Z-Coil Dual Capacitors

Technical Talk and Tips
barry
Posts: 5
Joined: Sat Jul 15, 2023 9:58 am

Z-Coil Dual Capacitors

Post by barry »

Hi all. Another quick question coming up.

The Commanche has 0.22 capacitors for the tone but, when i use my varitone pedal at the e.g 0.47 position what would be the end value output to the amp? Would it be the sum total of both caps being used together or would the pedal determine the cap value output.

Regards
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DanDoulogos
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Joined: Tue Dec 20, 2016 9:08 am
Location: Canada

Re: Z-Coil Dual Capacitors

Post by DanDoulogos »

An onboard varitone circuit (on the comanche treble pot) would replace the 0.022uF cap with a rotary switch, allowing the player to change the default tone cap value so that instead of shunting the higher frequencies to ground via the 0.022uF Cap, it can shunt more or less of those frequencies to ground by using different cap values in the rotary switch.

A pedal cannot swap out the cap value on the treble tone, all it can work with is the whole signal, which will include the bass tone and volume (which is essentially another treble tone, that can pinch out all the signal).

In other words, all the pedal can do is scoop the entire signal coming from the guitar. It is just adding an additional set of selectable low-pass filters to the signal. It won't really be affected by the bass pot since that is cutting the signal from the other end (removing low frequencies rather than high), but your output will still include a signal already modified by two low pass filters (treble pot and volume pot).

The signal that is coming out of the guitar has already been "filtered" - that is, it has already bled off some of the high frequencies via the treble and volume pots. Those frequencies were removed by the tone caps in the guitar. The signal has already passed through those capacitors removing some of the higher frequencies.

The pedal only modifies the signal that leaves the guitar, it doesn't add to the cap values of the treble and volume circuit - as the signal has already been modified by those caps. if any capacitance were left in the signal (and there shouldn't be), it would be a very negligible stray capacitance.

A pedal would just let you scoop the signal through several discrete low-pass filters. The length of your cable will add around 40 pF per foot, but other than that, no (viable) capacitance is coming out of your Comanche. You can put a meter on your output jack to verify that there is no capacitance coming from the guitar when you strum it.

I hope that helps.
Last edited by DanDoulogos on Wed Sep 13, 2023 4:52 am, edited 2 times in total.
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barry
Posts: 5
Joined: Sat Jul 15, 2023 9:58 am

Re: Z-Coil Dual Capacitors

Post by barry »

Thanka