Stompbox Base Unit

[JKowalski]

Hi

I had this planned out a while ago and I forgot about it until I saw Zvex's inventobox the other day. So I finally built it up.

Basically, there are alot of effects that I want to build that are small and something I may not use very often. I did not want to spend all the money to build them all into nice enclosures with all the expensive hardware. So this is my solution:



The PCB inside the pedal contains the footswitch circuit, a millennium bypass LED, power supply filtering and protection, and a buffered Vref. The header from the PCB contains the V+, GND, Vref, Effect Input, and Effect Ouput wires.

I build all the "interchangable" effects onto a certain size PCB template to fit into the space available (which is quite a bit, actually) with the PCB mount pots in the correct places, and an optional secondary LED (for LFO, or whatever) at the top for the corresponding hole on the top of the pedal. To change out the effects, all I do is take off the knobs, unscrew the pots, disconnect the header, pull the effect assembly out, then put the new one in the same way.

The knobs were made the way they were so that one, two, or three knobs would all have the right holes to make it look good, i.e. one knob will go on the bottom, centered in the pedal, two knobs on the top, three knobs... You get it.

For each effect I will have a square aluminum plate that goes with it to place on top of the enclosure and be tightened down onto it by the potentiometer nuts. This panel will have the effect specific control titles, etc, and also serve to cover up whatever holes were not used on that particular effect.


So now whenever there is a simple, interesting effect I want to build, all I need is a piece of PCB, some PCB mount pots, the circuit board components, and a piece of aluminum! And the effect doesn't need a Vref system or any protective components. Very cheap overall.

I don't have any effects built up for it yet cause I finished the box yesterday  

And you can tell that I messed up by forgetting to think about the screw protrusions into the enclosure, so  had to cut bits off my PCB and the text on it 

[caress]

 

[John Lyons]

Looks more useful that the inventobox already!!
Nice work.

John

[JKowalski]

Looks more useful that the inventobox already!!
Nice work.

John

Thanks!

May not be as versatile as the Iventobox is but it's sure got a number on it for reliability and ease of interchangeability

More of the veteran DIY'er solution to the endless drive to make more circuits, more, more!    I have so many cheap parts amassed but not many expensive enclosures, I kept forcing myself to stop at the breadboarding stage because I felt the circuit was just shy of getting it's own box and permanent place on my pedal board. No longer! Wacky noise boxes and freaky effects are guilt free now  


Now I just got to decide what my first board for it will be.....

[soggybag]

Great idea. There are a lot of things that I want to build and test. But I'm not sure if I want to box it up. It's hard to test these out without a box. I've built up a lot that maybe don't deserve a box.

Why not use a short length of wire from the pots ending in a little three prong plug with a header on your FX PCB. Similar to the jack this guy has in this picture.

http://axeandyoushallreceive.com/images/Socketed%20Screamer%20populated.JPG

[~arph]

Nicely done!
Only thing that would bother me is the location of the input and output jacks. They are prone to be stepped upon being so close to the front of the pedal.

[JKowalski]

Why not use a short length of wire from the pots ending in a little three prong plug with a header on your FX PCB. Similar to the jack this guy has in this picture.

It just makes it easier to exchange effects this way, you don't have to mess with changing pots out as well as the PCB and referencing what pots you need for it, you just stick the PCB in and you are done. It's also to hold the PCB in place, the potentiometer nuts are the connection to the chassis. That screamer uses those sticky standoffs, I didn't want to deal with those.

Nicely done!
Only thing that would bother me is the location of the input and output jacks. They are prone to be stepped upon being so close to the front of the pedal.

I think they are okay, at least for me. I won't have a problem with them. I put them there to get the most room for the effects PCB as possible, and it's a small box, so... If you want some room to breath it would be best to do this in a 1590 box instead, the jack/switch/peripheral PCB could be layed out across the width and the jacks placed farther up, and you'd have much more effects room. I wasn't planning on building anything really complicated in this fella, but something like a rebote 2.5 could definitely fit.

[JKowalski]

Here's what I was talking about as far as the "plates" with the control info on them, effect specific. This one's just a general distortion/fuzz plate, with gain, tone, and volume. Sadly, still no circuit! I barely managed to squeeze this into my schedule, I have a massive homework load that just got dumped on me this week 

[soggybag]

Nice work. I like the plate. I was thinking about etching a name plate myself. I like the idea that you can take this off and install a new one for another module.

[soggybag]

Those knobs look like some I got from Futurlec. Mine are a little too small to fit a 1/4" shaft. Though they look like you could force them over a knurled press on type shaft.

[realizewhoitis]

Here's what I was talking about as far as the "plates" with the control info on them, effect specific. This one's just a general distortion/fuzz plate, with gain, tone, and volume. Sadly, still no circuit! I barely managed to squeeze this into my schedule, I have a massive homework load that just got dumped on me this week 

Im digging the plate..could someone share how thats done?

[JKowalski]

Those knobs look like some I got from Futurlec. Mine are a little too small to fit a 1/4" shaft. Though they look like you could force them over a knurled press on type shaft.

I think these are the same, ordered from futurlec a while back. They fit fine over a 1/4", that's kind of weird?

Im digging the plate..could someone share how thats done?

Just go and buy a thin sheet of aluminum, and etch it like you'd etch an enclosure.

Cutting it to size is the annoying part.... Though the right kind of wire cutter tool can cut through the plate marvelously like a pair of scissors as long as you go slow with it and make sure you aren't bending the plate as you cut    Then a file to get the edges down smooth and precise.  In other situations, I have used a drill press (drill a bunch of holes along the line you want to cut and then cut the bridges between the plate and the piece) and a hacksaw (self explanatory)

Finally drill some holes for the pot shafts, and then to attach to the enclosure just screw the nuts onto the pots over the plate and it's not gonna go anywhere.

[realizewhoitis]

awesome! thanks for the info. where would you recommend getting the aluminum and is there a thickness i should look for?

[JKowalski]

Hmmm.... I just had a couple sheets lying around in my shop that I could use, but I think you can get a good medium sized piece of aluminum sheet at any home depot. I think that's where I got one of my sheets, but I remember it being a little bit expensive. Look around for a metal yard in your area, if you want something cheaper?

As far as thickness it's totally up to you and what you want but the thicker pieces are obviously harder to cut. Mine was like.... You know when you get a spiral notebook and the back cover is made of this card material? It was that kind of thickness, maybe very slightly thicker. Kind of a weird comparison I know but hey its the first thing that came to mind 

[dano12]

That is really great work. I love the PCB to header connector!

I've been working on a breadboard implementation of the same idea. I went with a larger BB enclosure that has 5 replaceable pots. I figured 5 pots would handle 90% of the designs out there.





As far as the plates thing goes, yours looks very killer. I envisioned 1mm thick aluminum strip, one with 5 holes, one with 3, etc. That way you could easily remove the pots you don't need and have a nice cover to boot.

I'll post pix of the plates that I came up with.

Either way, your work is most excellent

[Quackzed]

I think it's a great idea for any diy'er to have a 'base unit'. brilliant design!
the fact that , like you said, you can build any weird circuit and not have the expence of box jacks switches, to prevent you from using it is a big plus for many diy'ers.
and the fact is, you could build  3 or 4 'base units' and then  plug any of your 'plate circuits' into them individually in any combination.
less drilling, painting, wiring, etc. as well.
i like that the pots are discreet to the circuit as it solves the problem of mounting,
as well as making it more user friendly and less complicated.
i was playing with the modular  idea, using a molex connector for +,-,in,out.
but here you've figured out a simple way of 'plugging in' your circuits.
very cool, i hope people read this thread and see how valuable this idea really is.
+10

[Quackzed]

what about using plastic plates with aluminum tape shielding. like pickguards!
1. easier to cut
2. cheaper
3. can be grounded through volume pot
you could use clear acrylic sheets that 'light up' via a super bright led...
you could use waterslide decals. print stickers even...
paint pens and clearcoat...
or something different for each one...
though i do like the etched aluminum look!

[trjones1]

Hey JK, how are you attaching your pots to the different boards?  My experience with board mounted pots is that once you started desoldergin/resoldering them their reliability nosedives and they'll soon be intermittent.

[JKowalski]

I think it's a great idea for any diy'er to have a 'base unit'. brilliant design!
the fact that , like you said, you can build any weird circuit and not have the expence of box jacks switches, to prevent you from using it is a big plus for many diy'ers.
and the fact is, you could build  3 or 4 'base units' and then  plug any of your 'plate circuits' into them individually in any combination.
less drilling, painting, wiring, etc. as well.
i like that the pots are discreet to the circuit as it solves the problem of mounting,
as well as making it more user friendly and less complicated.
i was playing with the modular  idea, using a molex connector for +,-,in,out.
but here you've figured out a simple way of 'plugging in' your circuits.
very cool, i hope people read this thread and see how valuable this idea really is.
+10

Thanks! Yes, I was thinking about making more then one of these "base units" for the exact reason you described  

what about using plastic plates with aluminum tape shielding. like pickguards!
1. easier to cut
2. cheaper
3. can be grounded through volume pot
you could use clear acrylic sheets that 'light up' via a super bright led...
you could use waterslide decals. print stickers even...
paint pens and clearcoat...
or something different for each one...
though i do like the etched aluminum look!

That acrylic sheet idea is an interesting one, I might have to try that! I have the space for the led that sticks OUT of the front (if you want it there), maybe sanding around the sides of the LED in a circle might shine some of the light sideways and light up the sheet a little bit...

If you using plastic there is no need to shield it. The metal enclosure underneath does the job for you, the plate is just totally decorative! The only thing that might be "unshielded" is if you don't use all the holes and leave some of them open, but that won't make enough of a difference in the shielding to go through the effort.

Hey JK, how are you attaching your pots to the different boards?  My experience with board mounted pots is that once you started desoldergin/resoldering them their reliability nosedives and they'll soon be intermittent.

I think you are assuming I will desolder the pots again and replace them for some reason, the answer is no. The pots are permanently soldered on to each individual effect board, they never come off. To remove the circuit (with pots) you just unscre the pot nuts and slide the board out of the enclosure, then slide the new board (with pots on it) into the pot holes and screw it on. You don't have to deal with individual parts or anything, it's a complete self contained board, you just hook up the header to it and you are done!

I will have a (germ?) fuzz board done for this unit very soon and you guys can see exactly how it all works  






Also, I was thinking about making a "big daddy" base unit - two foot switches, and two side by side pot hole systems in the same shape as this box has. So you could put two different units side by side in the same box, with a switch for each, or one really big effect spanning the whole box. The switching would be electronic, controlled by momentary switches, with a interior switch that can turn one switch into a tap button for tap tempo effects. (Took that idea from the invetobox 

[JEPorter]

Wow that is really clean work...very nicely done:)
Jeffrey