Insertion Loss?

Your pickups might be out of phase

 

If the bass is wired properly there should be no need for an external booster in order to use both pickups simultaneously. The volume drop shouldn't be that severe. From the description it sounds like your pickups may be out-of-phase. Have you tried reversing the polarity on one pickup?

must learn to type quicker... what he said above!

 

Swap the hot/gnd on one pickup.

 

For a somewhat contrary view , "insertion loss" is very very real and well documented. However if your pickups are correctly wired (phase, grounding, etc.) the drop in level when two pups are passively blended equally should not be all that bad. Noticeable, real, but not significant.

The Villex boost works by robbing energy from one frequency range, and using that energy to boost another range.

 

I think (speculation only) that it takes from the highs, and exaggerates the resonant peak at the corner frequency where the highs begin to roll off.

 

Insertion loss is different from impedance loading, which is what's going on when you mix two pickups.

Insertion loss is when you send you signal to a passive tone stack (bass/treble controls), and there is usually a gain recovery state to make up for that loss.

If the output drops to almost nothing, with very little low end when two pickups are mixed, they are out-of-phase with each other. As others have said, just reverse the polarity of one of the pickups.

What I think Villex is doing is using transformer type circuits to achieve a resonant boost system. You can get small boosts from a passive system, and that's exactly what happens when you turn a passive treble cut tone control all the way off.

 

I agree. I also think he uses transformers to boost the level of lower impedance coils. I base that idea on the fact that he invented the Lace Transsensor and Alumitone pickups, and that's how they work.

 

Yep...the pickup is primarily and inductor (L)...and the tone control rolled completely off is essentially a capacitor (C)...when you combine an inductor and a capacitor in this way, you get an LC resonant circuit. If you knew the effective inductance of your pickup(s) and the value of your tone capacitor, you can pretty accurately calculate the frequency of your resonant peak. Fr = 1 / (2 pi L C)

 

Alumitones, and the Transsensors, both use a single loop coil. The Transsesnsors used a copper loop. This becomes a very low impedance coil, but with higher current.

Then they have built in stepup transformers to get the level and impedance to match high impedance amps.

If you want to look up the patents, they are 5767431 and 5831196. It's a really clever design.

People forget about the Transsensors because they look very "normal" compared to the Alumitones, but they sound very good.

 

So in other words, Lace Sensors are low-noise, low-impedance and low voltage coils but generate a high current so the transformer can then bring the voltage up to nominal value?

 

Not Lace Sensors, just the Lace Alumitone and Transsensor pickups.

The Lace Sensors are high impedance pickups.

 

My bad, misread it. Thanks for clearing it up, really interesting stuff.

 

So, thread necromancy.

I'm about to wire up my Ibanez SR605 with a pair of Nordstrand Dual Coils. I have two options for blending, an ungrounded MN500K blend pot, but I also have an EMG ABC active blend. It would be nice to keep the bass all passive and not requiring a battery (for the active control), but then again this insertion loss thing... I would like to maintain all my top end intact. If I use the ABC control I will also be able to use two individual passive tone controls between each pickup and the ABC blend's buffers. I was thinking of what to do with the available holes after removing the preamp and thought of that possibility, not sure how much fun dual tone will be in practice. What would you guys do, passive blend or active blend against insertion loss?

 

I would try both options and keep what I like.