GT Rack Effects Remote Switching
It is obvious that if your effects are in a rack, you probably won't be sticking your foot into a rack to switch them on and off! For any racked effects to be used conveniently, they need remote switching capabilities. That is the main function of our module switching.
Rack Effect Switching
The footswitches on guitar pedals turn the effect on and off. Some pedals may have an extra footswitch or two to turn specific effect features on and off (eg a Boost switch) or switch between features of an effect (eg Channel Select or ABY switching). The vast majority of pedal switches are used in those ways. There are a few other functions you see from time to time (eg Tap Tempo), but mostly the footswitches are performing very simple functions. Our current switching system performs those same types of functions - turning effects or features on and off and selecting between features.
You don't have to look far to find opinions and discussions about the merits of different types of switching technology and design. For a while, "true bypass" would seem to be the only acceptable type of switching on the planet. Those words seemed to be in the description for nearly every modern pedal, and its specific meaning has become a little less clear. One thing that seems pretty clear is that the debates about switching will probably continue for as long as there are switches.
We view these discussions from a slightly different angle here at GT. When you get down to it, what is really important? First, whatever technology you choose, the switch must work. When you push the button, it should switch. Obviously, every reasonable switching technology meets that criteria, as long as the switch isn't somehow damaged, connected incorrectly, or experiencing some similar problem situation. The switches work reliably, conveniently, in an easy-to-understand way. No problems there.
The other important aspect of switching for us, and the subject of much of the debate, is whether or not the switching technology changes your tone. That is a very valid concern. Over the years, different switching methods and circuit designs have been used in guitar pedals. In many popular pedals, the combination of switching design and effect circuit design most definitely impacted tone, even when the effect was switched off. In some cases, particularly decades ago, the cost, availability, capabilities, and reliability of switches influenced the circuit design. In some later (and current) pedals, the designer intends for the pedal to impact the audio signal even when the pedal is off. We won't debate the merits of the switching methods selected or designed in any of those cases. The point is that these weren't accidents, they were decisions. Perhaps a decision to select from among unattractive options available, but decisions none the less. It isn't so important to us that specific switching technologies work differently, perhaps impacting tone. What is important is the designer's choice to do that. It isn't the "fault" of the technology. It is a design decision. The facts are the facts about the switching technologies. But the reason some pedals impact your tone even when they are off is because someone decided that was OK.
GT Switching Technology
We made design decisions about our switching, just as everyone else has. We picked a simple, inexpensive electronic switching methodology that met our design criteria. In addition to being reliable, we wanted switching that didn't have any audible impact on tone. Due to our overall product design, we added some additional constraints. The footswitches would have to work a considerable distance from the effect circuit. We didn't want to require additional cabling to the footswitch for power. We didn't want to use any exotic parts that were expensive or difficult to find. We didn't want any custom cabling - we wanted to use something widely available for cheap and easy replacement. We wanted it to handle all the types of switching functions that are commonly found in guitar pedals. We wanted it to be rugged and easy to maintain. We didn't want the audio signal to travel through long cable runs. We wanted it to be simple, not requiring any programming or technical training for users. And we absolutely cannot tolerate electronic switch popping!
Even with our rather lengthy list of requirements, there were still multiple technologies that we could have investigated and probably found acceptable. So we made our choice, built numerous prototypes, and tested and tweaked our design until we were satisfied that we had a solution that met all those requirements. At the time, we thought we were doing something clever and unique in the pedal world. But as is almost always the case, about anything you can think of related to pedal and effect design has also been thought of and tried by others. So we discovered that others had also looked into the approach we chose, and we even found one case where another manufacturer was using the same technology. As a result, even though we thought we were doing something original at the time, we certainly can't claim to be the only ones using this approach. But it is still clever! And it works great.
We selected a common CMOS switching IC that has been around for a long time, and designed our switching around it. Like classic effects circuits themselves, this is a bit "old school", and is all analog. That's our choice. No doubt, some will discuss that technology and point out that whether our effects are on or off, the audio is passing through that IC and the tone is impacted. Yup, that's true. Tone is also impacted if it passes though 1mm of solid gold, cryogenically treated, sealed in argon, braided in a secret proprietary manner, and costing $100,000/inch. You can't conduct electricity without impacting it, regardless of your switching or cabling technology. The only real question to ask is whether that impact is audible. And you don't even have to ask the question. You can just listen. With true mechanical bypass switching, whether the effect is on or off the switching adds a very short length of wire to the signal path. Assuming proper construction and function, human ears cannot get even remotely close to hearing the extremely tiny difference in the sound caused by that extra inch or so of wire. In our opinion, it is silly to even discuss it for all practical purposes. The situation is pretty much the same with the CMOS switches we use. They have the same inaudible impact as adding a small piece of wire in the signal path - again, assuming you use them correctly, as we do. Nor do they add any audible noise or distortion. Theoretically, sure - in practice, no. The key is "audible". But since we're dealing with sound and tone, "audible" is the criterion that matters. You can hear clear, clean tone through these switches. Of course, we're still in the world of analog sound, so noise can creep in, but there is no "extra" source of audible noise in our switching design.
What about switch popping? Let's take a detour and discuss what actually causes popping. A popping sound can be produced when you connect two different voltages in your audio path. Something about those different voltages coming together does that. If you want to avoid popping, you avoid that specific situation. Turns out that when you're switching, it is practically impossible to avoid connecting two wires carrying different voltages. That's kind of what switching does. So the problem can be changed into something else that we can manage. If turns out that the further apart the two voltages are, the louder the pop. So if you can get the voltages to be very close to the same, the pop is so quiet that it cannot be heard. That's actually pretty easy to do, and we do it. That's why you won't hear any popping in our switching. In fact, if you don't get the voltages to be near each other you can have popping regardless of what type of switching you use. In other words, managing what you are switching to and from can be more important than how you actually switch, when it comes to popping.
Let's take this to one more level of detail. In effects circuits, your incoming guitar signal is an AC electric signal. You probably know that means it is a combination of sine waves, with the voltage peaking at some positive value, dropping through zero volts, becoming negative, and climbing back up to zero before repeating the whole process over and over. You may also know that the voltage your pickups produce is very small, usually somewhere around 0.1 to 1.0V, perhaps a bit less for low-output single coils or a bit more for high-output active humbuckers. One of our test strats produces around 70mV, or 0.07 volts. Of course that means it varies from -0.07 to + 0.07 volts, depending on the exact timing of the sine wave when you measure. Hold this thought for a moment.
In effects, you will also encounter DC current. Almost always DC is used to power the circuit. Sometimes DC current gets added to or removed from your signal for various reasons specific to that effect circuit and its components. DC electricity doesn't vary in a sine wave the way AC does. DC voltage remains constant, with (usually) very slight fluctuations. DC voltages in pedals can be much higher than the AC guitar signal, from 9 to maybe 24 volts are common, usually positive, but sometimes negative.
Now, back to the popping. It is probably obvious that if you are switching a signal with DC voltages, you have a mathematical possibility of having a voltage difference of several volts, between wires carrying different DC voltages. A voltage difference of that size is very loud and you will definitely hear it. There are multiple ways to avoid it, like making sure you have the same voltage on both wires before you connect them, or maybe removing any large DC voltages before you switch.
You cannot remove the AC audio signal. That's the signal you want to hear in the first place. Without getting even further down in the details, we'll just say that when you switch AC signals you can't generally guarantee that you can have matching voltages on both wires at the exact instance in time and position on those sine waves. You will almost certainly have a voltage mis-match, resulting in a pop. But recall that the AC voltages are much smaller than the typical DC voltages. In a common switching situation you will be connecting your AC voltage to a wire with 0 volts, or as near zero as the real world permits. So the voltage difference would likely be somewhere from 0 to 0.07 volts in the case of our testing strat. Or perhaps closer to 1V with high-output active pickups in the worst case. Can you hear that? Sometimes you can. If you are closer to the low end of that voltage difference, you either can't hear it or you can hear it only in a silent room with your volume cranked up. How about those high-output pickups? Maybe, but it will likely be faint, maybe inaudible. This is independent of the type of switching employed.
So does our switching pop? Yes, as does every type of switching. The key is whether it is audible or not. Try this. Get your quietest pedal with the best switching technology on the planet. Get your guitar that has the quietest high output pickups that you have. Plug the guitar into the pedal and the pedal into your quietest amp. Crank the amp volume up. Switch that pedal on and off repeatedly, with and without playing any notes on the guitar. If you do it enough times, chances are you'll hit the timing that maximizes that tiny voltage difference and produces a faint pop if you listen closely. Sorry, I know you paid a lot for a pedal that doesn't pop, but it does! That's not a very realistic situation though. During normal playing or even when you aren't playing, that pop is inaudible. Or maybe you couldn't hear it even under those conditions - great! That's as good as it gets. That's how our switching is. The popping is inaudible under anything like "normal" conditions. If you can't hear your "silent" pedal pop, then you shouldn't be able to hear ours pop, either.
We won't go so far as to say that anyone telling you their pedals don't pop is stretching the truth or maybe misleading you a bit. We just think they really mean that under normal circumstance you won't hear any switch popping at all. That's what we mean. The higher the voltages (and gain and volume) that are produced in your setup, the more likely it becomes that a "silent switching" pedal (or our module) will begin to make faint audible popping sounds sometimes.
That's a lot of words to say "our modules don't pop", but we hate popping so much that we get a little fanatical about it.
I don't care about all the details, just tell me how it works!
No problem! Most of it is really simple. In our Modules discussion we already described the most likely way you'll set it up and use it. Let's go through it again, touching on some options and extras along the way.
There are three main components to the switching system: footswitch units, switching modules, and switching boards in effects modules. All that's really going on is you are connecting a switch on the footswitch unit to the switching module and from there to the switching board in the effect module so you can switch something on/off in that effect module, like stompswitches on pedals do. Everything else is just extra detail about how that is accomplished.
Let's start in the middle.
We offer three switching modules: Rack Switch, Switch +, and Switch X. The Rack Switch module is the heart of the system. There are two versions of the Rack Switch module, Rack Switch VGA and Rack Switch DIN. Before we discuss the differences, let's describe what they do.
The Rack Switch module controls a footswitch unit and makes the switching output of the individual switches in the footswitch unit available to other modules to "switch stuff" in those modules. Our switching is done using voltage changes. A voltage of +12V is an "on" switch and a voltage of 0V is "off". Actually, there is a range of voltages at each end that are "close enough". "On" might be more like 10 - 13V and off might be something under 3V, depending on the specs and exact performance of the CMOS switching chips we use. As you'll see in a bit, that range may be important to you under unusual circumstances.
All the Rack Switch does is provide about 12V to each switch in a footswitch unit. The switches in a footswitch unit each return a switching signal of 12V or 0V, denoting on or off. The Rack Switch routes those signals to jacks on its back panel for use by other modules. That's it. The two different Rack Switch versions do exactly the same thing, but just give you a choice between different footswitch units.
Footswitch units, which we just call "footswitches", are exactly what they look like - several individual stompswitches in an enclosure that you use to switch your effects modules. We have two types.
Our 3-Button Footswitch is an inexpensive third party footswitch that was designed primarily as a replacement for certain amp footswitches - you may see them sold elsewhere for that purpose. It has 3 individual stompswitches, with LEDs to indicate on/off for each switch. We modify these footswitches internally so they will work with our switching system design. They are reasonably well built. Since they are mass produced, they are relatively inexpensive. Some players use few effects, so they may not need many switches to control those effects. Those are the two reasons we offer this footswitch - lower cost and smaller and simpler functionality. They come with a permanently attached cable with an older DIN connector found mostly on amps. The Rack Switch DIN module is required to use these footswitches. You can attach from 1 to 4 of these footswitches to a single Rack Switch DIN module, for a max of 12 switches per Rack Switch DIN module. If you have a small effects setup, you can start with 1 or 2 and add others when you need them. Or since they are not expensive, you might keep a spare on hand for when one of the stompswitches eventually wears out and stops working.
Our 12-Button Footswitch is a beast. It is made of very thick metal with a design that makes it very rugged and a bit on the heavy side. There are some really well-built heavy duty pedals out there, like those old Sovtek Big Muffs and some of the heavy duty steel-enclosed boutique pedals. You could knock down concrete buildings with those pedals, but they seem fragile compared to this footswitch! It has 12 individual stompswitches, with big, visible LEDs to indicate on/off for each switch and an LED power indicator. There are also silver "tags" on the side of the footswitch and on the top near all the stompswitches. You can use markers on the tags to label your switches, depending on what you have each switch doing. The tag on the side is for labeling the footswitch in case you are using more than one of them in your setup. These footswitches use a standard computer monitor VGA cable to connect to the required Rack Switch VGA module. VGA cables some in a variety of quality levels, lengths, and colors and are widely available in a broad range of prices at computer and electronics stores, as well as at many websites. At GT we use some inexpensive 25ft VGA cables that are sold in quantity at a local electronics retail store. They are nothing special. Be sure to get the ones with jack screws on the connectors so you can screw them to the footswitch and Rack Switch securely. Those screw-on connectors are another reason why we chose VGA cables. It helps prevent them from getting disconnected accidently. A 25ft cable is probably more than what is necessary for small venues, home, or studio use - we end up with most of it coiled up on the floor (in the way) most of the time, so consider the length you need. These footswitches are more expensive, probably the most expensive single part in most setups, but they are meant to take several lifetimes of use. The LEDs and switches can be replaced without soldering when they eventually wear out. Internal boards and connectors can also be replaced, although that shouldn't be necessary.
If you play large venues, you may want a longer cable. The longer (or lower quality) the cable, the more the voltage drops over its length. We don't know the practical limit on length. The voltage drop is undetectable on our particular 25ft cables. Even if we chain a couple of them together, we still have only a negligible voltage drop. It is clear that with even average quality cables, you could run them a long ways. If you do run them a long ways, check the output on the back of the Rack Switch with all 12 switches "on" and make sure you're getting at least 11V, although a little less should still be OK, maybe down to around 10V. If you are also using other switching modules in some complex switching setup, just test the switching to make sure that the long cables aren't pulling the voltage down too low.
Other than the features noted above, there are some other differences to be aware of between the two footswitches, so check their product descriptions for information concerning availability of repair parts, service, and details related to their usage.
Almost all of our modules have some switchable feature or can be switched on and off. You'll see a few exceptions in the detailed individual module descriptions. By far the most common, is simple on/off switching like you have in pedal stompswitches. But you'll also see a second or third switch on some modules to control other features. Regardless of what specifically is being switched in the module, the switching works much the same.
There is a jack(s) on the back panel of the module for a footswitch. You use a standard 1/8" male-male cable, preferably shielded, either mono or stereo, to connect that module's footswitch jack to one of the outputs on the back of the Rack Switch. The stompswitch on the footswitch unit that corresponds to that output jack on the Rack Module will then control that module. Simple. It doesn't matter technically which Rack Switch jack (and thus, which stompswitch) you use. Just remember or label your stompswitches so you know what they do. Of course, you might prefer to have the switches connected in a particular order. If you want to switch two modules at the same time, you might want to connect them to adjacent switches on your footswitch. The order of the switches has no impact on how your chain is ordered - your audio cables determine that, not your switching cables. Ordering your switches is sort of like placing your pedals on your pedalboard. Whether a pedal is to the left or right, above or below another pedal does not determine whether it comes before or after another pedal in your chain. Your audio cables determine that. If you are using the Rack Switch DIN and 3-Button Footswitch, make sure you are plugging into "live" switching outputs on the Rack Switch. If you don't have all four footswitches connected, the output jacks not connected to footswitches won't work. The top DIN connector on the module controls outputs 1 - 3, the next DIN connector down controls outputs 4 - 6, and so on. Using an output jack that doesn't have a footswitch connected will give random on/off results, although mostly it'll send "off" all the time.
That's almost all you need to know to hook up and use the switching system for your modules. But of course, we have options.
First, for each footswitch jack on a module, there is also an override switch. The override switch has two settings. In the normal setting, the switching is controlled by the footswitch signal going to the jack. In the override setting, the pedal is switched on, regardless of what, or if any, signal is going to the footswitch jack. This is useful for "always on" pedals. You don't have to tie up a footswitch just to leave something turned on. Using these override switches may enable you to control more than 12 modules with 12 footswitches.
Switch + and Switch X
You may recall we said there were four switching modules, but we've only discussed two of them. What do those other two modules do?
First, they are not substitutes for the Rack Switch module. You must have at least one Rack Switch module, either the VGA or DIN version, to connect a footswitch to your system. These other two modules would be used between your Rack Switch module(s) and your effects modules to provide some additional switching functionality.
Switch + has 12 switching jacks on the back panel, like Rack Switch. Unlike Rack Switch, some of the jacks are outputs and some are inputs. The 12 jacks are grouped into 3 sets of 4 jacks. In each set of 4, one is marked as an input jack (+) and the other 3 are output jacks. For each set of 4 jacks there is also a switch on the front panel. You set the switch for "Same" or "Opposite". Connect the input jack in the group to an output jack on a Rack Switch so it is getting a control signal from a footswitch. Connect 2 or 3 of the output jacks in the group to the footswitch jacks on some effect modules. If the switch is on "Same", then when you turn the footswitch on, the 2 or 3 modules you cabled to will all switch on together. If you turn the footswitch off, they will all be turned off. Just like you stepped on 2 or 3 pedal stompswitches all at the same time. If you set the switch to "Opposite", then when you turn the footswitch on, it will turn the modules off. If you turn the footswitch off, it will turn them all on. It may not be clear why you would want to do that. We'll get to that in a moment...
Switch + gives you the option to create 3 sets of 2 or 3 modules that you can switch on or off at the same time. That's nice. What if you wanted to turn 4 modules on/off together? Pick one of your groups of jacks, like above, set your switch how you want it, connect the input jack as described above, and use 2 of the output jacks to connect 2 of your 4 modules. Then connect the third output jack to the input jack of another group. Set the switch for that group the same way, and connect two more modules to two of the output jacks in the second group. Now your footswitch will switch all 4 modules at the same time. You can use all 3 groups, or even add more Switch + modules and use groups on additional modules to simultaneously switch a bunch of pedals at the same time. Easy!
But that's not the only option. You don't have to set the switches for linked groups the same way. You could set the first group switch to "Same" and the second group switch to "Opposite". Then when you turn your footswitch on, the modules in the first group will be turned on and the modules in the second group will be turned off at the same time - cool! Your imagination may already be running ahead with the prospects.
Using only what we've described to this point, you can create some pretty cool and useful switching options to make it easier to "change tones" as you play. But you can also get yourself into some complexity pretty quickly, too, so think about what you want to accomplish, draw it up, think how you would use it, then give it a go. Sounds great, right? Well, if you are really going "whole hog", you'll probably run into an issue pretty quickly - not a show stopper, but it can certainly balloon the size and cost of your rig beyond reason. You'll probably have a situation where you need the same module in several control groups. You may have an overdrive you use in your core tone, and for some songs you use it with one group of effects and in another song you use it with a different group of effects. Do you have to buy two of those overdrive modules to do it? Maybe, or maybe that's the easiest way to do it if money is no object. But there's one more option in our arsenal of switch options - the Switch X module.
We named the Switch + module with the "+" because it lets you switch more modules with one switch. We didn't really know what to call the Switch X module, so we picked the "X" sort of in the same way you might call a secret or complicated endeavor "Project X". It's easy to describe what Switch X does, but using it or even having a switching problem that can be solved with Switch X can be confusing. But we'll give it a shot here because it may just allow you to do something you've wanted to do but couldn't. Examples of using it quickly get complex, so we're not going to wander into that. We'll give you the flavor of how and why to use it, then let you draw up your own example. Take a breath, clear your mind, here we go!
Switch X lets you control one module with multiple switches. Similar to Switch +, the jacks on the back panel are grouped into 3 sets of 4 jacks. Each group has 3 input jacks and 1 output jack. The output jack gets connected to the footswitch jack on some module you want to control with 2 or 3 of that group's input jacks. What would those input jacks be connected to? They could be connected to footswitches, but probably only 1 footswitch at most. More likely they would be connected to an output jack from some Switch + group, or some other Switch X group. Let's table that for a moment. How does that group of jacks work? The module that is connected is obviously either on or off at any given time. Regardless of whether it is currently on or off, it will be switched to match the state of whichever of the 3 input jacks was last switched. So if jack 2 was the last input that was switched of the 3 input jacks in that group, and jack 2 was switched off, then the module will be switched off if it was on, and left off if it was already off. Or if jack 2 was switched on, the module would be left on if it was already on and turned on if it was off. If jack 2 or any of the jacks is switched after that, the state of the module will be set (or left) to whatever signal it receives next. Remember that situation where you needed that overdrive pedal in two different Switch + groups? This lets you do that without buying another overdrive module. Instead of cabling the two overdrive modules you would need into two Switch + groups, you instead run those two switching cables into two of the inputs in a Switch X group and connect the overdrive to the output of the Switch X group. Now it seems like the overdrive is in both Switch + groups. And it doesn't matter whether the overdrive is on or off - when you stomp the switch the "right thing happens". That is very cool. Of course, if your example is that simple, it's about the same cost to purchase a second overdrive module or a Switch X module, so maybe you wouldn't add this complexity. But if you start designing your switching so that you are switch "tones" instead of switching "effects", you might have several groups needing that overdrive, or you have multiple groups needing 2 or 3 modules in common, and maybe it would be useful to add in a Switch X at that point. Options!
If you followed that description of our switching modules, then you know you just received a two-fer explanation. Our simple switching allows you to do simple "effect" switching, or more complicated and perhaps more useful "tone" or "multi-effect" switching.
Even in the long-winded discussion above, we were trying to keep it simple to explain the basic functionality of the parts of our switching system. We sort of left out a few things, and dropped in a few statements here and there that could be a bit misleading to keep it simple. Everything above is true, but there's one more thing to highlight that we only mentioned in passing. All that switching stuff can be combined and cascaded using multiple footswitches and switching modules, creating layers and complexity to your heart's content and your mind's detriment! Somewhere along the way, you may encounter the limits of what's practical, maybe not. But eventually if you build a scheme big enough and complex enough, you will probably find a physical limit. Long cable runs and chaining switching signals may eventually get you to a situation where you have enough voltage drop that the switching stops working. We've not yet hit that limit with any of our setups, but there is a chance that you could if you push far enough. You'll have to carefully, and in detail, plan such a switching scheme. It will probably take a fair amount of testing and tweaking to get it right. Check with a voltmeter as you build it up to make sure that wherever you are expecting an "on" signal you're getting sufficient voltage. Take your time with the design, think it through carefully. It is very easy to make mistakes in both design and cabling of a complex switching solution. Don't forget that those tone groups are just groups of modules that are on or off. They are also connected in some order in the audio chain. You may need some additional signal routing complexity along with the extra switching. Or you may need more than one of the same effect modules - don't forget different control settings you may need on those modules!
In addition to normal switching, some modules have other types of functions that require specialized footswitches for technical reasons. Our Tube Reverb and Super Nova modules are examples. Both modules have unique technical requirements for their footswitches. As a result, each of those modules has its own specialized footswitch that are not a part of the switching system described above. These modules are still controlled by the normal switching described above. The specialized footswitches are in addition to normal switching. For example, the Super Nova footswitch selects presets and has tap tempo. Like our regular footswitches, the audio in your effect does not go to the specialized footswitches, so you don't have to worry about tone loss in the footswitches or cabling.
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