P-Bass Stomp Box.

Over a month ago I posted a few words about some sort of invention in the DIY stomp box world.
The idea was simple and genius: Using the p-bass pickups as a sound transformer.
The majority of the DIY stomp boxes I saw so far have a piezo buzzer for this goal.
And as with any piezo element, it comes with 2 common issues:
1. “Dirtiness” of the sound. Not only the kick of your foot is transmitted but all possible squicks and even the smallest rustles.
2. Huge feedback. You have to be a sound engineering guru to get an acceptable sound. So it is loud enough and without the self-generated feedback sound.

The regular magnetic pickup supposes to solve both problems at least the big part of it.
Just because it’s only able to transmit the vibrations of the metal object.
In the case of the guitar, it is the vibration of the string. But you can use any metal object for this goal.

Now. Why p-bass pickup?
Well our DIY stomp box is a foot drum, right?
Therefore we want to get as low a frequency of the drum sound as possible.

MATERIALS USED IN THE PROJECT:

1. Cohiba cigar box.. In the beginning, I was thinking about the bigger box as I saw on the internet and described in the blog article. But finally, I have decided on this one. The main reason – is portability.

2. P-bass pickups. The cheapest solution was to order the set of p-bass pickups on eBay. Its price was just $6.50 at the moment of ordering from (surprise!) China shipping is free. The first test showed significant electric feedback. Well, that’s the consequence of the low price I guess. Therefore I had to add item 3:

3. Self-adhesive aluminium coil. The best solution for the shielding of the box would be a copper coil of course. But the aluminum coil is much cheaper and still does the work. The covering of the interior of the box will protect the pickups from electromagnetic interference and thus will decrease the unpleasant sound.

4. 1/4″ Guitar/Phone Jack. This is a standard part of any DIY project. You have to have a plug to connect the amplifier cable. Right? The only relatively complex job in this project is soldering the pickup wires to this jack. You can buy them in any store’s electric department just for $0.7 or 10 pieces for $6 or so. Make sure to sand them a bit the contacts before soldering.

5. Self-Adhesive Double 2-Sided Sticky Strong Mounting Tape. Of course, you can use the screws or glue to mount the parts inside the cigar box. I’ve found for myself that this mounting tape is the best solution. Just be patient and don’t rush to remove the protecting paper from the other side until you are sure all stripes are in place and ready to catch the item.

6. String Replacing Metal Object. Remember that we need some metal object vibrating on the foot hits? After some thoughtful search in the recycling bin, I’ve made my decision on the Fisherman’s Friend metal box for the lozenges. I’ve ruthlessly detached the lid and that’s what I will use as a “string”.

WORK.

Step 1. Drilling. Drill a hole for the 1/4″ jack (#4 above). You can use one of the end faces of the box but not the one you plan turn toward to you while playing. I usually use left/right side ends but the top side end might be even better. Oh. And I turn the box to me with the side opposite to the one which has a lock.

Step 2. Shielding. This step is fairly simple. Just cover tightly the interior sides of the box with the self-adhesive aluminum foil. All sides including the cover lid. Don’t leave the uncovered spaces between the stripes. The overlapping is better. For example, take a look at the resulting image at the bottom.

Step 3. Installing Jack. I guess this step doesn’t need any detailed directions. Just put it through and tighten the nut. Don’t forget the washer though.

Step 4. Mounting the pickups. The position is not really important. Just as a rule of thumb the central position should be the best considering the fact that the maximum vibration occurs in the center. Firstly stick two stripes of mounting tape on the bottom sides of the pickups. Then take them in one hand ready to put in place and remove the protecting paper with another hand and stick them to the center of the bottom with wires side facing the installed jack.

Step 5. Connecting the Pickups to the Jack. This is the only step where you probably will need some special tool. I mean a soldering iron. I saw some people just tying the wire to the jack contacts holes. Well, it might work. But not for a long time. So if you want a good device then solder it. Remember that the black wire is for the ground. Actually, I’m not sure that polarity, in this case, is important. But I’m trying to be just accurate here.

Step 6. Final. Installing the “string”.As I said I used the lid from the small Fisherman’s Friend metal box. Just because this is the first suitable thing I was able to find. But feel free to use whatever you can find. Any piece of metal which is thin enough to produce the vibrations will work. Now the important part. The GAP between the metal plate and the pickup. I would vote for 2mm max. The closer – the better the response. But at the same time, you have to make sure the plate won’t touch the pickup during the hit. While using the mounting sticky tape put it on the 2 far ends of the pate so the middle is left free for better vibrations. But remember that it has to hold the plate strong enough to fight the pickup magnet attraction. Put 2 or even more layers of sticky tape (one on one) if you need to set the plate closer to the pickup.

RESULT.

That’s actually it.
You are pretty much done.
I also would advise putting some rubber legs on the bottom so it will not slide while in use.
Some people put the bigger/higher legs on the outer side so the box is comfortably inclined towards to your foot.
But it really depends on personal preferences.
I personally use the roll of the soft carpet.

The following image demonstrates the interior of the p-bass stomp box:

The demo video is to come shortly.