Sourcing a Fender Precision Bass Control Plate

[MacSwell]

Funny you should mention Henry Ott's book, I'm quite familiar with his work! The various resources that Mr. Ott has published online over the years have been invaluable in both my professional career as an electrical engineer AND my hobby of tinkering with audio electronics!

Regarding the full shielding of cavity and pickguard with copper tape or equivalent, I have a few guitars with it and a few guitars without it. On the guitars I shielded, EMI from various sources like phones and other transmitting devices nearby was greatly reduced, essentially leaving only the hum picked up from the coils of the pickup to deal with. However, I have also found that making twisted pairs out of the signal leads to reduce loop area AND eliminating all ground loops / redundancy in the instrument's circuit has a very smilar effect even when the shielding is not present. YMMV!

 

[Deleted member 409896]

Funny you should mention Henry Ott's book, I'm quite familiar with his work! The various resources that Mr. Ott has published online over the years have been invaluable in both my professional career as an electrical engineer AND my hobby of tinkering with audio electronics!

Can we be best friends?

So...I think we can assume we are operating at "Low" frequency. Not just in the musical sense but also in the EMC sense.

How did you make twisted pairs of your signal leads? I am not sure whether any of my instrument cables employ that strategy, but it seems like a low-hanging fruit.

 

[MacSwell]

PM'd you! Just so this thread can stay relevant for anyone else that needs it

 

[Brich]

I had a hard time sourcing these for some of my builds. I ended up making it out of left over birdseye maple. I'm sure you could do this with other materials as well

 

[Deleted member 409896]

My P-Base plate is stateside, and through customs. Don't know when I will get it. Will post again once it arrives.

 

[Peter N]

A beautiful Precision Bass body (internally wired + accurate pickup cavity) with the PBase control plate (photo from a happy customer).

 

[walterw]

Is there a reliable way to tell whether it's present or not? I've tried probing what I thought was conductive paint with my multimeter but couldn't tell. My MIM P and J both have control cavities that are (poorly) coated in a thin layer of chalky black paint.

Not sure. I did the same thing - diode-mode continuity test with a multimeter. No continuity on whatever the cavity coating is.

What got me thinking about this is, I noticed that there is a ground lead bonded to...the body of the bass, at the bottom (backside of bass) of the cavity. Huh.

you need to set your meter for actual resistance, not just dead-short continuity. jam your probes into the wood a few inches apart (push through the clear coat if you have to) and if you get any numbers at all, even in the hundreds of ohms, then that is indeed shielding paint and needs to be grounded or it'll turn into "antenna paint"

that is exactly what the wired-up wood screw is for

 

[Deleted member 409896]

Received my P-Base plate.

Unfortunately, I have to report that it does not fit at least some Fender Precision basses.

Mine is a 1995, US-made bass. There are 4 screw holes near the controls, which should line up with the 4 holes in the P-Base plate. At most, I can get 2 of the holes to line up. The difference is not great - half a screw-width or less - but is enough to prevent installation.

That is a shame, as the P-Base is a beautifully-made product. I was looking forward to fitting it alongside what was left of the original pickguard. Mirror finish, as seen in the photos, tastefully laser-engraved Positech logo on the reverse side.

Before you order a P-Base plate, you'll want to confirm screw hole spacings. There are apparently some variations of exactly where the screw holes are placed on a Fender Precision bass over the years, despite having the same number of screw holes (13).

 

[MacSwell]

Got mine installed last night! Two of the four holes were just barely lined up enough with the plate on my 2023 MIM, but once fully secured to the body you can't tell there's any misalignment at all. Making the guard cutout by hand was a HUGE pain in the butt with the tools I had available, so I was initially expecting it to be a trial-run piece I would scrap and remake later. However, after getting it all together, I'm pretty happy with the result! Up close my cut is not perfect, but from far away the plate and guard look very nice together. Now my P-Bass is a perfect (inverted) match for my J-Bass!

Thank you @Peter N for the awesome hardware!

 

[Peter N]

This P-Bass & J-Bass couple looks very nice I must say and it is indeed a completely black & white inversion (even the headstocks)!

I can understand the "pain in the butt" to make the pickguard cut-out by hand with less than optimal tools (you really need a suitable vice + an accurate jig saw for this). However, the end result is impressive and not "just" a trial run by the looks of it. You could even optimize it a little bit more by gently and slightly rounding off the "sharp" right-hand side so that it sticks out a few mm less. I did that myself as well as you can see on the example on my positechdesign.com website. Likewise shaving off a shade of the left-hand inner curve of the contact area with the PBase plate. Close to perfection!

I'm also very happy to see that even with a marginal misalignment you managed can get the heads of the screws fully flush.

The marginal variations in Fender P-Bass screw-hole patterns is something I have no control over unfortunately. However, I am confident that by mounting the control plate as smartly as possible, it can be done without adjusting screw holes on the body itself. I will keep a close eye on further comments on this. I have shipped more control plates to the US, UK, Japan, etc. so will get a better view on this over time and try to cater for best of both worlds in a potential next production run. However that will be not earlier than some time next year (or the year after that).

I hope this gives some more clarity from my perspective.

Peter (Positech Design).

 

[MacSwell]

Thank you for the feedback and the kind words! I was just wondering myself if I could improve it slightly by shaving away in the two places you mentioned, I think I will (carefully) give that a shot later tonight!

 

[Hundred proof]

Gotta agree with the G&L L1000 suggestion you would lose the stack knob and gain a switch

 

[MacSwell]

Did another pass of filing and sanding the guard last night, I think I got it to as good as I can get with hand tools. It came at the cost of some scratches to the face of the guard at the edge, but I think the end result was well worth it.

 

[Deleted member 409896]

that does look nice!

Sure wish it were possible to install the P-Base on my Fender. It would look great. But there's no amount of angling screws, or wishing and hoping, that would make it so.

 

[MacSwell]

that does look nice!

Sure wish it were possible to install the P-Base on my Fender. It would look great. But there's no amount of angling screws, or wishing and hoping, that would make it so.

This might be a wild suggestion, but what if you chopped off and glued the heads of two screws (or something else) into the two misaligned holes of the plate to cover them up, and then used the two inner holes for mounting? That plate is so thick that two screws should be plenty to hold it firm to the body, and having screw heads in all 4 holes will keep it looking pretty.

 

[Deleted member 409896]

I looked at it again, and it's actually worse than I thought at first.

If I position the P-base plate so that 2 of the holes (the middle ones) line up properly, it sits at an angle so that the jack and controls can't use the provided holes. There isn't a lot of slop available in where the pots and jack hardware sit, side-to-side. The pots bump into the walls of the cavity.

The only way to have the jack and controls fit the plate is if I have one screw, the one at the lower "tip" of the pickguard, line up. Then the other 3 holes are functionally useless, and the plate isn't held on very well.

If I wanted to have the P-base install securely, I'd have to fill in at least one screw hole & drill a new one, somewhat overlapping with the old one. That is a lot more work than I signed up for.

 

[Peter N]

I can acknowledge that the control cavity of a Precision Bass is a tight fit (also in this area I suspect marginal slippage over the years). On my own P-Bass I also had to turn the pots and jack input in an optimal position to obtain the required maneuvering space for installation; this worked fine for me.

As I delivered an unplanned 2nd control plate to you due to a mistake I made in your address details (so no costs for you), this can be an opportunity to try out the following on this 2nd plate:

Mount two "mini pots" and a jack input with a small footprint on the plate (if needed with an additional washer at both sides). This will cost you only a few dollars and the wiring of a Precision Bass is dead simple. This will give you much more space to optimize alignment of the screw holes. Plus you can store your 1st control plate (or pickguard) with the original pots/jack input in case if you ever want to revert to the original config (e.g. in case of selling your bass).

I hope this suggestion helps to solve you problem.

Best, Peter

 

[Loiner91]

This P-Bass & J-Bass couple looks very nice I must say and it is indeed a completely black & white inversion (even the headstocks)!

I can understand the "pain in the butt" to make the pickguard cut-out by hand with less than optimal tools (you really need a suitable vice + an accurate jig saw for this). However, the end result is impressive and not "just" a trial run by the looks of it. You could even optimize it a little bit more by gently and slightly rounding off the "sharp" right-hand side so that it sticks out a few mm less. I did that myself as well as you can see on the example on my positechdesign.com website. Likewise shaving off a shade of the left-hand inner curve of the contact area with the PBase plate. Close to perfection!

I'm also very happy to see that even with a marginal misalignment you managed can get the heads of the screws fully flush.

The marginal variations in Fender P-Bass screw-hole patterns is something I have no control over unfortunately. However, I am confident that by mounting the control plate as smartly as possible, it can be done without adjusting screw holes on the body itself. I will keep a close eye on further comments on this. I have shipped more control plates to the US, UK, Japan, etc. so will get a better view on this over time and try to cater for best of both worlds in a potential next production run. However that will be not earlier than some time next year (or the year after that).

I hope this gives some more clarity from my perspective.

Peter (Positech Design).

Just want to say I think this is an awesome idea for a product-great to hear there might be some further fine tuning in future production runs. I was going to ask if theres an option to ship without drilled holes so people could potentially match up their own guards and put the holes in themselves. Is your current stock all drilled?

 

[Peter N]

My latest production run was all drilled with the original US P-Bass pattern, so unfortunately I don't have "blanks" available. My stock is running out gradually as I am getting orders from around the globe.

It may be risky to drill the screw holes into a control plate blank (with only the pot and jack holes). It's stainless steel plus countersunk holes are required (unless you decide to skip this). For sure you can't do this accururately with a hand drill. Also, measurement needs to be precise.

Only with sufficient interest I can arrange a run of blanks (this cannot be based on single-item orders). If anyone wants to jump into this gap, I'm open to suggestions.

Cheers,

Peter (Positech Design)

 

[Loiner91]

My latest production run was all drilled with the original US P-Bass pattern, so unfortunately I don't have "blanks" available. My stock is running out gradually as I am getting orders from around the globe.

It may be risky to drill the screw holes into a control plate blank (with only the pot and jack holes). It's stainless steel plus countersunk holes are required (unless you decide to skip this). For sure you can't do this accururately with a hand drill. Also, measurement needs to be precise.

Only with sufficient interest I can arrange a run of blanks (this cannot be based on single-item orders). If anyone wants to jump into this gap, I'm open to suggestions.

Cheers,

Peter (Positech Design)

That makes sense. Im working on a part’s build at the moment, and have decided to go with the fender American Standard pickguard pattern that Armstrongs Music in the UK make. They have a massive variety of fender pickguard patterns they can produce and I figured the ‘modern USA Standard) would give me the best interchangeablity down the line. Im wondering if your P-Base would be a direct fit over the silhouettes of my pickguard screw holes. Like some others have expressed, I’d be more inclined towards a Jazz style fit as ut would be much easier to adapt to an existing pickguard. Hats off to you mate for getting into this-its a great idea. I hadn’t even considered something like this for my build but with it having a solderless loom, being able to pop off a plate instead of the whole pickguard makes it even more modular! Cheers