Restoration of a Fender Boxer (Jazz Bass Special) '85 MIJ

[Vini Sasso]

Hi all!

This is my first post, so if it's at the wrong place, please let me know)

 

I'm trying to get my older Fender Boxer bass (P/J setup) restored to the closest to the 'factory settings' possible.

 

I bought it used in 2022' and it was in rough conditions. I still wanted it anyway because I like to restore things from time to time.

 

It took me some time, and analysis from a local luthier, to find out that its electronics were all messed up. The pickups were original at least, so it wouldn't be hard to make it sound the way Fender intended it to, at least that was my first thought.

 

But I am having a hard time in this restoration. The closest to a wiring diagram that I found around the web is a PDF book written in german (and I'm utterly incompetent at reading german, so I resorted to Google for some help) - it presents what looks like a Fender PJ-555 (one of the product codes for it) which matches the Made in Japan Boxer. However the diagram offered seems wrong. It doesn't even mention the pickup selector switch. (sigh!)

 

I tried different forums and many places around the Web with not very reliable results.

 

Does anyone here happen to have a true and reliable schematics for the Boxer Bass to share? Does someone remember important info about its electronics?

 

All I could find via YouTube reviews is:

 

- the Boxer PJ contains a pickup selector Switch (P/P+J blend/J) and is wired in Series (I mean, not only the split coils from the P are in Series. The route from P to J pickup also is - apparently to give it even more sound pressure and output?). If a pickup volume knob is dropped to zero, the bass is muted altogether no matter what the other volume cap setting is. (and I read somewhere that this is another outcome of Series wiring). Its tone pot is a TBX control pot, not a conventional one. Total 3 pots: V / V / T (with TBX) 

 

As for volume cap values, I've read them both are 250 Kohm and them both are 500 Kohm. I am not sure who is right among these two but I am not too concerned because as far as I know any of these values can be fine and are a matter of taste.

 

As for other pieces, capacitors, I really don't know what are the right ones and where they should be connected to.

 

So, if anyone has reliable info to share, or a nice schematics, I appreciate a lot.

 

I apologize if my english is not optimal. It is not my first language.

 

Thanks in advance

 

 

Edited April 20 by Vini Sasso
Additions

[ikay]

If you haven't seen these TB posts already there may be some clues here (no wiring diagram though):
https://www.talkbass.com/threads/help-with-the-controls-on-a-mij-pb-555.1585452/

https://www.talkbass.com/threads/fender-boxer-pj-80-wiring-diagram.1642052/

[BreadBin]

I was wondering if @KiOgon would know anything about these?

 

I have the same bass with a bit of a buzz and was thinking of refreshing the electronics.

[KiOgon]

What more do you need, all the info is there?

[neepheid]

God bless Cadfael's cookbook.

[PaulThePlug]

Pics Please...

I think @Duarte Did-Up a Boxer PJ... which inspired my J PJ Bitsa.

Edited April 21 by PaulThePlug

[Vini Sasso]

13 hours ago, ikay said:

If you haven't seen these TB posts already there may be some clues here (no wiring diagram though):
https://www.talkbass.com/threads/help-with-the-controls-on-a-mij-pb-555.1585452/

https://www.talkbass.com/threads/fender-boxer-pj-80-wiring-diagram.1642052/

I read some of these, didn't read others. (actually I was at one of these, I'm familiar to TB ) I'll check them out. Thanks!

[Vini Sasso]

3 hours ago, KiOgon said:

What more do you need, all the info is there?

I see this is the most similar you found. (Well...and the book in German again 😊) This is a P boxer with P/P configuration, so this is not completely out of hand. However, as I already mentioned:

 

- Boxer PJ has V / V / T (TBX) pots. This one is clearly different as it mentions: V / Tone / TBX Tone

 

I see this is a similar model. But still I want my instrument to replicate factory settings the most possible.

 

Thanks anyway

[Dood]

I’ve three Power Jazz (PJ-755) basses (which are electrically different) but the manual covers some information you may or may not find interesting about the 555 too.

 

https://www.fmicassets.com/Damroot/Original/10001/OM_leg_bass_Power_Jazz_Bass_Japan_1987.pdf

[Dood]

[Dood]

I also just found this old advert for a PJ555 harness too so you can see the components

[Vini Sasso]

2 hours ago, PaulThePlug said:

Pics Please...

I think @Duarte Did-Up a Boxer PJ... which inspired my J PJ Bitsa.

I'll send pics of mine soon. Nice Bass!

[Vini Sasso]

18 minutes ago, Dood said:

I also just found this old advert for a PJ555 harness too so you can see the components

 

Cool! This might help...

 

The manual is an interesting read, I have a copy here. Thanks

 

The other diagram, I saw one of these in Pinterest. Can't tel how accurate it is (or isn't). Seems like a standard PJ wiring (an innacurate diagram) though.

[Dood]

Comparing the diagram to the image of the harness, it's looking good. You can see what pins the pickups would have been connected to (absent) and the other shielded cables go to the expected components. You'll be looking at 250K Audio Taper pots for the two volumes and the TBX can be bought still if the one you have doesn't work. 

To be honest, there's nothing really unusual about the harness at all. It's a pretty standard set up, as you'd find in say, a standard jazz bass. Save for the inclusion of the TBX tone control. Finally, the P coils will be wired in series and will hum-buck. The switch configuration means that when it's in the central position the P coils and the J coil will be in parallel to each other which is exactly the same on my Power Jazz basses as well as... well.. countless other 2 pickup basses with one three way switch. (Gibson Les Pauls too etc etc) 

Good luck! They are great basses!

 

I'm not actually a fan of VVT ha ha, I'd rewire it with a master volume, but of course that would leave you with a DFA control  (I appreciate that might not translate, so here's Lee Sklar's Producer Control to explain) ha ha!

[Vini Sasso]

12 hours ago, Dood said:

Comparing the diagram to the image of the harness, it's looking good. You can see what pins the pickups would have been connected to (absent) and the other shielded cables go to the expected components. You'll be looking at 250K Audio Taper pots for the two volumes and the TBX can be bought still if the one you have doesn't work. 

To be honest, there's nothing really unusual about the harness at all. It's a pretty standard set up, as you'd find in say, a standard jazz bass. Save for the inclusion of the TBX tone control. Finally, the P coils will be wired in series and will hum-buck. The switch configuration means that when it's in the central position the P coils and the J coil will be in parallel to each other which is exactly the same on my Power Jazz basses as well as... well.. countless other 2 pickup basses with one three way switch. (Gibson Les Pauls too etc etc) 

Good luck! They are great basses!

 

I'm not actually a fan of VVT ha ha, I'd rewire it with a master volume, but of course that would leave you with a DFA control  (I appreciate that might not translate, so here's Lee Sklar's Producer Control to explain) ha ha!

 

Thanks! I'm ok with V V T, I like to blend pickups and try different sounds from them.

 

Regarding TBX, the previous owners of the instrument messed so badly w/ the electronics, that it was absent at first. There was just a regular pot in there. I could install a new TBX quite easily, it was a available for purchase, I like it a lot. A bit subtle, but it does transform the way the Bass is perceived tonalwise.

 

The only thing that doesn't check (I am newbie in electronics) is the serial connection between the pickups. Not only the P splits are in serial. in a Boxer in factory settings, if I drop any of the pickup pots to zero, the sound of the Bass altogether is cancelled, no matter what setting the other pickup pot is. This is due to the serialized connection. Probably it was intended for a fuller and more aggressive tone?, as a serial connection does imply that all pickups with a single output gives a louder signal with a bit of variance in frequencies it seems. Só Maybe that is part of the "voice" of the instrument even though we know that mostly it's about the pickups. Fortunately the pickups are original, so there's hope. 😊

 

Let's see how it gets.

 

Edited April 22 by Vini Sasso
I said caps but I meant pickups, sorry

[Dood]

Absolutely. The wiring you're describing is not stock and has been messed about with - especially as it doesn't work properly. If you desire the ability to switch the pickups from parallel to series, it can easily be done with the inclusion of a DPDT switch and you'll be able to have volume controls that work properly too. 

 

I've used this config on a PJ bass before - interestingly, a bass that had been suggested to have influenced the Boxer range in the first place, but I can't find any authenticity to that story. The series setting will sound a little louder and have more prominent mids in most cases (but not all, depending on the pickups of course - and make sure the phase is correct!!)

 

So, if you are looking for truly stock, then use the diagram above, but if you're after more options, obviously, seek out a new schematic to follow

[Dood]

17 minutes ago, Vini Sasso said:

 

Thanks! I'm ok with V V T, I like to blend pickups and try different sounds from them.

 

Regarding TBX, the previous owners of the instrument messed so badly w/ the electronics, that it was absent at first. There was just a regular pot in there. I could install a new TBX quite easily, it was a available for purchase, I like it a lot. A bit subtle, but it does transform the way the Bass is perceived tonalwise.

 

The only thing that doesn't check (I am newbie in electronics) is the serial connection between the caps, not only the P splits are in serial. in a Boxer in factory settings, if I drop any of the cap pots to zero, the sound of the Bass altogether is cancelled, no matter what setting the other cap pot is. This is due to the serialized connection. Probably it was intended for a fuller and more aggressive tone?, as a serial connection does imply that all caps with a single output gives a louder signal with a bit of variance in frequencies it seems. Só Maybe that is part of the "voice" of the instrument even though we know that mostly it's about the caps. Fortunately the caps are original, so there's hope. 😊

 

Let's see how it gets.

 

 

A good trick is to trace out the current schematic (using the same symbols in the diagrams above). It's good practice anyway, but sometimes it helps to visualise where issues are! 

[Vini Sasso]

9 hours ago, Dood said:

 If you desire the ability to switch the pickups from parallel to series, it can easily be done with the inclusion of a DPDT switch and you'll be able to have volume controls that work properly too. 

 

 - and make sure the phase is correct!!)

 

So, if you are looking for truly stock, then use the diagram above, but if you're after more options, obviously, seek out a new schematic to follow

The DPDT switch is an interesting idea, might try this in the future.

 

Really, I felt so frustrated when I learnt that the Bass was all messed up, I just want it to recover its voice and characteristics for now. I like the way a Boxer sounds when in factory conditions, this is why it's the focus today. In the future I might look into nice changes and mods maybe.

[Duarte]

On 22/04/2024 at 05:22, PaulThePlug said:

Pics Please...

I think @Duarte Did-Up a Boxer PJ... which inspired my J PJ Bitsa.

 

Just saw this! I love your slanty bitsa. Yes I restored a Boxer PJ535, however I moved from Thailand to Australia before I managed to figure out the electronics properly. I was attempting a vol/vol/tbx with 3 way pickup selector (as original), but with an added series/parallel switch. I couldn't get it working properly before I left the country so it is sitting in my apartment waiting for me to finish the job. I will share videos as soon as I'm back and able to get it up and running. 

Good luck with the project - these basses are wonderful and should be preserved

[Vini Sasso]

On 01/05/2024 at 06:05, Duarte said:

 

Just saw this! I love your slanty bitsa. Yes I restored a Boxer PJ535, however I moved from Thailand to Australia before I managed to figure out the electronics properly. I was attempting a vol/vol/tbx with 3 way pickup selector (as original), but with an added series/parallel switch. I couldn't get it working properly before I left the country so it is sitting in my apartment waiting for me to finish the job. I will share videos as soon as I'm back and able to get it up and running. 

Good luck with the project - these basses are wonderful and should be preserved

 

And I've got some great news! I see the schematics found on the Web aren't exact. I luckily have another boxer PJ (one 2021' reissue) sitting here for my recordings, so I decided to open its cavity and figure out what it is like under the lid.

 

As I am a newbie in electronics, it was hard for me to tell exactly what I found. I just marked the parts and wires visually.  I see there are some wire tubes containing one white wire (I suppose it's signal/hot?) and another bare wire (grounding wire?), and there are also single white wires coming from small holes that lead to the pickups, probably signal wires taking their signal. And some thin black wires also.

 

The TBX is a bit different to the one Fender offers currently. Maybe because that one in the Reissue is from Japan?

 

Two parts are definitely there: one 0.022 uF Capacitor labeled '223K' (for treble rolloff of the tone knob I suppose?) and one 82K resistor (took longer to decode, because it uses coloured bars I had to search what they mean), both soldered into the TBX tone pot in their distinct positions.

 

And now by replicating the reissue Boxer circuit, I got the serial wiring back in place. I can be totally wrong, but I suppose the serial connection is a kind of 'two-way exchange' between the pickups - they both have a ground wire that will meet the other pickups' signal wire ahead in the pickup selector? At least that's what it seems, but never to be taken literally, because I will check everything until I get all reliable info.

 

And what a difference it makes! I can hear it. It's quite growly. And in PJ blend settings, one volume pot can cancel the signal altogether if set to zero, as expected.

 

There's still some work to be done on the frets - they are basically dead. Once it gets past the fretwork I will be happy to share some recordings. I might also share the schematics so other fans of the Boxer PJ will be able to replicate factory settings too if they wish to, except it will be in portuguese instead of german 🙂 Ok, I might take some time translating that into english too. 

Edited 16 hours ago by Vini Sasso