Vintage/Modern switch for a Q-Tuner equipped bass?

[kalipigeon]

Hi guys, I have an idea that I was wondering if any of you could make suggestions on. I've got some Q-Tuners that will be here sometime this week and I'll be installing them in my Peavey Grind NTB-4. I plan to upgrade the pots with the pickups by going to a Master volume, blend, Varitone, and master tone knobs.

What I'd like to do is make the master tone pot a push/pull switch with a capacitor that would take the extra high end the Q-Tuner pickups are famous for and shunt it to ground. The idea would be to have a single switch, independent of the tone control that would allow a quick change from that modern "wide range" sound to a more vintage growl. I'm just not sure which capacitor value would be a good range to start in.

Does anyone know of any formulas for calculation of cutoff frequencies for cap values in a tone circuit? I think that something around a 8-9kHz cutoff would probably do the trick without sacrificing too many overtones to sound vintage. Then the tone knob could handle anything else. Any help you guys might have would be greatly appreciated.

[4StringTheorist]

The corner frequency will depend on the resistance in the circuit. The resistance in the circuit will depend on your volume and blend knob settings, but you can use the formula at that link, and the resistance values of the Q-Tuners to give you a ballpark for what you want.

From there, get a pack of caps at different values and experiment.

[alexlotta]

But take care about "High-end".
I think That Taming Highs wont do what you expect.
They don't sound as Vintage+"more high end" part,IMO.
I think You will have to experiment with an external Eq Once plugged (also a plugin for pc ,just look at a transparent One),
and to add some Notch (or emphasis) to different parts of the spectrum to get results.


in The End ,i believe You wont get vintage-oriented tone with q-tuners without using Active Eq(because You will need to touch not only the high end ,which is passive style territory),you could add a preamp a la Sadowsy for example if Passive style will not "get You there"(But I'm just guessing ,i did'nt try With mines).

Anyway I'm curious to know if With the varitone you can get Interesting tones from them ,
A fretless + q-tuners+ varitone for example is a thing I would like to try first or late.

[SGD Lutherie]

If you just want to take the high end off, and leave the mids, you can try a small value cap like 0.01 or 0.02mF. A lot depends on the impedance of the pickups. The higher impedance they are, the more effect the cap will have. If that's taking off too much, either go to a smaller cap value (like 0.005mF) or put a resistor in series with the cap. You could even use a small trim pot wired up like a regular tone control, so you can set if where you want.

Also using a resistor shunted to ground would simulate lower value volume and tone pots. So if you are using say 500K controls, the vintage switch could switch in a 150K resistor connected from the hot to ground. You can also use that in concert with the cap. A larger value resistor will have less effect.

I use a 0.02mF cap on the tone control on my passive bass. it rolls off just the top end.