Shielding a Tele - is it worth it?

Philly_Q

I dismantled my recently-acquired secondhand Tele this weekend and was surprised to find the bridge pickup cavity has been lined (quite neatly, I must say) with copper foil.  There's a bit of foil in the control cavity too, but only around the sides, not the bottom.

I've always understood that shielding was an all-or-nothing kind of thing, that just shielding part of a cavity is pretty pointless. And some people say shielding can dull the sound as well as reducing the noise.  So do I:

- Finish the copper foil job in the control cavity (bearing in mind I hate using copper foil)?

- Strip out the foil and use shielding paint instead?

- Strip out the foil and WTF, just leave it unshielded?

Any thoughts?

capo4th

To shield or not to shield that is the question?

ThePrettyDamned

Shielding paint! No more cut fingers, and so much neater looking. A few solid coats and test continuity.

I was advised to shield the control cavity but not pickup cavities to avoid capacitance. Should reduce buzz nicely, it won't affect hum though.

frankus

shielded cable.

a tele is meant to chisel your ears off with glorious unrestrained treble shielding will mess with that.

ecc83

I have a Squier Tele here and I have never had the scratch plate off it so I don't know  if it is shielded or not.

IF not I shall do it, post crimble and make a careful note of the capacitance at the jack (tho I suspect it will be too low to measure) before and after.

I shall also try to devise some means to measure the HF response B&A.

I do not want to pre-judge an "experiment" but I am very confident that  the wiring is so far away from the shield that there will be buggerall difference!

Did Russ Andrews' dad have a bike or what!

Dave.

thermionic

Should be interesting. I did the guitarnuts job on mine and it still sounds very much like a Tele. The noise reducing benefits are overrated IMO, but a before/after test on that would be good. You'd have to closely replicate the guitar position relative to the amp though, ideally in both quiet and very noisy orientations.

Philly_Q

@ecc83

That all sounds a bit beyond me, but I'll be interested in the results.  I've often shielded guitars in the past but it almost always coincided with a pickup change so it was very hard to assess how much difference it actually made.

ICBM

It depends on what type of sound you want and how much gain you're using. If you want a true vintage tone and don't use much gain, use as little shielding as you can get away with. The more gain/more modern sound you want, the more shielding. It *can* make an audible difference if you overdo it, but only if you use too much fine shielded cable or shield the insides of the pickup covers, especially on Strats. I went to a huge amount of trouble to completely shield my first Strat like this, following advice in a book - all-shielded cable, foil inside the covers, as well as the whole cavity - and it really took away all the sparkle and 'life' from it. I had to take most of it back off again - a useful lesson...

Shielding the pickup *cavities* is OK, they're far enough away from the coils. A Tele already has a shielded neck pickup (which is why they often sound dull) and a partly shielded bridge pickup anyway. There's not a lot you can do about the Tele bridge pickup either since the whole bobbin is open and unshielded, although reversing the coils of both pickups so the outer wrap is grounded should make it quieter than the inner end being grounded as is normal. (Remember to move the baseplate ground wire if it has a baseplate - and you must also do the neck pickup or they will be out of phase.)

I would fully shield the control cavity, the jack cavity and use shielded cable from the jack to the volume pot - also make sure the ground connection from the jack goes to the volume pot, not the tone pot as Fender usually do it. I prefer foil to paint, but if the paint is well-enough done it works fine. For the pickup wiring to the controls, I would use the standard unshielded wiring but tightly twist the two wires.

ThePrettyDamned

@icbm I was going to ask, why does the ground going to volume matter? Surely if they're all connected, they're all common ground?

/electronics novice.

Philly_Q

I've always wondered that too.  I've read about "star grounding" and I know there's such a thing as a "ground loop", but whether or not it can happen in a guitar circuit I don't know.

The suggestion about reversing the coils of both pickups so the outer wrap is grounded is interesting, I've never heard that before (I should've mentioned that the neck pickup on this Tele is a Duncan minibucker, but I may swap it to a conventional Tele neck pickup).

I've noticed that Fender usually leave the jack socket hole on a Tele (and the separate jack cavity on a Strat) unshielded, because the jack can touch the shielding and short the circuit.

ICBM

ThePrettyDamned said:

@icbm I was going to ask, why does the ground going to volume matter? Surely if they're all connected, they're all common ground?

Philly_Q said:

I've read about "star grounding" and I know there's such a thing as a "ground loop", but whether or not it can happen in a guitar circuit I don't know.

Yes, that's it. Also, if the pots aren't tightened up very well and when the guitar gets old, corrosion can get into the contact between the pots (and jack, on Jaguars and Jazz Basses etc) and the control plate, and produce a poor ground.

Philly_Q said:

I've noticed that Fender usually leave the jack socket hole on a Tele (and the separate jack cavity on a Strat) unshielded, because the jack can touch the shielding and short the circuit.

It's not a good reason not to shield it. Just put tape over the shielding if you can't get an orientation where the jack doesn't touch.

Devil#20

Philly_Q said:

some stuff about shielding his telecaster

Did you make a decision on your tele (to shield or not to shield)? I'm about to change pickups on my cheapo affinity tele and was thinking I might shield the cavities if the conclusion was that it was worth doing. Anybody else recommend it or otherwise? I've got the copper foil ready to go. I decided not to use paint because that's non-reversible. I tested and discovered that the adhesive is non-conducting so assume each cut piece of foil will need to be electrically bonded to the adjacent piece then? Or does it? Is it just acting as a Faraday cage. ie. does the copper foil all need to be at ground potential, or the same potential? 

ICBM

Devil#20 said:

I tested and discovered that the adhesive is non-conducting so assume each cut piece of foil will need to be electrically bonded to the adjacent piece then? Or does it? Is it just acting as a Faraday cage. ie. does the copper foil all need to be at ground potential, or the same potential? 

It's always best to spot-solder across each joint between any two pieces - you only need one spot, not to do the whole seam. Even if the adhesive is supposed to be conductive, many of us have found that it dries out over time and stops being. Unless there's a really positive ground contact (eg a screw terminal, like on USA Fenders) I prefer to solder on a wire and connect that to a grounded point as well just to make sure - the shield doesn't work if it's not connected to ground.

Devil#20

ICBM said:

It's always best to spot-solder across each joint between any two pieces - you only need one spot, not to do the whole seam. Even if the adhesive is supposed to be conductive, many of us have found that it dries out over time and stops being. Unless there's a really positive ground contact (eg a screw terminal, like on USA Fenders) I prefer to solder on a wire and connect that to a grounded point as well just to make sure - the shield doesn't work if it's not connected to ground.

Cheers ICBM. Still like confirmation from somebody that it makes a difference and it's worth the effort. I suppose in most cases though it's done along with a pickup change. 

Philly_Q

Devil#20 said:

Philly_Q said:

some stuff about shielding his telecaster

Did you make a decision on your tele (to shield or not to shield)? I'm about to change pickups on my cheapo affinity tele and was thinking I might shield the cavities if the conclusion was that it was worth doing. Anybody else recommend it or otherwise? I've got the copper foil ready to go. I decided not to use paint because that's non-reversible. I tested and discovered that the adhesive is non-conducting so assume each cut piece of foil will need to be electrically bonded to the adjacent piece then? Or does it? Is it just acting as a Faraday cage. ie. does the copper foil all need to be at ground potential, or the same potential? 

Well now, this is slightly embarrassing.  I got an email today saying someone had posted on this thread... then I saw I had made some posts... and then I saw I'd started the thread, in 2014!

Reading the OP, I couldn't even think what Tele I was going on about.  Then I remembered, '52 Hot Rod... I've still got it, but no, I never got round to shielding the rest of it.  In fact I'm not sure I've done any guitar DIY at all since 2014.

@ICBM is definitely the man for advice on this.  The only thing I'd say Is that personally I'd always use paint rather than foil (except on scratchplates and backplates), it's too easy to cut yourself with foil, nasty stuff.

ICBM

Philly_Q said:

@ICBM is definitely the man for advice on this.  The only thing I'd say Is that personally I'd always use paint rather than foil (except on scratchplates and backplates), it's too easy to cut yourself with foil, nasty stuff.

It certainly is... but I have to say, it's more effective than paint. If moderate shielding is going to be good enough, paint is fine - but I've had to do quite a few jobs where it wasn't, and adding copper foil over the top fixed the problem.

I know there's more than one variety of paint, and I think Jonathan @FelineGuitars has some special stuff he uses and recommends, but the standard carbon or nickel stuff isn't brilliant.

Philly_Q

I had some paint from StewMac which seemed OK, but I always used three coats to make sure everything was evenly covered.

Years ago you could get shielding paint in spray cans from the Maplin catalogue.

I know foil is better but I just hate using it!

Anyway, I'll probably never bother with any of this again.  My guitars stay in my house, same as they always did.  I don't know what fantasy world I was living in thinking I "needed" shielding or noiseless pickups.

Devil#20

Philly_Q said:

I had some paint from StewMac which seemed OK, but I always used three coats to make sure everything was evenly covered.

Years ago you could get shielding paint in spray cans from the Maplin catalogue.

I know foil is better but I just hate using it!

Anyway, I'll probably never bother with any of this again.  My guitars stay in my house, same as they always did.  I don't know what fantasy world I was living in thinking I "needed" shielding or noiseless pickups.

Yes I realised the post dated back to 2014 but didn't want to open a new thread when there was already one on the subject. Thinking about it I could just be wasting my time. I'm changing the pickups and if I shield the cavities I wouldn't know if I've improved things or otherwise. I'd have do a controlled test. I've decided to leave the cheap pickups in and record the guitar and then take the cheap pickups out, shield and then put them back in and record again. Then I'll put the new pickups in with/without shielding depending on what I conclude from above. 

LastMantra

Philly_Q said:

I dismantled my recently-acquired secondhand Tele this weekend and was surprised to find the bridge pickup cavity has been lined (quite neatly, I must say) with copper foil.  There's a bit of foil in the control cavity too, but only around the sides, not the bottom.

I've always understood that shielding was an all-or-nothing kind of thing, that just shielding part of a cavity is pretty pointless. And some people say shielding can dull the sound as well as reducing the noise.  So do I:

- Finish the copper foil job in the control cavity (bearing in mind I hate using copper foil)?

- Strip out the foil and use shielding paint instead?

- Strip out the foil and WTF, just leave it unshielded?

Any thoughts?

No option for leaving as is? If it ain't broke... 

Philly_Q

Devil#20 said:

Yes I realised the post dated back to 2014 but didn't want to open a new thread when there was already one on the subject.

No argument with that, I wish more people would do the same although the search function isn't the most user-friendly (sorry modmins)! 

It was like a bit of time travel reading stuff I wrote five and a half years ago.

Good luck with the pickup changes and shielding project.  And I think ICBM's excellent first post in this thread is worth re-reading, shielding can be overdone.

Philly_Q

LastMantra said:

Philly_Q said:

I dismantled my recently-acquired secondhand Tele this weekend and was surprised to find the bridge pickup cavity has been lined (quite neatly, I must say) with copper foil.  There's a bit of foil in the control cavity too, but only around the sides, not the bottom.

I've always understood that shielding was an all-or-nothing kind of thing, that just shielding part of a cavity is pretty pointless. And some people say shielding can dull the sound as well as reducing the noise.  So do I:

- Finish the copper foil job in the control cavity (bearing in mind I hate using copper foil)?

- Strip out the foil and use shielding paint instead?

- Strip out the foil and WTF, just leave it unshielded?

Any thoughts?

No option for leaving as is? If it ain't broke... 

Which is exactly what I did, see later comments.  Procrastination is my friend - or maybe more like a life partner I wish I could get rid of.