Wanting to make a Digitech FS3X footswitch for JAMMAN

[dan_plus_o]

I have a jamman an I want to get the optional footswitch (For changing the loops), but $85 CDN is too much for a thing like that IMO.
So I thought I would make one, but I have no idea of what I need and how to wire it together. I love working with stuff like this and had a lot of fun soldering in my EMG active pickups. It would be a fun project for me and in the end I would have a nice pedal.....

So does anyone have any information on making a Digitch FS3X?
Link: http://www.digitech.com/products/FS3X/FS3X.htm

Any help would be super 

[aron]

I have no idea how they do the switching, but one way to test would be to insert a TRS (Tip ring sleeve) plug into the jack and try different combinations with the lugs. Like short the tip to ground, short the ring to ground etc.... and see what happens.

[dan_plus_o]

not sure what a Tip ring sleeve is, or were I could get one.

I just found this pic:


So would a 1/4 jack stereo jack work?

Then that would tell me which one does what then I could just strip the chrod and wire the right ones up to some switches and then make a custom box for em. Or get a jack for the chord to plug into, that was I don't have to reck a good chord.

heres another nice picture:

that one show you were the wires come out on the other side 

[dan_plus_o]

I just tried with a Stereo 1/4 chord and the tip changed the record mode and the ring changed the loop down...... but I couldn't get the loop to change up. Is that because I was using a stereo chord and it only had two wires (spots)?
Is there more then one way to make the thing react? Like could loop change up and down both be on the ring but have diffrent ways to set them off.

heres another pic thats helpful.

[aron]

Tip = record mode and Ring =  loop down.... OK how about BOTH connected to ground?

[dan_plus_o]

Tip = record mode and Ring =  loop down.... OK how about BOTH connected to ground?

You sir are a smart one.... Both of them make the loop go up. Thankyou

so I need three switches and one of them has to set both the ring and the tip off.
not sure how to wire it yet (probably figure it out when I get the stuff)... So would I wire the tip to one switch then the ring to another then wire both the tip and the ring to the other one? Or would that work even work?

If you could help me out with what parts I need and how to wire them that would be great.... Sorry for the newb questions.

Would I need something like this?


Or will I need more "spots" like this?



Here are jacks for guitars but they would still work... right?
Stereo:

Mono:


My guess would be that I just need a stereo one for tip and ring....

[RickL]

If it's like the footswitch used with Digitech's early multi effects you'll need three momentary contact normally open switches, a stereo jack and a couple of diodes. Wire one contact of each switch to the ground of the jack. Wire the other contact of one switch to the tip, the other contact of the second switch to the ring and the other contact of the third switch to both the tip and the ring, through the diodes (anodes of both diodes to the contact, cathode of one diode to tip, cathode of other diode to ring). I'm pretty sure I have the diode orientation correct but if it doesn't work try reversing them.

If you want to live dangerously you could just wire up the first two switches and get the third combination by simply stepping on both switches at the same time.

[dan_plus_o]

Does it matter which contact on the switch I solder to the ground of the jack? Or are both contacts on the switch the same?
And could you explain the diodes a bit more... I have no idea what a diode is or what they are used for... does it need diodes?
Would radio shack sell diodes? or do I have to order them online? If you have time and feel up to it, a quick drawing would be great.

So the red would be the tip and the blue would be the ring.


Should I get one of these jacks?

or one of these jacks?

And is this the kind of switch I would need?
it says 102P SPDT on/on... so is that the one were in only makes contact when you hold the button down? and would on/off be the one that clicks into place then stays on untill you click it again?

[any]

I've got one of those footswitches, actually a FS300 (older model for rack units, but same switch)
and it has a diode somewhere in the path (forgot where) probably to block current in a certain direction.
I don't have easy acess to the switch right now (moving between houses) but mayebe someone with a FS300
could check it out since it's identical to a FS3X, you could probably find a cheap FS300 on ebay as well...

[calpolyengineer]

You only need SPST switches. I didn't feel like spending lots of money so I got two 2 packs of plastic SPST's and two 1N4001 diodes. It is actually really simple to do. I'm going to attempt an ASCII schem for you:

                                rec              loop dn         loop up
                             __I__              __I__           __I__          <--switches  
                             o     o              o     o           o     o
                           gnd    |            gnd    |          gnd  |
_       ring                      |                      |                  |
| | V-----------------------( |)-----------------L----->|------|              the L's are junctions, the brackets is a jump
| |    ^----------------------L------------------>|------------L                                            where the vertical is not
T      tip                                                   diodes                                                    connected to the horizontal
gnd

Now I don't know if that is comprehendable, but if you can read it that is what you need to do. I made the exact same thing like this and it works great. Hope this helps,

-Joe

Edit: Oh, forgot to answer your previous question. If you use SPST's then either post will do the trick. It just closes the connection momentarily between both poles. And either jack will do, but the switchcraft would be easier because the other one is a switching jack and it is easy to use the wrong lugs on it.

[dan_plus_o]

I'm not sure if I know how to read that....
I drew a picture of what I thought of the layout you did, so tell me if any thing is wrong in it.


So do the diodes keep the current from going to the loop down switch? Because if they went to that switch then the loop down and record mode button would send current thru both wires. So is that what the diodes are for? Keeps current from going to switch but lets current go from switch???


not sure which switch to get...here are a few I found at circuit city? 1.5A, 0.5A, or 3A??
Mini SPST momentary push switches. Normally open. 0.5A.
SPST normally open momentary switches. 1.5A. 1.2cm (1/2") mounting hole.
SPST mini momentary push button switch. 3A. Normally open.


Is this the diode I need?? Micro Diodes: Type: 1N4001. 50 PIV
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=Diodes&product=2761101

What wire should I use? or does that matter?

[calpolyengineer]

That layout is correct, just make sure the diodes both point into the loop down switch. The diodes act to prevent the rec or loop up from triggering the loop down. So for instance if the diodes weren't there, you push the rec button it grounds the tip. Since the ring and tip are connected at the loop up switch, the current from the ring can travel up the tip wire and ground through the rec switch too, hence the diodes. The amperage of the switch does not matter at all because this circuit is extremely low current, the only thing that matters is that the switches are big enough (size wise) and that they are SPST normally open. Those diodes will work, thats what I have, you can get a two pack at RadioShack. I also got my switches there but they are cheap plastic ones so you might upgrade to a better switch. And any wire will do, it is helpful to have three different colors though.

-Joe

[dan_plus_o]

Confused at which way they are suposed to point...
And how do you tell which way the diode is pointing

Is this diode pointing up/right or down/left???


So is this the way?? Which way should the bottom diode point?

[calpolyengineer]

The way you put those arrows is the way they are supposed to go. The way you read it on the diode is that the arrow points in the directio of the silver band. So that diode points to the upper right. And on you're drawing they are both correct.

-Joe

[dan_plus_o]

Thanks for all the help. I should be good to go now.
My local Circuit City doesn't have any diodes in right now so I will have to order them in or something (hopefully they do that).
Do you know of any other place I could get diodes (Besids radioshack.... the local Radioshack closed down because of circuit city).

Also, do you have any advice on making the casing? I was thinkin about using wood because its easy to work with.

[calpolyengineer]

To be honest, you can make the case out of anything since this circuit is not sensitive. I built mine into the travel case for my Sonicare toothbrush. Other potential cases were an old xacto knife box, a 2x4, or any other similar shaped thing I could find. As for diodes, I would look for maybe a car audio place or radio repair shop, they should have diodes. Remember that the diodes are unspecific, just about any diode you find will work.

-Joe

[dan_plus_o]

But aren't there diffrent kinds? like switching diodes and rectifier diodes.
Here are some diodes that the source does have in stock.
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=Diodes&product=2761141
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=Diodes&product=2761123
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=Diodes&product=2761661

Which one would you get?

there has to be a reason why they have so many diffrent kinds... Or does it not matter because of the type of project I will be making?

[calpolyengineer]

Most of the difference is in the current handling and breakdown voltage, both of which don't matter here. In this project you only need the diodes to block a very small current from going through the reverse direction. The other types of diodes like rectifier diodes and signal diodes are just designed with certain specs that are more suitable for those specific applications but it does not invalidate their use in other situations. My recommedation would be a small signal diode like 1N4001, 2, 3, or 4 since anything else would be much more than needed. Think of it like capacitor voltages where a voltage too high doesn't matter but too low does. The same works here for current handling, too high a rating doesn't matter (in this case) but too low does (in all cases). In the examples you gave, the first one has a current handling of 3 amps, the second is germanium so it would clip more smoothly (but in this case we don't use it to clip so ge is an unneccessary expense, and the third is a 6 amp diode used mostly for ac to dc conversion. All three of these are beyond what you require, but they also would work.

-Joe

[dan_plus_o]

alright... I would rather pay an extra $1 to get it sooner though, so if they work I might as well get one now. They also have some switches in stock.... Now I just need to find a jack. I am not sure if the source has any jacks but my local music store could probably order them in, but hopefully they already have some in stock so I can start working on it soon.

Thanks for the help.

I guess I will pick up the first ones, because they are the cheapest and they come in a pack of two.
http://www.thesourcecc.com/estore/Product.aspx?language=en-CA&catalog=Online&category=Diodes&product=2761141

So which way wold this diode be pointing?

[calpolyengineer]

Unfortunately I can't help you with that one. There will be some kind of identifier on it and the packaging should tell you. Good luck with the build!

-Joe