First Build. 2 mutes with a tuner out

[dnosewor]

So, I'm attempting my first build.  I wanted to try something that I thought was relatively easy and something that I would actually use.  I play mandolin and banjo in a band.  I switch back and forth quite often.  In my current setup I have each instrument running into their own DI and I rely on the sound guy to mute me.  And I use headstock tuners which are a pain.  I'd like to build a pedal which has 2 inputs for my instruments, 2 outputs to my DI's and 1 Tuner out for my pedal tuner.   My plan would be for my pedal tuner to be on at all times.  When I hit the tune switch on my new DIY pedal, I'd like to have the ability to silently tune which ever instrument is currently not muted.  Does this make sense?

I've done some reading and searches but I can't seem to find exactly what I'm looking for.

Here's a pic which shows what I have pictured in my head.



Here's a sketch I did where I attempted to connect of the parts but I'm lost.



Here's a blank picture with just the components shown.  I'm hoping some of you experienced builders might be able to quickly rough in some lines for me.  



Thanks in advance for any help you can give me.

[mth5044]

I drew something you could try.



Rather than have two switches to choose an input, which I don't think makes sense unless there is some time when you want neither input selected, I condensed it down to one selector switch. The way it's set up, when one input is selected, the other input is grounded (off). The signal then goes to the tuner switch. The selected signal is either routed to it's respective output or it's sent to the tuner. Both switches have an LED indicator (or two). The highlighted parts around ground and need to be tied together.

Follow the signal in all four scenarios to make sure it makes sense to you.

[GGBB]

I like Matt's idea, but I worry that leaving the outputs ungrounded when they are muted/bypassed could be noisy.  With a 4PDT you can take care of this with a couple of changes.  This gives you A/B selection with the unselected input going to the tuner.  The tuner out is always active (there will always be one muted input).  The second footswitch is a DPDT that is just a master mute - and you can leave this one out entirely if you don''t need a master mute.




Otherwise, if you don't want to use a 4PDT, or you want independent input selection, here's the original three-switch idea.  Each input has it's own mute and there's an optional master mute.  Tuner input is always connected to the muted input, which could be both or neither.  Note that all sleeves are connected to ground, and you need to add current limiting resistors for the LEDs.

[mth5044]

Nice design GGBB, I would go with that TBH. However one problem is that when you switch over to tune, you'd have the output of the second instrument coming through (if the master mute wasn't engage). That could give problems if you are tuning mid song where the alternate instrument is vibrating or something and passing on whatever noise it's pickups are making.

[GGBB]

Nice design GGBB, I would go with that TBH. However one problem is that when you switch over to tune, you'd have the output of the second instrument coming through (if the master mute wasn't engage). That could give problems if you are tuning mid song where the alternate instrument is vibrating or something and passing on whatever noise it's pickups are making.

Yes - that is a drawback of independent mutes.  On the upside, it has the added benefit of allowing both instruments to be used at the same time.  But definitely don't try tuning them at the same time.

[dnosewor]

Wow guys, thanks for all the quick replys. 

The reason I was thinking of having separate mutes for each instrument instead of just a selector between the two is because there will be times I'll want both intruments muted at the same time.  Could be while i'm switching over or during an a cappella song.  I think I'm going to attempt one of the ones you've posted GGBB.  Both seem like they'll do what I want. 

GGBB, in the first one you've drawn, the 4PDT is the selector switch and when I want to tune, I hit the master mute switch?   So in my live situation, I hit the master mute, grab my instrument, select instrument A or B, a quick tune if I have to, then hit my master mute and I'm playing?  Sorry for all the questions, just trying to make sure before I start that this is going to work like I wanted it to. 

Thanks again for all your help.  I'll let you know how it works out. 

Dean

[electrosonic]

The logic of a schematic is easier for me to follow.

How about this?




LED indicators not shown, use a 3PDT for SW1 to add LEDS, use DPDT for SW2 to add LEDs to tuner selector.

Tuner selection is independent of DI selection.

Andrew.

[GGBB]

GGBB, in the first one you've drawn, the 4PDT is the selector switch and when I want to tune, I hit the master mute switch?   So in my live situation, I hit the master mute, grab my instrument, select instrument A or B, a quick tune if I have to, then hit my master mute and I'm playing?  Sorry for all the questions, just trying to make sure before I start that this is going to work like I wanted it to. 

You don't need to hit master mute to tune - whichever input is muted is always sent to the tuner regardless of whether or not master mute in on.  Same thing for the second one - any muted input is sent to the tuner.  So if you are switching inputs and tuning, first hit master mute, then tune, the switch inputs, then unmute.  The only difference between the two is the way you switch inputs - the first one is a single toggle/one press, the second is separate toggles/two presses.  Master mute works the same both ways, but in the second, you technically don't need it because each input has its own mute.  However, as Matt pointed out, tuning when both are muted could be an issue since they are both going to the tuner.

If you wanted to, you could change the master mute to a 3PDT and use the third pole to switch the tuner output (yellow wires) so that it is only on when master mute is on.  But that would mean you can't use one instrument while tuning the other, which is probably fine if its just you, and I don't see this as having any real benefit.

[GGBB]

The logic of a schematic is easier for me to follow.

How about this?




LED indicators not shown, use a 3PDT for SW1 to add LEDS, use DPDT for SW2 to add LEDs to tuner selector.

Tuner selection is independent of DI selection.

Andrew.

Yet another way to do it - also nice.  A switch to select instrument, a switch to select what you are tuning, and you could add a DPDT for a master mute as well.

Also, in all three cases, if you want to be clever, you can run the LED ground lug of the input selector switch(es) to the LED connection on the master mute switch and do away with the master LED.  You will know that it is muted when neither input LED is lighted.

[dnosewor]

So, my parts finally showed up.  I decided to go with my initial thoughts that GGBB was kind enough to draw up for me.  What I am unclear on now is how the grounds get connected.    Would someone be able to quickly enlighten me?   Thanks again for all the help

Dean

[GGBB]

All of your input and output jack sleeves need to connect to ground.  If you are using metal bodied jacks and a metal enclosure, the enclosure takes care of connecting all of them together, so you don't have to solder ground wires for them (except one - details later*).  If you are using a plastic enclosure or plastic bodied jacks so that there is no electrical connection between the jack and the enclosure just from mounting the jacks, then each sleeve needs a wire from it to the next.  Do not create a loop.  Star grounding is recommended where all ground points connect back to one common point, but that's a lot of wires at one point.  You'll probably be fine with a series setup - start by connecting out1 sleeve to out2 sleeve, out2 sleeve to tuner sleeve, tuner sleeve to in2 sleeve, then in2 sleeve to in1 sleeve.

*In either case, in1 sleeve needs to connect to the DC jack ground lug.

The switch grounds as drawn also need to connect the same way, 1 to 2 to 3 to DC jack ground.

Finally the battery ground needs to go to one of the inputs' ring - preferably the main input.  This switches off the battery when nothing is plugged in to the jack.  You could connect the other input ring as well so that either input will enable battery power - this is technically a ground loop which could introduce hum but it's unlikely that you'll have any problem.

Keep your wires as short as possible without making them taught and try to run them neatly.

[dnosewor]

That's perfect.  I have a metal enclosure, so that makes things a little simpler for me.   

Thanks again.

[GGBB]

And don't forget to add the LED resistors.