Here's an interesting article copied from Pete Cornish's web site, http://www.petecornish.co.uk.
The Case Against True Bypass

"Hey Pete, do you use True Bypass?"

Look out there's a lecture coming:

The "true bypass" function, which is promoted by some, can create dreadful problems with a system that uses many pedals. Take for instance a 15 ft guitar cable linked to ten pedals, each linked by a 2 ft cable, and then onto the amp by a 30 ft cable. If all pedals have "true bypass", and are off, then the total cable length hanging on the guitar output will be 63 ft. This will cause a huge loss of tone and signal level particularly if the guitar is a vintage type with low output and high impedance. The amp volume is then turned up and the treble control increased to compensate for the losses. The inherent background noise now increases by the amount of the gain and treble increase and is usually, in my experience, too bad for serious work. If one of the pedals is now switched on, then it's (hopefully) high input impedance (and usually low output impedance) will buffer all the output cables from the guitar and the signal level will rise due to the removal of some of the load on the pickups (i.e.: 17 ft instead of 63 ft of cable). The treble will rise and the tone and volume will not be as before. If that pedal was say a chorus or delay, devices which are usually unity gain, then your overall signal level and tone will vary each time an effect is added...not a very good idea.

Some pedals have an input impedance which is far from high in real terms; the input impedance of the vast majority of amps is 1 Megohm (one million ohms) and in my experience there are few effects pedals that have the same input impedance. A load on the guitar of less than 1 Megohm will reduce the volume and high frequency content of the pickup signal thus giving rise to complaints that "this pedal looses tone/volume" etc. Many effects I have tested have an input impedance of less than 100 Kilohms (ie: only one tenth of the amp input impedance) and cause serious signal losses in the effects chain.

My system, which I devised in the early 70's, is to feed the guitar into a fixed high impedance load, which is identical to the amp input, and then distribute the signal to the various effects and amps by low impedance buffered feeds. This gives a constant signal level and tonal characteristics, which do not change at all when effects are added. The proof that this works are in the recordings of our clients: Roxy Music; The Police; Queen; Pink Floyd; Bryan Adams; Lou Reed; Dire Straits; Paul McCartney; Sting; Jimmy Page; Judas Priest; Black Sabbath....

So the answer to your question re "true bypass" is no, I do not use this system in my Effects Boards/Racks as it can seriously degrade your sound. All my current effects pedals (excluding Vintage Series) which are derived from our large systems have, as the main input stage, a fiendishly clever pre amp that has the same characteristics as the input of a tube amp (1 Megohm/20pF), a highly efficient filter to eliminate the possibility of radio breakthrough and a low output impedance so that any following pedals/ cables etc. will not impose a load on the guitar signal. This pre amp is fitted to all our large stage systems and has always met with huge approval; not only from the guitarist but also the PA operator who is so happy to have constant level and tone presented to his mixing board. I go further with large systems and provide several inputs, each with the isolating pre amp and a gain compensation pre amp so that many different guitars can be level matched into the system. In addition a 20 segment PPM type display provides visual indication of signal level in our Effects Boards and Rack Systems.

©Pete Cornish 2003

Unit 5, Silveroaks Farm, Hawkhurst Lane, Waldron, Heathfield, E.Sussox, UK, TN21 0RS
Tel (0)1435- 813393, International - 0044 1435 813393, From US - 01144 1435 813393

Check this article out.  Worth the read @ premierguitar.com

by Thomas Scott McKenzie
A scientific approach to what we hear as Tone


The Ford Model T was revolutionary. The only horses involved were under the hood, which was a big enough deal at the time, but we now know that the assembly line process behind it would go on to revolutionize the way we manufacture tools, vehicles, and the rest of our modern appurtenances. In all honesty, the Model T had a long way to go. Consider how that horseless carriage would hold up today. When we put nostalgia and historic significance aside, it’s the last car you’d want take a long trip in or depend on for daily commutes. From a modern day performance perspective, the Ford Model T was garbage.

Now think about all the advances in guitar technology that we’ve witnessed over the decades—how much smarter we are now when it comes to acoustics, electronics and precision manufacturing? Sticking with this metaphor, isn’t it a bit crazy that we place such high value on the early designs that represent the Model T-era of the electric guitar’s evolution? We’re not just talking nostalgia and historic significance here—ask most guitarists to name the most amazing, best-sounding electric guitars ever made, and they’ll go all the way back to early-fifties Broadcasters, late-fifties Les Pauls, and early-sixties Stratocasters. Guitarists cling to the tones produced by what is, essentially, first generation technology.

Fender released the first successful solidbody electric guitar, the Broadcaster, in 1950. (Remember, the original Esquires were problematic.) Gibson produced the first Les Paul 24 months later. And a mere six years after that, a small run of sunburst Les Pauls flowed out of Gibson’s Kalamazoo, Michigan factory. Originally just another instrument, those Les Pauls now occupy a mythic status in the minds of guitarists and collectors everywhere. The instruments, along with a small handful of Fender Stratocasters and examples from one or two other manufacturers from roughly the same era, represent the Holy Grail in guitar tones.

To understand why these early guitar tones continue to be so revered—after decades of technological progress— we have to understand the science. Or more accurately, we have to confront a distressing lack of scientific proof.

Note from the Editors: While exploring the “Psychology of Tone” last month, we learned that digging into the mushiest part of any signal chain (the listener’s noodle) leads to a better understanding of the tonal journey involved. The journey itself may be more important than you realize. We continue this series dedicated to messing with your head with a look at the science involved with the creation of those tones. Everything can be explained with science, right?

The Dominance of the Subjective
When discussing the science of tone, it’s safe to assume that we all know how electric guitars work. Pickups are electro-magnets that sense string vibrations and produce a signal that ultimately blares out of the amplifier. Of course, we all know that myriad other factors influence the sound, as well. Body shape, wood choice, string selection, pedal effects, rack effects, humidity, amount of people in the room, and the guitar player’s recent fight with his girlfriend are just some of the items that can alter a guitar tone from performance to performance.

Can you scientifically prove the role of these influencers? Lab geeks and gadget gurus can measure signal strength, decibels, frequency distribution, gamma radiation, and other ranges. They can graph this data, create new data by creating logarithms, create even more data by creating even more logarithims, but they can’t decide what’s good or bad. Like it or not, you simply can not use a computer to prove that a ’63 Strat sounds “better” than a cheap 1988 import.

The Musical Acoustics Department at the University of New South Wales unequivocally states on their website that, “Whether a musical instrument is good or poor is a question for musicians rather the scientists.” That’s because scientists are primarily examining the effectiveness of an instrument.

Numerous sources, such as Physics by John D. Cutnell and Kenneth W. Johnson, state that the human ear can hear sounds ranging from 20 hertz to 20,000 hertz. A guitar is going to fall in this range because it wouldn’t make good business sense to produce an instrument that can only be heard by dogs. From a scientific perspective, just about everything within the normal human range would be considered effective, since the instrument accomplishes its goal. Beyond that, a researcher wouldn’t be able to designate what’s good.

It’s important to note in this discussion that loudness, generally measured with decibels, could potentially be labeled “good” or “bad” in so far as certain levels are known to usually produce pain in humans. For example, the United States government’s Occupational Safety & Health Administration (OSHA) regulates how employers and workers behave around noise levels that approach 85 decibels. As music fans, we may boast about how the Slayer concert caused our ears to bleed, but sling a jack hammer or stand under 747 jet engines for eight hours a day and see how fun those loudness levels are. But that’s volume, not quality of tone.

With an entire industry surviving off musicians’ insatiable desire for the ultimate guitar tone, it seems obvious that some company would have cracked the code for the greatness. After all, corporate chain restaurants can quantify that if they use X of fat, Y of salt, and Z of sweet in their latest enormo-burger, then consumers across the country will salivate. Unfortunately, it’s not that simple with music.

“Music is ineffable,” says Scott Waara, product manager at Line 6. His company has built a business around providing the widest range of tones possible to guitar players. But even for a firm dedicated to dissecting tone, it’s not easy to reduce things to a simple recipe. “Everybody hears differently,” Waara says, “and the frequency response of everyone’s brain is different, so some things that are cool to some guys are not going to be cool to other guys. You can put it on a scope and see what’s happening on a frequency graph and you’ll see some tendencies and trends and so on.” The trends seen by the Line 6 staff seem to indicate that warmer, fuller tones are more generally accepted and considered “good.”

“Tone that emulates the human voice is always more accessible,” Waara continues. “Otherwise, purely electronic music would have taken over, and we wouldn’t be making guitars anymore. There are some absolutes in human DNA about wanting to feel connection and that’s probably a fuller frequency tone, that’s tone that is more reminiscent of the human voice. Or, for instance, a violin or organic instruments that have been around for hundreds of years. When we talk about guitars having an organic quality, it’s because that’s rooted in what human beings know. Which is air moving, wood vibrating, people speaking.”

Beyond those generalities, replicating a standard formula for the be-all-end-all tone isn’t possible. Why? Because some people will genuinely pass on a ’59 Les Paul and Marshall stack combination—they might prefer what sounds like a vibraphone under water. Sometimes, a certain “it” factor just grabs musicians and won’t let them go. Waara explains that even in a business as technologically advanced and specialized as Line 6’s tone research, “There’s no escaping that we emotionally say ’Man, that just sounds cool.’ ” Frequently, part of that “cool” factor is imprinted on our brains as a result of a component that we often overlook.

The Forgotten Factor
When guitarists sit around and debate tone, they pontificate on the properties of this instrument or that amp. But frequently there’s a factor in the equation that is forgotten. Our templates of what we consider to be great tone are not simply a formula of instrument + amps + musician. Recording studios also play a vital role in the creation of those sounds.

“Most guitarists learn from records,” says Dr. Andre Millard, a professor at the University of Alabama-Birmingham, editor of The Electric Guitar: A History of an American Icon. “That’s how you learn to play. We learn from the classic records. And those classic records have that classic tone, which is ’58 to ’63.” And quite frequently, Millard points out, the studio had as much an impact on those recordings as anything else. He uses the Rolling Stone’s debut, England’s Newest Hit Makers which was released on London Records in 1964, as an example.

“It had ‘Walking the Dog,’ ‘Route 66,’ and others on it,” Millard says. “That has tone. The reason it has tone is that it was made in the worst damn studio possible. Everyone who worked there said this was a shithole. There was no sound separation, they used lousy mics, they never cleaned it. Andrew Loog Oldham, who was the manager at that point, said that was the key to the sound.”

But the question remains, was that environment good for the artists or for the equipment? Think of it this way: experienced chefs know very well the value of a seasoned pan or grill. Flip on any show from the Food Network and you’ll see cooks bragging about their 30-year-old griddle and how it imparts an amazing flavor to their corned beef hash. Preparing food leaves behind actual physical substances, unlike immaterial sound waves, so that comparison doesn’t work exactly. But the dirt and dust and grime could certainly effect the equipment. In a similar way, we have to ask ourselves, was that dirty studio, then, a source of inspiration or were the dirty, beer-smelling microphones actually improving the music? Regardless, the studio imbued the recording with an undeniable quality. Many guitar nuts can identify a particular instrument while listening to a song. Recording experts can do the same thing with studios.

“Back in the fifties and sixties, you could tell what studio they had been recording in just by listening to the song,” Dr. Susan Horning Schmidt says. She is a professor at St. John’s University who has researched and written extensively about sounds and the recording process. During the period Dr. Horning Schmidt is referring to, the recording facilities were also physically bigger and bands often played together in a more live-type setting. Horning Schmidt states that “there’s a lot more space in the recording, a lot more acoustical space and dynamics.” Unfortunately, we’re losing that space with contemporary recording and production techniques.

However, even for recording experts who can discern if something was done at Columbia Records Studio A or Olympic or wherever, it’s challenging to define a percentage of influence that the studio provides. “I don’t know that you can measure it in any way. It’s really more an ineffable quality of sound and aesthetics,” Horning Schmidt says. “You can measure frequency response and you can measure decibels but in my research I’ve found that back in the thirties and forties, you had engineers saying ‘you can’t just go by the meters. You have to use your ears.’”

This happens when discussing variables within a number of different art forms—you simply can’t rely on scientific equipment to make some assessments. You can’t trust the gadgets; instead, you have to rely on your ears. Even relying on your ears can be difficult because it is, once again, a subjective discussion. “We don’t hear what’s out there,” Millard says. “We hear what we think we hear. It’s the psychological or neurological way we hear. To think we hear what sound is out there is so naïve and so wrong.” Trustworthiness aside, this brings us to another concept that pops up frequently when discussing the nature of tone: the role of good old fashioned, organic, human beings.

The Human Element
As part of his Alien Music Secrets course, virtuoso Steve Vai often talks about a day when Eddie Van Halen paid him a visit. EVH stood in Vai’s home studio, picked up Vai’s guitar, played it through Vai’s effects, through Vai’s amps, and out came the classic Van Halen tone.

Similar stories abound—you can simply substitute Big Name Guitar Player X in any number of variations. In The Million Dollar Les Paul: In Search of the Most Valuable Guitar in the World, author Tony Bacon quotes an expert in guitar restoration who uses Jimi Hendrix as an example.

“He played an SG, a Les Paul, a Flying V, as well as a Stratocaster, but he always sounded like Hendrix,” Clive Brown states. “He didn’t suddenly sound like Jimmy Page because he played a Les Paul. That’s where everybody’s perception seems to go wrong. It’s the playing, and not necessarily the guitar.” In spite of an entire multi-million dollar industry revolving around selling musicians the latest gear, and in spite of thousands of axeslingers, aspiring and acclaimed alike, who readily gobble up that gear, it all seems to boil down to two implements— and we’re born with those.

“The tone thing is amazing because you can have one rig, have three different guitar players, and each guy can play the same exact thing and it’s going to sound different,” says L.A. Guns guitarist Stacey Blades. “It’s all in the hands.” Waara from Line 6 agrees. “Any guitar player will tell you, at the end of the day, it’s in your hands and you will sound like you will sound,” he says. The percentage of influence the hands wield is shockingly high.

Berklee College of Music professor Thaddeus Hogarth thinks the hands and the human element accounts for almost all of what we consider guitar tone. “Providing the instrumentation and the amplifiers are above a certain quality and in the general ballpark, I think it’s safe to say that we’re talking 90 perecent,” Hogarth says. In his classes and on his blog, The Quest for Good Guitar Tone, Hogarth argues that much of a guitar player’s tone is based upon the attack more so than the sustain. “If you take away the first second of the attack of a note played on any instrument, it is often very difficult to determine what that instrument is and certainly impossible to identify who played it,” he writes on the blog.

“It is the initial attack that the listener uses to identify a sound, since, if the sustain is removed, it is perceived only as that but does not make the sound difficult to identify,” says Hogarth.

Of course, as guitar players we still want to remain open to a number of tonal aspects that happen after the front end of the initial attack. These elements aren’t necessarily in the front part of the very beginning of a guitar tone, nor are they delegated to the trail of lingering sustain. “The reason why people sound a certain way is because of little nuances, those little pull offs, those hammer ons, those plucking [dynamics]— the sequence of those things. Think of it as a sonic palette. That sequence is what makes the artist sound like himself.”

By deleting the front part of a note, Hogarth has an intriguing and innovative teaching mechanism to convey the concept that the human element is all powerful in the quest for good tone.

Ultimately, his thesis is shared by every single person interviewed for this article. It simply does not appear that there’s any way to objectively measure what is “good” guitar tone. A major reason for that is the infinitely varied human element of the musician performing and the audience listening. The impossibility of proving anything doesn’t, however, change the fact that so many guitarists revere those early tones. Some argue that’s because the early days were just better. Others point out that we’re simply intransigent.

Adherence to the Past While acknowledging the impossibility of scientifically proving tone, many guitar players will still argue vehemently for a classic Les Paul crunch, or they’ll get ready to throw down if you claim solid-state amps sound better than valve amplifiers. They will concede the point intellectually, but on a more deeply rooted, emotional level, they can’t get beyond their own perspectives. It’s almost like observing fire-walkers at the circus. Your brain may understand how the technique works and how it can be safe. But your heart and nerves won’t let you take the chance of barbecuing your feet.

“Rock guitarists are incredibly conservative and traditional,” says Dr. Millard. “We like to think of ourselves breaking all the bonds and we go back to the fifties when rock and roll was revolutionary. It is not revolutionary. It is very traditional, very conservative, and musicians are really stubborn to change. We have a cultural understanding that old is better than good.”

As other articles in this series on tone argue, so many psychological and cultural factors change our perceptions. Ultimately, it’s not a question that science can solve.

“Tone is everything to guitarists,” Millard says. “That’s what we all talk about. But a big part of the answer has got nothing to do with tone. It’s got to do with other things that are not tone related. It’s that sound, but it’s also the look and it’s also whatever memories and prejudices and desires and yearnings we already have in our mind.”

Next month—don’t miss part III, The Cult of Tone, in which we explore the concept of religion in tone. Do all belief systems allow the heart to rule the mind?

     

There is a lot to say about cables, quality, affect on your signal, etc. I'll try to explain the fundamentals of guitar and speaker cables, signal loss and the help of buffers.
One important note: never use a guitar cable for speaker connections and vise versa!

Guitar cables 
The output signal of a passive electric guitar is weak (high impedance) and directly influenced by the capacitance of cables and the impedance (resistance) of the used effects and amplifier inputs. When you only use a short guitar cable of high quality you won't notice much signal loss. But when you use several effects and longer cables, the loss is apparent for most people. Typical signs are loss of highs (brilliance), less clarity, weak low end, mediocre attack, etc. To prevent this low capacitance cables should be used, in combination with a way to change the high impedance signal of your guitar to low impedance.

For normal guitar cables the most important factor regarding the signal loss is the capacitance of the cable. This is measured in pF per metre or feet. If the capacitance of the guitar cable is high then you will notice that your guitar lacks some presence/highs. Sounds a bit like you've turned your tone control on your guitar down a fraction. Because capacitance is directly related to the length of the cable, the longer the cable the more noticeable the signal loss becomes.Now there are some guitar players who love the way their guitar sounds with long guitar cables, but I rather have this factor over my sound more in control. Due to the low power nature of the guitar signal, resistance is not really a factor.

A standard guitar cable has a capacitance of aprox 120 pF/m, a good cable has a capacitance below 100 pF/m and a high quality guitar cable has a capacitance below 50 pF/m. So a standard guitar cable of 6 metres has a capacitance of 720 pF, while a high quality guitar cable would have a capacitance of 300 pF. How important are these figures? Well connect a guitar cable of one metre between your guitar and amp and then change it with a cable which is 6 metres. Most guitar players will notice the difference.

What can you do to prevent signal loss? Well there are several options:
   1.   Live with it,
   2.   Buy extremely expensive low capacitance gold/silver audio cables,
   3.   Buy active pickups for all your guitars,
   4.   Buy on board preamps for each guitar you own,
   5.   Buy an effect pedal which slightly boost the signal,
   6.   Buy a unit which changes the impedance, such as the VHT Valvulator,
   7.   Use a cable with a built in buffer.
Option 2 is a pretty nice solutions if you are a purist, but will cost you a fortune. The most cost and signal affective solutions are 3-7. They all change the impedance of the guitar and "protect" it against signal loss. Changing the impedance does not have to influence your sound, sometimes they are designed to boost the signal as well with some extra volume.

Because options 1-6 all had their down sides for me, I worked on a cable with a built in FET buffer placed in the jack that goes into the guitar. That way all my guitars have a buffered signal and I don't have to modify anything. The signal has improved a lot: besides the restored highs, I also noticed the clarity was much better, the attack more defined, the low end became powerful and the response of the volume knob was better. But best of all, when compared to a short high quality cable there was no change of my sound or the volume!  For more information on the buffer, check the Briljant Box Custom & Reactive Cable and the Guitar Signal Buffer page at the schematics section.

Shielding
To prevent noise, hiss, radio interferance a good shield is vital. Especially when you run them next to adapters, mains cables, transformers, etc. Never use cables with foil shielding, they will make a lot of noise.  Although the "armoured cable" does an excellent job in shielding, the quality of the cable it self is quite poor, so do some research before you spend money on hoaxes.

Materials
Most cables are made from oxygen free copper (OFC). Many high quality cables use silver and gold. The difference in conductance between copper, silver and gold won't be noticed too much. The main advantage is the way they react to oxygen. Silver and gold are more prone to to this and this prevents the cable from getting "rusty".
Cores
It's preferred to use a cable with two cores and a shield, like a standard mic cable. They can be soldered semi symmetric which is the best way to prevent noise. For more on this topic see the Cable Wiring - Semi Symm page.

Connector
Always use high quality (jack) connectors from brands like Neutrik or Switchcraft. They are designed to survive road abuse. There is nothing more irritating then unplugging your cord and finding out that the tip of the connector broke off and is still in the amp.
 
Speaker Cables 
With guitar signal cables, the capacitance was the most important factor, with speaker cables the resistance of the speaker cable is the key factor. Which is measured in most cases in Ohm/100 m or in Ohm/km. Anything from 6 Ohm/km is good.

Speaker cables are different from guitar cables. They have no shielding, but two thick cores. The more power your amplifier produces the thicker the cores have to be. For normal guitar amp use a 16 gauge cable would be a good choice. For minimum signal loss it's recommended to use 12 gauge speaker cables for 100 watt amps or longer speaker cables. The resistance of a 16 gauge cable is more then doubled, compared to a 12 gauge cable. Using even lower gauge (thicker) cables wouldn't give much more benefit. And finding suitable connectors will be quite difficult.

When you open a Marshall speaker cabinet you'll notice they use very slim cables. Upgrading to 16-12 gauge cables will improve the sound of the cab. Bogner for example uses 12 gauge for internal wiring of all their cabinets.

There are a wide variety of speaker cables available. When you buy it, keep a few factors in mind:
Gauge (how thick is it)
Resistance
Materials
Ease of use
A lot of people who are on a tight budget use lampcord as speaker cable, although this is a far better choice then a guitar cable

www.tubefreak.com/cablesbuf.htm,

True bypass, as often referred to with effects pedals, can be thought of as a straight wire connected from the input to the output of a pedal. With a true-bypass pedal, when the pedal is in bypass mode (off), the guitar signal is routed directly to the guitar amplifier without any of the interference, loading or buffering effects that are often caused by the pedals that are in between.

The easy way to check if a pedal is 'true-bypass' is to disconnect the power and see if the guitar signal passes through the pedal when the effect is off. (Make sure you toggle the on-off footswitch so that you is set to off or bypass to check this.)

The philosophy is simple: with 'true bypass' pedals, by connecting the instrument directly to the amp, the original tone of the instrument is retained and you enjoy a more natural tone and better feel. The question therefore beckons: If true bypass pedals are better, why aren't all pedals true bypass? Well the answer is complex and often a matter of trade off.

Most pedals are NOT true bypass because true bypass pedals 'in theory' are great but in practice, often introduce problems of their own. For instance, true bypass pedals are notoriously bad for switching noise. This is most audible when playing through high gain or distorted amp tones.

With pedals like a chorus, delay or reverb, the input buffer is the circuitry that is needed to drive the signal into the effect chip that makes it work. A buffer is in fact a pre-amplifier. Buffers are used EVERYWHERE in audio where a signal is driven with a power source. The battery powered built-in pre-amp in your acoustic guitar is a buffer. Your active bass is driven with a buffer. The input to your mixer or tape recorder is buffered. And all effects pedals from wahs to fuzzes employ buffers to make them work. Turning these pedals on or off usually introduces a popping transient when the circuit is charged that can be very loud. So the way around the problem is to simply never turn the buffer off. They are buffered and therefore not true bypass.

Buffers have several advantages: You can drive longer cables with less noise; have a tuner connected with less interaction; and loading no longer becomes a problem as you gang a bunch of pedals together. So clearly, buffers are great right? No, not necessarily. Buffers introduce another problem: you no longer are connected to your amp. Your signal is now active or buffered and invariably the buffer is altering the tone of your guitar! The quality of the buffer becomes a major issue.

So what is the solution?

It comes down to making choices. If you are a tone nut and want true bypass performance as if you are connected directly to your amp, then you need to make sure all of the pedals you are using are true bypass. Be prepared to live with some switching noise. When you connect devices like a tuner to the circuit, the tuner will immediately load down your pickup and thin out the tone. And of course forget about using a chorus or reverb in-line as these will almost certainly be buffered and not true bypass.

But what about long cables, noise and driving more than one amp?

Well, this is where buffers come back into the picture. Without a buffer, each time you introduce another pedal or a cable, more noise gets into your system. This is because guitar pickups are high impedance devices that are particularly susceptible to noise from power transformers, LCD screens, power cables and stage lighting. Furthermore, if you extend the hi impedance cable more than 20 feet, the tone of the instrument will change due to the capacitance of the cable and of course more noise will enter the circuit. Then of course there is the strength of the guitar signal itself. If the guitar signal is divided in two to drive two amps or in three when you ad a tuner, the tone will be severely altered.
The ONLY solution to circumvent these problems is to introduce a buffer. But wait a minute... Buffers sound bad do they not? Actually, it depends on the quality of the buffer and this once again comes down to making choices.
Most pedal manufacturers employ pre-packaged ICs (integrated circuit chips) to buffer their signals. These class-B chips are wonderful because they are designed to be extremely efficient, quiet and very compact making them perfect for pedals that employ 9V batteries that would otherwise quickly run dead. These chips are also really cheap! This reduces costs at manufacturing and best of all, because they are really easy to use and come with great application manuals from the same guys that make cell phones, anyone with basic electronic knowledge can use them.

Only one problem.... They sound bad.

Why? Well - Guitars are not buffered sources like an iPod. Guitars are musical instruments.   They breathe and spit and bark and cry. They are alive. For a buffer to work, you have to treat the guitar as if it is seeing the world's best guitar amplifier.  As soon as you connect a pre-packaged frozen dinner in between the pickup and the amp, the instrument becomes detached. It just is not the same. It is the way that the guitar reacts to the circuit that completes the instrument.

It is worth noting that class-B buffering chips divide the signal into two halves whereby the positive and negative portions of the signal are amplified separately and then recombined at the output. This yields much greater efficiency and less noise, but the trade off is the introduction of zero-cross distortion as the two halves are brought back together. Zero cross distortion causes phase distortion and inter-modulation distortion which are primary contributors to bad sound.

As any toneaholick or audiophile knows, the preferred method is to use a single amplifying devices to do the job. This is known as a class-A buffering circuit. Unfortunately, because Class-A circuits never shut off, they are very inefficient and draw a lot more power. This makes them impractical for 9V supplies as they need more power to achieve sufficient headroom. Furthermore, unless they are designed very carefully, they are much more prone to noise which as you know by now is a major concern with high impedance guitar circuits.

The cool thing is that because we are dealing with guitar signals, we do not care about being efficient. Our only goal is great sound.

 by Peter Janis President of Radial Engineering
https://www.musictoyz.com/guitar/pedals/choptrue.php

EQ Tips

Use an EQ pedal to reshape the guitar tone into the amp, or in an effects loop to modify the entire tone of the amp.

(many of the first tube amps to have EQ's in them, just had existing pedals transplanted into the amp!)

An EQ pedal can be used as a booster too - set all the sliders even and boost the gain.

Pickup King Lindy Fralin uses this trick into his collection of Gibson and Torres amps to great success.

Use an EQ before a distortion pedal to shape the overall tone more than the distortion pedal's tone controls can!
http://www.torresengineering.com/eqideas.html

Compressor Tips

Compression pedals and effects can be confusing. The normal understanding is "sustain, sustain, sustain." But your favorite "sustain kings" such as Carlos Santana DO NOT USE compressors to achieve the sustain!

(that is why we build all tube amps, correctly designed tube amps have a very musical compression effect when pushed hard.)

The compressor is better understood as a "dynamic control" effect. You can set it to even out your volume no matter how you attack the guitar. Absolutely fabulous for playing rhythm guitar - once you try it, you will always use it for that. You can hit the guitar as hard as you want, and the compressor will even out the volume keeping your sound exactly where you want it in the mix. THE trick for playing funky clean backup rhythms.

Compressors are also the other pedal that is best as a "compound pedal." Add a compressor BEFORE your distortion pedal and get tons of very smooth sustain from the two pedal combination. - again perfect for playing super distorted rhythm with lots and lots of "hold over" of the chords. Makes you sound big, and very professional.

For a very clear example of compressed lead guitar, listen to the lead in the old Carly Simon song "You're so vain."
http://www.torresengineering.com/comtec.html

Terminology

This is like shopping for single malt whisky - you have to check the terminology very carefully. If the broschure says anything other than "True Bypass" (in that order, with no other words in between), assume that the switching is one of the other variants. If it actually says "True Bypass", assume they are lying, and investigate...

Hardwire bypass (sometimes even called "true hardwire bypass"): This only means that the switching isn't electronic. In 90% of the cases, it's the good old half-assed bypass with a buffer section in front, to ease the signal loading. In the final 10%, the pedal simply doesn't have the buffer. For instance, MXR uses a buffer at the start of the effects circuit, which is designed to present a high enough input impedance to be "electrically transparent" - the idea being that the electrons will not even try to move that way, when the bypass line is open. I've even heard Dunlop techs repeatedly refer to this system as True Bypass. Well, it isn't. True Bypass depends on the effects circuit being physically disconnected from the input signal, in bypass mode. But does the Dunlop/MXR system (sometimes referred to as "electronic true bypass" - an oxymoron if I ever heard one) work as intended? Not really - it may be as "invisible" as it wants - it will still drop the overall input impedance the pickups "sees", compared to when it's active (thus changing the tone).

There's one exception to the above - Digitech markets a line of pedals under the name "Hardwire", and contrary to their name, they actually seem to be true bypass for real. They use relay switching to provide true bypass in a Boss-esque stompbox, and according to their own description, the circuit is disconnected at both ends in bypass mode, leaving only a straight in-out connection. True bypass, in other words. Thumbs up for Digitech (although the pedal series' name can be a little misleading in this case).

Also, MXR have recently put out at least one pedal which is actually true bypass, namely the Carbon Copy Analog Delay. It uses the same switch as the others, but uses a Millennium-type circuit to run the LED, which means they can now have true bypass. I'm not aware of wether this system is in use in any other of the new batch of MXR pedals (GT-OD etc).

Hardware bypass: A variant on the above, used by Hughes & Kettner. In their sales blurb, they say: "The sophisticated hardware bypass ensures the instrument signal remains 100% unaffected in the bypass position." Very interesting... but no cigar. The wiring is the same as in the earlier example. They even go so far as reference the MXR system, but they stop just short of calling it 'True Bypass'. Read here: "The TUBEMAN features a real audio treat, the hardware bypass. This type of signal routing, popularized by the MXR® Classics, ensures the instrument signal remains 100% true and unaffected in the bypass mode." Pffft...

True (hot-wire) bypass: I just spotted this one, and frankly I don't know what it is supposed to mean. Or rather, I know what it is supposed to make you think it means, but I don't know what it really means. My hunch is that it's the same as the other ones - a direct connection from input to output, but with the effects circuit still connected.

Split bypass: This term was introduced by ModTone effects, and so far I haven't been able to verify exactly what it means. It does, however, sound suspisciously like the mechanical output switching system used by MXR/Dunlop etc. And since they advertise some pedals as having buffered bypass and some as having true bypass, they don't seem to use the "split bypass" as a decoy. So it probably is the MXR-style mechanical output switching, but without trying to pass it off as something else...

Virtual bypass: This can be anything, really. Many times, these pedals have a round metal stomp switch that control the switching transistors in an electronic switching arrangement. Other times, it is the same as the Hardwire bypass, with a buffer to ease the loading, with extra high input impedance. Again, the theory is that once the gateway directly to the amp (via the switch) is opened, the high input impedance of the effect will make it "invisible" to the guitar signal. It's a nice heory, but it doesn't work in practice... no. (I have seen this on Diaz pedals) "mojoe"

Passive bypass: Used by Marshall, among others. I'm guessing it denotes a mechanical switching system of some sort, and I'm also guessing that it is the same output switching system as in the others. After all, if it were true bypass for real, they'd definitely want to use that term...

© Andreas Möller 2002 - 2008 aka Stinkfoot Electronics

Because some designs can noticeably change the sound of your guitar. You may be using any given effect only 10%-20% of the time, but your signal is going through each pedal/processor 100% of the time. So the issue of bypass is surprisingly important.

In order to decide what is right for you, you will need to listen to the products available. To properly audition the difference between these circuits, always test one pedal/processor at a time, using the same exact setup. This means the same guitar and amp with the knobs set at the same levels. More than one effect in the chain could give you false results, depending on the location of the unit in the signal chain.

Of course, in the end, what really matters is that you are happy with the sound. So use your ears, make your own decisions based on the sound, and don’t believe any hype. After all, Jimi did pretty well without “True Bypass.”

Set-Up Tips and Tricks:
1. The bypass circuit in some pedals can be improved by using a double-pull double-throw switch in a true bypass configuration:
a) Vintage pedals using a single-pole double-throw switch.
b) New or reissue pedals using a single-pole double-throw switch.

On the other side of the coin, some pedals will not benefit from a true bypass mod --sonically or mechanically: Boss® and Ibanez® type pedals.

2. You can overcome the sonic shortcomings of the true bypass switch by buffering your guitar’s pickups. This can be as simple as placing a pedal with a buffered bypass between your guitar and the pedal with the mechanical bypass.

3. Make sure you are supplying enough power to your active bypass pedal. A dying battery or weak power supply will reduce the amount of headroom.

4. Make sure you are using quality cables to connect your pedals.

by B. Andrew Barta
President
Tech 21 USA, Inc.

Players often wonder if it’s necessary to put the speaker through some sort of break-in process. Technically speaking, there is no benefit to the life of the speaker or other glaring justification for it—other than to avoid going through a phase where you’ll notice changes. Often, it’s even fun and enlightening to experience playing through the break-in period. However, you wanted your tone to be like your buddy’s, so you’d like to get there now, right? If that’s the case, you may want to consider some sort of procedure to get your speaker sounding the way it will be expected to for the majority of its usable life cycle. Let’s talk about how you can do that.

1. Recorded music is one of the most common methods to induce break-in. A good stereo receiver playing music at moderate volume for several hours or even days is a safe and reliable method. Use good judgment, and don’t overpower the speaker or feed it tons of low-frequency material. If it is distorting, you’re probably damaging the speaker. Get as much cone movement as you can, but you will know when you’re going too far.

2. Physical movement certainly works, if you have the time to sit there and work the cone up and down. I don’t recommend it, though. You could damage the speaker—or reinforce your significant other’s view that you’ve taken this guitar thing way too far!

3. Hanging speakers face down is often suggested as an option. In reality, that promotes suspension sag, which can displace the coil in relation to the top plate. This is not breaking the speaker in, but likely changing the intended tonality of the speaker forever. The stiffness of the suspension components hasn’t changed with this method, right?

4. Variacs are variable AC voltage controls with distortion-free output. This source will get the speaker moving, typically at 60Hz. If you can get your hands on one, it is a great way to break a speaker in.

5. Noise signal generators are my personal preference, accompanied by a multimeter to read the output voltage, and a frequency counter to read frequency. I’ll play a 20Hz–30Hz sine wave through the speaker with 15V–20V for four to eight hours. It’s an effective method, but pretty abusive. You have to use very good judgment in setting it up. I’ve been known to burn up a voice coil by mistake. This is likely not a practical solution for most people, because the equipment is not readily available.

6. Just playing it is a safe and reliable method. Play it hard and play it loud to shorten the time required. Don’t damage your hearing by any means! Fifty to a hundred hours should get you to the point that you no longer recognize tonality changes.

Anthony “Big Tony” Lucas
is a guitarist and Senior Lab Technician at Eminence Speaker LLC, where he specializes in guitar-speaker design and customer support. Big Tony has been with Eminence for over 10 years and is responsible for many well-known guitar speaker designs.

premierguitar.com

A Few Things to Consider...
Usually (not always) a higher wattage handling speaker—let’s say 30 to 75 watt range—means a clearer, broader frequency range from lows to highs. Lower power handling—roughly 15 to 25 watts—may be more midrangy, with less defined lows and quicker breakup. Do you go for super clean? Historically, players would gravitate towards JBLs, Altecs and EVs rated for 100 to 200 watts. If you have a higher-wattage combo, around 100 watts or more, definitely buy a higher rated speaker or get proper advice.

Also make note of the “SPL” or “Sensitivity” rating of a speaker, which usually ranges between 96–100dB, the latter being louder. Some old speakers from the sixties must have had a rating of 50dB! I’m exaggerating, of course, but when these are replaced, the amp’s volume and tonal spectrum can increase dramatically. Is your combo too loud for your gig? Consider dropping to a lower sensitivity rated speaker. Make sure you match the speaker’s impedance rating to your amp’s output impedance, most often either 16 or 8 ohms.

As for personal faves, I’m more of a Celestion guy. The G12M-25 has great crunchy midrange. The G12H-30 Anniversary and Heritage 55-Hz has more clarity than the 25, and is good for clear, clanging rhythms. Blue and Gold Alnicos have that “in your face” Alnico mag crunch. Vintage 30s and G12T- 75s in Master Volume amps are great. I love vintage Jensens in my Fenders, namely the higher wattage Concert or Vibranto series from the sixties. I’ve also experimented with Altec 417s from the late sixties and early seventies, which are very cool, along with the JBL E120 & K120 series.

Peter Stroud
Peter is co-founder of 65amps.
sherylcrow.com
65amps.com

Basically, the big divider is distortion. Some effects definitely sound better or more balanced when placed after distortion (such as delay and reverb), while others just sounds different (chorus, flanger, phaser etc). Tremolo before distortion will vary the amount of distortion much more than the actual volume, which may not be what you want. So, here goes:
   •   On an amp where you use the distortion channel, you may want to try at least delay and reverb in the loop. If you have a tremolo pedal and plan on using it on the distortion channel, stick it in there as well. Chorus, flanger, phaser etc are up to individual taste, and should be experimented with. Also, sticking a booster or eq pedal in the loop will give you far greater control over the overall volume, compared to in front of a distorted preamp.
   •   On a clean amp (or at least one where you don't heavily distort the preamp), I never bother with the loop. Taking the signal out of the amp (and lowering the level to fit stompboxes, then re-amplifying it again) can damage the tone far more than any benefits you'd reap from moving certain effects after the tone controls.
   •   If you distort the amp simply by turning it up to ear-shattering volume (as we did in the good old days), don't bother either. A lot of this type of distortion usually comes from the power amp stage anyway, which is located after any effects loop...
One final tip - if you have an amp that has a serial effects loop placed after the reverb, you have the perfect place to hook up a tremolo pedal. That way, the tremolo will most closely mimic that in a good old Fender amp (i.e. tremolo-ing everything, including the reverb), which sounds great!
But don't let anyone tell you that you have to use the loop for certain effects - nothing is that simple, and there are no universal truths!
http://www.stinkfoot.se/andreas/diy/articles/loop.htm