Building footswitch for Mark III

[Goldtop]

I'm looking to make a footswitch to cover all channels and reverb/eq. Anyone have a schematic of the footswitchs for a Mark III?

 

[Boogiebabies]

It's really easy.

The Lead and the R2 are simple circuit breakers that use a 1/4 inch jack and a Carling 110P. Wire the tip to one side of the switch and wire the sleeve to the other. The EQ/Reverb is the same circuit breaker, but uses a stereo 1/4 jack. Use two 110P's and wire the tip of the jack to one side of the switch and the other wire to the sleeve. On the next switch, connect one wire to the ring and the other to the sleeve. Mesa uses a shielded stereo speaker cable to connect the switch to the amp. A normal guitar cable will be fine for the Lead and R1. Even if you want to build all the switches within one unit, I doubt you will find 20+ feet of 8-10 wire cable very cheap. I would use the guitar and stereo speaker cable method.
If you want LED's for the Lead and R1, you will have to wire in a 3.3K resistor to the cathode of the LED.

 

[Shep]

wat is the carlington 110p

 

[Boogiebabies]

A switch that you step on.

 

[joepopp]

You can get them here:

http://www.tubedepot.com/p-110-p.html

They last a good long time!

 

[geoangus]

Is there a recommended minimum AWG wire size for the conductors if I went the single bundled wire route?

 

[Shep]

so it's a on/off type of switch..nothing special?

where would the led go in relation to the switch..?

also i found out that the mk III i bought had some really older looking mesa CA7's in the out sockets (A class ) does any one know what they are all about?

thanks BB and joepopp

 

[Shep]

anyone?

 

[joepopp]

Shep:

All I have is the single foot switch for my .50 cal. It does have resistor in the circuit of the LED. I am not sure if you make a dual foot switch you can share the same ground. I am guessing yes, but maybe someone has a dual foot switch here that can help you out with a pic.

 

[geoangus]

The switch is a simple single pole switch, with two contacts. The switch is either "open" (off) for the lead position, or "closed" (on) for the rhythm position.

Solder to the "TIP" contact of the input jack:
1) a wire to go to one side of the switch
2) a 3.3K resistor that is then soldered to the shorter leg of the LED.

Solder to the "Sleeve" contact of the input jack
1) a wire to go to the other side of the switch
2) the longer leg of the LED.

When the switch is closed, you are essentially connecting the tip to the sleeve, turning on the LED.

I took pictures, but I don't know how to post them.

The EQ and Reverb footswitch box is similarly wired, as described by boogiebabies. There is no LED on that switch.

Hope this helps.

geo

 

[Shep]

thanks...can you email me a few pic's of the switch.. i don't understand how the led will turn on and off if you have it in parallel with the switch..

 

[Tuna141]

I recently build a couple of switch boxes and found the place to be a great place to purchase parts ( switches, painted project boxes, LEDs, jack, etc.):

http://pedalpartsplus.com

I am not affiliated with them in any way, but thought they had a good selection and pricing and wanted to share.


Also, I'll try to answer your question: if you use a DPDT switch, the switch contacts will look something like this:
_ _ _
_ _ _

A DPDT switch is essentially two switches in one switch housing. If you wire it correctly, when you toggle the switch (push it down with your foot), you will both switch the channel or EQ or reverb and at the same time switch the LED ON which is a totally independent circuit.

To change the channels, as well as EQ & Reverb, you need to ground the signal with one pole (half) of the switch. The other pole of the switch will switch the LED power ON and OFF.

I made a footswitch for my Mark IIC. It has two switches - one switches channels and the other switches the EQ ON/OFF. I was able to power the LED indicating the channels by simply using the signal coming from the amp, but had to install a 9V battery in order to power the LED that indicates when the EQ is turned ON.

Hope this info helps some - it's tough to try to explain. I think your best bet is to try to find a schematic on the internet illustrating the wiring required to make this happen.

 

[Boogiebabies]

thanks...can you email me a few pic's of the switch.. i don't understand how the led will turn on and off if you have it in parallel with the switch..

All you are doing is providing resitance to the LED so it does not get burnt out by running higher than it's rating. Your getting the voltage from the LDR supply and the switch basically opens and closes the LDR circuit for LDR 3 and 4 thus engaging the lead circuit.

 

[Shep]

thanks..i competely understand it now...

thankyou everyone..

 

[geoangus]

did you get the pics I sent?

 

[joepopp]

BB:

Is there a way to make a switch that Tuna141 described without the battery for the EQ side?

 

[Boogiebabies]

Other than the Lead footswitch which gets voltage from the LDR supply, the EQ and Reverb are just circuit make or break connections. They provide no voltage because all they do is open or short to ground. If you want LED's, you'll need an external power source and the proper switch. With the proper switch your not adding 9V to the circuit, your just powering the LED's so when you stomp the switch, one pole shorts the EQ or Reverb and the other pole takes 9V's to light the LED.

 

[Vigo1999]

Other than the Lead footswitch which gets voltage from the LDR supply, the EQ and Reverb are just circuit make or break connections. They provide no voltage because all they do is open or short to ground. If you want LED's, you'll need an external power source and the proper switch. With the proper switch your not adding 9V to the circuit, your just powering the LED's so when you stomp the switch, one pole shorts the EQ or Reverb and the other pole takes 9V's to light the LED.

hey BB, wondering . . . can you build a Mk III's complete footswitch, like shep's wanting??? i like his idea, it will be great to have a single footswitch to change all the ch, eq/ reverb on the III . . .

if you can build one, i'm really interested in buying one 8)

 

[Shep]

virgo1999
this is wat i am going to do....

all you need is a box big enough to fit everything..( 4 switchs carling 101b's ( suggested by BB) , 2 LED's, 2- 3.3k resistors and a socket ..)

the cable should be a 4 core with a ground/bare wire. i'ii call it 1,2,3,4,ground...

one end should have 2 mono jacks ( 1 on one jack tip/core 2 the other jack tip, and the same ground going to each ) and a stereo jack ( 3 core on the the tip and 4 on the middle and the shared ground with the ground.. the other end should be the male plug so that can go straigh into your box...

in your box, wire one of side's of all the switch together making them all connented to the ground..wire core 1 to one switch and wire in paralell a 3.3k resistor and LED over the switchs termails...do the same for core 2 with the LED...wire 3 and 4 to the switchs the same way as 1,2 but don't pull the led in on those switchs as it won't work..


to basicly test it...get a multimeter if you have one... and put a probe over the tip and a probe over the ground of jack one and set the meter to make a beep or ring if there is a unbroken circuit..turn the switch on and off and if the ringing stop when the switch is off and starts when the switch is on then it is working..do this for each one..

i hope this all works..

BB can you comfirm...

 

[Vigo1999]

virgo1999
this is wat i am going to do....

all you need is a box big enough to fit everything..( 4 switchs carling 101b's ( suggested by BB) , 2 LED's, 2- 3.3k resistors and a socket ..)

the cable should be a 4 core with a ground/bare wire. i'ii call it 1,2,3,4,ground...

one end should have 2 mono jacks ( 1 on one jack tip/core 2 the other jack tip, and the same ground going to each ) and a stereo jack ( 3 core on the the tip and 4 on the middle and the shared ground with the ground.. the other end should be the male plug so that can go straigh into your box...

in your box, wire one of side's of all the switch together making them all connented to the ground..wire core 1 to one switch and wire in paralell a 3.3k resistor and LED over the switchs termails...do the same for core 2 with the LED...wire 3 and 4 to the switchs the same way as 1,2 but don't pull the led in on those switchs as it won't work..


to basicly test it...get a multimeter if you have one... and put a probe over the tip and a probe over the ground of jack one and set the meter to make a beep or ring if there is a unbroken circuit..turn the switch on and off and if the ringing stop when the switch is off and starts when the switch is on then it is working..do this for each one..

i hope this all works..

BB can you comfirm...

thanks Shep!! 8)

but man, have to be honest, my electronical and soldering skills sucks!! :lol: , i dont know if i can build such a thing . . .

and was wondering, why only 2 Leds??? why not one for each funtion?? i was willing to build/buy a footswitch like the FU3 that Mesa makes for the Mk IV, but with 5 functions: Rhy1, Rhy 2, Lead, EQ and Reverb. what i really dont know will be the cables and outs . . . will be one for each also?? (or the one for the EQ/Rev will have to be stereo on one end and two singles on the other??)

is that what you also have in mind???

thanks again bro!!