Audio Line selectror project

Audio Line selector project

Hi !
I want to build a audio line selector with 4 outputs controlled by 4 momentary switchs, so, i will have switch 1 to 4 that selects outputs A to D. If A output is selected and i press switch 2 ( output B ) the output A will go off and B on.
Sorry my English but i think you will understand what i´want.

My idea is to have one logical circuit to control relays or CMOS relays, and i also want to add some leds to know which output is selected or, a pretty way to do also is to add one display.

I need some tips that can lead me to the right direction.

Thanks.

You can buy AV switchs like this in almost any electronics store, why build one?

Thanks for you reply but i need just to control audio only, it´s for musical instrument use and i must be true bypass if possible.
I´m thinking in using 4 footswiches in a metal enclosure to place it in one pedal board.
Adding leds and displays is simple, i just need to use DPDt relays to control them, one part of the relay will control the audio and the other the leds or the display. My only problem is the circuit that will turn on/off the relays but only one of each time according to the switch selection.

Use a rotary switch so you can control more than outputs you require.

Gayan Soyza said:

Use a rotary switch so you can control more than outputs you require.

Click to expand...

And can you tell me how do i do that with my feet when i´m playing guitar ?

Samycasanova said:

And can you tell me how do i do that with my feet when i´m playing guitar ?

Click to expand...

Very carefully!

Nigel Goodwin said:

Very carefully!

Click to expand...

Usualy i play with my shoes on ! lol

I´m thinking using logical circuits to control, so, here´s what i thought !
Logical table:
Switch A : 00
Switch B : 01
Switch C : 10
Switch D : 11

So, one example, when i press the switch A ( 00 ) i will get 1 on relay A and 0 on all others, when i press C ( 10 ) i will get 1 on relay C and 0 on all the others.
So, this is theory and it looks like simple but the problem is that i don´t work with this for a very long time and i forgot almost everything.
The hard parts are:
- I will use momentary switches, so, i will press just for one moment the switch A, B, C or D and the relay must be always on until i press another switch.

Hi Samy,

Don't make it too difficult, use four SR-FF's. Each FF has one single
set input and three reset inputs. Connect the set input of one FF to
the reset inputs of the three others and add a pushbutton and some
other stuff. You gonna need four 2 input NAND gates and also four
4 input NAND gates, one CD4011 and two CD4012 packages.
Note that one set input has a different resistor.
You gonna need the datasheets too:

https://www.alldatasheet.com/datasheet-pdf/pdf/26846/TI/CD4011.html

https://www.alldatasheet.com/datasheet-pdf/pdf/26847/TI/CD4012.html

on1aag.

After a very useful tip from a user, i have decided to use the CD4013 IC.
This it´s what i have so far:
**broken link removed**
The circuit was successfully tested with leds and two outputs only, no relays were used now because i don´t have 9V relays.
I have tested it without the B to E resistors on the transistors, i have placed them in the drawing because they are used for stability reasons, i never had a problem without them so far.
The "hot spot" it´s the C1, i have used one 1nF it wasn´t stable, sometimes the results were quite weird, changed to 22nF and works fine but i can´t explain why ! Someone can help on this ?

I want to know what the experts have to say about this circuit, if there is something to improve it or correct it, i will be glad to hear about it.

Thanks.

This circuit is working ok, so, let´s move forward and make things a bit more difficult !

I pretend the same thing BUT, i want to find a way to store some presets to combine several different combinations !
What i have here are 4 switches for four "Audio Out", i pretend them to work like the circuit above and then when i push the "preset" switch ON and them pushing the 1 to 4 i will recall the presets. After turning the "preset" Off, it will go to normal.
To record the presets, that can be made in a simple way.

Any tip on this ?

Thanks.