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Best passive electronics upgrades?

#21
i think the idea is to take energy from the bass and treble and somehow throw it to the mids, creating a sound that's indeed louder, but narrower.

i recommend skipping all that weirdness and just using a couple good 500k linear volumes and a 500k audio tone. (the ultra Js are a bit fatter than regular jazz pickups, so opening up the circuit a little can sound good for them.)
 
#23
Hi guys, William Villex is here.
I understand your skepticism about boosting some frequencies without power supply.
Here Is the theory of this idea.
As you know (or you can ask electrical engineer) to get most from any energy source
the loading resistance must match internal resistance of energy source.
Since energy source - magnetic pickup has inductive nature it has mostly inductive reactance.
Inductive reactance is different within frequency range.
For example pickup with inductance = 5 Henry
and resistance 5 K.
will have @ 8000 hz ------------------- Inductive reactance = 251.3 K
Impedance = 256.7 K
same pickup @ 40 hz ------------------ inductive reactance = 1.25 K
Impedance = 5.15 K
Now, loading amp input is pretty much constant within given range of frequencies.
and is about 1000 K. As you can see now the higher frequencies are close to max
efficiency but lower frequencies are to much away from perfect and are under loaded.
And that's were the energy is missing. Villex circuit has inductive/capacitive nature is able
to recycle some of this energy.
As you can see there is strong theory behind this "perpetual mobile"
If anybody is not agree with my explanation I will be glad to continue discussion
I will be glad give the answer. That will be educational for all talkbass comunity.
Respectfully,
William Villex.
 
#24
Yes, that's pretty much how it works. The net power delivered by a passive circuit is always less than or equal to the amount input to it. However, since power = voltage * current, by adjusting the value and/or phase of the current waveform with clever use of L and C components, you can cause the voltage to be greater on the output than the input - i.e., have voltage gain.

There's no voodoo at all - we're depending on the amp or FX pedal that's next in the chain wanting a voltage signal as opposed to a current signal (like a telephone, for counter-example). There's a classic circuit they give to 1st year EE students to analyze called a bridged-T; it consists of totally passive components and has noticeable voltage gain over a wide frequency range. It just has a current *loss* at the same frequencies, which is OK if the following circuit expects a voltage signal out - i.e., is fairly high impedance.
 
#25
Allright! Real answers!

I admit, I don't entirely understand the explanation. But, is it a case where 'traditional' passive electronics are simply not letting the full potential through & the Villex circuit is simply matching the full frequency spectrum impedances? :confused:


As regards "perpetual mobile", are we talking the concept of "perpetual motion"? Perpetual Motion I am familiar with & is generally regarded at odds with current laws of thermodynamics and conservation of energy. Of course these physical 'laws' are subject to change, but is it likely to be upended the musical instrument industry?

Excuse my ignorance of the bulk of the theory behind this stuff,.. I'm a musician- not a physicist! :)
 
#28
Lincoln said:
Wow!
This is great stuff - not sure I understand all of it, but I know the Villex sounds good and functions well...and is priced well too!

Now as far as replacement pots go, what do people recommend? What's the difference between a 500k pot and a 250k pot?
Click to expand...

The Villex gadget looks like an interesting device, but my question would be what is wrong with $5 worth of pots the way it was originally? I mean it's only supposed to be a backup bass.

And the answer to your question is ... 250k Ohms! Ba dump...Pissssh! :hiding:

Seriously, as william Villex was explaining, in a passive circuit with a pickup you have the inductance of the wire, the resistance of the wire in the pickup plus that of the volume control and amp, and the capacitance of the wire and perhaps the tone circuit. All of these circuit elements form a filter that shapes the tone of your bass. A typical thing would be if you double the value of the volume control it will move the point to higher frequencies where the resonance of the pickup and the roll-off above that are located. The result which is widely known is that the instrument sounds brighter or perhaps harsher with the higher value. (although actual results may vary depending upon the actual values of the parts involved. )

The villex tone circuit is actually an expansion and variation upon these principles.
 

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