In 1978, the most versatile and influential distortion pedal of all time was invented in Kalamazoo, MI: the Proco RAT. Scott Burnham and Steve Kiraly first came up with the idea after playing, repairing and modifying every distortion pedal on the market. They wanted something that didn't exist in mainstream product lines like MXR, DOD and BOSS. They wanted a pedal that could go from overdrive to distortion to fuzz. By 1979, Scott had perfected the circuit in his RAT-infested basement workshop, and the rest is history.
The PackRat is the ultimate tribute to over 40 years of rodent evolution and its impact on guitar sound. Artists from all genres have used the iconic tones of this unassuming black box to create their sounds, including Nirvana, John Scofield, Pink Floyd, Metallica, REM, the Eagles, Jeff Beck and Radiohead.
Building on our multi-mode pedal series that includes the Muffuletta and Bonsai, the PackRat uses the same unique digital track system to direct the paths of 261 components via 40 individual switches. This means that when you choose one of nine Legendary or Rare modes, you'll play fully analog circuitry that perfectly reproduces that mode, even down to aging components (also known as component drift). If you bought these nine hard-to-find pedals on the used market right now, you'd pay around $4,000. When you put it that way, $249 seems pretty reasonable.
Let's take a look at the controls.
Operating the PackRat is about as simple as it gets. The “Volume” control adjusts the overall volume of the pedal. The "Distortion" control allows you to increase and reduce the amount of gain or distortion produced by the circuit, and the "Filter" control allows you to brighten and darken the sound of the overall effect. This is actually a simple low pass filter. Finally, we have the “Mode” control. This is a stepped pot that engages as you cycle through the nine legendary versions of this circuit. When you change modes, the analog circuits are rewired, resulting in completely new values of resistors, capacitors, diodes, and op-amps.
DISCLAIMER:
Although I have devoted several years of research into the history, circuit topology, and version history of the RAT, I know that my findings may still ruffle some feathers. I agree with that.
I tracked down over 100 different RAT specimens for study, and conducted nearly twenty hours of interviews with former ProCo employees about the design, evolution, and production circuits of this series of pedals at over the decades. And basically? Many of the widely accepted "facts" about the differences between RAT versions, including some of my own beliefs, were wrong. Most assumptions about how specific RAT models appear different or better than others are misinformed at best. Generally speaking, they are flat out incorrect.
To find the facts and give this circuit the proper understanding it deserves, every RAT model ever made (and many of the prototypes that never saw the light of day) was obtained and studied in detail. I wanted to understand the exact production differences over the years, so we took the units apart, analyzed them using state-of-the-art Audio Precision equipment, measured the individual components, built comparison charts, traced each circuit and closely examined the branding, logos and other identifiers of change. As far as I know, no one has ever come close to the level of research we did between 2018 and 2021.
Reliable sites like Reverb.com had inaccurate timelines with incorrect images of the respective models. Even the ProCo history timeline lacked tons of detail on the RAT variations that have been made over the past 40 years. And Wikipedia?… No. Just no.
There is a reason for this.
A vintage unit is usually dated by reading the manufacturer's codes on the back of the pedal's potentiometers/knobs. Unfortunately, this is an imperfect dating method. ProCo reportedly ordered thousands of potentiometers, and in doing so many pedals were made with parts pulled from backstock at least two to three years older than the actual pedal dated. In short, this means you will see V1, V2, V3 with dates that overlap with each other's true production years. Combine that with decades of people incorrectly “remembering” which RAT model sounds best, and you have a historically inaccurate mess on your hands.
To properly construct an accurate timeline and database of changes, I dated the pot codes, dated their components where possible, interviewed the respective people involved in the eras of production, and referenced over 1,000 photographs of online sales, and studied prototypes and evolving engineers' design ideas. I have done everything possible to build an airtight case for my work and not rely on previous dates and deadlines. The results may not be perfect, but they're damn close. See my full biographical timeline with photographs and specific details of my work here.
PackRat modes:
1. The OG V1 (1979-83)
OG mode is a perfect recreation of the first production RATs ever created. This roughly four-year era covers what are historically known as the V1 models.
The early V1s are also known as the Fringe Logo model and can be identified by the letters RAT in capital letters with a slight fringe graphic from the typeface. The V1 also has small silver-capped knobs and a tone knob instead of the more familiar and later produced V2 filter control labeling. Circuitry-wise, the Big Box V1 and V2 models are virtually identical, except that the V1's tone control increases the treble as you turn clockwise while the V2's filter control decreases. the treble in that direction.
When you switch to OG mode, you activate the exact circuitry of my Model 1979 V1 Fringe Logo, including the precise rotation and taper of the tone control.
Let me take a moment to clarify: the V1 and V2 models are the exact same circuit, and simple adjustments to the Tone/Filter control can achieve identical sounds from each unit.
I know the super nerds will ask why we didn't include a Bud Box mode. Basically, I would consider the Bud Box RAT a V1, as it is almost identical aside from having an input buffer as well as a few extra parts.
2. White Face V3 (1984-1986)
In 1984, the RAT moved to a smaller square case with a new white rectangle logo. The word RAT was in all black capital letters inside the white rectangle; this model earned the nickname "White Face" RAT because of this aesthetic. In 1986, this same model underwent a logo change that simply reversed the white and black colors, resulting in the more familiar white rectangle outline and font on the black case.
This "White Face" model gained a reputation as one of the Holy Grail RATs, and it even spawned a reissue in the 90s. The irony is that it is the exact same circuit as the previous Big Box V2 and the subsequent "Black Face" from 1986, as well as the RAT2 from 1989. The "White Face" V3 update was a purely cosmetic change due to screen printing errors that needed to be resolved. ProCo knew that the world wanted smaller pedals in the wake of brands like BOSS, DOD and Ibanez gaining more and more market share, and they wisely took advantage of the trend.
That said, why should I put this particular version in my PackRat if it's no different from the OG? On the one hand, nostalgia is a powerful thing, and on the other hand, this mode will switch to the reverse orientation V2-V3 filter control with a totally different feel and experience. In many ways, this expands what many consider to be the sweet spot for the most beloved RAT tones.
Like you, I want to believe in the magical designs of my favorite pedals, but sometimes the magic is just because we like the look or user experience of one version over the other. It's okay to admit it and move on.
3. Turbo V5 (1989)
The heart of the RAT's sound comes from a design technique called symmetrical hard clipping. In this approach, a simple amplifier circuit amplifies the guitar signal and pushes it through a pair of clipping diodes. The result is that these diodes cut off the top of the guitar's waveform and create a type of square wave distortion. Until 1989, each RAT used a typical silicon diode, as did the DOD 250 and BOSS DS-1, but the new Turbo RAT used LEDs (light emitting diodes). Yes, these are the same LEDs you see in flashlights, your car dashboard, DVD players, and almost every other electronic device on earth. This technique was a first in pedals (the same style of clipping was used in the Marshall Guv'nor) and offered a whole new RAT experience.
Silicon diodes in previous versions have a lower forward voltage, resulting in faster and more extreme clipping of the waveform. You could say that this type of diode creates a very saturated sound. The Turbo's LEDs have a much higher forward voltage, so they don't turn on or clip the signal as quickly or as loudly. It takes more signal to reach the point where they "cut off" the waveform, causing the phenomenon we know as touch sensitivity. You can set the distortion lower, and as you play lightly you will have an overdrive tone; dig into your guitar and play loud, and hear more clipping/distortion.
It's also worth noting that this model was the first RAT to feature the angled enclosure we see today. It also featured the new on/off status LED that had debuted a year earlier in the 1988 RAT2.
4. BRAT V6 (1997)
In 1997, ProCo got into the budget pedal game by releasing the BRAT and the Guitar Center exclusive, Roadkill. These two identical circuits with a different and very 90's grunge aesthetic have the most changes to date in the evolution of this legendary circuit.
This design added an input buffer circuit and soft clipping (inside the op amp loop) in addition to the standard hard clipping of previous RATs. We also see a return to cone/opposed rotation filter control and several capacitor value changes that alter the frequency response and distortion characteristics.
5. Dirty V7 (2004)
In 2002, ProCo released a 2-in-1 RAT pedal called Deucetone. This pedal allowed you to have two completely separate RATs and activate them independently or stack them together. It also introduced two new sounds to the RAT topology: “Clean RAT” and “Dirty RAT” mode. Due to the popularity of "Dirty RAT" mode, they released a single pedal called You Dirty RAT which featured this unique tuning in a standard angled RAT enclosure. This circuit uses germanium diodes in the symmetrical hard clipping section of the circuit. This technique gives the most saturation and waveform clipping of any version ever made.
In addition to the diode changes, this model has several different capacitor value changes, resulting in a different distortion character and feel.
6. LA (1986)
In 1986, Ibanez released the 10 Series pedal line which included three RAT style pedals. The Super Product and Fat Cat occupied the position of precise, traditional RAT style pedals, while the more eccentric LA Metal was, in my opinion, one of the best modified RAT circuits of the 80s.
It features an excellent input buffer, several key capacitor changes for frequency response, and no clipping diodes at all. Distortion is produced by overloading or "crushing the rails" of the op amp.
I don't play LA Metal, and I'm guessing you don't either, but I promise you'll love this mode!
7. Landgraff MO’D (1999)
Between 1999 and 2000, a man named John Landgraff began making pedals by hand in Pensacola, Florida. Each painted with a unique, wired point-to-point swirling paint job; John's pedals were and still are the true definition of the boutique and have earned a reputation for sounding incredible. His most popular pedal was the Landgraff Dynamic Overdrive, a version of the Ibanez Tube Screamer, but my favorite was his distortion pedal which he called the "MO'D", a distant cousin of the RAT and a truly fantastic pedal in its own right.
8. Caroline (2010)
A few years after starting JHS, I purchased a fascinating distortion pedal from a brand new company in South Carolina. I remember hopping on the phone and chatting with designer and company head Philippe Herndon. We talked about the track, his love for RATs and his intelligent view of the track. This pedal was called the Wave Cannon and when I started the PackRat project it was obvious that Philippe was the friend I needed to take along for the ride.
9. JHS Fashion
In 2003, I ran a small guitar store in northwest Alabama. One day a man came in with a small vintage RAT box and said he wanted to sell it. When the store owner said he wasn't interested, I said I was. I bought this RAT for $15, and it was probably the only event that led me to get off the pickup pedal