Capacitor switching for series or parallel in guitar signal

[wolf]

I've recently become interested in wiring capacitors in series with the guitar signal and I drew this circuit:
capacitors in series

After working with this circuit for a while, I wondered if these capacitors could be wired in series OR parallel with the guitar signal and I drew this diagram:


Will this work?
Also, if I use a DPDT on/on/on switch will the middle position turn the tone control off? (I think it will).

[sumgai]

wolf,


The answer is yes, your circuit will work as intended. But, be aware that putting a capacitor in series with a signal engenders a high-pass response. Unfortunately, the values chosen in your diagram will have virtually the same effect on the signal - the bass roll-off frequency will be so low as to show no difference in the final tonal output. Possibly the 0.001µfd will show something different than the others, but I wouldn't bet on it...

HTH



sumgai

[wolf]

Thanks for looking at the circuit sumgai
I got the idea for those values at this guy's you tube video:

If nothing else it should give you an idea of how those capacitor values sound.

I reworked the circuit with the topmost capacitor replacing a wire.
When the circuit is set for series, the wire connection goes straight out to the jack, which makes a good "off" position for the bass cut and you get an unaltered signal.
However, when set for parallel mode, the wire would create a dead short and the guitar goes dead.

[JohnH]

I too reckon it will work.

I think, when a cap is directly connected, not controlled by a pot, then th smaller values are the most interesting. So if it was mine, I think Id start with the 0.001, then do every third of th standard sequence of values, eg 0.001, 0.0018, 0.0033, 0.0056, 0.01

Also, I would put your circuit before the volume pot. This will give a more consistent result in parallel mode and let it chew into the bass more in series mode.
(edit: I had left out a few 0's when I first posted)

[Yogi B]

And I'll second John's suggestions (albeit without the jumps in magnitude, i.e. 0.001, 0.0018, 0.0033, 0.0056, 0.01).

Additionally another possibility potentially worth consideration would be replacing the jumper between the top terminals of the switch and/or on the switch terminal that goes to ground with yet another capacitor. With a set up utilizing both, I'd bump up John's intervals from the fourth root of 10 up to the cube root of 10 such that switched values become 1n, 2n2, 4n7, 10n, 22n & 47n (which are near enough your original values anyway); but with the additional values of 33n for the high pass mode and 100n for the low pass mode.

[wolf]

Well, I figured I'd finally finish this posting.
Here is the final schematic:

and here is the web page.
www.1728.org/guitar14.htm
Oh yes, I decided to put another link to Guitar Nutz 2 in there..

[JohnH]

Jul 14, 2015 2:02:44 GMT -5 wolf said:

Well, I figured I'd finally finish this posting.
Here is the final schematic:

and here is the web page.
www.1728.org/guitar14.htm
Oh yes, I decided to put another link to Guitar Nutz 2 in there..

I thought id make a plot of how the frequency response would vary. This is using GuitarFreak, with a single coil pickup, a 250k volume pot and no normal tone control:



The thicker dark blue line is as if it was disconnected. I placed it before the volume pot since the bass cut is more effective there and the treble cut is more consistent. I think it looks like it would be quite a useful control.

[wolf]

JohnH
Well, I didn't expect a chart! Thanks!
So, I guess the capacitor values cover a good musical range.
Thanks again.