4 man enter, 1 man leave - ABCD switch box

[garcho]

So, I recently had a gig in which I needed 4 instruments to be plugged in to my amp (long story). I also needed serial switching with the option to override and turn on more than one channel at a time (another long story). A small mixing board was not possible (you guessed it, long story). So, with very little time available, this is what I came up with (the third pic shows the manual override switches thrown on):



4x4 - ABCD switching:   [click on pic for bigger image]

schemo:

EDIT: One small thing - the LEDs are incorrectly shown as being connected to the upward-pointing arrow, indicating the positive voltage via the 1N4001 and 100R/100u filter. They are actually connected directly to the wall wart jack (not the 100R resistor). They should be shown connected to the '+V' with a box around it.
ANOTHER EDIT: The pots can be whatever values you'd like, 10k pots would mean full turn is theoretically 10% above unity.

The trace/layout is real crappy, I had to bang it out as fast as possible, so there are jumpers, vertical resistors, etc. At least it's verified!

trace PDF for etch in case you're in a hurry, too.

layout:


I just wanted to present this to y'all in case it helps out somebody in a similar spot, or if some of y'all have ideas for improvements (plenty, I'm sure). Feel free to respond with links to projects that do the same thing but better!

[pappasmurfsharem]

Please tell the long story! I'm interested.

Also I kind of like the board layout. has an old school feel to it.

[garcho]

...I kind of like the board layout. has an old school feel to it.

Ha! Thanks P Smurf. It is kinda old school. I probably should have just drawn it by hand     It's basically a custom breadboard. I don't really hate on vertical resistors, they're as tall as electrolytics and you shouldn't be bangin' your PCB so hard that they get knocked over in the first place! I know, I know, they do... One of these days I'll finally take the SMT plunge, at least for resistors and caps.

The long story, made short:

I had a gig with a modern ballet company. I needed to be on stage with only one amp and no board or sound reinforcement, no percussion table, etc., because of the cramped quarters. Four of us were playing twenty-odd instruments in a 20' by 6' space and we had to be 'part of the show'.   Man, I've been spoiled over the years, it was tough to do everything onstage silently and 'in character', under the watchful eyes of the audience (and the choreographer writing my checks!). One small, wrong move and bam! knock over a bell tree or a violin... I was playing a mandolin, guitar, cümbüş (12-string fretless banjo from Turkey), electronic toys and noise makers, darbuka (common Middle Eastern/Balkan goblet drum with many names), bells and claves and a shop vac hose, ha! You know, for that ghostly harmonic series thing. The music was very post modern, all over the place - in a good way!  

[Kipper4]

Someones been a busy boy.
Cool stuff man.Thanks for sharing.

[disabled_shredder]

Hey what kind of amp were you using? Would this work or mod to work w a dual rec that has the 1/4in channel sw outs? I would love to get rid of my midi foot switch and build a unit that can control 3 channels boost fx and then take 10 or so fx boxs and be able to use dip switches to run them in different configurations up to say 8.does that make since? I know this one is for only amp but if you had thoughts on what I would like I would love the collaboration in designing something that would work. I run most of the time 2 or 3 of the same pedal so I don't have to change settings.

[garcho]

Thanks for the kind words Rich

Hey what kind of amp were you using?

My jobber, the most sold tube amp of all time, Fender Hot Rod Deluxe, no Mesa/Boogie frosting here! Might seem weird to play stuff through it that doesn't originate from magnetic pickups and metal strings, but it worked fairly well. Less than optimum, for sure, but good enough for ballet.  

I was running all signal through the box to input; not using any looping, because I wasn't using any effects (outside of a buffer/eq and a tuner everything was routed through). The goal was to cut down on stage spaghetti.

I would love to get rid of my midi foot switch

Why?

Would this work or mod to work w a dual rec that has the 1/4in channel sw outs?

I'm not sure what you mean, sorry. Do you mean CMOS switching in general? Depending on what signal those send out, CMOS switching can certainly be modded into doing anything you want, however it wasn't designed with audio in mind. RG's website and Andrew (Tone God) have valuable information regarding this kind of thing I probably should have read before doing this, but I was short on time.

If you have more specific questions, I might be able to help, but I'm a newbie and you probably want to look elsewhere for advice.  

[ACElectronics]

Nice job!

I was looking for something similar for my pedalboard setup, but I would really like to have a separate switch for each input.
In that case I would have to have four switched instead of one, and every switch would have to have the function of turning ON one input and turning OFF the rest of them.
Since you seem really good at this C-MOS switching thing I thought I'd ask you for some pointers. Is it possible to do this in a fairly simple way with CMOS and schmitt triggers?

I haven't worked with this kind of switching before, but I'm trying to learn. ANY tips or trix will surely help!

Thanks!

[duck_arse]

hey, ACE, do you still need/want the sequence switching aspect, or just the one on/others off?

[ggedamed]

Nice job!

I was looking for something similar for my pedalboard setup, but I would really like to have a separate switch for each input.
In that case I would have to have four switched instead of one, and every switch would have to have the function of turning ON one input and turning OFF the rest of them.
Since you seem really good at this C-MOS switching thing I thought I'd ask you for some pointers. Is it possible to do this in a fairly simple way with CMOS and schmitt triggers?

I haven't worked with this kind of switching before, but I'm trying to learn. ANY tips or trix will surely help!

Thanks!

Maybe this project on the other forum (cannot use the F word here ) can give you some ideas. I made it 1 of 3 because of PCB real estate, but the command part provides 4 channels per CD4042.

[duck_arse]

garcho - the u5 being a 4017 should not have any of its outputs tied to ground. (I realise your box is complete and working, but ....) and those 5 spare inverters could drive your status leds, saving a 4066.

just saying, as a great man once said.

[garcho]

^ thanks, was unsure about those pins. I can't figure out how the spare inverters could be used though, can you explain? I was thinking of trying to find a bounce-free switch without an inverter and dropping the 40106.

[garcho]

"...I would have to have four switched instead of one, and every switch would have to have the function of turning ON one input and turning OFF the rest of them."
You can trigger the 4066 with footswitch for each channel. That same trigger can be inverted to turn the others off. Something like that anyway    There are some great articles floating around the web that can introduce the CMOS basics if it's alien to you. Check GEO, AMZ, tonegod has something on the 4066, i think.
I made this pedal as simple for my foot as possible, hence the switch cycle.

[duck_arse]

garcho, I have this very minute posted a new thread for abcd - pick one or sequence. it may be of interest or help to someone.

http://www.diystompboxes.com/smfforum/index.php?topic=106502.msg963863;topicseen#msg963863

if you take one of your pesky leds, and tie the clr to V+ and the led A, then tie the led K to the inverter OUTPUT, when the inverter IN (connected to yr counter outputs) goes HIGH, the out goes LOW and the inverter sinks the led current. so it works "like a" buffer, instead of an inverter.