Jackson Spectra 5 string truss rod wrench size

[Reedt2000]

So a friend of mine bought one of these for his son for Christmas:

He said in the store the action was high so Sam Ash "set it up" for him...

Whoever did it must have zero clue about what that means, cause the neck has significant back bow (anti-relief) and the strings are WAY too low, it literally buzzes on every fret of every string

So he brought it to me to adjust (which he really should have done in the first place). I thought it would be a quick adjustment, nothing looks terribly wrong, I just think the "tech's" idea of a setup is tighten the rod and lower all saddles (they skipped the whole play it and make sure it's ok bit...).

Problem is I can't seem to find an Allen key that fits it? Now I haven't spent any serious time trying, plan on doing that later today. I'd bet money the key is metric, 4mm is pretty typical, but that just floats in the hole in the nut. Nothing else is even close.

So, anyone know what size the Allen key is supposed to be? The bass did not include the factory keys (or a case, or anything else). There is a solid chance whoever "set it up" stripped the truss rod nut. Figured I'd see if anyone here has one and knows or could measure the key for me.

If you can it's greatly appreciated

 

[Zooberwerx]

This is a wild guess, but...

My Ibanez has a "collar" which rises ~3-4 mm above the actual truss rod nut...the key just spins freely. Once I get the orientation correct, the key drops into the hex socket below. I have to slacken at least one string...usually the A...and move from the slot for any degree of access. BTW: it does require a 4 mm hex key.

Riis

 

[taketwo]

This is a wild guess, but...

My Ibanez has a "collar" which rises ~3-4 mm above the actual truss rod nut...the key just spins freely. Once I get the orientation correct, the key drops into the hex socket below. I have to slacken at least one string...usually the A...and move from the slot for any degree of access. BTW: it does require a 4 mm hex key.

Riis

I have a Jackson Spectra. I can confirm it needs 4mm Allen wrench, and you need to line it up just right before it drops in.

You can't really use the Allen wrench in the usual way as the A string is in the way. So instead insert the short arm into a small bit holder or similar, then use the long arm to reach the truss rod nut.

Finally, the tech couldn't know this, as it's not written anywhere: the truss rod is dual action. It can adjust the neck to either bow direction, and does not come out as far as I know.

It's a great, lesser known bass. If it's as good as mine, you can get the relief and action as low as you care to without buzz.

 

[Zooberwerx]

I have a Jackson Spectra. I can confirm it needs 4mm Allen wrench, and you need to line it up just right before it drops in.

You can't really use the Allen wrench in the usual way as the A string is in the way. So instead insert the short arm into a small bit holder or similar, then use the long arm to reach the truss rod nut.

Finally, the tech couldn't know this, as it's not written anywhere: the truss rod is dual action. It can adjust the neck to either bow direction, and does not come out as far as I know.

It's a great, lesser known bass. If it's as good as mine, you can get the relief and action as low as you care to without buzz.

Removing the string(s) is inconvenient. I buy hardwood handles, drill a pilot hole, then whack the key's "short arm" into position with a hammer. Thanks for the corroboration!

Riis

 

[Reedt2000]

Very much appreciated

There is a collar with the rod behind it, might just (hopefully) be a matter of lining it up properly.

I'll try using the long end too, see if it helps. It really just looks to need basic adjustments. If I can get the neck set right the action and intonation should be easy.

The bass seems nice though I've yet to plug it in. It is really light, probably around 8 lbs.

I'm gonna fool with it tonight, will post an update.

Thanks again

 

[Reedt2000]

OK, the truss nut is not totally centered on the collar making alignment a little fiddly. The truss rod on this thing was cranked, super tight, way more than it should have been. It's lucky it didn't snap.

My guess is the Sam Ash cashier thought they knew how to adjust the action (apparently it was high in the store when they bought it) and just tightened the rod until they couldn't anymore.

After getting the key in and getting it to move it behaved as it should. Didn't take too long to make it play respectably. It has a couple high frets around 9 10 and 11 so it could go lower if that was addressed, but still not bad:

I plugged it in and it sounds OK, the bass boost on the pre is centered really low making it boomy if you boost. It felt a little scooped and not strong in the low mids.

Something else weird is the blend worked in reverse. Turing all the way clockwise solos the bridge PU, and counter clockwise is the neck. Anyone know if it's supposed to be like that or are the pickup leads reversed on the blend pot?

All in all it's not bad, could be a decent platform for upgrades/mods

 

[taketwo]

OK, the truss nut is not totally centered on the collar making alignment a little fiddly. The truss rod on this thing was cranked, super tight, way more than it should have been. It's lucky it didn't snap.

My guess is the Sam Ash cashier thought they knew how to adjust the action (apparently it was high in the store when they bought it) and just tightened the rod until they couldn't anymore.

After getting the key in and getting it to move it behaved as it should. Didn't take too long to make it play respectably. It has a couple high frets around 9 10 and 11 so it could go lower if that was addressed, but still not bad:

View attachment 4935425

I plugged it in and it sounds OK, the bass boost on the pre is centered really low making it boomy if you boost. It felt a little scooped and not strong in the low mids.

Something else weird is the blend worked in reverse. Turing all the way clockwise solos the bridge PU, and counter clockwise is the neck. Anyone know if it's supposed to be like that or are the pickup leads reversed on the blend pot?

All in all it's not bad, could be a decent platform for upgrades/mods

View attachment 4935426

I'm glad the truss rod wasn't busted! What a way to lose a just-bought gift!

The blend *is* reversed for some reason. I've heard this before. *shrug* I put little strips of white tape on the knobs so I can see where they are set.

I find the bass adjustment on the preamp is mainly useful as a cut, in conjunction with the pickup split switch:

• Split mode with the blend centered and all EQ at noon gives a good J-bass scooped tone. In that configuration, the split coils are humbucking.
  
• Split mode with either pickup solo'ed isn't practical, as there is no shielding and a lot of hum (at least for me, but I live in an area with lots of AC noise). It's too bad, because they otherwise sound very good as single-coils.
  
• When the pickup coils are paralleled, they are humbucking and very boomy, so a bit of cut on the bass EQ fixes that. It's especially good when solo'ing the neck pickup to get a P-bass sound.
• The mid and treble have some use as boost and cut, but lightly also.
• Because this is a very boomy bass overall, it's not great when played direct. It really benefits from some speaker emulation. The built-in 1st order 72 Hz HPF in a Behringer BDI21 or SansAmp BDDI knocks out the boom and makes it really shine.
• The preamp, otherwise, doesn't color the sound when set flat, so that's nice. There is a trimpot on it, which I presume adjusts the gain, but I have not tried.

The main strong point of the Spectra is the body and neck construction. Good details and solid. One of the few cheap 35" scale basses. Mine is the X series model (a step up from JS3, one step down from the Pro series) so it's neck-through. It's dead-straight. Not as stable as a high-end bass neck, but needs minimal relief adjustments as the seasons change.

The weak point of the Spectra is the uneven quality of the hardware, which is the main reason to mod it in my opinion:

• I've tried one in-store with defective pots right right off the rack.
• I had to change the nut on mine, as it was very cheap plastic that made the strings bind (GraphTec makes an exact replacement, fortunately, which made the change very easy). But another one I tried in-store had a nut of much better material.
  
• The Jackson-branded tuners on mine stay in tune, but they stick and make tuning a chore, so I'll replace them someday. And again, on another Spectra, they worked perfectly smoothly.
• The shielding in the main cavity is minimal and incomplete: there is some black paint, presumably conductive, and foil backing on the cover, but they aren't even touching! So someday I'll get it properly shielded.
• The blend knob is a 250K pot, which I suspect robs the pickup of substantial resonance. I don't find it useful except at noon and at the extremes. I may replace it with a plain pickup selector switch in the future.
• The pickup height screws are made of a rather soft steel. It is very easy to work off material from them with the head of a screwdriver, so I adjust carefully.

I don't think I'll ever replace my Spectra. It's a good workhorse, worth the work to improve it bit-by-bit over time.

Cheers,

-- taketwo

 

[Zooberwerx]

OK, the truss nut is not totally centered on the collar making alignment a little fiddly. The truss rod on this thing was cranked, super tight, way more than it should have been. It's lucky it didn't snap.

My guess is the Sam Ash cashier thought they knew how to adjust the action (apparently it was high in the store when they bought it) and just tightened the rod until they couldn't anymore.

After getting the key in and getting it to move it behaved as it should. Didn't take too long to make it play respectably. It has a couple high frets around 9 10 and 11 so it could go lower if that was addressed, but still not bad:

View attachment 4935425

I plugged it in and it sounds OK, the bass boost on the pre is centered really low making it boomy if you boost. It felt a little scooped and not strong in the low mids.

Something else weird is the blend worked in reverse. Turing all the way clockwise solos the bridge PU, and counter clockwise is the neck. Anyone know if it's supposed to be like that or are the pickup leads reversed on the blend pot?

All in all it's not bad, could be a decent platform for upgrades/mods

View attachment 4935426

How much relief do you have on-board? String heights? Looks a little low overall but could be the photo.

Reversed blend control is not THAT unusual. Also not surprised the bass boost is a little boomy especially with the pickup blend centered. Appears to be a solid bass...any shortcomings can be addressed without any major mods or upgrades. I know it's not your bass but I'll bet you're reluctant to release it until it's in tip-top playing condition.

Riis

 

[Reedt2000]

How much relief do you have on-board? String heights? Looks a little low overall but could be the photo.

Reversed blend control is not THAT unusual. Also not surprised the bass boost is a little boomy especially with the pickup blend centered. Appears to be a solid bass...any shortcomings can be addressed without any major mods or upgrades. I know it's not your bass but I'll bet your reluctant to release it until it's in tip-top playing condition.

Riis

Relief is pretty typical, about a playing card gap between the B string and the 7th fret when pressing the 1st and 15th frets. Action is low and it plays good as it is. I don't have the tools or experience to level and crown the frets, and it doesn't need it, you could get it a little lower if that was done but it is plays well after basic adjustments.

 

[Brian Finley]

Hi
I know this an old thread but I just acquired this same bass and the truss rod nut is stripped. Do you know if it is welded on or is it replaceable.

 

[Zooberwerx]

Hi
I know this an old thread but I just acquired this same bass and the truss rod nut is stripped. Do you know if it is welded on or is it replaceable.

If returnable, do so. Per earlier posts, the TR is dual-acting and the nut will NOT be removable. I take it the hex socket is hosed / rounded-out? Pics may help.

There are some work-arounds that may work but not for the inexperienced or faint-of-heart.

Riis

 

[Reedt2000]

Hi
I know this an old thread but I just acquired this same bass and the truss rod nut is stripped. Do you know if it is welded on or is it replaceable.

Make sure it's not just the end of the nut that's stripped. Try to seat the Allen key as fully in as possible before turning. You can also (if you can't return it, or just really want to keep it) try getting an Allen key one size too big, and carefully file each surface of the key, and it help if you file a slight taper as well, till it fits and will adjust.

 

[Brian Finley]

Not returnable…bought used. I was able to find a neck on line with a good truss rod nut. The hex nut is completely round. Too bad because is is a really nice neck! I will tinker with it to see if I can do something to get it with a larger hex key.