Popcorn

Smooth, buttery crunch

The Popcorn overdrive rack effect module compares to the Pete Cornish CC-1 Crunch Drive. It delivers clean to gritty to crunchy tones, with nice options for adjusting the bass, mids, and treble the way you want them. The concept is similar to a Klon Centaur, and may be at its best when used to drive a tube amp.

Description

There's not much debate about whether Pete Cornish builds good pedals. There's also not much debate about whether the high prices for his pedals prevents most players from trying them. The result is great pedals that most players will probably pass up based on cost alone. So if you haven't tried a Pete Cornish CC-1 Crunch Drive, you aren't alone. The GT Popcorn compares to the Cornish CC-1.

So what is the Popcorn? In concept, it is a bit like a Klon. It goes from clean to gritty to crunchy and may be at its best pushing something else, like a tube amp, with nice options for EQing your tone.

The dirt comes from a pair of symmetric soft clipping gain stages. As you may know, at low guitar volumes, soft clipping may not kick in at all, or only at low levels, giving you a clean to light grit. As you turn up your guitar volume, you start getting more clipping and can go from gritty to crunchy. Of course, this can be intensified by whatever comes after it in your chain, like that nice tube head you like to drive!

Soft clipping cleans up and responds well to your guitar volume control. But since there is enough headroom before the op amp starts clipping and distorting, your dynamics are kept intact, leaving you with a nice responsive feel.

The Gain control comes before the clipping, so you can use it to set the range of clean/grit/crunch you want, relative to your guitar volume control. Of course, lots of circuits have soft clipping, so that in itself isn't unique. But in the circuit, the soft clipping is a main feature you can use to give your hands and guitar volume knob some freedom to do their thing. Another clipping option is to go asymmetric, which some feel gives a bit more tubey result.

The standard config is designed around silicon clipping diodes. There are options to try LEDs, which clip at a higher voltage, or germanium diodes which clip at a range of lower voltages that top out at about the same level as silicon. Lower clipping voltages yield more dirt and less clean tones. Higher clipping voltages lead to less dirt and cleaner tones at higher gain. However, this circuit is thoughtfully designed, and we don't recommend any changes unless you are familiar with it and have a very specific goal to achieve.

The Popcorn has a Bass, Mids, Treble tone stack that gives you a nice way to tweak your tone before it heads on down your chain. The Volume control is a master volume, right at the output of the circuit. Adjust it for always on unity volume or crank it up a bit for solos or giving a nice push to the rest of your chain. It's great for that more of what you have clean tone, or a bit of dirt for country and blues, and also for getting your money's worth out of your tube amp. Or even just a nice way to EQ your tone.

Of course, this circuit has the standard Cornish buffer at the front.

But, wait, there's more! The CC-1 covers that lower gain range with a nice 3-band tone stack. The Cornish GC-1 uses the same circuit with some different component values to cover a higher gain range, also with a 3-band tone stack. The tweaks in the component values are substantial. Not only is the gain range different, so also is the clipping and tone stack. Most people probably wouldn't guess that technically they are almost the same circuit. Our Caramel Corn configuration compares to the GC-1 and offers up that great higher gain range. The gain range overlaps the Popcorn at the lower end and pushes towards some of the Cornish fuzzes at the high end of the gain range. But the tone is a bit different, in each circuit, even if the gains are set to be about the same.

The Caramel Corn cleans up with the guitar volume, oddly without much volume reduction - just gain reduction. While you can feel the gain when it is turned up, the pick attack doesn't change the tone much - just the volume of the note. The gain level stays about the same. The 3 tone controls and gain control all change the volume quite a bit, so adjustments to one will probably require a Volume adjustment, too. There is a great range of tone control, though. If you get Volume, Gain, and the tone controls turned up, you'll have plenty of feedback available. Turn them up a bit higher, and you'll probably get some squealing.

Although not 100% accurate, it's easy to think of the Popcorn being at it's best in the gritty to medium overdrive range, while the Caramel Corn is better in the medium to higher gain overdrive range. There is overlap between the two, but you probably wouldn't want either one to try to cover all the way from cleanish to high gain overdrive. That high gain overdrive sounds like what you get if you stack a fuzz in front of an overdrive. It's a bit like the core drive tone for Billy Gibbons or maybe David Gilmour. Not quite distortion, not quite fuzz, but a very driven overdrive with good note clarity.

Configurations

Popcorn - compares to Pete Cornish CC-1 Crunch Drive
Caramel Corn - compares to Pete Cornish GC-1

Options

Clipping Diodes Switch - This option can be setup in many different ways, but in general it will give you a front panel toggle switch to allow you to switch between different diodes on both clipping stages.
Custom Components - There are a few options that may be useful. You could change the clipping diodes (no switch), change the op amps (nice TL072 are standard), or perhaps try carbon comp resistors for a slightly more good noise, vintage sound.
Power - could run at 12V or 15V if you want more clean headroom and less crunch

Front Panel

On/Off indicator LED
Volume
Gain
Bass
Mids
Treble
(optional) Clipping Switch

Rear Panel

Audio In
Audio Out
On/Off Footswitch
On/Off Override
DC Power
DC Power LED

Module Width

Power Consumption (aprox)

15-20 mA

Base Configurations

Part #	Description	List Price
MOD-POPCORN	GT Popcorn module	$230
MOD-CARAMELCORN	GT Caramel Corn module	$230

Options

Part #	Description	List Price
MOPT-POPCORN-SWCLIP	Clipping Diodes Switch	$19 - TBD
MOPT-POPCORN-POWER	12V or 15V Power instead of 9V	$0
MOPT-POPCORN-CC	Component Changes	TBD