New Partsmaster build: Charcoal Frost Thinline Jazzmaster

[MayTheFuzzBeWithYou]

Originally I wanted to keep it a secret until it was done - but the „what to do with the neck“ questionnaire already gave most of the surprise away.

I won an eBay auction on a Charcoal Frost (Metallic? More like satin) Thinline Jazzmaster Body from Rosser some weeks ago and it arrived yesterday… as I‘m bad at waiting for something - I tried to make room and find time to build it up today.

I never was so fast before at assembling a guitar. It still took hours… but soldering and cable layout went fast, the Vibrato screw holes were luckily already there.
And I could do all the other drillings fast (tuner holes have been an end-boss for me before - but I found a good technique. )
The only thing that bugged me were the thimble holes as my 9mm drill (the holes were 8mm originally) was just a little bit too small - even the solder-iron trick didn’t work… but with some good files and a hammer they finally went in.

It features all the left-over parts (Squier Vibrato, Humbucker sized Firebird Pickups, CTS pots and electronics) I had waiting for two years or so - and said - now very cheap slightly blemished neck along with an also new Staytrem Bridge and Kluson Supreme Tuners (which might get exchanged for some others).
Matching the headstock is still on the table - but I wanted to try the neck first. Never had Jumbo necks before.







PAF-sized Firebird pickups from Rübezahl Tonabnehmer (one of the last sets he made before he sadly quit)



A view under the hood: first I thought about gluing them to the cover… but this really was easier.

Electronic wise the rhythm circuit‘s knobs are not connected yet. I have a C1M knob for a passive Bass-roll off somewhere - but I don‘t know what to do with the other knob - as the slide switch is used to split the Firebirds.
But I can live with a „producer“ knob.



It obviously needs a setup. I don‘t have saddle files st home. It might also need a shim (no angled neck-pockets at Rosser if you ever wondered) … so either I order both and learn how to do it - or I let a tech look over it…

[windmill]

looks good

Hope you get it in order.

[bodhi]

Nice one! I guess the humbuckers padded from the bottom as well, or how do you get them to stay in place? From the other thread it looked like you had a swimming pool route, are the screws for the JM covers just for show?

Given the setup, I guess you haven't played this one much if at all? I have the vague recollection of someone having written that firebird pickups don't sound that exciting when split, so wondered if you might have a take on the matter?

It does look like a shim would be in order, but if you have a capo you should be able to get a better idea by setting it at the first fret and checking what it all looks like. One of my current projects is a Squier Contemporary Jag, which already has an angled neck pocket, but that one seems to need a shim just since the pocket is cut a bit deep anyways...

[MayTheFuzzBeWithYou]

looks good

Hope you get it in order.

Thank you!

Nice one! I guess the humbuckers padded from the bottom as well, or how do you get them to stay in place? From the other thread it looked like you had a swimming pool route, are the screws for the JM covers just for show?

Yes, they‘re padded from below as well - I used the packaging material of the Kluson tuners by the way. Works great and has a spongy feel!
And no, you actually can control the Firebird Pickup‘s height using the Jazzmaster Pickup screws.
The swimming pool is high enough in the middle to let the screws catch some wood.

So the Firebird PU is not screwed in at all. I thought about drilling a hole in the JM covers - but this works fine.

Given the setup, I guess you haven't played this one much if at all? I have the vague recollection of someone having written that firebird pickups don't sound that exciting when split, so wondered if you might have a take on the matter?

It does look like a shim would be in order, but if you have a capo you should be able to get a better idea by setting it at the first fret and checking what it all looks like. One of my current projects is a Squier Contemporary Jag, which already has an angled neck pocket, but that one seems to need a shim just since the pocket is cut a bit deep anyways...

I heard that they should sound more or less like Lipstick pickups… I had the PUs in my BMM Jag for a while - but something moved internally - and so the neck pickup didn‘t catch signal from the high E string… didn‘t install them since… if the split signal should indeed be too thin, I‘m gonna follow Fralin‘s advice and use a 7k resistor to only partially split it.

I only tried some chords and slide with a mini booze bottle… will plug it in now and check if I was successfull at first try (which would be a first) and will try your tip with the capo. Thank you.

[MayTheFuzzBeWithYou]

A little update: I had a faulty slide-switch and no replacement at hand…also the neck pu was shorting out…took a while to find that… tried to make coil split variable with the rhythm circuit‘s knobs…(do I need Blender knobs to pull that off?) either I hear no difference or the wiring is funky elsewhere…

Anyhow: it makes sound and both Pickups work! Which is a relief.
But I‘ll need longer Pickup screws for the Bridge PU.

A „filter-tip“ shim changed the action to already almost playable. Still need to get that nut filed.
But it already feels great. Very resonant. And also a bit lighter than my Thinline Jaguar.
The Squier Vibrato works great too…just don‘t like the way it is (not) bent.. too straight and too low for my taste.

[bodhi]

A little update: I had a faulty slide-switch and no replacement at hand…also the neck pu was shorting out…took a while to find that… tried to make coil split variable with the rhythm circuit‘s knobs…(do I need Blender knobs to pull that off?) either I hear no difference or the wiring is funky elsewhere…

No special pots needed as such, but with large resistance on the pot you'll essentially have no variability available, more of an on/off at one extreme. One wiring diagram can be found here, maybe compare notes to what you've set up?

https://www.seymourduncan.com/blog/late ... -split-mod

[MayTheFuzzBeWithYou]

A little update: I had a faulty slide-switch and no replacement at hand…also the neck pu was shorting out…took a while to find that… tried to make coil split variable with the rhythm circuit‘s knobs…(do I need Blender knobs to pull that off?) either I hear no difference or the wiring is funky elsewhere…

No special pots needed as such, but with large resistance on the pot you'll essentially have no variability available, more of an on/off at one extreme. One wiring diagram can be found here, maybe compare notes to what you've set up?

https://www.seymourduncan.com/blog/late ... -split-mod

Thanks, Bodhi!
This helps a lot.

[solfege]

It obviously needs a setup. I don‘t have saddle files st home. It might also need a shim (no angled neck-pockets at Rosser if you ever wondered) … so either I order both and learn how to do it - or I let a tech look over it…

That is odd, b/c the old Rosser Jag body I have very definitely had an angled neck pocket. (It got replaced for weight reasons with a GuitarMill body that does not, and I had to get shims as a result.) So he must have changed his formula on the thinlines, or this is his JM setup. Anyway, nice build.

[BoringPostcards]

It looks wonderful. I love Charcoal Frost so much.

[gibs]

A little update: I had a faulty slide-switch and no replacement at hand…also the neck pu was shorting out…took a while to find that… tried to make coil split variable with the rhythm circuit‘s knobs…(do I need Blender knobs to pull that off?) either I hear no difference or the wiring is funky elsewhere…

Anyhow: it makes sound and both Pickups work! Which is a relief.
But I‘ll need longer Pickup screws for the Bridge PU.

A „filter-tip“ shim changed the action to already almost playable. Still need to get that nut filed.
But it already feels great. Very resonant. And also a bit lighter than my Thinline Jaguar.
The Squier Vibrato works great too…just don‘t like the way it is (not) bent.. too straight and too low for my taste.

My understanding is 25k pots work best for spin-a-splits, but I think the stock 50k will well, I think most people say no higher than 100k for spin-a-splits. Also, I think you’re going to need one dedicated pot for each pickup. Running both pickups to the same pot might cause some problems when switching to neck or bridge. You could essentially wire it like the classic player jag HH. Or look at Rothstien, I think they had one where the side switch can act as the on/off while the pots can be preset for level of cut you want on each pickup. I’ve got a rough idea how one would go about that, but not totally sure.

Do the Rosser Thinlines have a belly contour? I notice yours has the rare forearm contour near the f hole, maybe not as pronounced as is on solid body offset, but cool to see some effort to retain the ergos of an offset.

Also, how do you like the charcoal frost? Does it have a bit of that greenish/bluish undercoat appearance like old fenders in that finish? The new fenders that are “charcoal frost metallic” always look more like a pewter grey and not nearly as interesting as the original finish.

[MayTheFuzzBeWithYou]

My understanding is 25k pots work best for spin-a-splits, but I think the stock 50k will well, I think most people say no higher than 100k for spin-a-splits. Also, I think you’re going to need one dedicated pot for each pickup. Running both pickups to the same pot might cause some problems when switching to neck or bridge. You could essentially wire it like the classic player jag HH. […]

Thank you for that. I will play around with it, once the new switches arrive.

Do the Rosser Thinlines have a belly contour? I notice yours has the rare forearm contour near the f hole, maybe not as pronounced as is on solid body offset, but cool to see some effort to retain the ergos of an offset.

It does indeed have a belly contour. It feels great sitting and standing.

Also, how do you like the charcoal frost? Does it have a bit of that greenish/bluish undercoat appearance like old fenders in that finish? The new fenders that are “charcoal frost metallic” always look more like a pewter grey and not nearly as interesting as the original finish.

I guess I‘ve never seen a real old Charcoal Frost Metallic.
It looks great but as I already said it seems less „metallic“ and almost Satin. It remembers me a bit of a much greyer variant of the Sonic Grey of the AmPro/Squier Bullet Mustang. So I‘d say it has a bit of Blue but definitely no Green.

[MayTheFuzzBeWithYou]

Update: my parts from CWGP, Musikding and eBay arrived and I could replace the faulty switch successfully.
6,8k resistor for (partial-) splitting works fine. Takes away just enough to make it single-cool-ish.
The Neck Pickup sounds fuller and louder even though it sits way lower. Can‘t tell if it was rewound or otherwise altered when it got repaired.
Now I have to figure out what to do with the roller knobs.
Dual Volume, PTB sounds like the way to go - because I‘m missing a switch to activate it. Or a push/pull knob on the tone pot? Never worked with one before.

Also the Muspor 1degree shim gave it an instantly perfect action. Just had to cut it a little smaller (don‘t know if the neck pocket on the Rosser Body is smaller or if the shims are more universal than just „fits fender“.
Still need (let someone) file the nut slots… you can play it already - and it is a lot of fun to do so - but especially the high strings sit rather far from the fretboard.

I also changed the toggle tip to black and improvised a black/metal tip for the vibrato arm… which will be replaced as soon as my next parts order is ready/arrives. I never thought these would be a better fit than white/parchment parts but I really dig the aesthetics now.

Next up (in the hopefully near future): painting the headstock, giving it a name and order a custom decal.
Upgrading the vibrato…at least a little (the arm rattles and the behind the bridge harmonics sound like sh**).

Photos will follow soon.

[MayTheFuzzBeWithYou]

Name wise:
The colour makes me think of Gandalf (the Grey) - servant of the secret Fire (who also likes Big Birds, and those PAF sized Firebirds are well hidden) - wielder of the flame of Anor.

So maybe
Mithrandir SECRET FIRE
Or something similar.

Or Beskar KNIGHT as a nod to The Mandalorian. But this would scream for a (black or metal) Pickguard that would show the Firebirds…
Anyhow. As this build has only about 2% Fender parts: the Bridge Thimbles. - I‘d rather not put a Fender logo on it.

[Shadoweclipse13]

Gorgeous!! CFM is my favorite color on a JM or Jag! I've been dreaming about a Thinline Jazzcaster/Telemaster for a while now, and this is just awesome!!

Name wise:
The colour makes me think of Gandalf (the Grey) - servant of the secret Fire (who also likes Big Birds, and those PAF sized Firebirds are well hidden) - wielder of the flame of Anor.

So maybe
Mithrandir SECRET FIRE
Or something similar.

Or Beskar KNIGHT as a nod to The Mandalorian. But this would scream for a (black or metal) Pickguard that would show the Firebirds…

I love ALL these ideas. As much of a SW fan as I am, I almost love the idea of Gandalf a little more. Or maybe a combination of the 2? The tie-in with loving big birds almost puts this a bit ahead of the Mando reference for me...

[MayTheFuzzBeWithYou]

Gorgeous!! CFM is my favorite color on a JM or Jag! I've been dreaming about a Thinline Jazzcaster/Telemaster for a while now, and this is just awesome!!

Name wise:
The colour makes me think of Gandalf (the Grey) - servant of the secret Fire (who also likes Big Birds, and those PAF sized Firebirds are well hidden) - wielder of the flame of Anor.

So maybe
Mithrandir SECRET FIRE
Or something similar.

Or Beskar KNIGHT as a nod to The Mandalorian. But this would scream for a (black or metal) Pickguard that would show the Firebirds…

I love ALL these ideas. As much of a SW fan as I am, I almost love the idea of Gandalf a little more. Or maybe a combination of the 2? The tie-in with loving big birds almost puts this a bit ahead of the Mando reference for me...

Thank you.
I thought about it a lot yesterday night and I also clearly prefer Gandalf/Mithrandir.
And as it has this worn parchment guard... it could possibly cover both Gandalf the Grey and the White - if I'd like to go extreme: I could even work on the vibrato arm tip so it would resemble his staff (the white one, not one of the wooden ones). Probably 3D printing would be easier in this case.