slowly blending the in-parallel Precision pickup into the Jazz pickup yielded some very satisfying tones in particular (Jazz bridge position but with some scooped additions? Difficult to describe but a little fuller than the J bridge alone; it was actually not so different from mixing two J pickups). My pal was very happy to be able to switch quickly using the 3-way, and the blender was fun to play with (and has a centre detente, so you can just leave it in the middle and have Les Paul-style switching if you so choose). The in-parallel Precision on its own was less punchy than the usual Precision thump, but sounded rather good with the tone backed off just a little. All told probably a bit fiddly, and as with any multi-option switching set-up, he will probably only end up using two of the half a dozen or so options available, but he was happy, and it all worked as it should, which was pleasing!
Many thanks to everyone who made suggestions, and I can report back that the game is just about worth the candle, especially if you are looking for subtle ways to flavour the basic tones we know and love.
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