#1

This is the official thread for UG Electronics, you may pose questions about guitar/amplifier/effect electronics. We will be able to go into much more depth than the stickied FAQ's due to handpicked experts listed below. For links to many other great threads, check out the

PM either myself, or guitarcrazy1991 for an invitation

I will be willing to help people gain expert status, along with other members once the group becomes bigger.

Expert "God" List:

mcw00t

guitarcrazy1991

losenger

Denthul

Gabel

MrCarrot

stevo_epi_SG_wo

Honorary Experts (those that have not yet accepted invitation):

Post away, FAQ coming soon!!

**GB&C Central Hub.**PM either myself, or guitarcrazy1991 for an invitation

I will be willing to help people gain expert status, along with other members once the group becomes bigger.

Expert "God" List:

mcw00t

guitarcrazy1991

losenger

Denthul

Gabel

MrCarrot

stevo_epi_SG_wo

Honorary Experts (those that have not yet accepted invitation):

Post away, FAQ coming soon!!

*Last edited by mcw00t at Jan 6, 2008,*

#2

**Simple Projects**True bypass looper with LED (PM me if you want one without the LED.)

True bypass looper strip

Fuzz

Selection of wah mods

BYOC (Simple to build kits.)

Killswitches

A/B Box

Power booster

I'll add more some other time, PM me what you think should be here as well. I want your suggestions.

Note: This isn't just a building thread. FAQs, and explanations on how all the above works will be coming. Some people will learn a lot from this thread.

*Last edited by guitarcrazy1991 at Dec 31, 2007,*

#3

**Useful links**

**How to use a multi-meter for beginners:**http://www.doctronics.co.uk/meter.htm

*Thanks to Losenger*

**Circuit Simulator**http://www.falstad.com/circuit/

It's a circuit simulator that lets you make virtual circuits using different components like capacitors, transistors, op-amps etc. It shows you voltages, current flow and you can view them for particular components in an oscilloscope type thing. There are also loads of preset circuits. It's helped me to visualize and understand a lot of things in electronics. You can make pedal circuits in it to help visualize what's really going on.

*Thanks to loonyguitarist*

**Useful Links**Might as well list some of the other pages.

http://www.electronics-tutorials.co...tron-theory.htm

http://www.electronics-tutorials.com/basics/voltage.htm

http://www.electronics-tutorials.com/basics/current.htm

http://www.electronics-tutorials.co.../resistance.htm

http://www.electronics-tutorials.co...capacitance.htm

http://www.electronics-tutorials.co.../inductance.htm

http://www.electronics-tutorials.co...s/impedance.htm

http://www.electronics-tutorials.com/basics/diodes.htm

http://www.electronics-tutorials.co...s/soldering.htm

http://www.electronics-tutorials.co...ve-feedback.htm

http://www.williamson-labs.com/480_opam.htm

http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm

Lots of reading, but why type it all out here? The included diagrams and formulas will also be beneficial.

Thanks to Losenger

Thanks to Losenger

*Last edited by guitarcrazy1991 at Dec 31, 2007,*

#4

**1) Voltages and Currents**These are two things that describe electricity (in most cases, but not limited to just electrons), and if you have an understanding of what they are then you'll be off to a good start.

A current is moving charge - anything charged and moving can be considered to be a current. This is a bit of a brief description, but it's difficult to describe a current without using voltage, so more on them in a second.

A voltage is a difference in electrical potential between two points. You're probably thinking, what's a potential. Let me make an analogy using gravity, we all encounter that every day. If I have an object on the ground then its gravitational potential is zero with respect to the ground. If I hold the object 1m above the ground then the object now has a different gravitational potential to ground, and work can be done - if released the object it will fall!

Electrical potential is caused by different amount of charge, for example if I have a positively charged ball and a negatively charged ball there will be a potential difference between them. In fact just a positively charged ball in space will have a potential field around it. This is getting off topic, basically if you have a potential between two points then work can be done between them - a current will flow (electronics people -yes I've missed something here, but I'll get back to it, one step at a time).

Finally, we will touch on ohms law slightly (more in a bit), just to explain about resistances and loads. For the moment I will use the general term load, because resistance as we will see is a bit more specific. The equation for ohms law is:

V = IR, where V is voltage, in volts, I is current in Amperes, and R is resistance in ohms.

What this tells us is that if we have a current flowing through a load then across that load there will be a voltage. Conversely, if I apply a voltage (potential difference) across a load then a current will flow.

If the current is 1A, and the load is 1Ohm then the potential difference between will be 1V - that's the way the maths works.

**2) AC/DC**

Firstly direct current, DC as it's easier to understand.

This is essentially where the voltage and current do not vary with time - are constant. [Conventional] Current will flow in one direction, from the higher electrical potential to the lower, for example from +18V to +9V, or 5V to ground, which is chosen to be 0V.

When I say conventional current, this is something that goes back a few hundred years to when they first discovered electricity. This is that if one part of a circuit is at a more positive voltage than another part then a positive current will flow from the positive voltage to the lower voltage (this could be a lower positive voltage, ground or 0V, or a negative voltage). However, electrons are negatively charged, so what they do is a move from the lower voltage to the more positively charged region. Confused? Don't worry, just think in terms of a conventional current (ie positive to negative).

Alternating Current - AC

This is what comes out of the walls (120V @ 60Hz for people in the states and the like, and 230V @ 50Hz for people in Europe and other places).

Also, electrical signals - more specifically electrical signals that correspond to sound will be alternating currents - so this is something that you need to grasp.

If we apply a voltage like this:

+10V ----------------|load|------------------ 0V

Then a current will flow forwards to 0V - this is a positive current

Now we switch the polarity:

-10V ----------------|load|------------------ 0V

Now what happens is that a current will flow from 0V to -10V. It's flowing backwards, compared to the first diagram, so we could say that this is a negative current compared to the first one.

Now, imagine that the voltage source alternates sinusoidally with time between +10V and -10V, we have an alternating voltage source, and the current flowing is an alternating current.

So this is what an alternating current is.

**3) Frequencies, harmonics**

I'm sure many people have been a bit perplexed by what is talked about by frequencies in terms terms of tone (ie mid, high low, etc). They may think, 'there are other frequencies present, what? I thought I was just playing the frequency of the A above middle C, 440Hz' (it's the only note I can remember the frequency of).

Here's the way things work (I'll try to avoid maths here, for a better explanation look up 'fourier series' in wikipedia)

Any waveform can be produced by a series of sine and cosine oscillations. Take any waveform, for example at 440Hz, this will be at the fundamental frequency, 440Hz. It will then contain higher order harmonics (at 880Hz, 1320Hz etc) which add in varying amounts to make the full shape of the waveform.

Each of the harmonics are the frequencies that are multiples of the original fundamental frequency. The timbre and tone of a sound is defined by what harmonics are present, and by altering these harmonics the tone and timbre can be altered - this is exactly how many effects work.

I know this isn't really explaining it that well, I suppose people should pose questions and I'll answer. Without going into the maths it's quite hard to provide a qualitative explanation.

**4) Impedance**

This is basically something that impedes electrical current - stops it. Some people like a water analogy, like I said this works with DC, so this can be thought of as a restriction in the pipe, such as narrowing of it. However, for AC you can't really explain this so easily.

There are two types of impedance, resistive and reactive. Resistive impedance is the same for all frequencies and phases. Reactive impedance varies depending on the frequency of a signal, and also introduces a phase relationship between current and voltage.

Let me first explain phase.

Take a sinusoidal oscillation. It repeats every 360 degrees, or 2 pi (in radians, wikipedia radians if you're not sure what this is - basically it is the proper mathematical way of describing an angle, degrees was introduced by the samoans or babylonians or someone because the year roughly has 360 days in it). The instantaneous phase is the angle that the wave is at at that point. So, for a sinusoid 7at 0* it's value is 0, 90* it is 1, 180* 0, 270* -1 and 360* it is back to 0. The phase is just a way of explaining the evolution of the wave.

A phase difference is the phase between the same point on two waves. This is also an angle, and tells you interesting things such as what the sum of the two waves would be if they are added together.

If you have a phase relationship between voltage and current then they will not be in phase, but one will lag by a certain amount, expressed in degrees or radians.

Ok so resistance is easy, it's a constant value (such as 5ohms) for all frequencies. Reactance is a function of frequency, and phase. Now the next bit needs a bit of maths.

the way of expressing an impedance mathematically is with complex numbers. These basically have a real and an imaginary part. An imaginary number is a number that is a multiple of i (or j if you're an engineer) - i being the square root of minus 1. For electronics people tend to use j, so we will.

so, an impedance, Z = R + Xj

R is the resistance, X is the reactance.

A [perfect] capacitor is purely reactive (a real capacitor will have a resistance), it's impedance is 1/(j*2*pi*f*C), so is inversely proportional to the frequency. So if we measure the voltage across the capacitor as a function of frequency the voltage will decrease for higher frequencies (the impedance goes to zero as frequency goes to infinity). The j takes care of phase shifts - basically if you look at the signal in to the signal out there will be a different phase relationship depending on phase.

A perfect inductor has impedance j*2*pi*f*L, so impedance goes to infinity as frequency goes to infinity. This means that inductors don't allow high frequency currents to pass through, but like low frequency currents.

Using a combination of capacitors, resistors and inductors lots of different frequency responses can be achieved....

Ok, how are we doing, anyone stuck let me know and I'll try to explain in more detail.

*A big thanks to isotone for taking the time to write all that out.*

*Last edited by guitarcrazy1991 at Dec 31, 2007,*

#5

**Electric resistance:**A material's opposition to the flow of electric current; measured in ohms. A resistor slows down current flow for both direct and alternating currents. For a given voltage (electrical pressure, or energy), if you increase the resistance by a linear amount, the current through it will be reduced by a linear amount. This is where Ohms law comes in, which is V or E=IR. Where V or E equals voltage, I equals current, and R equals resistance. Using basic algebra, in a DC circuit, if you know two of the values, you can calculate for the third. Another related formula has to do with DC power. P=IE, where P equals power, I equals current, and E equals voltage/electromotive force. Power, in my opinion, is the most important factor in any electrical circuit. Power out must be less than, or equal to, power in. It can never be greater. In all practical circuits, it will always be less.

So for example in a tube output circuit, if it's rated for 50 watts output, that means in order for the speaker to receive 50 watts, the tube(s) must push at least 50 watts of power through the output transformer. Because components aren't perfect, much of that power is lost as heat, so the output tube(s) have to provide more than that, which they get from the plate voltage, and current run through them. P=IE see?

**Capacitance:**the ratio of the charge stored by a capacitor to the voltage across the capacitor. Formerly called capacity. The SI unit of capacitance is the farad. Think of capacitors sort of like storage tanks. Energy in = energy out. But it's more complex than that. Regardless of materials, all capacitors are basically made of two metal plates or foils separated by a non-conductive material. With a DC circuit, if you connect a positive voltage to one side of a capacitor, and don't change it, the plate of the cap will charge up to that voltage (over time, depending on the amount of the current, which is dependent upon the resistance of the conductor before it), and stay there, until the charge can dissipate through a conductor. The charge of the other plate of the capacitor changes at the same, but inverse amount of the first plate. With AC, the charge between the plates changes along with the frequency of the change of current, but it's dependent on the value of the capacitance. If we look at what isotone said: So if we measure the voltage across the capacitor as a function of frequency the voltage will decrease for higher frequencies (the impedance goes to zero as frequency goes to infinity)... What he means is, if the voltage across a capacitor decreases with given frequency, it is actually passing more current, or more correctly, electrical power, with a higher frequency. Here's another water analogy to show that: http://www.satcure-focus.com/tutor/page6.htm

In a DC circuit, one plate of a cap charges to an amount, which affects the charge of the opposite plate by the same amount. But in an AC circuit, the amount of voltage is constantly changing, which causes the other plate's voltage to constantly change. For a given amount of capacitance(farad), the lower the frequency, the less the amount of change gets passed through. To decrease the amount of change (frequency) that gets passed to the other plate, increase the capacitance.

**impedance:**

A measure of the impediment to the flow of alternating current, measured in ohms at a given frequency. Larger numbers mean higher resistance to current flow. Basically (hush guys, this is BASIC electronics), impedance is the opposite of capacitance. Unlike capacitors, where a high rate of voltage change is passed through, inductors tend to only pass lower frequencies. Here's a site to show you more: http://www.williamson-labs.com/480_rlc-l.htm Because of the fact that sending current through a wire creates a magnetic field, and a moving magnetic field induces a flow of current in a wire, the act of passing a current through a coil induces a magnetic field around each turn, which induces opposite current flow in the wire. So, the faster the voltage changes over time in a coil, the faster magnetic fields are created, and the faster opposite voltages are produced, so less current from the source can get through. This is BASICALLY why inductors pass only lower frequencies.

**Resistance**

Resistance is the imaginary part of electrical impedance, a measure of opposition to a sinusoidal alternating current. Reactance arises from the presence of inductance and capacitance within a circuit, and is denoted by the symbol X Reactance, as the guys said, is a very abstract concept. Reactance refers to the difference in phase between the current and voltage in reactive circuits, and is used when calculating capacitance and inductance in a given circuit. If you're only building stomp boxes and amps, this really isn't going to concern you. As long as you are able to distinguish among the basic concepts of voltage, current, resistance, impedance, inductance, and capacitance, you'll be fine.

In order to fiddle with circuits, all you need to know is what each component does regarding the way you want to use it, and what the common electrical terms are referring to. Only engineers need to know what the slew rate of an op amp means. All you need to know is, the higher the slew rate, the better.

So, to sum up, resistance, for both AC and DC, slows down current flow, which increases voltage across it(important). Capacitors basically block DC, but pass AC. In tube circuits, they block the high voltage DC of the previous stage from the input of the next stage. Also, the higher the capacitance, the lower the frequency is passed. Inductors basically the opposite of capacitors, will pass DC readily, but not AC. Used in filtering circuits. Transformers are inductors, but tuned to be used with certain frequencies and power levels. Transformers are used to couple differences in voltage and current. For example, in tube output circuits, they couple a high voltage/low current to a low voltage/high current circuit. Power out is always less that power in because of losses.

One quick thing... the tone of your instrument is utterly dependent upon the components in your signal passing circuit. If you make a change in the value of a component, regardless of what it is, it will change the tone that comes out the end, either subtle or significant. Electronics, especially audio-related can't be learned in a few hours or days. It's an ongoing learning process. All the geniuses that frequent this forum are still learning. Nobody knows everything, and people make mistakes. We'll all be around to help as much as we can, but remember that we aren't perfect, and part of the fun of experimenting is the learning process.

*Thanks again to Losenger!*

*Last edited by guitarcrazy1991 at Jan 3, 2008,*

#6

So, op-amps. What are they? Wikipedia says

So what does that mean? A single op-amp has two inputs, the inverting and the non-inverting and one output. The inverting, like it's name suggests, inverts the input voltage. For example, if you fed 3VDC into the inverting input of the op-amp and set it up to have a gain of 1, then you would get -3VDC out at the output. Likewise, feed any waveform into it and it will come out 180 degrees out of phase. Here's the basic symbol for an op-amp. V+ is the non-inverting input, V- is the inverting, Vs+ is the power supply, Vs- is the same as Vs+, except the opposite polarity and Vout is the output.

Op-amps themselves have a HUGE gain. For example, the LM741C (an old op-amp) has an open-loop gain of 200000. Imagine you feed a 1V signal into it - it tries to output a 200000V signal, which it obviously cannot do. Op-amps can swing within roughly 1V of the power supply rails. That is, if you connect the op-amp up to +12V and -12V for Vs+ and Vs- respectively, the largest signal it can output will be roughly +11V to - 11V. As soon as it hits this level, it clips/distorts as the voltage cannot go any higher. Obviously, you won't always want a distorted signal coming out of the op-amp, so there must be a way to control the op-amps gain. This is called negative feedback.

How negative feedback works is by sending a portion of the output signal back into one of the inputs, so it will cancel a bit of the output signal out. This can be precisely controlled to choose the exact gain that you're looking for.

Without going much into WHY the math behind working out the gain of an op-amp works, here's the basics of how you can calculate the gain. Negative feedback uses two resistors, which are basically a voltage divider that chooses how much output signal is fed back in. Let's call these resistors Rf/R1 and R2.

As you can see, the output signal will be divided across the two resistors and therefore you can control how much negative feedback is applied. As the diagram says, the formula for gain (Av) in this application is Av = 1 + (R1/R2). Say both resistors are 10k. The gain is 1 + (10k/10k) = 2.

Next up is the inverting amplifier. Sort of same deal on how it works, but you can see that the input signal has just been moved to the inverting input and before the first resistor, while the non-inverting input is tied to ground.

Once again, as you can see from the picture the gain is Av = - (R1/R2). If both resistors are 10K, gain is - (10k/10k) = -1.

It's late now and I need bed. I'll continue later on - I've still got to cover input and output impedances and some basic op-amp applications.

An operational amplifier, usually referred to as an op-amp for brevity, is a DC-coupled high-gain electronic voltage amplifier with differential inputs[1] and, usually, a single output. In its typical usage, the output of the op-amp is controlled by negative feedback which largely determines the magnitude of its output voltage gain, input impedance at one of its input terminals and output impedance.

So what does that mean? A single op-amp has two inputs, the inverting and the non-inverting and one output. The inverting, like it's name suggests, inverts the input voltage. For example, if you fed 3VDC into the inverting input of the op-amp and set it up to have a gain of 1, then you would get -3VDC out at the output. Likewise, feed any waveform into it and it will come out 180 degrees out of phase. Here's the basic symbol for an op-amp. V+ is the non-inverting input, V- is the inverting, Vs+ is the power supply, Vs- is the same as Vs+, except the opposite polarity and Vout is the output.

Op-amps themselves have a HUGE gain. For example, the LM741C (an old op-amp) has an open-loop gain of 200000. Imagine you feed a 1V signal into it - it tries to output a 200000V signal, which it obviously cannot do. Op-amps can swing within roughly 1V of the power supply rails. That is, if you connect the op-amp up to +12V and -12V for Vs+ and Vs- respectively, the largest signal it can output will be roughly +11V to - 11V. As soon as it hits this level, it clips/distorts as the voltage cannot go any higher. Obviously, you won't always want a distorted signal coming out of the op-amp, so there must be a way to control the op-amps gain. This is called negative feedback.

How negative feedback works is by sending a portion of the output signal back into one of the inputs, so it will cancel a bit of the output signal out. This can be precisely controlled to choose the exact gain that you're looking for.

Without going much into WHY the math behind working out the gain of an op-amp works, here's the basics of how you can calculate the gain. Negative feedback uses two resistors, which are basically a voltage divider that chooses how much output signal is fed back in. Let's call these resistors Rf/R1 and R2.

As you can see, the output signal will be divided across the two resistors and therefore you can control how much negative feedback is applied. As the diagram says, the formula for gain (Av) in this application is Av = 1 + (R1/R2). Say both resistors are 10k. The gain is 1 + (10k/10k) = 2.

Next up is the inverting amplifier. Sort of same deal on how it works, but you can see that the input signal has just been moved to the inverting input and before the first resistor, while the non-inverting input is tied to ground.

Once again, as you can see from the picture the gain is Av = - (R1/R2). If both resistors are 10K, gain is - (10k/10k) = -1.

It's late now and I need bed. I'll continue later on - I've still got to cover input and output impedances and some basic op-amp applications.

*Thanks to the_random_hero**Last edited by guitarcrazy1991 at Jan 3, 2008,*

#7

Last reserved. Feel free to post now.

#8

i think you reserved enough is this like my pedal building thread?

#9

Similar, but not the same, focuses on things like troubleshooting, understanding what components do, all that kinda stuff.

#10

Dammit I'm never first post.

#11

Nah, it's not pedal building. Just general electronics. Doesn't have to be to do with pedals. Thanks so much to the people that deleted their posts.

#12

I think this thread defeats the purpose of the GG&A Forum.... If all questions about amps, effects, and guitars, no one would post outside this thread. Then this thread would get so big it would turn into a forum section of it's own.

Clarify please.... do you mean ams, effects and stuff in general? Or things like caps, Trannies, and electronic theory and what not?

If so, go on ahead.

Clarify please.... do you mean ams, effects and stuff in general? Or things like caps, Trannies, and electronic theory and what not?

If so, go on ahead.

#13

I think this thread defeats the purpose of the GG&A Forum.... If all questions about amps, effects, and guitars, no one would post outside this thread. Then this thread would get so big it would turn into a forum section of it's own.

Clarify please.... do you mean ams, effects and stuff in general? Or things like caps, Trannies, and electronic theory and what not?

If so, go on ahead.

The latter, specifically the electronics side of things.

For example, how the electronics components work in things like Amps, Guitars and Pedals

#14

This is an electronics thread....About 99.9% of the posts in GG&A Forum consist of "What amp should I get, I have like £200/$400. The MG looks good!" and us answering with "MG Sucks, Marshall cons people etc etc etc buy an Epi VJ and an O.D etc etc etc.

#15

The latter, specifically the electronics side of things.

For example, how the electronics components work in things like Amps, Guitars and Pedals

Hmm, this might have a better place is GB&C though...

#16

Hmm, this might have a better place is GB&C though...

"toshay"

tbh i think its relevant to both. GB&C-ers probably need less advice on it anyway

#17

Yeah I'd put this in GB&C...

#18

Hmm, this might have a better place is GB&C though...

To be honest, it was a toss up as to which I put it in, however, the people in GB&C seem to talk less about electronics than the people in here. However, I will be quite happy for it to be moved if needs be

#19

Well, I've asked frenchy but he doesn't seem to be there. If anyone would be so kind and move it, that would be great.

#20

WIN!!!!!! mcw00t i just figured that schematic out all on my own

al post it in a sec

al post it in a sec

#21

WIN!!!!!! mcw00t i just figured that schematic out all on my own

al post it in a sec

haha, awesome! is that the one on the profile?

#22

MESSY ALERT!!!!!!

i did this in paint in about 5 seconds and there are 3 things to point out

1) nothing is earthed, but thats obvious

2) diodes are missing but theyre obvious

3) the schematic symbol for a 3PDT is like a DPDT but with an extra section directly below it....i hope

right:

ta da!

if you study it for a bit, it seems to check out

i did this in paint in about 5 seconds and there are 3 things to point out

1) nothing is earthed, but thats obvious

2) diodes are missing but theyre obvious

3) the schematic symbol for a 3PDT is like a DPDT but with an extra section directly below it....i hope

right:

ta da!

if you study it for a bit, it seems to check out

#23

In the Ultimate Pedal Building thread all those topics mentioned are discussed.

#24

MESSY ALERT!!!!!!

i did this in paint in about 5 seconds and there are 3 things to point out

1) nothing is earthed, but thats obvious

2) diodes are missing but theyre obvious

3) the schematic symbol for a 3PDT is like a DPDT but with an extra section directly below it....i hope

right:

ta da!

if you study it for a bit, it seems to check out

I have an idea worked out in my head that uses a 3PDT and stereo jacks so that it turns on the LED's when you're plugged in, and it switches LED depending on what you have selected. I'll draw it up tomorrow in neat for you

#25

In the Ultimate Pedal Building thread all those topics mentioned are discussed.

I'm going to be writing about all the electronics theory behind the circuits, just it's too late in the UK now, and I'll make mistakes

#26

I have an idea worked out in my head that uses a 3PDT and stereo jacks so that it turns on the LED's when you're plugged in, and it switches LED depending on what you have selected. I'll draw it up tomorrow in neat for you

nice one, thanks!

#27

ok, this really doesnt continue the topic of pedals, and I really dont like asking n00b questions, because I know what most electrical stuff is, but what does that symbol mean that looks like a 'u' or a 'p' that is on capacitors. I have always seen it but don't know what it means

#28

it means 'micro' as in micro farad (farad being the unit of capacitance)

its just like kilo or mili etc

it is 10^-9 (RLY small) in maths and can be applied to other units too

its just like kilo or mili etc

it is 10^-9 (RLY small) in maths and can be applied to other units too

#29

ok, thanks, but wait, I thought there were 2 different ones, one that looks more like a u, and one that looks more like a p

#30

you can get pico farads too the prefix will be 'p'

thats 1000 times smaller (10^-12)

thats 1000 times smaller (10^-12)

#31

ok, thanks, and I have this scematic for a champ, and it calls for a .05-600 cap.

Problem is, I can't find a .05-600, but I can find a.048-600. Would it be safe to substitute like this?

Sorry for all the questions, Im about to build an amp.

Thanks for helping so much

Problem is, I can't find a .05-600, but I can find a.048-600. Would it be safe to substitute like this?

Sorry for all the questions, Im about to build an amp.

Thanks for helping so much

*Last edited by EVH92 at Dec 27, 2007,*

#32

np

#33

That will work fine, EVH92. You can, in fact, change the value to suit your taste. A larger value will pass more bass, and a smaller value will pass less. Too high of a value will sound muddy. A 600 volt rating is high enough for just about any guitar amp.

#34

can anyone tell me what the blue thing with red dots on them is? http://www.diystompboxes.com/tbbox/tbbox.jpg

its right in the center.

its right in the center.

#35

It's a 3 pole, double throw switch. With one click, the in and amp/next jack tips are connected together. With another click, the guitar in and effects in tips are connected together, the battery is connected to the LED, and the amp/next and effect out tips are connected together. All of the jack sleeves, the LED cathode, and the battery minus are always connected together (negative ground.)

Edit: Oops, forgot one thing. The effect in jack is stereo, and the only way the 9 volt battery minus will be connected to the sleeves is if the ring of the effect plug is connected to the sleeve of the effect plug.

Edit: Oops, forgot one thing. The effect in jack is stereo, and the only way the 9 volt battery minus will be connected to the sleeves is if the ring of the effect plug is connected to the sleeve of the effect plug.

*Last edited by Losenger at Dec 28, 2007,*

#36

hey, what would happen in the following scenario:

where you have an un-earthed wire coming from the signal wire.

would it cause hum or is it earthed anyway....i think it might be

where you have an un-earthed wire coming from the signal wire.

would it cause hum or is it earthed anyway....i think it might be

#37

can anyone tell me what the blue thing with red dots on them is? http://www.diystompboxes.com/tbbox/tbbox.jpg

its right in the center.

It's a 3PDT switch.

To all th people doubting this thread, those ^ are the sort of questions it's here to answer. It will be added to soon...

#38

This needs to get stickied.

#39

i think if this gets stickied, the ultimate pedal building thread should also^

because EVERYTHING iv learned is from the guys in that thread, who have an endless stream of knowledge

because EVERYTHING iv learned is from the guys in that thread, who have an endless stream of knowledge

#40

+1 for sticky-ness. EVH92, where'd you get a Champ schem?

s.r.v.

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Invader Jim

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