I don’t often like to complain, but sometimes you just have to be aghast at the state of technology and our inability to make positive changes in the way we do things.
The target of my little rant here is the lowly 1/4″ (quarter inch) or TS (tip/sleeve) connector and jack. For simplicity, for the rest of this article I’ll just call it the TS. For the most part I’ll lump TS and TRS in to same category, but will explain the differences later.
For anybody that’s ever seen an electric guitar you know the TS. Pretty much any bass, guitar, amplifier, PA, effect unit ever made uses the TS. It’s been the main stay of the music industry ever since the first electric instruments were made. But being old doesn’t make it good. In fact it isn’t good at all and has a number of deficiencies. We’ll talk about them here. In fact the TS is akin to the slot headed screw. It’s old and doesn’t work very well and there’s lots of better alternatives. But unlike the slot headed screw, the TS is still the most commonly used connector.
First let’s talk about their history.
The TS (actually the TRS) was first used in telephone switch boards dating back to around 1900. Operators would connect calls together using large panels of jacks and plugs. (See wiki for more) My first recollection of TS connectors was as a kid when my uncle gave me some old electrical equipment. This included a set of what he called headphones. They were actually military, probably WWII, headsets. Gray metal bands with little rubber earplugs and mono TS connectors. When my parents would complain about the music being too loud, my friends and I would listen to music with these old headsets.
Going back to the 1950’s, TS connectors were the norm for electric guitars from the earliest days. Bet you’ve never seen any old 50’s Fenders with anything but TS connectors. I certainly haven’t.
When it comes to signal connection for musical equipment there are a number of choices, but the despite being the poorest choice, TS is the most common choice.
Before I talk about the problems with TS and their solutions, I’d like to talk about the types of connectors that are already out there.
TS – Tip/Sleave or 1/4″ mono connectors with 2 connections – high-impedance unbalanced signals or medium power speaker connection – short cable runs – non-locking
TRS – Tip/Ring/Sleeve or 1/4″ stereo connectors with 3 connections – lo-impedance balanced signal or headphone cable – effects send/return – non-locking
XLR – (3 pin – standard) mono connection – low impedance balanced signal – phantom power capable – long cable runs – locking
XLR – (5 pin) (not popular) stereo connection – low impedance signal – locking
Speakon– high power speaker connections – locking
So here’s the problem…
Problem #1 – Too Many Uses The single biggest problem with 1/4″ jacks and plugs is that they are used for too many different and incompatible functions. The most obvious problem is that you can easily plug a TS plug into a TRS jack and never know the difference. Why is that a problem? Keep reading.
Secondly, high power speaker outputs and very sensitive signal inputs use the same connectors and can be connected together. Even though the average musician is much too smart to do this, the potential to damage equipment is high.
You can also do some equally ridiculous, but at least benign, by plugging a low power signal directly to a speaker cabinet.
I have actually walked in to a room once and seen something connected like this. Some poor music student’s hope of a career dashed by their inability to get some sound out of their guitar. But is it their fault, or is the musical instrument industry failing to follow the KISS principle?
Problem #2 High Impedance In this case I’m talking about TS signal cables as they are used for basses, guitars and effects. These are virtually always high impedance. Really the only problem with high impedance circuitry is that there can be signal loss over long cable lengths. But the real problem is that high impedance cable are normally not balanced. Low impedance XLR cables are always balanced. Which brings on the next problem…
Problem #3 Not balanced TS cables by definition are not balanced. With two connections you have one signal line and one connection that is both the return and the shield. A balanced cable has three connections. Two are signal lines and the other is a shield. The signal lines are in reversed phase and the two wires are twisted together. The design provides an excellent way to reduce noise (EMF) (see electrical noise) that may result from proximity to other electric devices. In this way, balanced cables are superior to unbalanced cables.
So even though low impedance cables may not be necessary be balanced, signal cables are mostly either low impedance/balanced or high impedance/unbalanced. So why not just have low impedance/balanced and eliminate both disadvantages? Good idea!
Problem #4 Not always High Impedance Often with PA systems you see a 1/4″ jack the might say something like “Line Out”. The question is, is it low impedance/balanced or high impedance/unbalanced? A lot of times it may say balanced or unbalanced. Sometimes it won’t say. And does it even mater? Mostly you’ll just never know. If it works then what the heck. Most modern circuitry probably doesn’t care. In the days of vacuum tube circuits and matching transformers, you needed to match impedance to get optimum signal transfer from one component to another. Maybe in solid state circuits it doesn’t mater. And, if you are plugging a TS connector in to a balanced TRS jack aren’t you shorting half the signal path to ground? If you just had one type of signal, therewould be no second guessing.
Problem #5 Lack of noise rejection This was really addressed above, but simple matter of fact is that TS connections are noisier than TRS or XLR connections. For me I hate those buzzing noises. But for many guitar players it’s just SNAFU. It’s normal, get used to it. But why should you? (Cables and connectors aside, it’s acknowledged that most guitar noise comes from the instruments pickups. This is a whole other discussion.)
Problem #6 They fall out As silly as that statement sounds, it’s true. Other connectors have locking mechanisms. 1/4″‘s don’t really. They just stay in place by the jack holding the notch in the plug. This was a great thing for those 1900’s phone systems. But on a stage when you are rocking out, it’s just an accident waiting to happen. Most experienced bassist and guitarist will wrap the cable through their strap, but I can’t count the times I’ve seen somebody step on their own cable and unplug their guitar. You never really see this on microphones. This is because microphones use XLR connectors.
Problem #7 Phantom power This one of those things that make you shake your head. Phantom power is simply a way of providing a DC voltage to a device over the normally AC signal cable. Microphone developers have used this for decades. Virtually every condenser microphone requires power to operate it’s on board preamp. In more recent years DI makers have adopted this same idea to power their DI’s. What if basses, guitars and effects units had XRL connections. You would no longer need to have batteries in your active guitar, or batteries in your effects or power supplies and power cables running all over the stage. What a wonderful world it could be!
Problem #8 Signal or Speaker Cable Okay, you have a TS cable in your hand. Is it a guitar cable for a speaker cable? First you might ask, what’s the difference? Well, one is designed to handle relatively high power with no shielding required. The other, low power, and the more shielding the better. The problem is, sometimes you can’t tell one from the other. Some speaker cables have a distinctive two flat wires, like a power cable. Many don’t. The only way to know, is to know your gear. Or, if you can unscrew the cable end and see the wires. If the there are two symmetrical wires, it’s a speaker cable. If there is one wire and shield, its a signal (guitar) cable. But why should you have to do that?
Problem #9 Effects send and returns To me this one of the weirdest ones. A Y-cable to connect the inputs and outputs of an effects unit. How do you know which TS is send and which is return?
Problem #10 Stereo or Balanced Just like with TS signal or speaker cables, TRS cables can either be balanced, twisted pair and a shield or a headphone cable, with three conductors. How do you know which is which? In general if the cable has both male and female ends its a headphone cable. Otherwise it’s probably balanced.
Problem #11 Input or Output – Which way is the signal going? One of things that’s really smart about XLR cables is that you can always tell your inputs from your ouputs. That means there’s no accidentally plugging an input to an input or an output to an output. Imagine having a pedal board with only XLR’s. You could never get the connections mixed up. Well mostly.
So the question is, why do we use TS cable? The answer can only be, because that’s what we’ve always used.
So what if…
XLR 3-pin connectors were used exclusively for all mono signal level devices. Guitars, basses, microphones, DI’s effects in and out connections/
XLR 5-pin connectors were used exclusively for all stereo signal level devices and effects send/return connections?
Speakon connectors were used exclusively for speaker connections?
TRS connectors were use exclusively for headphones?
TS connectors were all sent to the Smithsonian.
The argument of course that doing this would be too expensive. That XLR connectors are more expensive than TS. It’s true that it would cost the musician a few dollars more for equipment. But you’d no longer need as many types of cables. And, you wouldn’t need batteries and power supplies and power bars. Even setup would take less time and effort.
Staying with the existing system, is of course great for the cable manufacturers. Just take a look inside your cable bag. You have TS’s and TRS’s and XLR’s and TS to XLR male adapters, TS to XLR female adapters, TRS to XLR male adapters, TRS to XLR female adapters and even TS to Speakon.
Spending a few dollars more for equipment with standardized connectors would, in the end, be cheaper for the musician, simpler for the musician and less of a bother for all. Only the cable manufacturers would suffer.
But you may have to keep one extra adapter for when you want to play all those vintages basses you have.