Confused by my ASAT tribute wiring -- why so many grounds?

[tprice504]

Ok, so I'm a newbie. Just a few months ago, I came back to playing after not touching a guitar for nearly 30 years. I'm excited to re-learn how to play. I also am enjoying learning about guitar electronics for the first time.

I bought a used (but pristine) ASAT Tribute Special. It looks to be the current model, and I have no reason to believe it's been modified.

I've been reading up on guitars, and I've gotten excited about doing some upgrades and mods on my ASAT: upgrade to US pots and caps; put in a 5-way switch; maybe even add a stacked pot with a bass tone control or drill out a control panel and add a kill switch. I thought that I was getting a grasp on guitar wiring, and then I opened my ASAT. It does not appear to correspond to any schematics that I've seen (for example here: https://web.archive.org/web/20170610200 ... rawing.pdf)

I see one lower ground wire, which I assume is going to the bridge. That matches what I see online.

The neck pickup, however, has three wires: yellow, green and black. The schematic does not show a ground (I assume the black is ground) coming from the neck pickup.

The bridge pickup in the schematic shows a white wire and a black wire. On my guitar, there is a white wire and two black wires, and one of the black wires is sightly thinner than the other wires used on the guitar.

The volume pot has a cap labeled 201, which I understand to be the 200pf cap for the treble bleed.

The cap on the tone control does not have any numbers on it that that I can see.

I am also confused by how the tone control is wired into the circuit. Both the hot the ground of the plug go back to the volume, which also does not match the schematic linked above (or any other wiring schematics that I see for other guitars).

[tprice504]

I'm not sure how to upload photos to this forum, but you should be able to access this folder of photos on Google with the link below:

https://photos.app.goo.gl/AaT2JNXaAPF5oPVt8

[Craig]

To post photos inline, see this tutorial: Tutorial: Posting photos.

Let's see full shots of your Tribute ASAT Special. Also, post the first 4 digits of the serial number, which will tell us the build YYMM.

Are you sure that there are three wires coming out of each pickup? I think the extra black wires are probably ground wiring for the graphite shielding in
the control pocket, and the neck pockets. If you have (can take) closeup photos of the pickups we can confirm if they are ASAT Special MFD pickups.

We have some wiring diagrams and schematic in our Gallery. Take a look at the one for the ASAT Special Deluxe/Tribute ASAT Special Deluxe Carved Top
because the pickup and control wiring will be the same as an ASAT Special except the controls are rear-loaded. It does not include the shielding wiring
because the US model does not including shielding like the Tribute model has.

Looking forward to seeing more of your Tribute ASAT Special.

[tprice504]

Ah, mystery solved. Thanks, Craig.

It didn't occur to me that the extra grounds were to ground the pickup cavities. I haven't pulled the pickups to look under them. I just opened the control cavity, which is covered in a gray-ish paint (presumably that's the shielding).

And I was looking at the wiring diagrams for ASATs with single coils, not the one you linked to. My circuit matches the ASAT Special Deluxe diagram.

The serial number starts with 2008, so I gather it was built in August 2020. It's kind of wild to think about a guitar factory being up and running during the height of COVID.

I absolutely love this guitar. I'll post more photos later today.

[tprice504]

Here's my ASAT hanging with its siblings. It looks naked now because the pick guard is off. I mailed off the 3-ply white pick guard to get a custom perloid one made.

When I get a chance, I'll open it up again and check the wiring against the schematic Craig posted above.

[tprice504]

Finally had a chance to open up my ASAT Special Tribute. It's close to the wiring diagram Craig posted, but not exactly the same. I think, however, the differences don't affect the function.

Here are the differences in my guitar from the wiring diagram in the archives:

-- On the volume pot, there is a a 200pF cap connected to lugs 1 and 2 as a treble bleed

-- As I noted in my first post, I have the extra ground wires. Craig helpfully pointed out these are grounds to the shielded pickup cavities

-- My switch is grounded to the volume pot, while the switch is not grounded on the ASAT Special Deluxe wiring diagram. Is that grounding necessary?

-- The ground wire from by bridge (not the bridge pickup) is grounded to the volume pot and not the tone pot, as it is in the wiring diagram (I don't think this matters, does it?)

-- On the volume pot, there is a white jumper from lug 1 to 3 (and lug 3 is grounded to the case of the pot). Why is my guitar wired this way?

-- The tone control is wired differently. Instead of a green wire going wire going to the lug 2 and also ground to the back, I have a red wire that is grounded to the back of the tone pot and also goes to lug 3. The cap is wired from the center lug to the back of the tone pot. (I think, if my shaky but growing understanding of circuits is correct, that change doesn't matter)

One question: Since my guitar has grounding paint, should the control cavity be grounded? Should I attach a ground wire ot the painted wood?

[bigjim711]

Finally had a chance to open up my ASAT Special Tribute. It's close to the wiring diagram Craig posted, but not exactly the same. I think, however, the differences don't affect the function.

-- My switch is grounded to the volume pot, while the switch is not grounded on the ASAT Special Deluxe wiring diagram. Is that grounding necessary?

This actually is shown on the ASAT Special Deluxe diagram but is shown as a shield wire coming from the insulation of the red wire (to the switch on one end and to the back of the volume pot on other end - notice the green and gray wire also have shield wires coming out from the insulation. They look like scratched out lines but are just representing the braided shield. If you look at your wiring the gray cable has a white wire coming out of it and also the shield wire).

-- The ground wire from by bridge (not the bridge pickup) is grounded to the volume pot and not the tone pot, as it is in the wiring diagram (I don't think this matters, does it?)

Looking at your photos; it looks like there is a red wire from the back of the volume pot to back of the tone pot so the grounding would pass through either way. There's no reason it would have to be to one or the other since this circuit ties them together. This wire seems to perform the function of the shield wire shown coming from insulation of green wire (on ASAT Special Deluxe schematic) that goes from pot to pot. So yes, that doesn't matter.

-- On the volume pot, there is a white jumper from lug 1 to 3 (and lug 3 is grounded to the case of the pot). Why is my guitar wired this way?

This doesn't make sense to me. I only see a reason for the 3 to be grounded to pot. Does the guitar function properly? Do the tone and volume function ok? I don't know if this is some kind of modification but I'm not familiar with it. I'd probably change it to match the diagrams myself.

-- The tone control is wired differently. Instead of a green wire going wire going to the lug 2 and also ground to the back, I have a red wire that is grounded to the back of the tone pot and also goes to lug 3. The cap is wired from the center lug to the back of the tone pot. (I think, if my shaky but growing understanding of circuits is correct, that change doesn't matter)

The red wire is covered above. It's performing the function of the shield wire (out of insulation of green wire on diagram). Pin 3 to ground is ok but I'm not sure why they don't have the capacitor on there. I don't know why they have pin 2 grounded through the capacitor. If this is a modification I'm not familiar with it. This too I'd change to match the diagrams but maybe someone else can figure out what is going on here.

One question: Since my guitar has grounding paint, should the control cavity be grounded? Should I attach a ground wire ot the painted wood?

I don't know if this is necessary but it wouldn't hurt anything. Would you just ground it to the back of a pot or something? I'd probably not bother unless I had excessive interference.