Do-it-yourself overdrive - simple circuits. Tag Archives: overdrive circuit

Assembling a clone of a guitar gadget
Boss SD-1 Super Overdrive.

The article discusses the BOSS SD-1 Super Overdrive, widely known among guitarists. Physical principle Overdrive is the same as Distortion, that is, the signal is distorted by limiting its amplitude. The difference is that with Overdrive the sine wave is cut not in a step, but smoothly; for clarity, see the picture below:

In general, Overdrive introduces soft clipping, as shown in the picture yellow, therefore, the amount of distortion directly depends on how much you “clunk” the strings, and Distortion will distort the signal regardless of its level.

Power is supplied from a 9 Volt Krona battery, or from an AC adapter. The circuit has low current consumption, approximately 6 mA. As you can see in the first picture, the circuit has three controls: level, tone and drive (distortion amount). The effect is turned on/off using a pedal, but when repeating the circuit, you can simply display a DPDT button. The LED lights up when the effect is turned on. And so, the circuit diagram of the SD-1 Super Overdrive. The initial diagram looks like this:

Everything seems to be fine, but some elements are hard to read, so the diagram had to be redrawn in the Splan7 program, this is what happened:

The circuit is assembled on a double operational amplifier 4558D in DIP-8 package, appearance and the location of the pins, see the following image:

Field effect transistor 2SK30-A, reference below:

Transistor NPN structure C1685:

If you do not have the 2SC1685 transistor, you can try replacing it with 2SC1684, 2SC945, BC238 or extreme case KT3102D.

The Super Overdrive effect circuit board is designed in Sprint Layout program, the LAY view is shown below:

Photo view of the Super Overdrive SD-1 printed circuit board:

What can be improved.

● Replace electrolytic C10 1uF with metal film;
● Replace electrolytic C7 1uF with metal film;
● Replace R6 4.7 kOhm with 2.4 kOhm metal film to increase distortion;
● Replace capacitor C3 0.047 µF with a 0.1 µF metal film - increase bass;
● Replace capacitor C2 0.018 μF with a 0.1 μF metal film;
● Replace resistor R2 470 kOhm with a 620 kOhm metal film - the input resistance will increase slightly;
● To smooth out distortions, you can install an additional capacitor with a capacity of 47...51 pF in parallel with diode D4, similar to what is done in the Tube Screamer TS-9 pedal.

On one of the foreign sites it was proposed to use the junction of some kind of germanium transistor instead of the D6 diode. If this transistor is a PNP structure, then the emitter will be the anode and the base will be the cathode. According to them, the result is not bad in terms of distortion introduced by the pedal.

Photo of the pedal guts:

We hope that this information will be enough for you to make a copy of the BOSS SD-1 Super Overdrive with your own hands, but you can download all the material, including the circuit diagram, board in LAY6 format and datasheets for the elements, in one file using a direct link from our website . Archive size – 1.7 Mb. Happy designing.

Suhr Riot is a full-fledged distortion pedal, suitable for working in all styles (in my opinion). It is responsive to dynamics, far from the cheapest (one of the good reasons to do it yourself), although of course it is not a harsh boutique. The most important discovery for me was the sound in Various types amplifiers.

It sounds in everything (!) (well, or almost everything, 99.9%), in all amplifiers! Either in tube stacks or in tube combos different power, even a transistor with 10 watts, even a transistor with more power. In all cases, we get a readable dynamic sound in any style, be it rock and roll or some fierce metal in the C tuning. Quite a rough comparison, but it is true.

Preface

When the decision was made to assemble this device, I, without thinking twice, took the first signet I came across (a drawing of a printed circuit board) on Google, actually in the form of a picture, with labels of parts and the like.

It was a long time ago, I didn’t really understand the hardware and in general the process of creating the board and the device as a whole, so I thought that the board design was 1 to 1. But knowledgeable people They helped, they made it clear that no, not 1 to 1. They helped me redraw it, it seems in P-CAD.

Simply put, I made this board where I did my internship, at the factory, in general, which I was very happy about, because everything turned out very high quality. But not everything turned out to be so rosy - after soldering everything necessary for work, it turned out that there was extremely little overload. I looked for mistakes in the diagram and couldn’t find them. I wrote on one forum and received some recommendations. Did not help. And then, out of nowhere, someone not from Russia answers this topic. In Russian, but Google Translate is clearly visible. He writes that the diagram is incorrect, here is a link to a foreign forum, where they have sorted it all out to the smallest detail.

For some reason I was unable to register on this forum, which is what I answered to this friend. And he ended up sending an archive of materials, which I will eventually publish here with comments, especially since I haven’t seen any review articles on assembling this pedal in Russian.

So, the scheme

This requires a three-position ON-ON-ON toggle switch with 6 contacts, which I did not find in our city, so I made a slightly simplified version, but, apparently, not entirely correct in terms of switching modes. This circuit differs only in the lower stage with a toggle switch (the so-called clipping module).

This option requires a three-position ON-OFF-ON toggle switch with 3 contacts, which are available even in small radio kiosks. Please note that this module is made on a separate scarf.

This execution, judging by the comments, is not entirely correct, and the modes actually switch somewhat strangely; 2 out of 3 generally seem to be the same. Although I hardly touch this toggle switch.

And the most important thing is that all these materials contained a divorced signet on a scale of 1 to 1. My circuit design is not good and I would hardly be able to route the circuit correctly quickly. And I wanted it faster.

Everything is mirrored and ready to use. The file is called “clipping module.pdf”, print 1 to 1. So, we make the board using the LUT (laser iron) method. There are a lot of reviews of this method on the Internet, so I’ll describe it briefly.

We will need:

1. Foil-coated textolite, foiled on one side.
2. Ferric chloride (as brown powder).
3. Glossy paper. They say it is suitable for photo printing (namely glossy, not matte!!!), but it is also suitable from some magazines. I have already torn out pages from the magazine about musical equipment “IN/OUT” more than once. Everything prints well on it.
4. Laser printer.
5. Hacksaw.
6. An iron (preferably one that is not used to iron clothes in your home; there is a possibility of damaging its surface. It is, of course, cleaned, but there is little good. But if there is only such and such, a clean A4 sheet placed between the iron and the board drawing attached will partially help to the textolite blank.).
7. A container that you don’t mind is better than plastic and durable.
8. Alcohol, acetone.
9. Old toothbrush.
10. Sandpaper.
11. Soldering iron, solder, flux (if the solder is rosin-free. From fluxes: liquid rosin, soldering acid)
12. Mini drill, set of drills 0.6-1 mm.
13. Marker for writing on CDs.

We print the image of the boards on glossy paper using a laser printer. If this is your first time doing something like this, it’s better to make a couple of copies, just in case. Cut it out. We saw off the workpieces of the required size with a hacksaw; it is better to saw off with a margin of 2-3 millimeters.

If you plan to mount a large board to the case on stands, then provide this distance for screws accordingly (add 6-7 millimeters to the workpiece on its two sides).

Step 1: Stripping the PCB

We clean the copper-coated surface with sandpaper. Without fanaticism, so as not to completely tear off the layer. Then degrease with alcohol.

Step 2: transfer the circuit to the board

We attach the printed drawings of the boards with a pattern to the copper layer of the textolite blank. We go through the iron 3-5 times. Here, only by experience can you determine how many times you need to iron it with your iron so that the design does not spread (like on one of my boards), but at the same time it prints well. Therefore, I recommend printing out the drawings with a reserve.

Next, take and pour warm or hot water and throw these blanks there. We soak for about 15 minutes and carefully begin to clean off the paper with an old toothbrush. You can rub it with your fingertips - the main thing is not to tear off the design.

As you can see, the left handkerchief turned out disgustingly; I overexposed the iron and accidentally moved the sheet of paper with the design while “transferring” the design. Since there was no spare drawing (as well as a personal laser printer), and the drawing was not complicated, I then completed it manually with a marker on a CD. On the right board, I later retouched the spaces with the same marker.

Step 3: Etching

Pour water into a container that will contain your board blanks and add ferric chloride. In what proportions - look on the packaging. Stir. It is better to stir with something plastic or wooden, but not metal. Be careful, the resulting solution gets very dirty, especially if it is spilled on the floor.

If the solution is freshly prepared, then the etching time is 10-15 minutes. Scarves can be driven back and forth in the container to speed up the process. As a result we get this:

Let me remind you that the one on the left is drawn by hand. And in the right one I didn’t finish drawing one path. Subsequently, I installed a jumper there.

If there is acetone, then wash off the black pattern with acetone and lightly sand it again. I didn’t have acetone, so I immediately cleaned everything off with sandpaper and then degreased it with alcohol.

We tinker, we drill. I simply tinned: I moistened the board with flux, took the solder on a soldering iron, and carefully distributed it along the tracks. I drilled with a mini drill, a fairly cheap model, low-power, but it copes with the task of drilling boards. Total:

Step 4. Soldering elements and assembling “brains”

We will need:

We solder resistors, diodes, capacitors. I strongly recommend soldering microcircuits not directly onto the board, but through sockets. Those. First we solder the sockets, and then insert the microcircuits into them. Don't forget to wash off the flux.

As an analogue of 1N34 diodes, you can take D9Zh.

The LED diodes I took were two red and one blue.
Now comes the fun part. Nuances that are not in the pictures. An attentiveness test, to put it simply.

!ATTENTION! In the area of ​​capacitor C13 there is a place where you need to solder a jumper; after soldering all the elements, two holes will remain there. Here's how to connect them. Although this place is quite obvious.

But what is not obvious. The island in the upper central part of the board is the ground. Must be. And it needs to be connected by wire to the ground, which is connected to the power ground. Well, or to another point where there is ground on the board. Or there are two holes in the area of ​​capacitor C10 and the volume potentiometer.

As a result, here are these two places:

This is what it looks like for me if the potentiometers are not soldered directly to the board:

Step 5: Assembling the Case

In two cases of manufacturing this pedal, I used the same case - GAINTA 0473. In one case, I soldered the pots to the board and, accordingly, the board was attached to the case with potentiometers. The seats were positioned in a “triangle” and the range of rotation was not entirely normal. In the second case, I attached the main board on stands to the case cover (the cover is on the bottom), all the pots were placed in a row at the top and their rotation range was completely standard.

In one case, the body was painted, but without varnish. As a result, the corners are pretty frayed, but it’s not very visible in the photo. The second time I did without painting, I simply engraved the inscriptions with a mini-drill with an engraving attachment.

As for the button on - off the lotion. A so-called 3PDT button with fixation, 9 contacts is required. To indicate the on-off effect, you need an LED (not super-bright! It’s very blinding if you don’t select a resistor), a 4.7 Kom resistor. This is how everything is connected:

Well, here's what happened:

The article contains materials from a foreign forum with two versions of the clipping module and an explanation of the operation of this module.

39 3

Hi all! Today’s article is devoted entirely to gadget construction. After reading it, you will be able to assemble your first working device with your left heel of your right foot with your eyes closed. Well, or almost.

The question “What makes a guitarist pick up a soldering iron?” There are several possible answers.

Firstly, financial situation. Yes, yes, decent staff costs a lot of money and is collected over the years, bit by bit. And, since a pioneer, having decided to make friends with the magical world of electric sound, has acquired an electric oar and an electric device, he certainly has a reasonable desire to diversify his sound. And he firmly believes that he will get the lotion of his dreams for free.

Secondly, banal curiosity. Man is a curious creature. Loves to discover new interesting and mysterious things. Not so long ago, ZVEX released a kit from the “assemble it yourself” series, where you had to conjure up something like a breadboard with wires in your hands. And there were fans... Yes, in the end, who doesn’t want to feel this indescribable sweet feeling of satisfaction from the work done, when a bunch of lifeless cold radio components are filled with sound and tube warmth!?

Thirdly, someone wants to take over the world. But more about this some other time.

So, no matter what category of guitarist-soldering iron you consider yourself to be, we begin. And we will collect the well-known TROTSKY OVERDRIVE in narrow circles. This is the simplest circuit known to us, it also has a fairly passable sound, does not require any configuration and is quite suitable as a first device.

The circuit is a single amplifier stage based on a bipolar transistor with an anti-parallel diode limiter and a low-pass filter. Having read the previous sentence, a guitarist-soldering worker uninitiated in the mysteries of radio engineering will probably grab his head: “amplifier stage”, back-to-back limiter”, “filter of something there”?? WTF?! But nothing, Moscow was not built right away. In the end -finally, within the framework of this article, no special knowledge is required to assemble the device. You will only need attentiveness, perseverance, a bunch of free time, soft and comfortable armchair, a case of cold beer...)

We will assemble it from stones and sticks... by hanging installation - this means without bothering with the manufacture of a printed circuit board. We’ll just make a few holes in the dielectric base and place the legs of the elements in them. To do this, you will need a piece of non-foil PCB, plexiglass (gorgeous!) or other plastic.

We just used a piece of plexiglass.

Well, a list of what else is needed.

Materials:

Soldering iron (any one will do: even Soviet, even Chinese; 40-60 W);
- neutral flux (aka rosin: either solid pine in a jar, or liquid in a bottle like LTI-120; I strongly do not recommend active fluxes and soldering acids);
- solder (tin-lead POS-60, POS-61);
- side cutters or nippers;
- a roll of thin wire 1 meter (I recommend MGTF);
- a tool for drilling (this can be a small or large drill, a screwdriver);
- drill 1-1.5 mm;
- a piece of non-foil PCB, plexiglass or other plastic measuring 30x50 mm;
- it is advisable to have a multimeter on hand to measure resistance;

Details! ^___^

Capacitors:
I recommend domestic film type K73-17 (or imported analogues) for a minimum voltage.
- 22 nanofarads (= 0.022 microfarads);
- 47 nanofarads (= 0.047 microfarads);
- 100 nanofarads (= 0.1 microfarads);

Diodes:
- Silicon or germanium diodes - any 2 pieces (for example, 1N4148, 1N4001, 1N914);

Transistors:
- Silicon n-p-n 2N3904 (or, as recommended, Soviet KT312);

Potentiometers:
- 50 kOhm with linear characteristic (Gain) – type “B”;
- 100 kOhm with a logarithmic (possibly linear) characteristic (Volume); - type “A” or “B”

All of the above actually fits easily on an A4 sheet of paper:

Other:

Button... Most weakness, it’s usually difficult to get (especially in the wilderness like Zamkadye). The button is needed with a locking type 3PDT - 9 contacts (for bypass with indication) or, at worst, type DPDT - 6 contacts (without indication). At worst, you can use a similar toggle switch with 6 or 9 contacts. It's true that pressing with your foot won't work. Well, if the end is really bad, then you can do it without a bypass.)

This is what the buttons should look like:

Toggle switch for 6 contacts type ON - ON;
- Two stereo jacks for 6.3 jacks per body (plastic or metal);
- Power socket for housing type 5.5x2.1;
- Two knobs for potentimeters (optional, but will give the creation some completeness);

And of course the body: it can be can from under sardines or a beautiful box from under Cuban cigars. It's up to your discretion.

We chose a Soviet mounting box with the proud name “Granit-X”. In fact, it is made of thin aluminum. Actually, it had been lying around for a long time and was an eyesore.

We will assemble the device according to the attached diagram. It clearly shows the location of all the parts on a piece of plexiglass. In addition, a schematic diagram of the device is shown at the very beginning of the article.

When assembling, pay special attention to the pinout of the transistor. A transistor is a cockroach with three legs. Each leg has its own designation: collector (C), emitter (E) and base (B). In the figure above, next to the transistor, there are all these symbols - where to solder which leg. But it is necessary to check them with the actual physical pinout of the specific transistor. For the KT312 transistor, the pinout is shown in the circuit diagram at the beginning of the article. For 2N3904 - in the figure below.

How to make a bypass?

Bypass is a device feature that allows a signal to pass directly bypassing an effect, without processing. In short, there are “cold” and “hot”, “true” and “netrue” bypasses, and there is also a “millennium bypass”. In this article, we are interested in the cold (or otherwise called “mechanical”) pipe bypass.
It is implemented using a switch (button, footswitch, toggle switch), which has two fixed ON-ON positions. In practice it looks like this:

Each press “throws” the middle contact from left to right, from right to left in each group. There can be two such groups (DPDT), three (3PDT), four... Everything is quite simple, the main thing is to understand the principle itself. Well, the connection diagram for the 3PDT button for the bypass looks like this:

Same for DPDT (without LED):

In more detail, how to connect sockets, buttons and power to the effect board is shown in some detail in the figures (taken from here

Option for DPDT button(without LED). The power socket can be connected in the same way as the following figure.

Option for 3PDT:

Phew, well, we've sorted out the theory, now a few practical advice directly by soldering:

Don't skimp on the gumboil! Apply flux to the soldering area before the soldering iron tip touches it with solder. After soldering, the solder should shine; if it has a dull color, it means it has oxidized and there was not enough flux;
- Try not to overheat the parts. For a soldering iron without thermoregulation, the temperature of the tip can reach 320-380 degrees. Therefore, the maximum touch time should not exceed 3-4 seconds. This applies to a greater extent to semiconductor elements: transistors and diodes;
- Get yourself a damp cloth and regularly wipe away carbon deposits from the soldering iron tip;

Well, that's all! Go for it! Enjoy watching and good luck!

The whole process was captured on video, the pedal got a nice sticker - please take a look:

P.S. We'll exchange the experimental box from the video for some goodies.

For questions, contact our group

Assemble a guitar gadget. And not just any effects pedal, but a legendary pedal. Jimi Hendrix himself, a brilliant musician and composer, played through this one. Partly this gadget influenced his signature sound. Although we cannot dispute that Jimmy was a genius in his own right, as a genius and a pioneer in many guitar matters.

2016 marks the 50th anniversary of Dunlop's ingenious creation, the Fuzz face. Now you can assemble this pedal yourself.

Here is a diagram where we see one of the typical two-stage amplifier circuits. It is capable of clipping (cutting off the amplitude) of the signal, initially amplifying it and at the same time limiting it with transistors. Unlike distortion or overdrive circuits, where back-to-back diodes are often used to cut the signal. In this case, the clipping level is regulated by a variable resistor included in the feedback.

I would like to draw your attention to the fact that the circuit has a negative mass. Although the original was positive, this will not affect the work in any way. All this is due to standardization and ease of use. The diagram is exactly the same, just drawn differently.

Added: LED indication of switching on, changed the bypass circuit (switching to start the signal bypassing the effect). A 2.2 M resistor has been added. They say it can protect against cracks. A filter capacitor has also been added (you don’t have to install it).
Transistors, since original ones cannot be obtained, can be supplied with MP42b, GT402i.
Having previously selected them by gain.

Here's the PCB.

You can download the printed circuit board in “lay” format here. (downloads: 577)

You can buy the case or make it yourself. For example, bend it from a sheet of metal, or solder it from foil PCB. One advantage is that we have now learned to do printed circuit board, and the parts have become smaller compared to old models. The nice thing is that you don’t need to have a huge “frying pan” to place a fairly simple circuit in it.

Here's an example of how you can style your pedal. I would like to emphasize the accuracy of the author of this work. This can be a model for your aspirations. After all, no one wants a sloppy, unattractive lotion. Which is also covered in rosin)). Although the opposite can be said, for example, that beauty does not affect sound. You'd be right.

Thank you all for your attention. Collect beautiful, neat, and most importantly good-sounding pedals.

After all, only when you make a thing with your own hands can you be sure of what you can get from it. And also satisfy your personal cockroaches.

Probably everyone who is interested in rock music has heard the sound of a guitar with the effect overdrive. This is a moderately overloaded sound with a characteristic hissing sound. Nowadays, guitar sounds with this effect are used in many musical styles, but in the mid-twentieth century, as sound reinforcement technology developed, people were quite skeptical about musicians who experimented with the sound of their guitars by overloading their amplifiers. This was considered a defect. Some guitarists "damaged" the speakers of their amplifiers in order to achieve the overdrive effect. Over time, the overdriven sound became business card rock performers. He was a bright experimenter with guitar sound. At that time it was practically a revolution in guitar sound.

How the overdrive effect works

Let's consider first theoretical basis. The overdrive effect is a distortion of sound by smoothly limiting the amplitude. In the picture, the dotted line shows a sine wave - this is the signal from the guitar pickups. The effect limits the amplitude of the signal, as if “cutting off” the tops, but still leaving these tops rounded. Therefore, guitar overdrive is perceived softer by ear, which is why it has, so to speak, a “warm” sound. Also, using overdrive, the guitar sound is enriched with many harmonics, so we hear rustling tones. And I would like to draw your attention to the fact that when overdrive is applied, the sound of the guitar is sensitive to the dynamics of the game.

For those interested in electronics, I can give an example of an overdrive circuit.

Overdrive circuit

It is worth noting that many amplifiers are available with a built-in overdrive effect. Also, many manufacturing companies perform this effect in the form of floor pedals. Such overdrive is very often used in rock and funk music. The most famous overdrive pedals for electric guitar are: