Josh Scott of JHS Talks Gain Styles and Pedal Circuitry

Now officially the first-ever returning guest to TPS, Josh Scott of JHS Pedals is dangerously close to becoming a regular on the show. While his last visit to Dan & Mick’s den of tone was to tour through and talk over JHS’s latest innovations out of Kansas City, this time it was to give a bit of a history lesson. Gain, fuzz, overdrive, where did they all start and what are their differences under the hood?

This episode is a must watch for pedal-heads with a mind for the ongoing history of guitar gear as well as interest in what makes pedals tick. Here’s three main insights into how different styles of overdrive achieve their signature sounds by using different core components.

Crunchy Transistors and Sagging Power Supplies

My knowledge of pedal circuitry is just enough to be dangerous: I know that when I stomp on the footswitch, stuff happens, and the resulting sound makes me happy. It was great, however, to hear Josh walk through some key components and explain how they react and respond when put in a circuit.

Take transistors, for example. A common term, but what are they? As Josh explained, these are effectively what amplifies your incoming guitar sound. Without them, pedals aren’t possible. As Josh remarked, “I like pedals that, when you roll the volume back, it cleans up and that’s the evidence that more volume causes more distortion in the transistor…when you back it off you’re actually lowering the amount of current [going into the pedal].”

But where does power factor in to the creation of tone and gain? As Josh described, “More input from your guitar will distort [the sound] but more voltage from the power supply or the battery will clean it up.” This is where that old school phenomenon of dying batteries comes in. “Dying batteries are lowing the voltage to the transistors and giving them less headroom as though it was a lower wattage amp.” So, simple math would say, if a fully juiced 9-volt battery is powering the pedal, it’s getting all the power it can handle for high headroom. Drop that down to 5-volts as the power is slowly drained and you get less headroom. The result is that saggy, brownish style of distortion.

Germanium vs. Silicone Transistors

Now that we know a bit more about the bits beneath the footswitch, a whole other area of circuit creativity relates to the material quality of components. Generally, you’ll see either germanium or silicone used for the transistors. Arguably, this comes into play most when exploring the design and sounds of fuzz pedals.

As Josh noted, germanium components are “our very first type of amplifier devices…yet they’re also very unstable.” For example, even the temperature of a germanium component can change the gain structure. So if you’re headlining an outdoor gig on New Years Eve in the Riff City parking lot, chances are your vintage Fuzz Face will sound different from your Spring Break gig in Orlando. While this can be a challenge in some settings, it’s also an asset. As Dan reflected on his experience with playing a line of Analog Man fuzz pedals, “every one of them has its own character.” Yet for those interested in consistency, technology advanced to find something more stable and reliable. Enter silicone.

So which is better? Is it worth losing friends through fights over circuit components? Probably not. As Josh underscored, “It doesn’t matter what the part is, it’s all about whether the part is being used in the way it was meant to be used. Design is more important than the part.” Call your buddy, apologize and make up.

Op Amps and the Question of Categories

“The next point along the evolution,” continued Josh, “is that people wanted even more consistency than silicone for a more controlled environment for circuit design.” The op amp comes along and you’ll know one when you see it: they look like a little eight-legged spider with a chip for a body. These are also technically and I.C. (that is, an integrated circuit) because if you pop one the spider, its guts are a whole other circuit. As Josh summed up, these have the ability to amplify in a very clean way while elevating headroom without distorting the sound. “But then, if you place diodes, or clamps, at the output of the op amp, then you create drive and distortion that way.”

This then, raises the question of if these components map onto specific type of gain: distortion, overdrive, and fuzz. As Josh noted, the ProCo Rat is a great example of this conundrum. It has an op amp at heart “but it does all three.” In this case, there is no definitive statement, it all depends on context. “It’s difficult because everyone either remembers or plays it a certain way,” commented Josh, which results in the variety of descriptions and debates for various pedals.

So how do you decide on the best style of gain for you? Do yourself a favor and stop lurking among the dredge of opinions on forums and do as Dan suggested, “You’ve got to experience these things. Sit down with your guitar and an amplifier that you know, plug them in, and see if you like them or not.”

TPS Rig Rundown:

Guitars: Fender Custom Shop 1952 Telecaster Relic, Fender Custom Shop 1963 Telecaster, Macmull S-Classic.

Pedals: D’Addario Pedal Tuner, Colorsound Power Boost, Dunlop Volume (X) Mini Pedal, Dunlop Eric Johnson Fuzz Face Distortion, JHS Super Bolt, Analog Man/Maxon OD9/808 Standard Mod + Bad Bob, Analog Man Bad Bob Boost, ProCo Rat, Marshall Blues Breaker, Klon Centaur.

Amps: Fender Super Reverb 4×10 combo, Matchless King Cobra 1×12 combo.

Leave a Reply

Your email address will not be published. Required fields are marked *