Copper Tape Shielding

[Ou7shined]

[quote name='LawrenceH' post='965387' date='Sep 23 2010, 10:55 AM']I have wondered this same thing. A quick google brings up this from Audere, see about a third of the way down:
[url="http://www.audereaudio.com/FAQ_PUNoise.htm"]http://www.audereaudio.com/FAQ_PUNoise.htm[/url]

Although they're talking about their pre-amp, in HiZ mode as far as I understand it's mimicking the loading of passive pups straight into an amp, so the same would apply. They refer to compensating, I don't know how they'd achieve this though - any ideas anyone?[/quote]
That's a very interesting link. Cheers.

What the link is saying is that in an overly cautious shielding job (which the you have carried out on the advice of someone here) you add approximately 90 pF of capacitance. To compensate for this you need to put in a cap with a value 90 pF less than that of the one installed.

Yes earth that wire.

[LawrenceH]

[quote name='Ou7shined' post='965438' date='Sep 23 2010, 11:40 AM']That's a very interesting link. Cheers.

What the link is saying is that in an overly cautious shielding job (which the you have carried out on the advice of someone here) you add approximately 90 pF of capacitance. To compensate for this you need to put in a cap with a value 90 pF less than that of the one installed.

Yes earth that wire.[/quote]

Hmm, that sounds like a rather piddling amount compared to a 47000 pF cap.

[Bobby K]

[quote name='Ou7shined' post='965438' date='Sep 23 2010, 11:40 AM']That's a very interesting link. Cheers.

What the link is saying is that in an overly cautious shielding job (which the you have carried out on the advice of someone here) you add approximately 90 pF of capacitance. To compensate for this you need to put in a cap with a value 90 pF less than that of the one installed.

Yes earth that wire.[/quote]

Overly cautious to a degree maybe, but I didn't shield the pickups themselves, or even do a star grounding job, just bog standard shielding I think.

I've read a little about whether shielding adds capacitance and there seems to be a debate as to whether this is true. Who knows. Certainly has changed my sound. The orange drop is 0.047 pF, so will maybe look into a lesser value version, maybe the 0.022 pF one.

When you say [i]"yes earth that wire."[/i] I'm assuming you mean run a wire from the copper to a ground point such as the jack ground?

Edited September 23, 2010 by Bobby K

[Ou7shined]

[quote name='Bobby K' post='965470' date='Sep 23 2010, 12:07 PM']Overly cautious to a degree maybe, but I didn't shield the pickups themselves, or even do a star grounding job, just bog standard shielding I think.[/quote]
Yeah I known but you've shielded earthing wires. Nice touch but pointless unless you were experiencing specific problems. I like the old [url="http://en.wikipedia.org/wiki/KISS_principle"]KISS principal[/url].

[quote name='Bobby K' post='965470' date='Sep 23 2010, 12:07 PM']I've read a little about whether shielding adds capacitance and there seems to be a debate as to whether this is true. Who knows. Certainly has changed my sound. The orange drop is 0.047 pF, so will maybe look into a lesser value version.[/quote]
It's worth a pop but LawrenceH does have a point.
I think you've just installed a new wiring kit. Try the cap from your old setup.

[quote name='Bobby K' post='965470' date='Sep 23 2010, 12:07 PM']When you say [i]"yes earth that wire."[/i] I'm assuming you mean run a wire from the copper to a ground point such as the jack ground?[/quote]
Everything needs to be earthed.

[LawrenceH]

[quote name='Ou7shined' post='965485' date='Sep 23 2010, 12:26 PM']Yeah I known but you've shielded earthing wires. Nice touch but pointless unless you were experiencing specific problems. I like the old [url="http://en.wikipedia.org/wiki/KISS_principle"]KISS principal[/url].


It's worth a pop but LawrenceH does have a point.
I think you've just installed a new wiring kit. Try the cap from your old setup.


Everything needs to be earthed.[/quote]

If the orange drop is 0.047pF then I think I see where the issue is...but I'm guessing you mean microfarads? In any case try the old cap first as suggested

[Bobby K]

[quote name='LawrenceH' post='965828' date='Sep 23 2010, 05:04 PM']If the orange drop is 0.047pF then I think I see where the issue is...but I'm guessing you mean microfarads? In any case try the old cap first as suggested[/quote]


Yeah, sorry, the Orange drop is actually a 047mfd 100volt cap

The old cap is a green one (has the digits 2G473 on it, so not sure of the values of it) and was wired in differently.

I wired the orange drop in according to this diagram:

[url="http://www.fender.com/support/diagrams/pdf_temp1/basses/0136000B/SD0136000BPg2.pdf"]http://www.fender.com/support/diagrams/pdf...0136000BPg2.pdf[/url]

But with the original green capacitor, one leg was attached to the left lug of the volume pot (where the pickup hot wire is attached) and the other leg attached to the centre lug of the tone pot.

I was under the impression that P basses were all wired the same, but hey ho - maybe I should try putting the green one back in as it was, or even try the orange drop wired as the green one was.....

My head is battered with it all

[Ou7shined]

Keep it the same as your diagram.

There are couple of different ways to wire a P that essentially do the same thing.

[Bobby K]

I've given up on the whole shielding thing altogether now. The sound was just far too different from what I was used to. Imagine your bass had a helmet on; it's audible but has lost it's tone. Then you take off the helmet and the bass sings clearly again. Rubbish metaphor but you get the idea...

I've removed all the copper and the bass is pretty much as it was now. Left the orange drop in though. Bass has got its tone back but with the added bonus of being able to roll off a bit more treble it seems, thanks to the orange drop. A wider range of tones now it seems.

I'll never be absolutely certain whether it was my shoddy workmanship or the copper shield itself that caused such a tonal change, but I'd bet it was the copper adding a tonne of capacitance; it was a bit of a Fort Knox job after all!

I've learnt my lesson though; [b]IF IT AIN'T BROKE, DON'T FIX IT!![/b]

Thanks to all for advice and guidance along the way ; at least I got some good soldering practice in

Edited October 2, 2010 by Bobby K

[flyfisher]

[quote name='Bobby K' post='965435' date='Sep 23 2010, 11:35 AM']Well, I was convinced that I'd knackered my tone pot with too much solder iron heat after first doing the job. This was after trying to unsolder the blob on top of it, having the iron on the pot for ages before realising it wasn't hot enough (but still heating up the pot!)[/quote]
That's an important point when soldering. It can be as important to use a large iron as a small one when the circumstances dictate. It's not really a question of temperatureas such, but heat capacity. A small iron with a small bit will actually be cooled down by applying it to a large bit of cold metal, like a pot casing for example. For such things, you need an iron with enough thermal capacity so it won't cool when applied to large items such as pot cases and some connectors and will enable you to make the soldered joint quickly enough to remove the iron before the entire piece of metal gets too hot.

But don't try to use such an iron to replace a surface-mounted component!

[Bobby K]

[quote name='flyfisher' post='975271' date='Oct 2 2010, 06:26 PM']That's an important point when soldering. It can be as important to use a large iron as a small one when the circumstances dictate. It's not really a question of temperatureas such, but heat capacity. A small iron with a small bit will actually be cooled down by applying it to a large bit of cold metal, like a pot casing for example. For such things, you need an iron with enough thermal capacity so it won't cool when applied to large items such as pot cases and some connectors and will enable you to make the soldered joint quickly enough to remove the iron before the entire piece of metal gets too hot.

But don't try to use such an iron to replace a surface-mounted component![/quote]

I was using a Solderpro 50 - a little gas powered iron - supposed to be rated the same as an electrical iron between 30 and 70 watts. I did test all my pots later on with a meter and they all seemed to be showing what they were supposed to. Maybe I didn't damage the original ones after all.

Anyway, next time (if there is one!) I'll probably get somebody experienced to do the job.

[LawrenceH]

Really interested to hear your experiences here. Based on these I'll be proceeding with caution with respect to shielding when I put my jazz back together!

[Bobby K]

[quote name='LawrenceH' post='975413' date='Oct 2 2010, 09:00 PM']Really interested to hear your experiences here. Based on these I'll be proceeding with caution with respect to shielding when I put my jazz back together![/quote]
Yeah, let me know how you get on mate...

[chuck_stones]

Hi all,

This is a question which isn't directly related to this thread, but it is about copper shielding tape.

Does anyone know a good UK based source for the stuff? I've done a quick bit of googling, but being a total novice in this area, I can't see the wood for the trees - most the suppliers I've found are US based - I've just installed an East preamp into my Tanglewood Baron and realised I really need to shield my electronics cavity.

Also, does anyone know where you can source a barrel jack socket which is wired for active circuits? (i.e. has 4 connections; pos, neg, ground and connection to the battery to engage the circuit when the jack is plugged in).

Any suggestions warmly received Sorry if this has wandered way off topic!

[Ou7shined]

[quote name='chuck_stones' post='1146831' date='Mar 2 2011, 10:16 AM']Hi all,

This is a question which isn't directly related to this thread, but it is about copper shielding tape.

Does anyone know a good UK based source for the stuff? I've done a quick bit of googling, but being a total novice in this area, I can't see the wood for the trees - most the suppliers I've found are US based - I've just installed an East preamp into my Tanglewood Baron and realised I really need to shield my electronics cavity.

Also, does anyone know where you can source a barrel jack socket which is wired for active circuits? (i.e. has 4 connections; pos, neg, ground and connection to the battery to engage the circuit when the jack is plugged in).

Any suggestions warmly received Sorry if this has wandered way off topic![/quote]
Ebay.

[dougie]

[quote name='chuck_stones' post='1146831' date='Mar 2 2011, 10:16 AM']Hi all,

This is a question which isn't directly related to this thread, but it is about copper shielding tape.

Does anyone know a good UK based source for the stuff? I've done a quick bit of googling, but being a total novice in this area, I can't see the wood for the trees - most the suppliers I've found are US based - I've just installed an East preamp into my Tanglewood Baron and realised I really need to shield my electronics cavity.

Also, does anyone know where you can source a barrel jack socket which is wired for active circuits? (i.e. has 4 connections; pos, neg, ground and connection to the battery to engage the circuit when the jack is plugged in).

Any suggestions warmly received Sorry if this has wandered way off topic![/quote]
[url="http://www.convertape.com/guitar-shielding-kit-483-p.asp"]http://www.convertape.com/guitar-shielding-kit-483-p.asp[/url]
They do copper tape,guitar tape,Super high strength clear acrylic VHB tape,•Hide bra straps tape,toupee tape,slug tape,reflective tape,sellotape,insulating tape,magnetic tape,carpet tape,anti slip tape,helicopter tape,gaffer tape,glow in the dark tape,gravitape,every f***ing kind of tape........their ad is indeed on E bay,that amazing source for hard to fund stuff,like tape.

[chuck_stones]

[quote name='dougie' post='1146870' date='Mar 2 2011, 10:47 AM'][url="http://www.convertape.com/guitar-shielding-kit-483-p.asp"]http://www.convertape.com/guitar-shielding-kit-483-p.asp[/url]
They do copper tape,guitar tape,Super high strength clear acrylic VHB tape,•Hide bra straps tape,toupee tape,slug tape,reflective tape,sellotape,insulating tape,magnetic tape,carpet tape,anti slip tape,helicopter tape,gaffer tape,glow in the dark tape,gravitape,every f***ing kind of tape........their ad is indeed on E bay,that amazing source for hard to fund stuff,like tape. [/quote]

Haha, brilliant. You don't work for them by any chance do you?

No sooner said, than found and ordered. Cheers for the help all.

In relation to the jack I was after, turns out that was a red herring and the one I've got will do fine (the ever helpful) John East came to the rescue with that one. Can't wait to get home and finish off installing the thing. The Baron is going to be sounding AMAZING!