Switchy Thing

[moosapotamus]

Thought I would share this little switching idea for having both a latching and a momentary stomp switch on a pedal. The latching switch would engage/bypass the effect (as expected). Whatever state the effect is given by the latching switch, the momentary switch reverses it. When bypassed, tap the momentary to briefly engage the effect. Or, with the effect engaged, tap the momentary to briefly bypass the effect.



I think this would be fun on a ring modulator or over-the-top fuzz to punch in short phrases, or to accentuate a delay with some non-repeating notes/phrases.

Question... It seems like this could this be done more simply, say, with just the two stomp switches (one latching and the other momentary, 3PDT maybe?) and no relay. But, for the life of me, I can't figure out how. Anyone have any ideas, or thoughts in general?

[theehman]

 I did this a few years ago with a passive effects loop I called the Loop Garou.  You could engage the loop with a regular footswitch or use the momentary for short use.  I never listed it on my site although I probably should have since it was a pretty handy thing to have, especially for bass.

[Mark Hammer]

Holy crap!  Charlie, Ron, long time no see!  How the hell you been? 

[theehman]

Holy crap!  Charlie, Ron, long time no see!  How the hell you been? 

Doing good, Mark.  Been having some health issues over the last year but hopefully nearing the end of the latest.

[Mark Hammer]

Well as much as my initial response to your post was "Then I hope the end is near", that was not going to quite come out sounding as well-intentioned as I wanted.   

So...I hope whatever those troubles are, they will be behind you soon.  Thumbs up.

[blackieNYC]

I built a momentary (or latching) insert looper based on Boss fet switching. I found it to be the softest and quietest switch.   I love it.  Momentary action really opens some doors.

[GGBB]

Question... It seems like this could this be done more simply, say, with just the two stomp switches (one latching and the other momentary, 3PDT maybe?) and no relay. But, for the life of me, I can't figure out how. Anyone have any ideas, or thoughts in general?

The switching can be done with two 3PDTs:



But no effect input grounding or status LED. 4PDT might get you that - not sure.

[moosapotamus]

I did this a few years ago with a passive effects loop I called the Loop Garou.  You could engage the loop with a regular footswitch or use the momentary for short use.  I never listed it on my site although I probably should have since it was a pretty handy thing to have, especially for bass.

Sounds cool. Did the momentary switch do anything when the loop was engaged? The momentary switch in the Switchy Thing does the opposite of however the latching switch is set.

[moosapotamus]

Holy crap!  Charlie, Ron, long time no see!  How the hell you been? 

Hi Mark! I had another life as a high school math teacher for the past six years. Really interfered with my personal interests (LOL!). Time to get back to some DIY, now!

[moosapotamus]

Question... It seems like this could this be done more simply, say, with just the two stomp switches (one latching and the other momentary, 3PDT maybe?) and no relay. But, for the life of me, I can't figure out how. Anyone have any ideas, or thoughts in general?

The switching can be done with two 3PDTs:



But no effect input grounding or status LED. 4PDT might get you that - not sure.

Brilliant! I knew that must be possible with just two switches, but I was stumped! Thank you!

[theehman]

I did this a few years ago with a passive effects loop I called the Loop Garou.  You could engage the loop with a regular footswitch or use the momentary for short use.  I never listed it on my site although I probably should have since it was a pretty handy thing to have, especially for bass.

Sounds cool. Did the momentary switch do anything when the loop was engaged? The momentary switch in the Switchy Thing does the opposite of however the latching switch is set.

No, it didn't do anything if the standard switch was engaged.

[RickL]

Check this thread out. https://www.diystompboxes.com/smfforum/index.php?topic=120969.msg1135205#msg1135205  Two switches, the momentary gives you the opposite of what the standard switch gives you.

[amptramp]

The momentary switch means you don't have to build a burst box.  This is technology at its finest.  And no giant copper loop to add in.

[GGBB]

Check this thread out. https://www.diystompboxes.com/smfforum/index.php?topic=120969.msg1135205#msg1135205  Two switches, the momentary gives you the opposite of what the standard switch gives you.

I completely forgot about that - and it was less than two years ago.

Building on that - with a 3PDT momentary switch you can also ground the effect input/send when in bypass:



Obviously you give up the status LED on the 4PDT, but you might be able to use a millennium-bypass type of setup tied to the effect send for that.

[kraal]

Check this thread out. https://www.diystompboxes.com/smfforum/index.php?topic=120969.msg1135205#msg1135205  Two switches, the momentary gives you the opposite of what the standard switch gives you.

Obviously you give up the status LED on the 4PDT, but you might be able to use a millennium-bypass type of setup tied to the effect send for that.

Hi,

Why not using a  XOR gate to have the LED "ON" only when only one of the latching / the momentary switch is engaged / pressed ?
Would something like this work ?


Edit: replaced original text and diagram which contained an error (thank you GGBB)
Here is the fixed schematics:


Note: The question about the XOR gate is still open.

Cheers.

[GGBB]

Why not using a  XOR gate to have the LED "ON" only when only one of the latching / the momentary switch is engaged / pressed ?
Would something like this work ?

I could be mistaken, but if momentary is up/released and latching is down/engaged, it looks like the signal path is:

PEDAL_IN -> PEDAL_IN_MOM_RELEASED -> FX_IN -> COMMON -> PEDAL_OUT
as well as the signal from FX_OUT

If I'm reading that right then - no - that won't work.

[kraal]

I could be mistaken, but if momentary is up/released and latching is down/engaged, it looks like the signal path is:

PEDAL_IN -> PEDAL_IN_MOM_RELEASED -> FX_IN -> COMMON -> PEDAL_OUT
as well as the signal from FX_OUT

If I'm reading that right then - no - that won't work.

Hi,

I think that you're missreading it.

Edit: You were right, thank you. I fixed the diagram. Here is the fixed version:



Signal to FX_OUT can only come through two mutually excluding paths A & B:

• (A) PEDAL_IN_MOM_RELEASED -> SW LATCHING ENGAGED -> FX_IN -> FX_OUT
• (B) PEDAL_IN_MOM_PRESSED -> FX_IN -> FX_OUT

Likewise, signal to COMMON (should have called it BYPASS) can only come through two also mutually excluding paths C & D:

• (C) PEDAL_IN_MOM_RELEASED + SW LATCHING OFF -> COMMON
• (D) PEDAL_IN_MOM_PRESSED + SW LATCHING ENGAGED -> COMMON

Paths (A) & (C) cannot be followed simultaneously (LATCHING cannot be ENGAGED and OFF at the same time).
Same for Paths (A) & (D) + (B) & (C) (MOMENTARY cannot be PRESSED and RELEASED simultaneously)
Remains Path (B) & (D) with SW MOMENTARY in PRESSED state. In this situation at SW MOM B, there could be a collision between FX_OUT_LATCH_OFF and COMMON, however (C) and (D) show that no signal will come from COMMON as MOMENTARY is pressed, which excludes (C), and (D) implies using the FX_OUT_LATCH_ON path which is a dead end for the signal (also as MOMENTARY is pressed).

This all occurs here:



Here is the full list of possible paths:

LATCHING(OFF) & MOM(RELEASED)

Signal Path1: PEDAL_IN -> PEDAL_IN_MOM_RELEASED -> FX_IN -> FX_OUT -> FX_OUT_LATCH_OFF -> no connect  @ SW MOMENTARY B (dead end)
Signal Path2: PEDAL_IN -> PEDAL_IN_MOM_RELEASED -> COMMON -> PEDAL_OUT   (no signal from FX_OUT_LATCH_OFF)
Power Path(MOMENTARY): GND -> V+_MOM
Power Path(LATCHING): GND -> V+_LATCH
XOR(V+_MOM,V+_LATCH) = XOR(GND,GND) = 0 -> LED OFF

LATCHING(ENGAGED) & MOM(RELEASED)

Signal Path1: PEDAL_IN -> PEDAL_IN_MOM_RELEASED -> no connect @ SW LATCHING A (dead end) 
Signal Path2: PEDAL_IN -> PEDAL_IN_MOM_RELEASED -> FX_IN -> FX_OUT -> FX_OUT_LATCH_ON -> PEDAL_OUT  (no signal from COMMON, FX_OUT_LATCH_OFF)
Power Path(MOMENTARY): GND -> V+_MOM
Power Path(LATCHING): VCC -> V+_LATCH
XOR(V+_MOM,V+_LATCH) = XOR(GND,VCC) = 1 -> LED ON

LATCHING(ENGAGED) & MOM(PRESSED)

Signal Path1: PEDAL_IN -> PEDAL_IN_MOM_PRESSED -> FX_IN -> FX_OUT -> FX_OUT_LATCH_ON -> no connect @ SW MOMENTARY B (dead end) 
Signal Path2: PEDAL_IN -> PEDAL_IN_MOM_PRESSED -> COMMON -> PEDAL_OUT  (no signal from FX_OUT_LATCH_OFF, FX_OUT_LATCH_ON)
Power Path(MOMENTARY): VCC -> V+_MOM
Power Path(LATCHING): VCC -> V+_LATCH
XOR(V+_MOM,V+_LATCH) = XOR(VCC,VCC) = 0 -> LED OFF

LATCHING(OFF) & MOM(PRESSED)

Signal Path1: PEDAL_IN -> PEDAL_IN_MOM_PRESSED -> no connect @ SW LATCHING A (dead end)
Signal Path2: PEDAL_IN -> PEDAL_IN_MOM_PRESSED -> FX_IN -> FX_OUT -> FX_OUT_LATCH_OFF -> PEDAL_OUT (no signal from COMMON, NO SIGNAL FROM FX_OUT_LATCH_ON) 
Power Path(MOMENTARY): VCC -> V+_MOM
Power Path(LATCHING): GND -> V+_LATCH
XOR(V+_MOM,V+_LATCH) = XOR(VCC, GNS) = 0 -> LED ON

In other words, if I'm understanding correctly XOR gates (and this is my only doubt as I never used such ICs), it should work fine and turn on/off the LED when required.

Kind regards,

[moosapotamus]

Check this thread out. https://www.diystompboxes.com/smfforum/index.php?topic=120969.msg1135205#msg1135205  Two switches, the momentary gives you the opposite of what the standard switch gives you.

Thanks, Rick! I didn't realize this had come up before.
I love seeing the different ways of doing something that folks come up with.

[GGBB]

I think that you're missreading it.

I understand what you intend to do, but here's how I read what you've drawn - follow the yellow and green trail:




It looks very clear - is your drawing in error?

[kraal]

I understand what you intend to do, but here's how I read what you've drawn - follow the yellow and green trail:



It looks very clear - is your drawing in error?

Indeed it is in error, thank you for pointing it out.

Here is an updated version (I hope it is correct this time):



And the corresponding layout to make it more readable: