SPST Footswitch Guidance

finebyfine

finebyfine

Well-known member
I’m finally starting to get the appeal of relay switching, however long I am into this hobby. But I don’t really have a good grasp on what SPST footswitches are available out there in the same way that I have a preference for 3PDT switches that I could opine on for far too long if someone was unfortunate enough to get me started.

What switches do you like using for relays? Does it have an audible click, how’s the amount of force required?

Let’s pretend momentary 3PDTs don’t exist for the time being as well.
 
Ya know...speaking of the appeal...

What is the appeal here?

It seems like it's adding an extra mechanical device to a build...increasing the build complexity and footprint while creating an additional point for failure.

Granted, these are low current/low voltage devices and contact failure from inrush/arcing isn't a factor...that's the main failure mode for relays in my industry...

Latching relays are expensive, non latching relays introduce an inductive load INSIDE the guitar pedal enclosure...which has the potential to introduce noise.

Although I certainly get intelligent latching relay switching...having the ability to switch latching on/off and momentary on/off modes would be a boon to creative use of certain effects. I am curious though, what are the other potential upsides?
 
Stickman393 said:
Ya know...speaking of the appeal...

What is the appeal here?

It seems like it's adding an extra mechanical device to a build...increasing the build complexity and footprint while creating an additional point for failure.

Granted, these are low current/low voltage devices and contact failure from inrush/arcing isn't a factor...that's the main failure mode for relays in my industry...

Latching relays are expensive, non latching relays introduce an inductive load INSIDE the guitar pedal enclosure...which has the potential to introduce noise.

Although I certainly get intelligent latching relay switching...having the ability to switch latching on/off and momentary on/off modes would be a boon to creative use of certain effects. I am curious though, what are the other potential upsides?
Click to expand...
According to the data sheets I’ve found, a typical latching relay for this sort of application is rated for a minimum of around 10^8 cycles.

A typical SPST momentary footswitch is rated for 50,000 mechanical cycles, and if it breaks, it’s just two solder points to undo when replacing it. It also has a ‘silky smooth’ feel to actuate.

A typical 3PDT latching footswitch is rated for only 10,000 mechanical cycles, and that goes down significantly if exposed to too much heat when soldering (which is actually pretty common)— not to mention the fact that they have a fairy high random-failure rate. They also often have a clunky ‘thunk’ when you actuate them unless you buy an expensive premium footswitch. When it eventually breaks, it’s 9 solder points to undo when replacing it.
 
In addition to the use cycles although related is that I would guess that the production tolerances of a DIP10 epoxy cased relay are much tighter than the tolerances on a standard footswitch. I've opened up busted pedals to repair only to find the internal levers on a 3PDT completely misaligned on more than a couple of occasions. Something similar can happen on an SPST of course but there's 1/3 less moving parts to go wrong.

For me with relay switching (aside from multifunction/intelligent) my brain starts getting excited about funky ways to activate the circuit in terms of the mechanical design of it (I'd be surprised if I'm the only one on the forum who has built their own mechanical keyboard which is where my mind goes) Who knows if any are practical or if I'll ever even do them, but that is exactly why Boss uses them and was able to make such an iconic looking pedal base.

Plus, and maybe most importantly, the coolest footswitch actuator is, as far as I know, only on SPSTs: the rounded top joint

 
All fair points. The Taiways I source from LMS are 5 bucks a pop, 50k cycles, not too clunky.

A demont is 3x the cost, but 4x the lifespan. Can't argue with 10^8 cycles though. @4 bucks a pop for a panasonic latching relay....yeah, I can see it.

Especially given the low current requirements in switching guitar signals and LEDs...the Panasonics are rated for 10^5 cycles at 2A 30V, double that at 1A.

Yup. OK. You have my attention. That makes a lot more sense, in terms of reliability and longevity, to go the relay route over the super high end switch route. Creature comforts too...that click less actuation could be a plus, though I kinda like having that feedback in certain cases.

It certainly doesn't make for a great compact build choice, though...that's the trade off I suppose. No complicated modulation circuits with one of these unless it's in a larger enclosure.

For a "production/boutique" pedal, I definitely see the advantages. Reduced failure rate is a big deal if running a business. For a guy like me that's building lots of pedals for personal use at once and making big mouser orders...that extra cost in parts is a little difficult to swallow.

But certainly something I'm going to start giving more consideration to moving forward. I appreciate the input!
 
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The soft-touch silent-type switching is great for theatre gigs or similar, not so important for pub performances.
 
Stickman393 said:
All fair points. The Taiways I source from LMS are 5 bucks a pop, 50k cycles, not too clunky.

A demont is 3x the cost, but 4x the lifespan. Can't argue with 10^8 cycles though. @4 bucks a pop for a panasonic latching relay....yeah, I can see it.

Especially given the low current requirements in switching guitar signals and LEDs...the Panasonics are rated for 10^5 cycles at 2A 30V, double that at 1A.

Yup. OK. You have my attention. That makes a lot more sense, in terms of reliability and longevity, to go the relay route over the super high end switch route. Creature comforts too...that click less actuation could be a plus, though I kinda like having that feedback in certain cases.

It certainly doesn't make for a great compact build choice, though...that's the trade off I suppose. No complicated modulation circuits with one of these unless it's in a larger enclosure.

For a "production/boutique" pedal, I definitely see the advantages. Reduced failure rate is a big deal if running a business. For a guy like me that's building lots of pedals for personal use at once and making big mouser orders...that extra cost in parts is a little difficult to swallow.

But certainly something I'm going to start giving more consideration to moving forward. I appreciate the input!
Click to expand...

Of course! All of your questions were ones that - if I had been smart enough to come up with them too (lol) - made me reluctant to try them. And I'm by no means gonna use them all the time, because like you said that price gap between a 3pdt and an spst + relay is an annoyingly big one in the total cost of a pedal's components. I also like the actuation click of regular 3pdts which was part of the inspiration for starting this thread - I was hoping there was a commonly available one that had more of a click than the ones I've tried.
 
Stickman393 said:
It certainly doesn't make for a great compact build choice, though...that's the trade off I suppose. No complicated modulation circuits with one of these unless it's in a larger enclosure.
Click to expand...
There are compact relay options out there:
shop.mas-effects.com

DIY relay true bypass: Soft touch foot switch upgrade for Guitar Pedals

This is a true-bypass relay bypass kit for your DIY pedals. This is specifically to engage/bypass an effect. For general-purpose switching, see our other digital relay module instead. This bypass board has loads of features: Soft touch SPST foot switches are easier to use, less expensive, and...
shop.mas-effects.com shop.mas-effects.com
 
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