*Pictorial* Dingwall Series/Parallel plus Mid Sweep

[KodyAudette]

Dingwall Combustion Modification
Series/Parallel Switching plus added Mid Sweep


Parts:

2 mini DPDT On-On switches. (~$3)
1 John East Mid Sweep (~$115)
1 Stacked Log Taper Pot (1M ohm if you can find it, but I used 500k and it sounds great.)
22 gauge wire in several colors. It doesn’t matter what colors, as long as you can keep track of it. (Though if you want that retro sound, it has to be purple.)

Tools:
Phillips head screwdriver
Needle Nose pliers
Drill press (A hand drill will work, but a drill press will provide cleaner results)
Clamps (if using a drill press)
Soldering iron, solder.
Razor blade
Wire stripper
Time, concentration, and patience.

Here's the initial diagram:

Here's where we're going to end up.

Steps:

Start by removing the strings. Next, open the Control cavity and take some detailed pictures of the current wiring and setup in case you get confused. I referenced my initial pictures several times.

Carefully cut the tiny zip tie holding the wires together. Pull the wires gently back and out of the way so you can see the extra space you have in the cavity. Some blue painters tape or Low tack tape works great for holding the wires out of the way without gumming up or damaging your finish.

Take your two mini toggle switches and place them into the control cavity where you would like to mount them. Think about how they should be spaced to look good on the front of the bass. Since there are four knobs, I figured that putting one switch in between each pair of knobs would look good, plus that’s where there is space. Keep in mind the spacing between these two switches, the pots, and the active/passive switch that’s already in there. You will need a bit of space between the components so don’t put them too close to each other or to the walls of the cavity, otherwise you may not have space for the wires, or to rotate the switches to the most comfortable angle.

Now, once you’ve decided on your placement, either use a grease pencil or a regular pencil to gently mark the outline of your switches. Be sure not to scratch off the paint that’s in there, it is a conductive paint that helps shield the cavity and keep out extra noise. Once you have your outlines drawn, remove the switches and draw a dot right in the center of the square you’ve drawn. This will be the point where you eventually drill.

Now that you have your placement all worked out, it’s time to begin removing the electronics. Start by removing each of the knobs on the front of the bass, then use pliers to loosen the nuts holding the pots in place. I laid down some painters tape around the area because I’m pretty confident in my own ability to let the pliers slip and mar a beautiful finish. I figure an extra minute of time is worth it. I would suggest using your fingers to remove the nuts as soon as they are loose enough to minimize the risk of damaging the finish.

Once the nuts have been removed, the first part to remove is the active/passive switch. This switch is basically what you should be modeling your other switches on. I couldn’t find an exact match, but I got reasonably close.

The biggest concern with these mini toggles is whether the shaft is long enough to reach all the way through the bass. Now is a good time to remove the Active/Passive switch and compare the two side by side. It would also be prudent to try putting the new switch through the hole where the Active/Passive switch was to ensure that it reaches far enough through. If not, you can still put everything back with a minimum of effort until you have the correct parts.

Next, continue pulling each of the pots out of their holes. Once all of the pots are cleared, you can remove the output jack. This is done by first removing the two screws that hold it in. Next, you have to rotate the silver cup to unscrew it from the jack. I did this using the pair of needle nose pliers. After a moment, I realized it’d be a good idea to wrap the tips in tape uncase I slipped. If you have nylon tipped tweezers or needle nose pliers, those would probably work great. So rotate the cup counterclockwise to unscrew it from the jack, pull the cup out of the bass, then gently work the jack back out into the control cavity.

Now all of your control cavity components should be free. Open up the battery compartment and remove the battery. You can unscrew the four small screws holding the plastic battery compartment in place, and then squeeze the battery connector through the small gap in the plastic casing to remove the case entirely.

Now it’s time to unscrew and begin removing the pickups. It may be a good idea to take a picture of the way each of the pickups is wired for future reference should you want to revert to the stock configuration at some point. As you can see, the stock configuration is Parallel for the neck pickup and series for the bridge pickup.

Now, there should be three wires coming from each pickup, a red, a white, and a black wire. The red wire is the pickup Hot (+) signal, white is the Cold (-) signal, and black is the pickup shield ground wire. You will see that for each pickup, these wires go through into the control cavity and connect to their volume pot. The red wire is connected to the center pin, and the black and white wires are both grounded to the cover of the pot.

Desolder all three of these wires from the neck pickup’s volume pot so that they can be pulled through towards the pickup and it can be pulled free. Repeat this for the Bridge pickup.

The only thing left holding the electronics into the instrument now is the battery connector. Since we are going to be splicing an extra wire onto this later anyway (if you are adding the John East Mid Sweep), I decided to just cut both the red and black wires in a place where it would be convenient to work on later. If you aren’t adding the mid sweep and are just adding the series parallel switches, you could probably desolder the black wire from the output jack and unplug the red wire from the EMG preamp (though I didn’t try this, so I’m unsure if that wire will come out individually.

Drilling

**Note that if you are just adding the series/parallel functionality and not the Mid Sweep, a great option would be to just replace the current Volume controls for each pickup with Push/pull pots with built in DPDT switches. This means you don’t have to drill any extra holes.

You should now have successfully removed all the electronic components from the instrument. Time to get drillin’! As mentioned earlier, using a drill press really is the way to go for this. You will get much more reliable, clean results and not have to worry about whether you drilled at an angle. For my setup I laid a good thick stack of shop towels on the stage underneath my instrument, leaving a small gap where the drill would penetrate.

This ensures that you won’t damage the finish or the instrument by clamping it or scraping it along a hard surface.

Do you still have some tape on the front side of the instrument from earlier? If not, putting a strip or two of tape over the area where the switches will be will help diminish any chance of tearout or chipping from the drilling process.

Now, put a small pilot bit in the press and lay the instrument face down on the stage so that you can line up the bit to drill exactly where you made the mark in the control cavity earlier. Now, be sure to use a very small bit for this step, this won’t be our final hole, it is just a pilot hole for alignment. Once you have the instrument lined up under the drill bit just how you want it, gently but firmly clamp it with some rubber padded clamps, or a regular clamp with some sort of cloth in between to protect the finish.

Now, turn on the drill press and slowly with gentle pressure, drill down through the cavity all the way to the finished front of the bass. Release the clamps, align for the next hole, reclamp, and drill the second hole. Now you should have two small, clean holes all the way through the instrument.

Now we will drill the final holes. First, select a drill bit just a bit larger than the diameter of the threaded post of your mini switches. You don’t want this to bind when passing through the instrument; the nut will hold it in place. The next step is very important to ensure there is no tearout on the face of the bass. For the last holes, we drilled from the instrument cavity to the face of the bass, but for this step we want to do the opposite. When drilling through wood there is a good chance that as the drill gets to the opposite edge, it may tear out little chips of wood and finish if we aren’t careful, especially if we are drilling larger diameter holes. Now we obviously don’t want this to happen so we will drill the final holes from the face of the bass into the control cavity. This will ensure that if there is any tearout, it will be inside the control cavity where no one can see it. If you’re worried about that, you can place a bit of tape inside the control cavity across our pilot holes to help minimize the chance even further. Now repeat the process of aligning the instrument to the drill bit, this time using the existing pilot hole to align to. Clamp the instrument in place, and slowly with gentle pressure lower the drill bit through the wood.

Repeat for the second hole. Remove any tape and admire your handiwork.

Notice how I had just a little tearout on the control cavity side of the hole, but the front face looks very clean.

Even if you do get a little roughness, chances are pretty good that it’ll be hidden beneath the control knobs anyway.

Congratulations on successfully getting the holes drilled! Now it’s time for the wiring.

 

[KodyAudette]

Preparing the pickups

Let’s start by setting up the pickups so that we can use each coil individually. I’ve labeled each coil with + and – on the corresponding solder pad.

Now each of the two pickups is currently set up a little differently, but our goal is basically to have four wires leading out of each pickup, a Hot (+) and Cold (-) for each coil of each pickup. So for the Neck Pickup, we will first check the area to make sure there isn’t any excess epoxy (a clear, hard film) that would get in the way of our soldering. If there is, just gently pry it up with a razor blade or small flathead screwdriver.

Now, desolder both yellow wires that are connected between the two coils, we want to access them individually. Leave the Red and white wires connected where they are. These will act as the (+) and (-) leads for our lower coil.

Now, solder two new wires to the (+) and (-) pads of the upper coil. I chose Orange for my (+) lead and green for (-). The color doesn’t matter, so long as you keep it consistent between the neck and bridge pickups so that you don’t get confused. Make sure these leads are as long as the red and white leads that are already there.

Leave the black wire alone, as it grounds the pickup covers to reject extra noise. That’s a good thing, so we’ll leave it alone, the good folks at Dingwall know what they’re doing. Now, set aside the neck pick up and move on to the bridge pickup.

Again, clear any excess epoxy from the area. This pickup is wired a little differently but we want the two pickups to match so we’ll start by removing the yellow jumper entirely. Next we will desolder the red wire from the upper coil’s (+) contact and move it to the lower coil’s (-) contact to match the neck pickup.

Now we will solder two more leads to the upper coil’s contacts, taking care to match the colors we used on the neck pickup. For me that means Orange (+) and Green (-).

Okay, so now we can reinstall the pickups into the instrument. I found it useful to twist all five wires together and push them through the wire channel. Be sure to orient the pickups correctly with the Dingwall logo near the bridge. Screw the pickups in to secure the pickups in place. Now we can begin wiring in earnest!

Wiring the Pickups to the Series/Parallel Switches

I found it was a good idea at this point to lay a cloth over my bass to protect the finish in case I should drop a tool or touch it with my soldering iron. It also allowed me to rest a little stand with a clamp directly on the bass, holding the switch right where I could easily work on it. We’re going to start with the neck pickup, so unwind the black wire from the other four, as we won’t be needing it yet. A good idea at this point is to lay a paper towel over the control cavity and poke a small hole in it and pull the four remaining pickup wires through this hole. This ensures that if you drop any specs of solder or anything, it won’t fall on other components or into the control cavity.

Okay, begin soldering the pickup leads to the switch according to the diagram. The space is tight, so try to be as clean as possible with your soldering and ensure that nothing is contacting. Now we need to add a small jumper between two pins of the switch. I used a piece of black wire but it doesn’t matter.

Now we need to solder two final wires, the Pickup Output (+) and (-). I chose yellow as my (+) and black as the (-) since it will act as a ground. Now, since it’s tight in here, I went ahead and added some silicon in between the pins on the switch to ensure that nothing would bend over and contact anything else. This isn’t necessary and will be a pain if you have to go back and change anything later, but I checked my connections with a multimeter and everything looks good so I’d rather add the extra insurance now.

Repeat the process with the bridge pickup in exactly the same way.

Okay, so now we have our pickups wired to their selector switches with their (+) and (-)
leads as well as the ground wires from the pickup covers and from the bridge.

Now we can mount the switches in the body of the bass. Hand tighten the nut it so it’s solid, but don’t worry too much about it right now as we’ll be adjusting it later.

Volume and Tone Controls

**For my project I added the John East Mid sweep controller so I had to add stacked volume knobs. If you’re not doing this, just imagine that it is two separate pots (the push/pull pots you added the switch connections to). If this is the case, you’ll be working over your instrument, and I would refrain from mounting the pots into the bass just yet so you can pull them out a bit and have more room to work. I’m essentially just moving the existing connections over from the stock pots and putting them onto a stacked 500k Log (Audio) taper pot instead.

At this point it was very handy to have a couple of clamps to hold the components while soldering and desoldering. I’m pretty sure that humans were built with about six too few hands for soldering.

I chose to set the top knob of my stacked pot to control my neck pickup and the bottom to control my bridge pickup. If you’d prefer the opposite, just wire what I do on the top to the bottom and vice versa.

We’ll start by moving the white wire (Volume knob output) from the right (looking from the backshell side of the pot) pin of the neck pickup to the corresponding pin on the stacked pot. Now, make a ground connection between the left pin of both pots and the shell of the pot. Notice that since my pins are close together on the stacked pot, I just used a bare wire to connect both pins, then directly to the shell of the pot.

**If you don’t know what star grounding is, I recommend learning about it to help ensure that you don’t add extra noise if your setup is a little different from mine.

Okay, now let’s take the white wires from the old neck pickup volume control and solder them to the right pin on the new pot. This should result in one white wire connecting the right pin of the two pots together and another one that goes to the Active/Passive switch.

Finally it is time to move all of the black ground wires from the back of the old pots to the shell of the new pot (or pots if you have separate pots), keeping in mind star grounding.

**If you are not adding the John East Mid Sweep, you can skip this next section and move to “Power, Signal, and Final Ground Connections” to finish setting everything up and get playin’!

John East Mid Sweep Installation

The John East Mid Sweep controller has six pins whose functions are described below according to their installation information:

First we will solder a red wire to the uppermost pin for power. Make sure this a couple inches long as it will need to reach the power line for the EMG preamp later on.

Next we will solder a green wire to the third pin down. This will act as the output of the Mid sweep. I chose the color green for a specific reason here. The EMG preamp output wire to the Active Passive switch is green and we are placing the Mid Sweep in the circuit right after the active signal output of the EMG preamp. What this means is that the Mid sweep circuit will only be in the signal chain when the bass is in Active mode, so we still retain full Active/Passive functionality.

Next we will wire the ground for the Mid sweep as a black wire connected to the next pin down, the fourth from the top.

Now we will desolder the green wire (Active signal output) from the Active/Passive switch and solder it to the next lower pin on the Mid Sweep, the fifth from the top, the input according to their diagram above.

We can now solder the green wire from pin 3 of the Mid sweep to the same pin that we just removed the other green lead from. We are essentially just inserting an extra preamp in the chain after the EMG preamp.

Now we will connect the black ground wire from pin 4 of the Mid Sweep to the shell of the pot, our common ground point.

Congratulations! Our new tone circuit is essentially complete, now we just have to put it in the bass, connect the pickups and make all the power and ground connections.

Power, signal, and Final Ground Connections

First of all, let’s replace the battery connector and battery compartment. Push the red and black leads from the battery connector through the black battery casing and then through the wire channel into the control cavity. You may screw the battery casing screws back in at this point.

Now, bring the rest of the electronics over to the bass and place all of the components in their respective holes (except for the Volume pot if you need to use the side of the shell for ground connections as I did). Now hand tighten the nuts to hold them in place. Don’t tighten them down too much yet, as we may still need to adjust them later. Gently push the Output jack through its channel towards the edge of the bass and screw the metal cup back onto it, making sure to align the screw holes with those in the body wood of the bass. This you may screw back in and tighten down fully.

Now if you added the John East Mid sweep, it needs power just like the EMG preamp that’s already in the Dingwall Combustion. So we need to connect the red power wire from the EMG preamp to both the red wire coming from pin 1 of the Mid Sweep and the red wire coming in from the battery compartment. It’s a good point to mention that if you have some shrink tubing, this would be a great time for it. If not, a little electrical tape is good too. I basically held the two wires from the Preamp and the Mid sweep parallel, soldered the two together, then brought the wire from the battery compartment over from the other side, held it parallel and soldered it to the other two.

Next, isolate this connection using the shrink tubing or wrapping it neatly with a small piece of electrical tape. I only had a tiny piece left in this size, so it's a little short.

**If you didn’t add the Mid sweep, then you just need to reconnect the red battery wire with the red wire from the EMG preamp using the same method as above.

Next, reconnect the black wire from the battery connector to the black wire from the Output jack that we cut it from earlier. This allows the battery to be connected only when the instrument is plugged in, drastically increasing battery life.

Well, we wouldn’t get much sound out of the bass if we didn’t connect the signal wires from our pickup switches to our volume controls would we? At this point you can take the yellow signal wire coming from each of the pickup switches and connect it to the middle pin of its corresponding volume pot.

Now solder the black lead from each pickup switch to the shell of the corresponding pot. Also solder the bridge ground wire to the shell of the pot. I only had one choice since I used a stacked pot, but you may choose to use the bridge pickup’s pot if you have separate pots since the ground wire is fairly short. If you’ll notice, there are a lot of ground connections. Since the shell of my pot was fairly small, it got crowded in a hurry.

If you have to solder a lot of leads into one place, just try to be neat and make sure that you have thoroughly heated the solder in the area you are trying to connect to. Once there is a lot of metal there, it will take longer to get enough heat to melt a large mass of solder and it’s is very easy to get poor solder joints if you aren’t ensuring that the joint is nice and hot before removing the soldering iron.

Congratulations, you are done wiring! Go ahead and place that volume pot into it’s hole if you still have it out and hand tighten the nut. Now, check each component to make sure it’s rotated the way you want it to be.

The biggest concerns with the pots are that their wires don’t have any bare leads or solder points that are contacting any others and that they aren’t being pinched. You may now fully tighten down the nuts on the pots. I very carefully used a pair of needle nose pliers to tighten them to where they needed to be.

Now, ensure that your Series parallel switches are oriented how you want them to be. If you matched mine, then when the switch is down toward the floor, the pickup is in Series, and if it’s up towards the strings, then the pickup is in parallel. So long as you have space with the wires, you can rotate it so that the opposite is true if you like. Otherwise, make sure that the angle that the switches are at is both easy to access and looks good. I set mine so that they were angled down and slightly back when in the Series position so that it was natural to reach down and flip them.

Once you have them aligned how you like, go ahead and tighten them down fully. Be sure not to over tighten them otherwise you could crack the finish.

Plug in the battery, close the battery cover, then replace the cover onto the control cavity and screw it down. Now put on the knobs for each of the controls.

Restring your bass, check the action and intonation to make sure nothing crazy happened to your setup.

Tada!


Plug in your bass and have a blast with all of your astounding new tonal options! Then call Sheldon Dingwall and thank him and the rest of the team for making amazing instruments!



I hope this pictorial was helpful, if you have any questions, let me know and I’ll see if I can help you. Most of this will apply to other basses as well, so long as you have dual coil pickups.

Kody Audette

 

[Stone Soup]

Not one of your images is showing up.

 

[KodyAudette]

Hmm, no pictures... I was linking them from flickr.

 

[Stone Soup]

You might have "no hot linking" (or a similar option) selected in your flickr account.

 

[Stone Soup]

I was able to do this, by selecting "original image" and pasting that url between the IMG tags.

If you right click the image, an options box comes up.

 

[KodyAudette]

Hmm, let me check it out. Thanks!

 

[SemiDriven]

Great job in explaining each step Kody! Looking forward to seeing the pics!

 

[KodyAudette]

StoneSoup, what browser are you using? In Firefox I don't see anything at all where the pictures should be. In Internet Explorer I see the little red x but when I right click it the only options I get are "Properties", "Copy", and "Show Picture" which does nothing. I checked Flickr and my settings are as wide open and shareable as possible. I don't see anything referring to Hot Linking or external linking, other than to social media which I left as open as possible as well. Anyone have any suggestions on how to make this work? I tried using the "Add Image" button on the post composer and put the picture's Flickr URL in the box. Anyone have a better method? I've done the same thing with a single picture before and it worked fine.

 

[FunkMetalBass]

The problem is your linking. You need to link to the picture itself.

For example, between the image tags you have the folder url
http://www.flickr.com/photos/kodyaudette/9069835652/

but you want to have the link to the actual image (notice the file extension ending on the url)
http://farm4.staticflickr.com/3707/9067610137_d2ecb7837e.jpg

If you click the "more ways to share" arrow underneath each picture, it generates the BB code for you to use. The one I referenced shows up like this:

20130615_131148 by Kody Audette, on Flickr

 

[KodyAudette]

Nevermind, got it! Thanks!

 

[KodyAudette]

Yeah, thank you, FunkMetal. I thought I had been linking to the actual picture but I had to select a specific size and link to that picture itself.