Crawls Backward (When Alarmed)

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Danelectro Series Parallel Pickup Switch

I was musing in the last post about putting a series/parallel pickup switch on the Daddy-O-Yellow Danelectro DC-2. I strung it up and used some test leads to see if there was enough of a tonal difference to justify putting a switch on.

Yes, yes there is.

Now, you may be aware that the stock Danelectro wiring has the pickups in series out of the box. Which explains why the middle position sounds so thick and midrangey, and has a lot more output than the other two positions.  Most every other guitar with 2 pickups has the pickups wired in parallel in the center selector switch position, but a Danelectro does not. A popular mod to those non-Danelectro guitars is a switch to allow the selection of series or parallel wiring. I have it on my Teles - with a 4-way switch.

Anyway, I liked both the series and parallel tones on the Danelectro, so I stuck a switch on to select either option.

With the pickup switch in the middle on a stock Danelectro, the positive output of the bridge pickup volume control (middle lug) goes to the third lug of the neck pickup volume pot.

The negative lead of the neck pickup is connected to that same lug, so what is happening with the switch in the middle is that the output of the bridge pickup is passed to the negative lead of the neck pickup, through the neck pickup volume and on to the output jack. The pickups are wired in series.

(Layout drawing is here for reference.)

In the picture above, you see this wire running from the center lug of the bridge pickup volume pot to the third lug on the neck pickup volume pot. And the red wire connected there is the negative lead of the neck pickup.

To run them in series, we just break that connection and give the bridge pickup a separate, parallel, path to the master signal output of the guitar. That connection could be made at the output jack, or alternatively, at the center lug of the neck pickup's volume pot. In my case, I ran this separate output to the input of the Blaster. Any of these work - we're just giving the bridge pickup's output a separate path to the output of the guitar.

And if we put a switch in there, we can direct the bridge pickup's output to its original place - that lug on the neck pickup's volume pot (series), or the second, parallel, location at the jack

On the right is the drawing I made to illustrate this (and to help me wire it correctly on my guitar).

If you've done this before, it will make perfect sense. If it's your first attempt, hopefully the diagram will help.

You can use an SPDT switch or a DPDT. I used the latter since that's what I had on hand. I used both sets of poles so mine is like a pair of switches in parallel. Maybe that's more reliable too. Who knows.

I needed to decide where to put the switch - I finally decided to plunk it between the new control for the Danoblaster and the output jack.

That's a knob on the new pot just for testing. I used another one in the end.

It will be a close fit between the pot and the output jack, but it will work. Hopefully.

If you've read the blog before, you know I hate to cut or drill stuff. But in this instance, after all the work to drill the new output jack hole, I wound up cutting more of the top away to make mounting the switch - and the jack - easier.

A razor saw made quick work of the new hole.

If you're going to break your own rule, be sure you demolish it.

At least it's sort of tidy.

The hole will get covered up by the pickguard in any event.

The wiring looks a little wild, but it's actually straightforward. (I notated the pic so you can see what's what if you click on it).

Note that I used coax (RG-174) for all of the runs of cable. I suppose you could use plain wire, but don't blame me if you have hum problems. I figured I was in there wiring all this stuff, and didn't want a noisy mess afterward. Just ground the cable shield on one end of each run of the coax - I have a couple grounds at the jack and one at the ground for the bridge volume.

The lead that formerly went from the bridge volume now goes to the new series/parallel switch on the center contact on the switch per the drawing.

One of the outside contacts on the switch has a lead that goes to the input on the Danoblaster switch, along with the lead from the selector switch. This is the parallel connection. This way either pickup individually, in series, or in parallel, passes though the Danoblaster, even if the Blaster is not engaged.

The other contact on the switch goes back to the original series location, on the third lug on the neck volume pot. That's not shown on the picture above, but it is on the one below.

This picture on the left shows everything connected.

With the neck pickup selected alone, you get that pickup with or without the Blaster.

With the bridge pickup selected, you get that pickup alone, with or without the Blaster.

With the pickup selector in the middle, you get both pickups in series or parallel, with or without the Blaster.

Again, the series/parallel switch really just breaks that original connection between the volume pots, and sends it to the Blaster on its own (parallel), or through the neck pickup per the stock wiring scheme, and that pickup goes through the Blaster.

I don't know if everyone with a Danelectro would want the Blaster in their guitar, but the series/parallel switch adds another very useful tone, and is easy to wire on its own. It gets a thinner, chimey tone good for rhythm.


Danelectro Stratoblaster Wiring and Installation

With the body ready for the Stratoblaster...err..Danoblaster, we can do the final wiring and put it in the guitar.

This is the factory location of the output jack on the control plate. We're going to remove it, and put the custom value push-pull switch/gain control in its place.

That pot has a little locator tab on it. We break that off since we need the pot to lay flat on the panel.

Mount the switch into the hole vacated by the output jack.

I printed the layout diagram from General Guitar Gadgets and then set about shortening and resoldering connections. Leaving the leads at the length I had them for testing is an invitation for noise and hum pickup.

Which we don't want.

In an effort to keep some RF out, I got a little crazy and wrapped the leads that run to and from the Danoblaster PCB to the switch with copper foil tape. It may not be necessary, but I figured with all that extra gain it can't hurt.

Then I soldered a lead to the tape and ran that to the most convenient ground point, which is the output jack.

I also have coax going from the output of the Blaster to the jack as well. The coax is grounded on one end only - I used the jack ground again. If you ground it at both ends, you'll have a ground loop which causes hum.

Here's the guitar semi-assembled for testing. It worked fine.

You may be able to see the battery for the Blaster tucked inside the lower rim of the guitar - I mounted a battery clip there. I wound up tying the PCB to the volume control leads with a wire tie - that way the all of the electronics are more or less one assembly, and hopefully be more reliable.

That way there will be less flying leads when it's time for a battery change. (I admit I accidentallly broke off a few of those tiny connections when fiddling with all of the wiring).

Also note where the relocated output jack will go - in the hole we drilled in the last post.

I'm contemplating a series/parallel pickup switch as well, but I'd like to test-wire one first before I commit to it.  So I need to string the guitar up at this point in order to test that switching and see if there is enough of a tonal difference to put it on the guitar.

I use DR strings on my electric guitars. Their packaging has just changed to this "corrosion proof" shrink-wrapped package. I like it.


Stratoblaster in Danelectro and Tape Binding Repair

In the last post, I mentioned I'm going to put a Stratoblaster into the Daddy-O Yellow Danelectro DC-2. Let's get on with it, shall we?

The Stratoblaster is an FET booster that runs off a 9 volt battery. It was originally designed by Alembic, and can be installed inside a guitar or in a pedal. It provides up to 20 dB of clean gain - just the thing for lowish-output pickups such as those in a Stratocaster - hence the name.

I'm fairly sure the first customer was Jerry Garcia as he was playing Strats at the time this circuit was invented.

Anyway, it's a simple circuit and the schematic is out on the interwebs. I procured a nice kit from General Guitar Gadgets. J.D. Sleep, the fellow behind GGG, has made a couple of nice upgrades to the circuit, so I went with his kit, which you can see above.

I felt like a Danelectro would be a good candidate for this addition - since the famous 'lipstick' pickups are pretty low output and a booster would provide some 'oomph' when needed.

Here we are testing the Blaster after populating the PCB. Worked great right away.

Now we need to mod the DC-2 to install the Blaster into it.

I think it's ok now to call it a Danoblaster.

You may recall back when I made the new pearl pickguard that I made an extra hole. I'm going to relocate the output jack more to the right, and use the former output jack spot for the Danoblaster push-pull switch/gain pot.

I used the pickguard as a template to start the new hole in the guitar body for the output jack using a Forstner bit.

The tip of the bit made a good centering mark. The I took the body over to the drill press and finished the hole.

Turns out the plywood internal rim on the body would interfere with the output jack. The arrow in the picture shows the area that will need to be cut away for the jack to fit.

This is also an opportunity to see the famous Danelectro plywood internals!

I made some rough marks on the top and inside the body so I'd know how much material to remove in order for the jack to clear.

I figured I'd cut the material away with a chisel. I keep my chisels sharp, but I had a hard time getting a good angle on the cut I needed.

At this point, I was wondering how Sven from Argapa or Toy Making Dad - actual craftsmen - would approach this job.

It did help to whack the chisel with my rubber mallet to really drive the chisel into the plywood.

Although it was probably my head that needed the whacking.

After getting some material removed, it dawned on me that I could grind the semi-circle shape I needed with my trusty Dremel, armed with an angle attachment.

Well, it ain't purty, but it is functional.

The jack has plenty of clearance as you can see on the test install.

Made a fair amount of wood chips and sawdust during the process.

If you do instrument repairs, you probably use toothpicks to apply glue or paint or even lubricant.

I just got these very nice Japanese bamboo 'repair picks' to use in place of toothpicks. Stew-Mac markets them as 'repair picks,' but if you search the interwebs, you'll find they are actually skewers!

Another instance where an item intended for one purpose can be used for guitar repair.

At any rate, I was going to use them to put glue under the binding tape on the guitar where it was lifting up as it is prone to do.

But the more I peeled back the area that had lifted, the bigger the area got. So I wound up using a brush for the glue instead.

The cool skewers will have to wait for another day.

Taped the reglued area down.

The tape in the cutaways on Danelectros is really prone to lifting. Doesn't like to stay stuck down on those curves.


Custom Reverse Audio Push-Pull Pot

I'm going to put a Stratoblaster preamp in the yellow Danelectro DC-2. I've never had one in any guitar, and for some reason it seemed like an interesting thing to try.

I've always been curious to try the Stratoblaster. One of my old guitar heroes, John Lees, had Alembic do some mods many years ago on his famous gold sparkle 1961 Stratocaster, including the Stratoblaster. After all these years, I figured, why not try one myself?

I have the kit from General Guitar Gadgets. There are some mods J.D. Sleep made to the circuit, including the use of a 50K reverse audio taper pot instead of an audio taper pot, which he says provides a better taper.

Now, the original Alembic circuit had a trimpot on the PCB, but it seems to be to be a better idea to put the pot where it's easily accessible on the fly - on the pickguard of the guitar. I also want to include a switch to turn the preamp on or off, again, while playing.

Which brings me to the point of this post. I don't want a separate switch - I'd like to have a push-pull pot to switch it on, and also to control the gain. However, try finding a push-pull pot with a 50K reverse audio taper! Does not exist.

Unless, that is, you modify a standard push-pull switch/pot to use the carbon track from a 50K reverse audio taper pot! Ha!

On the left you see a B250K ('B' meaning linear taper) switch/pot, and our victim donor C50K ('C' is reverse audio, aka reverse log) pot on the right.

Here are the backsides (hee hee) of the two controls. Note the DPDT switch on the left.

Trust me, this is not rocket surgery.

First we take apart the push-pull pot. Pry back the tabs on the pot section.

Then pry back the tabs for the switch section.

Not too hard, huh? Even I can do this!

Then disassemble the whole thing. It all just comes right apart.

I laid the parts out in order and I'm glad I took this picture. I needed it later.

We're going to swap out the B250K carbon track wafer that's the second piece on the right with the C50K one. Easy.

Take the back cover off the C50K pot.

You could do this with any value or taper you'd like - I see 250K, 500K and 1 Meg push-pull pots out there, but you could easily make a custom pot to whatever value and taper you need.

On this pot though, unlike the other pot and unlike a CTS pot, there is a tab at the bottom of the shaft that holds the wiper in place.

Originally I tried to drill out the tab, with no luck. Then I tried to cut off the wiper. I had the right idea, but I cut the wrong side (!), destroyed the carbon track, and had to get a new pot.

The things we sacrifice in the name of science.

Here's the right way to cut the shaft to get the wiper off.

Put your saw between the carbon track's wafer and the body of the pot. If you put it on the wiper side, you will destroy the carbon track. That's what happened to me, and held me up for a few days while I procured a new pot (I got three from Small Bear in case I wrecked another one...).

Here's what we wind up with. The wiper (on the right) is not needed.

What we need is the C50K wafer on the left. Now we'll transplant that into our push-pull switch! Bwahaha!

Here's all the parts about to go back together. Note the old 250K track in there - that will get thrown into my bin of 16mm pots - not sure why but there you have it.

Note there are some scrape marks on the 50K wafer - no big thing. It doesn't affect the performance at all.

I'll use the white wiper from the push-pull switch since the control shaft can go right through it.

I figured I should test the resistance of the "new" pot before it all went together to make sure I had the wiper the right way round. Worked fine. I just had to hold the wiper up against the carbon track for it to work.

There's a little pin on the bottom of the control shaft that engages with a slot on the switch half of the control (the black plastic piece on the bottom). We just need to make sure the tab is engaged in the slot when the two halves are put together

Pulling the shaft up then moves the switch up, and pushing it down moves the switch down. It contacts the respective contacts as it is moved.

Simple and effective.

An electro-mechanical device at work.

Reassemble the switch to the pot and push the tabs back down. Make sure everything is seated together before the tabs go back down.

Note that the switch terminals should face in the same direction as the pot terminals. It will sort of work the other way around, but it won't fully 'click' into place.

Don't ask me how I know this.

There you have it.

A custom value push-pull pot! Works perfectly.

Now to install it on the guitar.


White-Tailed Deer in the Garden

In the past, I've mentioned the deer that wander through our neighborhood.  In fact, I posted about one in the winter.

I've seen them singly or in small herds in the yard, but I had never seen this before.

This white-tailed doe was just lying in the garden munching on some grass.

What a life.

The whole yard is like a big salad bar for her.

She just kept eating and looking around.

Check out those ears! When she heard a noise they'd twitch and change direction.

After a while, she got bored (or full) and wandered off into the neighbor's yard.

I saw some of her doo-doo when I cut the grass later.

Saw this same deer again this morning. She was in the backyard, saw me, and went around to the front. I got to within 20 feet of her, talking to her, then she took off.

Hey! You eat my vegetation, at least you could stay and chat!


Fixing Sagging Danelectro Bridge

You may recall that I installed a CJ Tooling bridge on the Cancer Killer Danelectro guitar. I had intended to put one on this guitar as well. Unfortunately, I don't have one for this guitar since CJ Tooling has been closed for a couple of months due to 'unforseen circumstances.' I hope all is well there.

In the meantime, I'm retrofitting this guitar with a stock Danelectro 6-saddle bridge of the type that's found on some other Danelectro models.

One of the issues with virtually any Danelectro bridge is their tendency to sag in the center under string tension. The stock bridge on this guitar was doing that. So in addition to having better intonation, I want to solve the sag problem.

Did a search of the interwebs and found a video by my guitar repair hero, Dan Erlewine, in which he modifies a stock Danelectro bridge to fix the sag. It's easy to do, and I simply followed his direction.

This is the new bridge in its factory packing. It comes with mounting screws and a hex wrench to adjust the height of the saddles.

TMD's parental units had a huge collection of allen wrenches like this which they willed to him. I'm going to donate this to the collection.

What we're going to do is put a Gibson Nashville-style Tune-o-Matic threaded bridge insert and stud on the guitar body to support the center of the bridge. Simple and effective, as well as adjustable.

First we make a center mark where we'll drill a 5/32 inch hole for the top of the stud to pass into.

Over on the drill press we drill the hole. Lookit that brass swarf coming up! (The bridge is chrome-plated brass and is very easy to drill).

I screwed the bridge down to a caul and clamped the caul to the drill press table so it wouldn't move while being drilled.

Now we put the stud through the bridge and make a mark level with the top of the bridge. I used a razor saw to scribe the stud.

The excess stud has to be cut off so it doesn't interfere with strings or the bridge saddles.

At this point, you can see how clever and simple the idea is and how well it will work. We'll have a support right at the point where the stock bridge tends to sag under tension.

Since the caul has a hole drilled in it which is the same size as the stud, we can use it as a support to cut the excess off.

It cut easily with the razor saw.

Take off any sharp edges left from the cut with a file.

Test fit - the stud is perfectly level with the top of the bridge.

I'm not a big fan of chrome bridges. It's hard to 'age' chrome (ferric chloride works on nickel but not so much on chrome). I guess I'll have to settle for natural aging over time.

Now we put the bridge on the guitar body temporarily using the mounting screws. I put a wedge under the rear of the bridge so the front of the bridge would be flat to the body of the guitar and the hole would be square.

Then I drilled the pilot hole for the threaded bushing that will be pressed in. The hole should be about 9/32 to have a tight fit for the bushing.

This is again a 5/32 inch bit. After this hole, I drilled it again with a 7/32 to open it up more. I don't have a 9/32 bit, so I used a 1/4 inch bit and then used a file to ream the hole large enough to press the bushing in.

The bushing should be a tight fit. I reamed the hole until I could get the bushing to sit about halfway down in the hole.

Then I used a rubber mallet to drive the bushing all the way in.

Thread the stud into the bushing, and then screw the bridge down. The bridge is very solid now that it's supported at 4 points.

I'll probably need to adjust the bridge height upward during the final setup. I'll be able to use the roller on the stud to adjust it to support the final bridge height exactly.