Blend pot question

By mistake I had this posted in the Tele Home Depot...:oops:

Need a little advice from someone who knows his/her way around wiring.
I'm looking to wire two HotRod Filtertrons to a blend pot and a kill switch.
There will be no tone pot in this guitar. I was told I would need a cap in there somewhere. I can't find diagrams for this 'oddball' wiring.

Little more info;
Killswitch will have be used for 'machinegunning' as well as switching the signal off.
HotRod Filtertrons read out about the same as the usual Filtertrons (a bit over 10.5 IIRC).
I can use either a 250k or a 500k blend pot.

Can you help a complete and total n00b?

What is the cap for?

I think it is not a normal pot... Looks like two pots tied to one shaft... This may help...

http://www.stewmac.com/freeinfo/Electronics/Pots/i-4137.html

What is the cap for?

Not a clue. As I said I was told I would probably need a cap in there...
Could have been a 'wisenheimer' remark the guy made... He had no more info than just that.

think it is a normal pot... Looks like two pots tied to one shaft... This may help...

http://www.stewmac.com/freeinfo/Electronics/Pots/i-4137.html

Basically that's it. Here's a pic;
http://www.neighborhost.com/temp/blend_pot.png

I know how to wire the two pups to the blender, I'll figure out how to wire a kill switch in there too. It's just the cap remark kinda sticks to the back of my head.

Ideally the kill switch should be on-off-momentary and ground both neck (blue) and bridge (red) - i.e. dpdt. If only spdt available then ground the out (green) instead.

Okay, kinda simple question, and iv think its already been answered but i just want to check, with blend pots does it make any difference whether its 250k or 500k?

It's just the cap remark kinda sticks to the back of my head.

I thought you might have gotten a few more answers over here, Olav. :wink:

OK, I've refreshed my memory. Caps are on tone knobs where you are beading some of the signal to ground through the cap. You shouldn't need a cap on a blend pot.

Ideally the kill switch should be on-off-momentary and ground both neck (blue) and bridge (red) - i.e. dpdt. If only spdt available then ground the out (green) instead.

Option 2 I can get my tiny brain around, wire out to the switch that either leads that to ground (= off) or to jack (= sound).
How would I go about option 1?
Do I wire both to the switch first, then to the blend? Or to the blend, then 'splice' to the switch? I'm confused. Like I said; n00bsville here.

Okay, kinda simple question, and iv think its already been answered but i just want to check, with blend pots does it make any difference whether its 250k or 500k?

I guess it would make a difference, just the same when using 'normal' pots make a diff when choosing between humbuckers and singlecoils. Since I'm opting for no tone controls, I'm trying both varieties to see what sounds better.

I thought you might have gotten a few more answers over here, Olav. :wink:

OK, I've refreshed my memory. Caps are on tone knobs where you are beading some of the signal to ground through the cap. You shouldn't need a cap on a blend pot.

Thanks for redirecting me Bill.
I got where a cap isn't used on a V pot, that would ultimately make it a T pot. The guy I spoke to (many moons ago) warned me to be wary of pots getting charged by the blend pot. I really didn't grasp what that was about, but as these pups are pretty costly overhere I'm not chancing anything.
I think he said to wire in a cap over the blend to 'bead' off some of the current to ground.

Maybe I'm just confusing the issue here, if so, apologies. I guess what I'm asking for is a wiring diagram for the configuration I proposed;
2 hums/1 blender/1 killswitch/1 mono jack

Again; small words please,. n00b at work.

I think he said to wire in a cap over the blend to 'bead' off some of the current to ground.



When you bleed current to ground through a cap, you are only bleeding the high frequencies. So, I would think any cap on the blend pot is going to change the tone.

When you bleed current to ground through a cap, you are only bleeding the high frequencies. So, I would think any cap on the blend pot is going to change the tone.

See, that's precisely the thing I don't want... Thanks.

Option 2 I can get my tiny brain around, wire out to the switch that either leads that to ground (= off) or to jack (= sound).
How would I go about option 1?
Do I wire both to the switch first, then to the blend? Or to the blend, then 'splice' to the switch? I'm confused. Like I said; n00bsville here.

In both cases "on" or "mom" connects that lead (e.g. green) to ground. i.e the kill switch is "parallel" to the exisiting circuit, *not* inseted in "series" between the circuit and the jack. If this is unclear I'll draw a diagram.

In both cases "on" or "mom" connects that lead (e.g. green) to ground. i.e the kill switch is "parallel" to the exisiting circuit, *not* inseted in "series" between the circuit and the jack. If this is unclear I'll draw a diagram.

Can you please?

Here's how you wire up a kill switch, http://alexplorer.net/guitar/mods/killswitch.html. I had the exact setup you're going for on one of my guitars once. Keep in mind that with a blend pot you can't have both pickups at 100%. It's 100%/0%, 75%/25%, 50%/50%, ect...This works fine, but dedicated volume controls for each pickup (like a Les Paul) will get the same results with more room for variation. If space is a premium you could use a dual concentric pot.

With M-N taper pot, it is possible to get both pickups at 100%. Not sure which one OP has.

Here's how you wire up a kill switch, http://alexplorer.net/guitar/mods/killswitch.html. I had the exact setup you're going for on one of my guitars once. Keep in mind that with a blend pot you can't have both pickups at 100%. It's 100%/0%, 75%/25%, 50%/50%, ect...This works fine, but dedicated volume controls for each pickup (like a Les Paul) will get the same results with more room for variation. If space is a premium you could use a dual concentric pot.

O! I hadn't thought of that. I do have a couple concentric pots from a wrecked Dano, but thought a blend would serve my purpose better. I really like the middle setting for these pickups just sometimes feel I want a little more of either bridge or neck in that mix.
Space isn't an issue, the guitar in question is an Ibanez hollowbody.

With M-N taper pot, it is possible to get both pickups at 100%. Not sure which one OP has.

Well I ordered a couple Bourns blender pots
one of these
http://www.allparts.com/Bourns-250K-Blend-Balance-Pot-p/ep-5385-000.htm
and one of these
http://www.allparts.com/Bourns-500K-Blend-Bal-Pot-p/ep-5386-000.htm
though obviously from a store based in The Netherlands.

Now I get word they won't be able to deliver for a week or two...

Would these do to get both pups to go 100% at the same time? If not, please point me to which would, because that would defeat the whole purpose of my do-over of that guitar...:sad:

http://i872.photobucket.com/albums/ab289/cc9cii/blend-kill-dpdt-v1.jpg

http://datasheetz.com/data/Switches/Toggle/7207SYZBE-datasheetz.html

The tricky switch is only needed if you want:

1. no sound (up)
2. sound (center)
3. no sound (down - momentary)

A normal center off dpdt is also ok, so is simpler on-off dpdt.

Thanks cc, I'll just see what kind switch works better for 'machinegunning'.

[edit; it would also appear as though the blend pots I ordered are capable of having both pick ups go at 100% at the centre detent.

Element #1 has a linear output increasing from 0 % to 100 % output over 50 % of the mechanical travel in the clockwise direction. The element then stays at 100 % output for the remaining 50 % of mechanical travel.
Element #2 is at 100 % output over the initial 50 % of mechanical travel in the clockwise direction. The output decreases linear 100 % to 0 % over the remaining 50 % of mechanical travel.

http://www.bourns.com/data/global/pdfs/Bourns_PDB182_Blend-Balance_Guitar_Pots_AppNote.pdf