This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Wednesday, June 8, 2016

555 Relay Bypass

I know there are a bunch of you out there who like your 555 timers, so this one's for you guys. This relay bypass uses a 555 as a bistable flip-flop combined with a simple relay trigger designed by MicTester. His original design uses a latching footswitch, but with the addition of the 555, a momentary switch can be used for a soft touch bypass. MicTester says that the relay must be a Takimisawa AL5WN-K, but they are easily found on eBay and other vendors. Schematic and further discussion can be found here.

17 comments:

  1. Just a question, the "reversed" layout side should be the "copper side" of the vero and the layout with the components already on it should be the back of the vero, I'm right?
    Thanks for this amazing site.

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    1. Yes, the reversed side is how it should look if you flip the board over. And FYI, vero and perf aren't the same thing. Vero is stripboard, and perf is also known as pad per hole. Good luck with your build!

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    2. oh, I can believe that only one person is doin all this things, u may be the coolest person on Internet. have a great day and thanks!

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  2. not working :(
    Will try again on proto this time.

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  3. Problem solved, i guess the first pcb wasn't perfectly etched. Did it on proto and works great so you csn mark this one as verified. Thanks for the amazing job!

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    1. Found another little thing, when you unplug the 9v power supply the relay doesnt turn off but the led does, so when you power it again the effect remains on but led indicator off, until you press the switch again. If you remove just the 9v positive wire or the ground wire coming from the power supply (on protoboard) the relay does turn off as well as the led. I guess is just a design problem.

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  4. do you have the schematic. thanks

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  5. what is the difference between the following?
    -(sw1 and sw2)
    -(input jack and FX input)
    -(output jack and FX ouput)


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  6. Should Input Jack and FX Input be swapped? Also I am having the issue where it seems the LED is on during bypass and the it turns off when I engage the effect. Any thoughts?

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  7. I want to control two relays at the same time. Can another relay be connected in series at 1 pin

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    Replies
    1. Increase the capacitor to 220µ, and wire the relay coils in parallel/

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  8. Shouldn't the relay have 8 pins not 10?

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    Replies
    1. It has eight pins, but there's a gap between the coil terminals and the first pair of switch contacts, so the numbering reflects this.

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  9. The 555 needs to be replaced with the CMOS version - the 7555 - to keep the current consumption right down.

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  10. how specific is this relay? i found A5W-K and ALD5W-K, are they all different?

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