From these humble origins, the RAT has evolved from a single, hand built prototype into a family of the most versatile and most recorded distortion pedals in the world. Do you want to see how the RAT has evolved? Also, since there is no accurate way of dating a RAT pedal by its serial number alone, this timeline can help you determine the general age your pedal. All of the holes were hand drilled and were finished in a black crinkle coating with a bright florescent silk-screened logo.
Only twelve of these pedal were built, one prototype and eleven production models. To give the RAT a unique look, a custom 20 gauge wrap-around enclosure was designed. The white RAT logo was silk-screened on black, painted metal. The Tone control increased high frequencies when it was turned clockwise, the opposite of later models. The Rat ver. The Filter cuts high frequencies as it is turned clockwise. While the circuit remained the same, the enclosure evolved into a more compact version, with a gauge U-shaped base.
The Pro Co logo sat next to the RAT logo on the pedal top, silk-screened in black inside of a white box. Inthe logo was reversed to white on the black, painted metal.
The two units could be used separately or cascaded together for a more powerful distortion. Essentially the same circuit with different clipping diodes, the Turbo RAT provides a more aggressive tone. The Turbo RAT also introduced the now standard sloped face enclosure. The Vintage RAT can easily be identified from an original in two ways. Still built in the USA, the BRAT featured a tone similar to its more expensive brothers, but was built with a less indestructible enclosure.
The BRAT was adorned in a florescent purple and yellow color scheme.You Are right. I had some really great results. Goes really well with a VOX amp and humbuckers. I don't have any original Rat unit myself, so i have to rely on the internet So i'm not sure. Thanks for the layout! Give your opinion, If you had a handful of diodes 1n, as you implement these on the circuit?
Fixed the description accordingly. Note that i placed the diodes so that they can be taken on a switch : So swap the 2M2 for K and have your way with the clippers. Thanks a lot for any help! Place your diode choices across pins 1 and 4, and 3 and 6 for a DPDT switch and hey presto. Thanks for your help! One more step! There are also a lot of mods which can be implemented, of course, like the Ruetz mod for chaning the 47R resistor to a pot for smoother overdrive.
I guess you can verify it. Built it and all functions work. Seems to be cutting to much treble. I'll check my values.
Call it good. I think the doides on a switch would be well worth building in also. Got a nice little bit. Thanks guys.It is able to read the incoming audio signal and create effects on the four 8x8 LED matrices. The project is designed to be fitted in a metal enclosure Hammond BBS for better protection. There is a big library of codes available written in standard C that can inspire you.
You can also post your creations in the Arduino Audio Meter online forum. The Dallas Rangemaster Treble Booster is a booster guitar pedal that especially emphasizes the upper mid and treble frequencies coloring the signal.
The effect became popular because of its sweet coloration, slightly bending the signal and giving a soft compression when maxed out. The apparent simplicity of the circuit and the limited supply of this discontinued effect make it a perfect target for builder and guitar pedal enthusiasts. It uses two PT delay integrated circuits to archive up to ms delay.
Also, with the help of 4 analog switches, the internal configuration of the pedal can change: placing the PT delay chips in series or parallel and adding extra features:. The code for the Arduino chip is programmed in C and it is Open-Source, so users can re-program the functionality or add new effects and share them in the forum.
There are 9 effects included by default in the pedal: short delay, delay, echo, reverb, tap echo, chorus, telegraph, acceleratorand psycho. The schematic and bill of materials are public, the circuit was designed using easy-to-find and through-hole components. The Guv'nor was the first guitar pedal designed by Marshall, released in and in production during 4 years.
There are later Guv'nor MK2 models in a different enclosure, but most people prefer the sound of the original discontinued model. In this article, we are going to study the original design and see what are the bits that make this effect so desired. It enjoys the most enduring reputation probably due to Jimi Hendrix use and abuse of this pedal. But not all the Fuzz Faces sound the same, in the old days, players sorted through dozens of pedals at a time to find the best sounding fuzz of the store.
Why is that? Seems like pretty simple stuff, and in principle it is, but there is plenty of black magic and mystery associated with a good sounding Fuzz circuit, and it takes a lot of effort to get the things sounding just right.
The circuit layout in a pedal with a huge gain like this is critical and the component selection will leave its footprint on the sound. This integrated circuit has also demonstrated that with a careful design and good tuning, could be a fantastic sounding solution.
With a minimum delay of 30ms and a maximum of ms that could be extended up to 1 second at the expense of sound quality makes it perfect for delay, echo and reverb effects. The official Princeton Technology PT datasheet is vague and many of the internal functions of the IC are not explained either, giving the foundations for mods and think-out-of-the-box solutions. In this article, we are trying to give more insights and information about how this chip works.
The original stompbox did not have external power jack or indicator LED. It includes a 1.The original circuit and appearance suffered some changes over the different revisions but the tone remained the same. Although the pedal was originally built as custom-order product inPro Co began to mass produce it in Pro Co Rat Schematic. Power Supply Stage. Clipper Amplifier. Tone Control. Output Stage.
Pro Co Rat Frequency Response. The design is based on the LM single op-amp. The distortion is produced using a variable gain circuit with diodes clipping the waveform.
The distortion stage is followed by a tone filter and an output buffer stage that ends up with a tone control. Pro Co Rat Circuit Layout. It uses a single layer PCB with standard through-hole components which easily fits in the steel enclosure.
ProCo Rat2 vs. ProCo Turbo Rat
The Power Supply stage provides 9V for the active circuits op-amp and transistor. Generating 4. The Clipping Amplifier is the core of the circuit, it is made of a non-inverting op-amp amplifier with variable voltage gain and some filters to shape the distortion response.
Pro Co Rat Input Impedance. The voltage gain is trimmed with the distortion knob, in the non inverting topology can be calculated as:. However, the voltage gain of this stage will not reach such a values as 67dB. The gain will be limited by op-amp characteristics and also by the clipping diodes action, as it will be studied in the Diode Clipping Section. It is usual to find a combination of low pass and high pass filters before or within the clipping stage in distortion pedals.
The distortion makes the original guitar signal more harmonically complex, this means that more amounts of distortion are being added, it can be more difficult to give each sound its own space in the band mix. Artificially band-limiting a distorted signal, using both high and low-pass filters, can help it sit more comfortably in a mix, by preventing its spectrum from spreading over too wide an area.
In the image above, the response of the Clipping Amplifier is shown. The signal is band limited in high and low frequencies. Harmonics below 1. In high frequencies there is also a roll-off because of the low pass filter and the op-amp gain-bandwidth product, both effects more noticeable at high-gain blue lines. Low pass Filter.
The small pF capacitor C 4 across the feedback resistor works as a low pass filter, softening the corners of the guitar waveform and mellowing out the high end before the clipping.
The cut-off frequency of the filter is defined by the formula:.
When the distortion knob is not maxed out, the f c goes higher being less noticeable. High Pass Filter. They are an active high pass filter, placing two poles and attenuating frequencies below the cut-off frequencies:. The Slew Rate. It refers to how fast the op-amp can swing its output.I was going to make your old layout tonight Thanks man.
Incidentally, which is your favorite version? Was going to start with the original. I lean more towards the Original myself.
Good Proco Rat mods?
Hello Cody. I'm going to build the RAT2. Here's a dumb question: what to do about R12? Congrats for this great work and thanks! Thanks Sir, you are a great person to shared this. You might be over thinking things a little. All components are on the same side of the board non-copper side. Components on one side, solder on the other. The only exception is the pots if you decide to go with board mounted ones—they need to be mounted from the solder-side of the board.
Hope that helps. I was able to get the perf working. No typo. And you can put whatever you want there. Use sockets and try out some different diodes. I tried finding a data sheet on them and it kept pulling up 2n series transistors. I almost have this one done, no pots on yet and took readings but not sure how to interprete them fet is seeing source voltage.
Sounds like you're using a positive ground psu. You need a negative ground one. Hello again. Got this built up at the moment on the bench, whats the deal with R12? Do i jump it? Just don't populate it. I'm not entirely sure why I included itSo I first had the idea to clone it, meanwhile with the original components not those that are used nowadaysand with a negative centered DC socket, to make it compatible with my Boss power supply. However, by investigating a bit on internet, I figured out that some people proposed interesting modifications on the RAT, and I decided to try them on my protoboard.
The results were satisfactory for some of them to my ears. Thus, I decided to make my version of the RAT including those modifications and I want to share the results here. Actually, the RAT is still available, but some of the electronic components have been changed. On the other hand 1N diodes substitutes the 1N clipping diodes . In this article, we deal with two modifications on the RAT you can see a list of possible modifications in Ref. In the second one we have short-circuited one resistance connected to the operational amplifier, leading to a thicker bass response.
The goal here is not to give a detailed explanation of the overall electronic circuit. For those who are interested, Ref. Here we just want to address the points that are needed to understand the modifications mentioned above.
To our knowledge those points are not addressed in detail elsewhere. Finally, at the end of this writing I provide the perfboard drawing I designed to fabricate my own model. Following ref.
In music the different forms of linear distortion have specific names describing them. In the context of music, the most common source of nonlinear distortion is clipping in amplifier circuits and is most commonly known as overdrive. The following graph illustrates this statement showing a Hz wave in black, clipped by some circuitry in red. Figure 3: Sine wave black and clipped sine wave red. The clipping of a signal can be produced easily with one diode conected forward between the signal and the ground.
See figure 4 for an illustration. If the voltage of the signal exceeds 0. As a consequence, when the signal is less than 0. With one diode we will have an asymmetrical clipping, whereas with two identical diodes mounted in inverse parallel, we will have a symmetrical clipped output as shown by the red curve in graph 3.
In the figure 5 we show the schematic of the pedal where both modifications treated in this article have been circled in red. We first deal with the clipping diodes substitution.How To Get CRAZY Distortion With The ProCo Rat 2
As said before, when the signal is larger than the threshold voltage of the diode typically 0. This leads to an enhancements of the produced harmonics and to a distortion of the sound. If we choose a diode with a different threshold voltage, the amount of distorted signal will vary.
This means that we should expect a less distorted signal. Maybe more like an overdrive. An other thing to expect is that the intensity of the signal should be larger than with a Si diode.Log in or Sign up. The Gear Page. ProCo Rat2 vs. Nov 28, 1. Messages: Would anybody be able to really give me a crash course on the differences between the two? I need a pedal that duals as an overdrive and a fuzzy distortion pedal. Any advice or recommendations would be appreciated. I play a Jazzmaster single coils into a Fender Hotrod Deluxe.
Fuzzgun91Nov 28, Nov 28, 2.
Pro Co RAT
Messages: 6, Older Rats and turbo rats have the LMn chip that supposedly sounds better than the OP07 that they now come stock with. Personally, I feel the difference is small, and the sum of the parts and their tolerances have as big of an effect or bigger. Nov 28, 3. I had both with the LM chip. I kept my RAT2. The problem that I had with the Turbo RAT is that it has so much output, that's it's hard to dial it in to it's really sweet spot Which is around in the volume.
At that volume level, It just sings. My RAT2 is more compressed and has less output than the Turbo, and found that to be more managable. I thought that they had the same amount of gain actually. The Turbo RAT is just less compressed. Hope that helps. ZeroChanNov 28, Nov 28, 4. Cool, thanks. Will the Turbo still be able to give me some darker settings and some overdrive settings? Nov 28, 5. Nov 28, 6. Nov 28, 7. Nov 28, 8. Nov 28, 9.
IndieHeadNov 28, Nov 28, I have compared the usa rat 2 with china rat 2, and i loved my china one better. The usa one was either too muddy or too bright. Gain was quite unstable as well, too sensitive, while the chinese rat 2 was more "stable".