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Post subject: Re: Jazz Bass MIM output volume
Posted: Wed Aug 03, 2016 1:45 am
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Nice job of upgrading......looks like it turned out swell.

And a special commendation for using masking tape to protect the finish during the installation. Experienced luthiers always use this technique to guard against accidents.

Rawk on!

8)

Arjay

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Post subject: Re: Jazz Bass MIM output volume
Posted: Wed Aug 03, 2016 2:52 am
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Loud single coil pickup output does not equal good full range tone. Generally the louder the pickup output the less upper mids (treble) you will get because it is over-wound. Another option is to add an active EQ on the instrument, which is rarely as reliable as a passive instrument but sure is loud! With today's preamps such as the one on your head you really do not need a bunch of output. In 1967 higher output would have been a big advantage when about 100 watts was considered obscene power, but much less so today.

Hope you used this diagram and from what I can see it appears you were on that road:
http://support.fender.com/service_diagrams/bass_guitars/019-6208A_SISD.pdf

I hope you take the rest of this in the spirit in which it is offered. It is not criticism of what you have done but some advice that i would give anyone doing this project if I was looking over their shoulder. I am not trying to be a know-it-all or self appointed expert. I have done these things lots of times and learned a lot. There are a few things I noticed you could review or use for future reference on your next upgrade, or better yet that you could revisit and make sure you covered the bases.

1. The copper foil needs to be grounded. Check that all shielded areas hit ground with a meter.

2. Any seams in the tape can be spot soldered for improved connectivity since the adhesive may make a connection but every layer of shielding tape adds some resistance because of the adhesive which you can totally eliminate by dropping one bead of solder somewhere on each seam.

3. The pickguard can also provide some shielding benefit for the neck pickup on a Jazz Bass if the back side of the pickguard is foiled. To connect the pickguard foil backing to the shielding circuit the foil in the neck pickup cavity is applied so that it OVERLAPS the lip of the neck pickup cavity where it can make contact with the foil on the back of the pickguard when the pickguard is in place and the pickguard screws are tightened down. Lots of Jazz Bass players SOLO their neck pickup a lot and shielding the pickguard can reduce hum when soloing the neck pickup.

4. Foil the SIDES of the bridge pickup cavity also. RF enters from all directions and not just from the back of the pickup. Your goal is to shield to ground every pickup and control cavity in all directions except the FRONT of the pickups facing the strings.

5. The entire control cavity should be shielded with the foil overlapping the top edge of the cavity where it will come into contact with the metal control plate when the control plate is seated. This effectively builds a shielded cage for the controls and control wiring where some additional hum can get started.

6. Standard Fender wiring is white for positive and black for ground. But you can use any colors you like. Confusing future techs that try to do a repair or mod is fun!

See this page for keys to copper foil shielding a single coil instrument as perfectly as possible and pay attention to the photos as they depict the steps above. (Even though the instrument shielding project in this case is a Strat, all the principles for a good shielding job on a Jazz Bass or any single coil bass are precisely the same as on a Strat.) http://www.artandtechnology.com.au/guitar/shielding-strat.html

Doing a shielding job correctly is a tedious and time consuming procedure. So one might as well do it right. It is one of the best things you can do for a single coil Fender bass like your Jazz Bass or a first generation single coil P-Bass/Tele Bass.

One final word about shielding. Covers. Most players hate them because they get in the way of playing right over the pickup, but C.L. Fender put them on the originals for a couple of reasons and one was to improve RF rejection. The second was protection of the pickup and the third was aesthetics. They are not as beneficial on a Precision as on a Jazz though. Their benefit is slightly improved if you run a tiny ground wire soldered to the pickup cavity shielding and conceal it wrapped around one of the cover screws. Fender did exactly that on the first 1951 Precisions. Nobody but you will know the little wire is there. To cover or not to cover is a personal decision. You can also make a compromise. Since the bridge pickup does not have the benefit of the pickguard shielding trick a bridge cover that also covers the pickup is a good compromise since more players play over the neck pickup than the bridge pickup.

I would have picked a different tone cap, but if you like Orange Drop poly caps then enjoy! Early Jazzes used ceramic disc caps. Ceramic discs have a distinct edge to them that is very apparent to me on a full range cab with a horn or tweeter. To me they are part of the flavor of a Pre-CBS Jazz tone. You simply will not get that tone from any poly cap. Vintage correct ceramic disc caps are relatively cheap and you can get them lots of places including from http://axegrinderz.com/ which I have had good experiences with for a long time.

Another cap option would be to use a Vitamin-Q type paper in oil cap which results in no edge whatsoever for a perfectly clean tone. I use Vitamin-Q caps a lot on my passive Precisions and P/J's because I use effects to add grit or I go very clean with lots of compression which also adds grit. If nobody ever remembers anything else I have said, remember this. "You can always dirty up a clean tone but you can not clean up a dirty tone." So when setting up most of my basses I want to start as clean as possible coming from the instrument. However an exception to that would be if I am going to plug a passive bass directly into a stage rig with no effects. In that case I would want a vintage ceramic disc in that instrument. It adds just the right edge to make the instrument sound more serious.

Orange Drop poly caps are a middle of the road choice. Use them when you do not know what you really want because they not totally clean but not very edgy either. Guitar parts houses sell tons of them mainly because people think they are an upgrade when actually they are more of a compromise. They are cleaner than a ceramic disc sure, but not perfectly clean. I am a big fan of extremes and prefer either the ceramic disc like the original Jazz Basses used or a super clean tone with Vitamin-Q type caps that I can dirty up with a bass driver or compression as a situation demands. I find Orange Drop Poly caps have just enough distortion to not be crystal clean, but they are too clean to have enough grit in their tone to approach the mojo of a vintage ceramic disc when going direct into a full range cab without using a bass driver or other effects.

Orange Drop Poly caps should have been called Vanilla Drops instead. In Sprague Orange Drop caps I strongly prefer the Orange Drop Mylar caps that are very clean and so close to a Vitamin-Q type paper in oil cap. They cost the same as the Poly Orange Drops but are more rectangular than rounded plus are way harder to find, however they are worth the effort to seek out if you want a crystal clear tone with no coloration. The Mylar Orange Drops sound so close to Vitamin-Q in cleanness that I have trouble telling them apart. The Mylar Orange Drops have only one disadvantage compared to ceramic disc, Vitamin-Q or poly caps and that disadvantage is a lower heat tolerance. However if your instrument ever got hot enough to melt the Mylar film chances are you aren't going to be playing it again anyway without a major overhaul due melted pickup covers, dead pickups due melted enamel, melted knobs, etc.

I do not know who started the Poly Orange Drop craze making them the default upgrade tone cap for passive electric bass, but they sure led lots of people to the middle of the road with misinformation and vague claims about exactly what they do tone-wise. If you are plugging directly into a stage amp and you want vintage character try a vintage ceramic disc next time instead. Some people, mostly engineers, say the tone cap doesn't matter at all but I believe that if you replace that Orange Drop Poly cap with a vintage ceramic disc on a single coil bass and use a full range cab that you will notice some added character on your rig. Sometimes the difference can be startling.

I think you will learn to love those pickups!


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Post subject: Re: Jazz Bass MIM output volume
Posted: Sat Aug 06, 2016 1:33 pm
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Joined: Thu Jul 21, 2016 1:04 pm
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linnin wrote:
Wonderful photos, Andrea! Looks like you did an excellent job, and glad you like the tone. Just use the gain knob on your Rumble to adjust for different bass instrument volumes. I know you didn't want to do it that way, but that is just the way it is.



Hi, linnin
thank you so much
I tried to do my best ... I hope I succeeded

Andrea.

Retroverbial wrote:
Nice job of upgrading......looks like it turned out swell.

And a special commendation for using masking tape to protect the finish during the installation. Experienced luthiers always use this technique to guard against accidents.

Rawk on!

8)

Arjay


Hi Arjay,
thanks you so much,

I'm not a luthier, I'm a cad / cam programmer but I like to make precise and clean work ... I love very much my things

Andrea.


Last edited by Andrea69 on Sat Aug 06, 2016 2:27 pm, edited 1 time in total.

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Post subject: Re: Jazz Bass MIM output volume
Posted: Sat Aug 06, 2016 1:55 pm
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brotherdave wrote:
Loud single coil pickup output does not equal good full range tone. Generally the louder the pickup output the less upper mids (treble) you will get because it is over-wound. Another option is to add an active EQ on the instrument, which is rarely as reliable as a passive instrument but sure is loud! With today's preamps such as the one on your head you really do not need a bunch of output. In 1967 higher output would have been a big advantage when about 100 watts was considered obscene power, but much less so today.

Hope you used this diagram and from what I can see it appears you were on that road:
http://support.fender.com/service_diagrams/bass_guitars/019-6208A_SISD.pdf

I hope you take the rest of this in the spirit in which it is offered. It is not criticism of what you have done but some advice that i would give anyone doing this project if I was looking over their shoulder. I am not trying to be a know-it-all or self appointed expert. I have done these things lots of times and learned a lot. There are a few things I noticed you could review or use for future reference on your next upgrade, or better yet that you could revisit and make sure you covered the bases.

1. The copper foil needs to be grounded. Check that all shielded areas hit ground with a meter.

2. Any seams in the tape can be spot soldered for improved connectivity since the adhesive may make a connection but every layer of shielding tape adds some resistance because of the adhesive which you can totally eliminate by dropping one bead of solder somewhere on each seam.

3. The pickguard can also provide some shielding benefit for the neck pickup on a Jazz Bass if the back side of the pickguard is foiled. To connect the pickguard foil backing to the shielding circuit the foil in the neck pickup cavity is applied so that it OVERLAPS the lip of the neck pickup cavity where it can make contact with the foil on the back of the pickguard when the pickguard is in place and the pickguard screws are tightened down. Lots of Jazz Bass players SOLO their neck pickup a lot and shielding the pickguard can reduce hum when soloing the neck pickup.

4. Foil the SIDES of the bridge pickup cavity also. RF enters from all directions and not just from the back of the pickup. Your goal is to shield to ground every pickup and control cavity in all directions except the FRONT of the pickups facing the strings.

5. The entire control cavity should be shielded with the foil overlapping the top edge of the cavity where it will come into contact with the metal control plate when the control plate is seated. This effectively builds a shielded cage for the controls and control wiring where some additional hum can get started.

6. Standard Fender wiring is white for positive and black for ground. But you can use any colors you like. Confusing future techs that try to do a repair or mod is fun!

See this page for keys to copper foil shielding a single coil instrument as perfectly as possible and pay attention to the photos as they depict the steps above. (Even though the instrument shielding project in this case is a Strat, all the principles for a good shielding job on a Jazz Bass or any single coil bass are precisely the same as on a Strat.) http://www.artandtechnology.com.au/guitar/shielding-strat.html

Doing a shielding job correctly is a tedious and time consuming procedure. So one might as well do it right. It is one of the best things you can do for a single coil Fender bass like your Jazz Bass or a first generation single coil P-Bass/Tele Bass.

One final word about shielding. Covers. Most players hate them because they get in the way of playing right over the pickup, but C.L. Fender put them on the originals for a couple of reasons and one was to improve RF rejection. The second was protection of the pickup and the third was aesthetics. They are not as beneficial on a Precision as on a Jazz though. Their benefit is slightly improved if you run a tiny ground wire soldered to the pickup cavity shielding and conceal it wrapped around one of the cover screws. Fender did exactly that on the first 1951 Precisions. Nobody but you will know the little wire is there. To cover or not to cover is a personal decision. You can also make a compromise. Since the bridge pickup does not have the benefit of the pickguard shielding trick a bridge cover that also covers the pickup is a good compromise since more players play over the neck pickup than the bridge pickup.

I would have picked a different tone cap, but if you like Orange Drop poly caps then enjoy! Early Jazzes used ceramic disc caps. Ceramic discs have a distinct edge to them that is very apparent to me on a full range cab with a horn or tweeter. To me they are part of the flavor of a Pre-CBS Jazz tone. You simply will not get that tone from any poly cap. Vintage correct ceramic disc caps are relatively cheap and you can get them lots of places including from http://axegrinderz.com/ which I have had good experiences with for a long time.

Another cap option would be to use a Vitamin-Q type paper in oil cap which results in no edge whatsoever for a perfectly clean tone. I use Vitamin-Q caps a lot on my passive Precisions and P/J's because I use effects to add grit or I go very clean with lots of compression which also adds grit. If nobody ever remembers anything else I have said, remember this. "You can always dirty up a clean tone but you can not clean up a dirty tone." So when setting up most of my basses I want to start as clean as possible coming from the instrument. However an exception to that would be if I am going to plug a passive bass directly into a stage rig with no effects. In that case I would want a vintage ceramic disc in that instrument. It adds just the right edge to make the instrument sound more serious.

Orange Drop poly caps are a middle of the road choice. Use them when you do not know what you really want because they not totally clean but not very edgy either. Guitar parts houses sell tons of them mainly because people think they are an upgrade when actually they are more of a compromise. They are cleaner than a ceramic disc sure, but not perfectly clean. I am a big fan of extremes and prefer either the ceramic disc like the original Jazz Basses used or a super clean tone with Vitamin-Q type caps that I can dirty up with a bass driver or compression as a situation demands. I find Orange Drop Poly caps have just enough distortion to not be crystal clean, but they are too clean to have enough grit in their tone to approach the mojo of a vintage ceramic disc when going direct into a full range cab without using a bass driver or other effects.

Orange Drop Poly caps should have been called Vanilla Drops instead. In Sprague Orange Drop caps I strongly prefer the Orange Drop Mylar caps that are very clean and so close to a Vitamin-Q type paper in oil cap. They cost the same as the Poly Orange Drops but are more rectangular than rounded plus are way harder to find, however they are worth the effort to seek out if you want a crystal clear tone with no coloration. The Mylar Orange Drops sound so close to Vitamin-Q in cleanness that I have trouble telling them apart. The Mylar Orange Drops have only one disadvantage compared to ceramic disc, Vitamin-Q or poly caps and that disadvantage is a lower heat tolerance. However if your instrument ever got hot enough to melt the Mylar film chances are you aren't going to be playing it again anyway without a major overhaul due melted pickup covers, dead pickups due melted enamel, melted knobs, etc.

I do not know who started the Poly Orange Drop craze making them the default upgrade tone cap for passive electric bass, but they sure led lots of people to the middle of the road with misinformation and vague claims about exactly what they do tone-wise. If you are plugging directly into a stage amp and you want vintage character try a vintage ceramic disc next time instead. Some people, mostly engineers, say the tone cap doesn't matter at all but I believe that if you replace that Orange Drop Poly cap with a vintage ceramic disc on a single coil bass and use a full range cab that you will notice some added character on your rig. Sometimes the difference can be startling.

I think you will learn to love those pickups!


Hi brotherdave,

thank you so much for your help
I am an amateur who plays bass for 2 years and I really liked what you wrote.
Thank you for sharing with me and with all of your forum experience ...
Thank you.

the photos I've posted were not finished work ... I have shielded for good all cavities even the walls not only the bottom.
I also shielded pickguard like you suggested

https://drive.google.com/open?id=0Bx9vbJ0uWLFLZE9DSU9WYXBaekU

https://drive.google.com/open?id=0Bx9vbJ0uWLFLUlhId1V6dzc3WEE

I do not solder the copper at the joints ... I did not know this but now I know, and if I have to redo the work certainly I do it

I have followed the cabling instructions for American Standard Jazz Bass

http://support.fender.com/service_diagrams/bass_guitars/019-2400_02A_SISD.pdf

I for the condenser not know ... I have chosen Orange drop because I thought it was better than the one installed at the factory ... I have no experience in
thanks for making me understand.

The wire I used for wiring is what I found in the house ...;)

I'm thinking of doing the same job on my precision bass made in mexico
But I have a doubt about the choice of pickups ...
I write a message in the section the precision bass ... I would like to know your opinion

Thanks again

Andrea.


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Post subject: Re: Jazz Bass MIM output volume
Posted: Thu Aug 11, 2016 1:30 am
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Hi Andrea, A modern Precision benefits much less from a shielding job than a Jazz. They are pretty quiet stock as a general rule because of the humbucking out of phase pickup. Some of the Fender pickups, like the Fender Original Precision Bass pickup set, come pre wired and pre-mounted on a brass shielding plate. That should be more than adequate shielding. I have done full shielding jobs on several post 56 Precisions that probably didn't need it. In the end there was really no benefit to doing it on a modern P-Bass. I do not think I will shield a modern P-Bass again unless it is noisy for some reason. Pre-57 P-Basses benefit from shielding as much as Jazz Basses but not 57 and later P-Basses.


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Post subject: Re: Jazz Bass MIM output volume
Posted: Fri Aug 12, 2016 1:30 pm
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brotherdave wrote:
Hi Andrea, A modern Precision benefits much less from a shielding job than a Jazz. They are pretty quiet stock as a general rule because of the humbucking out of phase pickup. Some of the Fender pickups, like the Fender Original Precision Bass pickup set, come pre wired and pre-mounted on a brass shielding plate. That should be more than adequate shielding. I have done full shielding jobs on several post 56 Precisions that probably didn't need it. In the end there was really no benefit to doing it on a modern P-Bass. I do not think I will shield a modern P-Bass again unless it is noisy for some reason. Pre-57 P-Basses benefit from shielding as much as Jazz Basses but not 57 and later P-Basses.



hi,
Thanks for the answer
I did not know...
what you have written to me saves a little time in doing the work

PS. I also answered you in the Precision Bass section


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