Building very first pedal

Started by JONFROMJERSEY, October 10, 2006, 11:25:38 PM

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JONFROMJERSEY

Hi
This is my very first attempt at electronics, pedal construction, etc...  I am trying to recreate a footswitch for my old Vox amp.  It is a two button switch, one button controls the tremolo on my amp and one button controls a mid range boost.  The original switch by Vox had the MRB switch as momentary, but I would rather it not be.  Also, the cable to the amp was hard wired and I want a 1/4" jack instead.  The footswitch input on the amp is a single 1/4" female.  I have a photo of the inside of the original switch but the switches are enclosed and I cannot see the details.  I an email it out if necessary.
Can anyone help me figure this out, perhaps post a diagram of what should be connected to what?  I have searched the forums but I cannot find what I need.
Thanks a lot!

RickL

Why don't you want to use a momentary switch for the MRB? Assuming it works the way most momentary switches work (press once to engage MRB, press again to disengage) you *might* be able to wire a SPDT alternate switch to work. Since most SPDT are break-before-make you could try wiring the two outer terminals together and treating them as one pole of a SPST, the centre terminal being the other pole. Each time you press the switch it will go open for an extremely short period of time which may be long enough to switch the MRB.

To actually build the switch you'll need a box, a stereo jack and the appropriate switches. Wire one terminal of each switch to the sleeve of the jack, the other terminal of one switch to the tip of the jack and the other terminal of the other switch to the ring. If the switches control the wrong functions just switch the tip and ring connections. Don't forget to use a stereo cable to connect the switch to the amp.

JONFROMJERSEY

What are the appropriate switches?  DPDT?  If so, which two terminals on each switch should I use, there are 6.  Also, you said to wire it to the sleeve of the jack, does that mean the ground?  Thanks.

R.G.

Cool - another Vox nut!

The MRB button is really a momentary switch, and it is as you have described it - hold it down to make the MRB work. You can buy switches that are alternate action, that stay latched when you press them until you press them again. The tremolo switch is like that. You want the same footswitch we use for bypassing effects, a double pole double throw stomp switch.

Which amp is this? I have schemos for almost all of the Vox amps, including the Thomas Organ  American made Vox models that are hard to find. I probably have the same amp, as I have one each of the Nova, Pacemaker, Cambridge, Berkeley, Berkeley 2 and 3, Buckminister, Viscount, Royal Guardsman, and Beatle.

Does the footswitch have indicator lights on it?
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

JONFROMJERSEY

Hi

It's a solid state Vox Pacemaker.  The switch does not have indicator lights, though if I wanted I guess I could put in some LED's.  Basically, I have no real clue what I am doing.  I have an enclosure and a stereo jack, and two Switchcraft DPDT switches that I think I need to replace (covered in solder).  I just need to know how to wire the footswitch.  I have a photo of the inside of the original switch but I can't make it out.  Email me at jonseidman@hotmail.com and I will email it back to you.

Peter Snowberg

Welcome to the forum. 8)

A switch like this is a great 1st project.

I would wait for schematics to be sure, but there's a really good chance your footswitch is wired up with a stereo plug. If this is the case, the two switchable functions are probably switched by shorting either the tip or the ring to the sleeve (ground) connection.

This is the case with just about all footswitches that don't have indicator lights. Once you add LEDs, they generally get a little more complex.

As R.G. pointed out, a typical effects on/off style stompswitch is what you'll want to use.

Best wishes on your first project. :D
Eschew paradigm obfuscation

JONFROMJERSEY

 :)  Worked great!  I used 2 SPST switches and a stereo jack.  Term-Ground and Term-Ground on each switch!

SpicerAck

 I too am interested in building a pedal for my Vox, it is a viscount that had 4 buttons.  I haven't found any schematics for this and don't have the original pedal.  Any help would be appreciated.

R.G.

Congrats, Jon. Good work.

Spicerak, all of the "big head" Thomas Vox amps used the same circuits, just less of them for lower function from the Beatle on down. The Viscount (I have two of them) is the same internally as the Buckingham. There were three Viscounts, a V115, a V1151, and a V1153*6, all with slightly different internals.

All of the footswitches are contact closures to ground, but the bigger heads had varying numbers of them and some models had indicator lights on a separate circuit driven by +24V from the amp head.

Which amp model is yours?
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Peter Snowberg

Eschew paradigm obfuscation

pit

hi i'm new here...
i want to make my first pedal,and i need some ideas and directions to help me start with