Edit: Sorry! Please bear with me, this is my first post! Well, it seems that placing a buffer before certain fuzzes can chance their sound. However, placing an inductor after the buffer cancels this effect ("unbuffers"): http://www.muzique.com/lab/pickups.htm Sure, ditching the buffer would too but sometimes you can't or don't want to: http://www.muzique.com/lab/imp.htm . I wonder if a simulated inductor has the same effect, this could be useful for resonance adjustment and guitar synths. OLD: I would like to use a floating active inductor to "unbuffer" a guitar signal before a fuzz, made from off-the-shelf parts. After an exhaustive web search, the models I found either requires custom parts or is too technical. Eventually I heard of a "3-OTA conventional simulated inductor", but I could't access the schematic. So, does anyone know any circuits for this purpose? Low noise and ajustability would be nice.

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    \$\begingroup\$ It's really unclear what it is that you are trying to do or why you should want to do it. \$\endgroup\$ – Andy aka Jan 24 '19 at 12:57
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    \$\begingroup\$ From a non-musician, purely electronic engineering point of view, it is hard to understand what you want to achieve. What do you mean by "unbuffer"? Why do you think a "floating active inductor" is the solution? From my point of view, a buffer is something that lowers the output impedance (make the signal stronger). So unbuffering it would just imply putting a resistor in series between the buffer output and the fuzz input. But then, why put a buffer in the first place? \$\endgroup\$ – dim lost faith in SE Jan 24 '19 at 12:58
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    \$\begingroup\$ The words you are using to describe guitar signal processing are mostly meaningless to us electronic engineers. Perhaps you could draw a visual representation of the signals? \$\endgroup\$ – MIL-SPEC Jan 24 '19 at 14:39
  • \$\begingroup\$ Also, why does it need to be a simulated inductor rather than a physical one? \$\endgroup\$ – Hearth Jan 24 '19 at 14:39

I'll take a stab at this. Most fuzzes rely on BJT's of some sort, which are current driven devices -- for "musical" reasons, guitarists tend to like the sound of fuzzes when driven by high impedance sources (such as guitar pickups); that is, not capable of providing much current. Driving them with a low impedance source provides far more current, changing the behavior of the BJT amplifiers, subjectively to the detriment of the sound. I imagine you're hoping to place your fuzz after a buffered effect, such as a tuner or a not "true bypass" effect, rather than at the front of your signal chain. That, or you have active (buffered) pickups.

In your linked page, the point of the RLC circuit is not to "unbuffer" the circuit per se, but rather to provide an impedance and frequency response that roughly approximates a generic guitar pickup when driven by a low impedance, high(er) bandwidth source. This can be useful when you have a nice bench signal generator, but that's not the case here.

You are interested in "debuffering", or raising the output impedance of the preceding stage. This does not in any way require an inductor or capacitor, "simulated" or otherwise. Just putting a resistance in series with the input should increase the impedance "seen" by the BJT. This could take the form of a single resistor enable by a switch, a bank of resistors with a rotary switch, or a variable resistor in the form of a potentiometer.


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