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Does this exist? Tap Tempo Polarity Converter

Discussion in 'Effects, Pedals, Strings & Things' started by flatulentmatt, Nov 2, 2017.

  1. flatulentmatt

    flatulentmatt Supporting Member

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    I did a quick search on both the Google and here, and couldn't immediately find anything.

    I use a Boss MS-3 as pretty much a hub for controlling my rig. It's my intended source for all 'information', MIDI, expression, tap, etc. The problem is when it comes to controlling my time-based pedals with the MS-3.

    The MS-3 being a Boss product sends a NC (normally closed) tap signal. However, the majority of pedals (including those on my board I want to control) accept a NO tap signal. What I need is a little box (can be passive or active) that can convert the Boss NC signal to a NO signal my pedals can handle. I know things like the Disaster Area Smart Clock or Micro Clock exist; I'm hoping for something cheaper / simpler.

    I'd even be willing to DIY (I can solder) if someone can come up with a schematic! Any ideas?
     
  2. flatulentmatt

    flatulentmatt Supporting Member

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  3. jnepo1

    jnepo1 Silver Supporting Member

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    Google it and you will find one from a site: Vesselyn.com
     
  4. phil_m

    phil_m Supporting Member

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    Have you actually tried hooking up the MS-3 to your pedal(s) to try this? It might not matter. I guess it depends on how you want to actually control the tempo. It would still receive the tap information, it's just that it would receive the pulses when the MS-3 isn't closing rather than opening. If you're sending out pulses on a preset change, you probably wouldn't notice it at all. If you were sending tap tempo in real-time, it would mean that the pulses would be sent when you step on the switch rather than on it.
     
  5. awallace

    awallace Member

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    One pitfall to keep in mind- some pedals (including some of ours) have a "hold tap" function that may be inadvertently activated when using a NC setup.
     
  6. flatulentmatt

    flatulentmatt Supporting Member

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    Yeah, this is the problem - it engages the oscillation on my Rubberneck. On my Supa Puss it wasn't a problem as it would just engage / disengage the buffer.

    @jnepo - when I googled, I didn't find anything; I'm guessing it's because a circuit like this has a specific name? All I could find was one that had its own tap switch, with a second switch to change between NO and NC which isn't quite what I'm looking for.
     
  7. drive-south

    drive-south Member

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    All the Boss unlatched footswitches have a polarity switch. FS5U, FS6, FS7, etc.
     
  8. jes89

    jes89 Supporting Member

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    Tried to look for solution myself with my es-8 and strymon stuff,unless you want to try building/soldering something I recommend grabbing smart clock/quartz like I did
     
  9. soli528

    soli528 Silver Supporting Member

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    Could you just build a crossover cable?
    I could be misunderstanding the problem.
     
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  10. DisasterArea

    DisasterArea Owner, Disaster Area Designs and Alexander Pedals

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    If the Boss units can't invert the logic of those switches in software i'd be amazed. It's literally one byte of code. If you need a hardware solution, try this:

    [​IMG]
    NC switch connects to J1. Current flows from 9V battery V1 through resistor R1 into the LED inside the optocoupler OK4, lighting the LED.

    When the LED is lit, the opto-FET inside the optocoupler is activated and the path between its drains (pins 3 and 4) is essentially a short-circuit.

    Shorting out the TIP and RING of J1 will turn the LED off, which then makes the opto-FET drains an open-circuit. During normal use, the NC switch will be closed except when tapping, so that the LED will be OFF and the output at J2 will be an open circuit. When J1 is opened, J2 will close.

    While you might be able to do the same thing with a simple logic inverter or even a single transistor, the opto-FET is nice because it presents the same type of load to the pedals on either side and they never have to know anything is different than normal use.

    Current draw is pretty low, about 5mA during normal use so a 9V battery will last may hours. You could also use a power supply instead.
     
  11. flatulentmatt

    flatulentmatt Supporting Member

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    Unfortunately, the MS-3 doesn't, and that's what I'm using as my tap source, for subdivisions, etc.
    You'd think, right? As @drive-south said above, all their other switching hardware as a way to choose; but the MS-3, ES-5, and ES-8 only provide a NC out, with no option to change. It's kind of ridiculous, really.
    Dude. Thank you SO MUCH. This is exactly what I was looking for and I think will be a perfect solution for me! You are a legend!
     
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  12. Kez

    Kez Member

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    This is a really good idea to this problem! I am looking at buying the JHS Panther cub delay that has Tap out function that I believe is normally open and I wanted to send it to my Boss DD7 Tap tempo input (normally closed). Would this circuit work for that? and if so does the Optocoupler have to be a specific type? Thank you so much!
     
  13. flatulentmatt

    flatulentmatt Supporting Member

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    I would assume so.

    The component is labelled in the schematic, but I think it was a typo. It's labelled as TL222, but I think it's meant to be a TLP222, as I couldn't find anything on the interwebs for a TL222 opto-coupler.
     
  14. DisasterArea

    DisasterArea Owner, Disaster Area Designs and Alexander Pedals

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    Yes, that's correct - it's supposed to be a TLP222 which is an opto-FET.
     
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  15. flatulentmatt

    flatulentmatt Supporting Member

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    Sorry if I'm being a pain, but what if you wanted to do it with a TRS input / output (i.e. for 2 signals)? Could you use the same FET, but run a second parallel circuit of the other stuff and run both cables to / from connectors 1 & 4?
     
  16. DisasterArea

    DisasterArea Owner, Disaster Area Designs and Alexander Pedals

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    Use two optos and two resistors and you should be fine. Don't combine tap tempo connections and don't connect the grounds if the two signals need to go to two different devices. Ground loops = bad.
     
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  17. Kez

    Kez Member

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  18. DisasterArea

    DisasterArea Owner, Disaster Area Designs and Alexander Pedals

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    Nope. Won't work. Must be an opto-FET, not a transistor output like the 4N25, 4N28, 6N138, etc.

    I think it would be best if we just make these and sell them. No more worries.
     
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  19. On a Budget

    On a Budget Member

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    Is replies like this that are going to make me buy an disaster area or Alexander pedal next!
     
    Last edited: Dec 7, 2017
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  20. TheoDog

    TheoDog Silver Supporting Member

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    I agree. My rig is too small, so all I have from them are DA patch cables, but I would gladly wear a @DisasterArea logo T-shirt if I had one. Such awesome products and truly stellar service.
     
    Last edited: Dec 7, 2017
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