Taylor Expression System ES II Fused String Ground

[TomCarlos]

Ok... guitar techs and electronic friends....

I have a Taylor Acoustic Electric that has the Taylor Expression System (ES II). Just this week, I noticed some crackling coming through my amp. After investigating, I learned the strings are tied to ground via a fuse. There is a bar under the saddle, and the balls of the strings touch that. That bar then goes to a wire which goes through a fuse which then goes to ground. The fuse opened... and that disconnected the ground to the strings.

According to the Taylor Web site - "The fused string ground was developed by Taylor to make the world a safer place for those of us plugging in. Unlike traditional string grounds that connect the string directly to ground on the guitar, Taylor puts a small 10mA fuse in line with that connection. This means that voltage coming up the guitar will blow the fuse and protect the player by disconnecting the strings from ground. This does not cause the electronics in the guitar to shut down, it simply disconnects the strings from being part of the grounding circuit."

https://www.taylorguitars.com/taylor...d-fuse-trimmed

So... really, a fuse? I am not sure why I would have blown a fuse. I have no electrical issues at my house. But really... a fuse?

I know others have asked if it is safe to bypass the fuse... since this ground path does not tie to the preamp... but I cannot seem to find a legit response. Yes, I am trolling the guitar blogs but those guys have no idea.

Anyone?

Thanks, Tom

[Enzo]

Let me tell you a story:

Once upon a time there was a beautiful princes, and she...

Oh wait, that's the wrong story.

I used to tour back in the 1960s. That was the era of two-wire power cords. Once the stage was set up and the PA in place, we powered up and went around the stage flipping the ground switches back and forth to get the hum to a minimum and hopefully reduce the shock potential. Usually we got it pretty well set. One night, my guitarist was playing a solo, and he raised the guitar up while bending a note, and the strings touched the microphone. A flash of light, and the high E string burnt in two. Just burnt the string in half. Chris was OK, but he had to finish the set as a five-string. Fortunately he hadn't yet put his lips to the mic.

Your house may have no wiring issues, and your amp may be good as well. But you can't guarantee those conditions everywhere. You will play gigs that have no grounds, or the outlets are wired with the wires wrong. The stage might be OK, but the PA system is on a different ground. Exactly what happened to my guitarist. If you are holding your strings, you are connected to whatever your amplifier thinks is ground. If the PA system thinks something else is ground, there might be a large voltage difference between the microphone and your strings - and your body is the connection between them.

If a fuse opens the connection to your strings, then the PA can't make a circuit to your amp. If that fuse opens, your strings are no longer grounded, so the amplifier will likely make more noise, but that is the price you pay for safety. Your hands only touch the (now ungrounded) strings, so touching the PA makes no circuit.

How effective a 10ma fuse is, I can't say, and people who know anything about guitars probably have more insight than I do, guitars are not my area. But that is my take on it.

[TomCarlos]

Thanks Enzo... I get the story...

[DrGonz78]

You could modify that little circuit board to be able fit a fuse holder. Then buy cheapo 10ma fast blow fuses and never have to pay for obscenely priced fuses(sold in 2 packs for $16). We all play electric guitars with no fuse to ground on the bridge/strings. Personally I would just solder a wire in place of the fuse, but that's just me.

[DrGonz78]

Oh and there is another old post about this same topic.
http://music-electronics-forum.com/t19696/

I don't remember 10 milliamp fuses being available. The smallest one you could get used to be 50mA, which is still plenty enough to kill you, and a fuse can usually carry several times its rated current for a few seconds. I still wouldn't necessarily count on a 10mA fuse to save me.

If you're really concerned about getting shocked from your guitar, use a wireless system.

I was thinking the same thing and Steve Conner confirmed this better for me.

[TomCarlos]

Thanks Jer....

It seems the fuse blowing could also be due to effects pedals that can put a short burst of 9 volts on the instrument cable when inserted. So perhaps a solution here is to make sure you insert the instrument cable into the pedal board first, then the guitar, then power up the amp.

I play with two Acoustic Electric Guitars. On my pedal board, I start off with a Boss TU-3 tuner. So once everything is powered up, I put the pedal into the tuner mode and that mutes the signal going through the effects chain. That would allow me to change guitars without the "Thud" and since the instrument cable stays in the Tuner, I shouldn't see a 9v spike. I think ?

Anyway... fascinating stuff...and I think Dr Gonz has a good idea. There isn't much space on that PC board but I will look into a fuse holder and see if it can be retrofit on the board. Of course the headache is having to remove the end piece if you ever need to change the fuse!

[Enzo]

I myself am not opposed to wiring across it either, I just understood their reasoning, which I tried to explain. [I] have never seen a guitar so fused in all my days.

before you go wiring in fuse holders, check for 10ma fuses. I have a meter is a 32ma fuse, and they are not cheap at all. I have never seen a 10ma fuse.

Wow, I see Mouser has a selection of them. The slow blows are all about $4 each. The fast blows are special and sell from $15 to $45 EACH.

10ma fuse 10 mA Fuses | Mouser

[Leo_Gnardo]

The fast blows are special and sell from $15 to $45 EACH.

A 10 mA FB fuse is a tiny, skinny calibrated piece of wire. How $$$$ hi-tech!

Despite Taylor's "public safety" blurb, I'll bet the fuse is there because of safety regulations in some zone in this wacky world. IIRC, SEMKO, the Swedish safety organization at one time (1980's) had the strictest rules. Now Sweden is under CE rules. I noticed that some companies, Peavey most obviously, started fusing everything in their amps including bias and filament circuits starting @ late 1980's so their amps could be sold anywhere, without a special run to satisfy local safety regs. Others followed suit, now it's fuses fuses everywhere.

I wonder that a resistor as a bypass or replacement might not do just fine. Seen some gear that has a 27K quarter-watt R from ground to chassis when the ground is lifted, for instance Countryman 85 DI boxes in the 80's. For total ground isolation the user may snip that resistor out. You could try such an R in your guitar, small enough to fit, still connects strings to ground well enough to minimize hum & crackle. You'd still get an annoying shock if you got between hot & ground, not much chance of getting killed. And not much chance of burning the strings off the guitar. (A friend did that at the blues club, five strings burnt off, the sixth welded to some frets. Spectacular! He survived just fine, has a wonderful family. )

Sometimes I wonder if the fuse manufacturers have some lobbyists at the CE rules committee. When you want something done "your way" in the USA, that's what you do, send the lobby boys & girls to Congress and state legislatures. Charm and/or pester the legislators 'til you get what you want.

[g1]

Another variation on the isolated string ground:
(excerpt from Adrian Legg's "Customizing Your Electric Guitar")

"On any good quality guitar, you will find a wire running from the bridge
to the earth side of the guitar's wiring. This is the string earth, and is
essential for cutting down string hum and noise, and you can add this item
to replace it altogether.

Wire together in parallel, a 220k ohm resistor (red, red, yellow and
silver or gold) and a .001 capacitor with a minimum voltage rating of 500
volts. Twist the wires and then solder them together on both ends.

Wire this unit inside the guitar between the bridge or tailpiece and the
earth side of the circuit, replacing the string earth wire.

In the event of the chassis going live, it will only send about 40 volts
through the strings, enough to give you a warning tingle without hurting
you. It will allow enough leakage for the string earth to operate
normally. "

[52 Bill]

It seems the fuse blowing could also be due to effects pedals that can put a short burst of 9 volts on the instrument cable when inserted. So perhaps a solution here is to make sure you insert the instrument cable into the pedal board first, then the guitar, then power up the amp.

The fuse is between the circuit ground and the strings, so it would be more likely that a static discharge would cause the fuse to blow than a 9 volt spike on the signal hot line.

How much hum is there with a blown fuse?

[TomCarlos]

Hi Bill....

With the fuse out, I would say there is minimal hum. But the issue is an intermittent "crackling" sound, sharp, short bursts. And if you tough the metal of the instrument cable, you hear a difference.

Tom

[Leo_Gnardo]

The fuse is between the circuit ground and the strings, so it would be more likely that a static discharge would cause the fuse to blow than a 9 volt spike on the signal hot line.

How much hum is there with a blown fuse?

Rare that one could develop enough current with static to pop even a 10 mA fuse. But if the guitarss strings came into contact with AC that could cause a shock, bang goes the fuse. I expect it's static Tom's hearing now, and it's discharging thru the preamp circuit causing snap noises. Some plastic electric guitar pickguards pick up static similarly, especially multilayer ones I've found on Strats & Teles, snappity-snap-click noises. I like the Adrian Legg solution, certainly worth a try, & cheap.

[Mick Bailey]

I've been using the parallel resistor/cap in these guitars for years. Most of my customers have had these fuses blow and they're hardly an on-the-spot user servicable item. When I got the first one in for repair I thought it was due to a fault condition, but these things fail frequently enough with a broad range of users that it didn't add up that so many people had faults with equipment - especially as most are pro musicians with valid PAT certificates for their gear and no problems with shocks/tingles off any other instrument plugged into the same input.

Having said that, you can't assume that a fuse failing wasn't due to a fault so I think it prudent not to bridge the fuse, but to use the resistor/cap method. You may need to increase the cap to get the noise down to an acceptable level, up to a maximum of 0.022uf.

[Paleo Pete]

Enzo - Thanks for that explanation in your first post. I remember those days too, I started using a foam wind screen on my mic for that reason. Flip every ground switch in sight, double check everything, still get shocked when I touched my lips to a mic. Not fun. When I got my 73 Super Reverb and 74 Champ, first thing I did was give both of them 3 prong grounded power cords. I think the Champ had one and the ground pin was broken off. I refuse to use those, or extension cords with broken off ground pins. A few years ago 2 prong outlets were still seen at times so I kept a couple of ground adapters, to avoid breaking off ground pins, haven't seen one in years though.

For the younger guys who never had to deal with it, trust me it's no fun touching your lips to a mic in the middle of a song and getting shocked. Usually it's about like touching your tongue to a 9 volt battery, but it can be worse, even fatal at times. I've heard stories about pro musicians getting knocked unconscious. I can't tell you how many times I got hit in the 60's and 70's. Two prong everything, flaky wiring, we're getting zapped...man I'm glad those days are over...

I still use my wind screen, just in case, and I make sure everything we use is grounded. Can't get around flaky wiring though...

[TomCarlos]

Hey Friends... A quick footnote to this thread.

I was in San Diego this weekend and was able to get over to El Cajon to visit the Taylor Guitars HQ and U.S. factory. A special thanks for Jim Kirlin (Marketing Manager and Editor of the "Wood and Steel" magazine) for his time and providing the tour.

I had a chance to brief Jim on the fuse issue with the string grounding. I'm sending him a link to this thread.

If any of you visit San Diego, make it a point to visit the Taylor factory. It's a cool place, I learned tons, and probably spotted several people who built my 416ce.

Tom