Housing 3 FXs (distorsor) in a box, switchable bit A or B or C

[arma61]

Hi

I would like to house a BigMuff, an AMZ OD Pro and a Guv'nor in one box with 3 switches, but I want only one of the fx active at a time with no way to select another one together, so only one can work at a time, I remeber old radio with some mechanical push buttons, pressing one, the other button (already pressed) comes out.

Is something like this feasible ?

Thx 4 help
Ciao
Armando

[Processaurus]

Look at the geofex multi-vol footswitch logic with the 74c373 octal latch for an idea on how to make a logic based version of the old radio push buttons, then all you have to do is hook the logic up to some analog switches or relays.  I would lean toward analog switches because of lower power consumption and ease of use. 

You'd need something different to make it so stomping the switch that is "on" again would bypass the pedal, or you could put in a 4th switch that acts like the other three switches, but it turns the effect to bypass.  None of the switches would do anything if you hit them more than once, things only change when you hit a different button.  I actually think that setup of dedicated "effect off" switch would be very intuitive, you always know where it is without even looking.  Thinking of bypass as a positive rather than turning something off.

[Mark Hammer]

Another route is simply a rotary switch for which effect in tandem with a stompswitch for effect/bypass.

Another route is the somewhat more complicated sequential switch: http://hammer.ampage.org/files/quadsequentialswitch.pdf
Though the project is for a switch that lets you step through each of four choices with a momentary pushbutton or stompswitch, it is easily reconfigurable to 3 choices or whatever.

[arma61]

Thanks guys for answers, it's going a little bit complex for my skills, but I would like to give it a try.

Mark I like that Quad Sequential Switch, but I'll need help to figure it completely, I like because the schem is almost drawn (almost ready made, and I like thing like this!).

What I cannot understand is where is the input, so wich is the guitar's signal path, let's look at the schem as 3 parts, I understand this :

Left (IC1)            - it's the part used to send "high" signal to the 4017 to start the sequence
central (IC2)        - "high" signal goes to pin 14 that put "high" pin 3, that's "channel0"
central low part    - Leds part, in the above case D3 will lights up.
Right (IC3)           - signal goes to pin 13 that connect (shunt?) pin 1 with pin 2, so Input A with Output A

Am I close to it, or I'm completely far away from it ?, (I've studied electonic at school in middle '70s but IC were not yet in the programs! just tube and some tranny)

Where do you connect the guitar signal ? How do you connect the 3 (or more) FXs.

Pls tell me if this is going to get more complex so I'll stop it, I don't wanna be a pain in the ssa for you all.

Thx for vm help
Ciao
Armando

[Mark Hammer]

The 4066 chip is four independent SPST switches.  Each switch completes or breaks the connection between an input and output.  The 4017 is a counter chip that puts out a logical 1 (high) signal at each of 10 outputs, in order, each time it receives a pulse from opamp IC1.  The circuit shown only uses the first 4 outputs before recycling back to the beginning of the sequence.  Think of this like a synthesizer sequencer which only movwes to the next step when you tell it to.

If you wanted a "true bypass" version, you would need to send the Control A/B/C/D lines to a second 4066 chip.  All the "inputs" for one of those chips would be wired together, and all the "outputs" for the other one would also be wired together.

How would you use it, and what would happen?

With a normal mechanical stompswitch, you would have a wire coming from the input jack to the middle lug on the stompswitch and another from a second middle lug going to the output jack.  In the sequential circuit, all those "inputs" wired together are like the middle lug connected to the input jack.  All the outputs wired together are like the middle lug going to the output jack.  Where a stompswitch makes one set of connections from the jacks to a circuit board, and breaks another connection (direct from input to output), this circuit breaks the connection from input and output jacks to one circuit and makes the same connections to a different circuit.  The counter chip and the 4 "control lines" it has allows you to make the connection to only one effect at a time, while the connections to the others are broken.

The ideal arrangement (if you were to use it) would be to have one master switch for completely bypassing everything, and a second momentary switch to cycle through which of the 2 or 3 or 4 or more effects you wanted to use this time.  In practice, you would make your "which fuzz?" selection while bypassed, and then engage the effect.  The section with the 4 transistors is simply LED drivers to let you know which output has been selected.  It is not electronically necessary to the circuit, but VERY helpful for anyone using it.

Make sense now?

If a person wanted to cycle through more than the 4 possible outputs/selections, you could simply run more control lines from the same 4017 to additional 4066 chips.  Remember, however, that each 4066 only has 4 switches.  So, if you wanted to cycle between 5 circuits, you would need to have two additional 4066 chips for the extra in/out.

Other people here are more familiar with the different CMOS switching chips available.  There may be other chips that are better for doing this than the 4066, or that might allow you to switch more effects without needing as many additional chips as using a 4066 requires.

There is also the matter of whether you need a buffer for the input and output.

Finally, the circuit runs from a bipolar supply, something hard to do with a single 9v battery.  However, if you were providing power to 3 effects and the switching circuit at the same time, you would probably want to use a wallwart/adaptor.  If you use one with an AC output, you can regulate that and obtain +/-6v as the circuit calls for and the +9v you would need for the effects themselves.

[arma61]

thx Mark I'm always astoshied at your replies, full and clear,though I beg you pardon but I get lost somewere in there

The 4066 chip is four independent SPST switches.  Each switch completes or breaks the connection between an input and output.  The 4017 is a counter chip that puts out a logical 1 (high) signal at each of 10 outputs, in order, each time it receives a pulse from opamp IC1.  The circuit shown only uses the first 4 outputs before recycling back to the beginning of the sequence.  Think of this like a synthesizer sequencer which only movwes to the next step when you tell it to.

The ideal arrangement (if you were to use it) would be to have one master switch for completely bypassing everything, and a second momentary switch to cycle through which of the 2 or 3 or 4 or more effects you wanted to use this time.  In practice, you would make your "which fuzz?" selection while bypassed, and then engage the effect.  The section with the 4 transistors is simply LED drivers to let you know which output has been selected.  It is not electronically necessary to the circuit, but VERY helpful for anyone using it.

Finally, the circuit runs from a bipolar supply, something hard to do with a single 9v battery.  However, if you were providing power to 3 effects and the switching circuit at the same time, you would probably want to use a wallwart/adaptor.  If you use one with an AC output, you can regulate that and obtain +/-6v as the circuit calls for and the +9v you would need for the effects themselves.

.

I got these 3 (thanks God!!), I like the idea of a master switch.

If you wanted a "true bypass" version, you would need to send the Control A/B/C/D lines to a second 4066 chip.  All the "inputs" for one of those chips would be wired together, and all the "outputs" for the other one would also be wired together.

How would you use it, and what would happen?

With a normal mechanical stompswitch, you would have a wire coming from the input jack to the middle lug on the stompswitch and another from a second middle lug going to the output jack.  In the sequential circuit, all those "inputs" wired together are like the middle lug connected to the input jack.  All the outputs wired together are like the middle lug going to the output jack.  Where a stompswitch makes one set of connections from the jacks to a circuit board, and breaks another connection (direct from input to output), this circuit breaks the connection from input and output jacks to one circuit and makes the same connections to a different circuit.  The counter chip and the 4 "control lines" it has allows you to make the connection to only one effect at a time, while the connections to the others are broken.

Here I get lost, were the FXs' In and Out go in that schem. ? I've even tried to put on paper the connections but, nahh that's not for me! (that's why after the school I started to work in a transport company and now I work in a shipping company!!!!) 

Would it be a big trouble for you to drop down a little schem from where I can, at least, start!

Anyway I can still use 3 "good old" DPDT switches with MillBypass and go for it.

Thx a mill again
Ciao
Armando

[arma61]

So after having studied the schem proposed by Mark  (2nd page of  http://hammer.ampage.org/files/quadsequentialswitch.pdf) I re-drawn the schem in this way




trying in the mean time to understand it, it seems it's almost clear to me but still facing problem with FXs INs and OUTs, I've tried to put also them into the schem and see if it can clear a bit my mind, but still cannot understand it completely. Taking into account that FXs are connected in the right way,  how and were is the guitar signal connected to the 3 FXs. Could anybody have a look at it and correct/suggest change to the schem.

thanks vm
Ciao
Armando