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Thunderbird Club

First a little background and clarity so we’re all talking the same thing.

General reference, discussion, data and opinions on a “Blend Pot” are a mess because it’s more often than not mistakenly called that. In most cases when people talk Blend Pot pros and cons they are actually referring to what is technically a “Pan Pot”. It’s the potentiometer that is commonly used in guitar and bass applications and is a dual gang stacked pot layout with a single shaft and center detent.

A Pan Pot (commonly called a Blend Pot) at center detent is in effect 50% volume level from each pickup. Basically the same as setting each of your traditional layout Volume Volume knobs at 5 (unless yours go to 11, in which case it’s 5.5 ;) ). As you turn from center detent to either extreme the volume of the pickup you’re favoring increases and the volume of the other pickup decreases. The net effect is a noticeable volume drop (and in some cases a slight dulling of the tone due to resistance loading) at center detent. To picky players that’s a real issue, to on stage performers the negative impact is offset by the ease in use of only having to adjust one volume knob on the fly on stage. Of course a volume pedal or master volume would do the same thing.

There is such a thing as a TRUE Blend Pot that operates completely different and is well worth having if you can find one that will work with your bass. It’s quite different, with the center detent actually being 100% volume level from each pickup. Like setting each of your traditional Volume Volume knobs at 10 (or 11 if you’re a Spinal Tap guy). The obvious advantage is zero volume drop and minimal loading at center detent, and in effect it sounds exactly how you would expect a Volume Volume layout to sound as the two pickups interact at various volume settings relative to each other.

The catch - good luck finding a True Blend Pot. Fender has them but most if not all are made for plate or pickguard mounting, so the shaft may not be long enough for a through body installation. Someone in the club here did go on a quest about a year ago to find a true blend pot for their Tbird application, I think it might have been @Thumper but I’m not positive, and I don’t recall if he actually found one or ended up with something else.

To confuse the issue further - Fender does make a True Blend Pot, but because everyone else makes a Pan Pot and calls it a Blend Pot Fender decided to start calling theirs a Pan Pot in some cases. Again, good luck finding a true blend pot, it’s a mess out there.
Bookmarked. Thanks George, and everybody that has replied so far.

It came to mind as I was fiddling around with the SX Tele I bought to practice the F chord and other barre chords on. (Don’t ask 🤦‍♂️)
Any way, I had it on bridge pickup and wanted only a little neck pup in there… but of course it is only master V, master T and a 3way selector… no go. Anyway, started me in a blend pot mental cul de sac
 
Bingo...

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The “blend” or I guess properly, the pan pots I use are MN250K. Really the only usable range as far as audibly noticeable change is a little off center in each direction, and fully “off” at either end. When I tried MN500K, that “usable” range seemed to be even less. I don’t believe the pickups are only at 50% volume each when at center, so maybe the “MN” designation is what is different and what makes them 100%/100%. I sense no difference in volume between one of my double P Precisions that is VBT and one that is VVT.

I have always wondered if a MN100K pan pot would give a little more usable range off center?
 
First, Merry Christmas ya'll! Secondly, George, it wasn't me. I'm very much in the VVT camp, all of my builds have been set up this way, and also with a series/parallel switch (which I almost never use). Where you really helped me was with VTVT on the Thunderbird using 2015 PUPs.
Merry Christmas to all!
I’m a pretty big fan of stacked pots, you can get a lot of functionality in just a few knobs. I think I might have confused you with Stealth on his blend pot quest.

On basses with 2 pu's and V-T-V-T, I install a 'kill switch' mini-toggle to save optimal settings between sets instead of turning two disparate V's off.
An excellent solution that solves the on/off volume problem, which is key on stage.

So a "true blend pot" with pickup outputs 100/100 at center detent would be 100/0 at one extreme, and 0/100 at the other?

It acts to attenuate one pickup at a time while leaving the other maxed?

Have I pictured right?

Yeah, that'd be a very specific pot design; almost like a zero-load, but zero across 50% of rotation, and pot A reversed from pot B.
Exactly.
Now if the pot taper were Audio it would be fantastic, linear pot taper in a True Blend pot is gonna get mighty touchy around that center detent with just a hair off center either way throwing you into a perceived volume off on the disfavored pickup.

It was fun soldering the jumpers. Like playing tic tac toe with red hot metal.

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Looks like a nice soldering job though.

I have a Bournes MN500K pot in my parts collection. When I measure it at the center detent position, it's zero ohms from center to one side on the top wafer and zero from center to the other side on the bottom wafer.
It seems to me that center position would give you 100% of both pickups.
The threaded shaft measures about 8.5mm.
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You might have a unicorn there. I’ll have to look up the part number on that pot and see if there’s a reliable supplier. Also, to my ears, Bourns has the best Audio taper out there, more gradual than an Alpha pot and a bit better than a CTS as well. Do you know if it’s linear or Audio taper?

Bingo...

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Ding Ding Ding - we have a winner! Except that both M and N tapers appear to be linear vs audio. It’ll work, but might only be truly useable one or two notches off of center either way. That said, I’d probably take it vs a Pan Pot volume center detent drop situation.
 
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…no rain, no pots, no birds, happy Xmas to everybody….including support for this now insolvent manufacturer, about 30 miles away from my place…1966 verythin bass…

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Hofner's Violin basses never clicked with me, but I would like an old President. And, I really hope the company can be given new life. I really hate to see such important history literally become history.
And Merry Christmas to you as well!
 
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Merry Christmas! Joyeaux Noël!
From Sydney, Australia.

Currently 10:28am
Merry Christmas to all who celebrate!


So there is no misunderstanding, that is not me jumping out of the stocking, regardless of what Ken may say.
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Merry Christmas to all who celebrate!


So there is no misunderstanding, that is not me jumping out of the stocking, regardless of what Ken may say.
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Seconded-or thirded?

And to all my fellow 'Birders, a Merry mixed drink and a happy new beer.
 
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Well deserved!

We got a nice one ourselves. Marshall should appreciate the mention of Neil Young.

Awesome!
 

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