Alain Galvan ·6/9/2023 8:30 PM · Updated 1 year ago
Pedal circuit components make a big impact in the overall output of a guitar or electric instrument. How do components and their many circuit permutations create common sounds?
Tags: notesguitarcircuitelectricalengineering
Nailing the perfect guitar tone is an abstract goal that's hard to quantify, but one can at the very least attempt to do so by understanding how different circuit components affect the sound of your instrument.
The following have the biggest effect on your tone:
Clipping - how much the top and bottom end of the signal is squashed and what shape it takes on the waveform.
Equalization (EQ) - How loud or quiet a given part of the frequency spectrum is.
Mixing - Mixing different signals, be it fuzz, high gain with clean, etc.
EMGs use copper coils that connect to different parts of the preamp stage built into them to produce their sound, and use a smaller humbucker internally, about the size of a firebird pickup, with a solid magnet piece across. This results in a pickup that is less sensitive to interference and has a lower noise floor.
Fishmans use stacked PCBs instead of copper coils to design their pickups, which lets them control which parts of the pickup they can turn on/off to get a single coil/alinco sound with the different voice options.
Currently the state of the art in commercial pickups appears to be Fishmans, due to their dynamic nature allowing for controled voices.
Resistors typically function as low pass filters within a given circuit, which can be desirable at different stages of a circuit to say, cut the lows for a more punchy distortion.
Capacitors typically function as high pass filters, making certain frequencies louder, which can be useful when shaping the tone of your sound.
Transistors are the primary way to generate a classic fuzz sound, with very hard clipping on your input signal.
Big Muff Pi has 4 transistors.
Diodes limit the signal at various peaks, which serve to help soft-clip your signal.
The number of diodes heavily influences the sound, and how they're laid out.
Asymmetric clipping
Symmetric clipping
Amplification and voltage regulation - usually doesn't cause a strong difference in tone, but does affect volume and can offer some clipping with boosted signals:
Some of the most common are:
TL072 - Dual JFET-input op amp https://www.ti.com/product/TL072 - Tube Screamer
TL074 - Quad JFET Operational Amplifier - Amptweaker Fat Metal
TL082 Dual JFET Op Amp - Earthquaker Plumes
OP275 - Dual Bipolar/JFET Audio Amplifier - Mad Professor Honey Pedal
JRC4580D - NJM4580D by Nisshinbo Micro Devices - dual op-amp, DIP8 - King of Tone
There's also voltage regulators, often used to increase the voltage of a given circuit to affect the output tone.
LM108 - LDO Voltage regulator IC - RAT
TC1044SCPA - Switching Voltage Regulators
Kernom Ridge - the addition of controllable clipping, pre/post EQ, and mixing means this pedal can be a Klon, a Tube Screamer, and everything in between.
PCB design communities such as:
Wampler Pedals - How To Design An Overdrive Pedal Circuit
JHS Pedals How to Find the Fuzz Pedal You Need