Tuesday, 24 July 2012

Systech Harmonic Energizer

Not a lot of info on this old pedal, but it was a request so I'll let Vince tell you about it! :o)

I've omitted the reverse polarity protection part of the circuit to keep it more 1590B friendly, but if you do want to add some protection just put a 1N5817 or 1N4001 in series with the 9V supply.  The effect includes a buffered bypass and so only a SPDT latching stomp is required, or a DPDT if you want LED indication.






28 comments:

  1. This will be my first thing to do when i wake up tomorrow. I'll just prepare the board before bed... :)
    +m

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  2. Cheers mate! ;o) oh man they're C50k's I thought they were A50k ... damn, will have to order some. I'll use a DPDT stomp, would all the lug numbers remain the same? and which lug would I feed the LED to?

    Cheers.

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    1. I did the Sabro one with A50k and that works well so that could be an option...

      Regarding the info, all I know is that Frank Zappa used one to get his fixed wah tones.

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    2. Mate I must have been on autopilot, they're are log, not reverse log. I'll update.

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  3. Oh and ground lug 5, LED to lug 4

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  4. Hey IvIark - it seems all of the layout png files are gone (no longer displaying, and not there when you click on them) - from everywhere.. I've used a couple of different browsers so I can confirm it isn't that. Hopefully it is something simple to fix?

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    1. I'm getting them all from here. Can't you see this?

      http://2.bp.blogspot.com/-6955XYE-pjg/UA8rotuprAI/AAAAAAAAB7U/zYe905zQnAs/s1600/Systech+Harmonic+Energizer.png

      Your ISP could be having a bad day or something :o)

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  5. scratch that - my work has filtered the images as 'malicious content' (it is very sensitive.. dammit). crisis averted.

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    1. Maybe someone from Fulltone, Lovepedal or ZVex has had me added to a malicious content list! :o)

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    2. Haha! I find it malicious to charge in excess of £300 for a fuzz pedal.. A very 'woolly' price indeed ;o)

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    3. :oD

      Yes it's funny that the WM seems so ridiculously expensive despite the fact that it's only marginally more complicated than a Super Hard On, but it's probably because the circuit was designed by Chuck Zwicky and not Zack, so I bet he's paying a royalty for every pedal sold hence the mark up. I would dispute that anyway, the circuit was designed by Arbiter, Sola Sound or Vox. Let's face it, the complexity of the "design" of pots replacing resistors isn't exactly going to bring Apollo 13 back safely.

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  6. Vince, you can safely use B50K pots here.. :)

    Works. Tag. It.

    Can't really say much about how it sounds, since it's 4:23 in here and this is still an apartment building. Damn i need to get a house with closest neighbour at least 1km away..

    Buffered side sounds like my bypassed clean (like it should) and effect side is pretty close to the demo above. But. I'll play with it in the morning and maybe i'll get some more out of it :) Anyway. My deviations this time were 2n2 instead of 2n and C50K pots i replaced with B50K - this doesn't seem to matter that much...
    +m

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    1. Quickest verification for ages! :o) Thanks mate! So much for doing it in the morning eh! Ha ha

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    2. :) Well.. I planned to.. But once i had the board with cuts, links and sockets, i though that "if i just quickly solder the resistors... And i've been away for over a week, so no wonder i missed my iron.

      This would make quite a special wah if the freq pot was mounted on a wah box. I wouldn't call it "noise" circuit though. Moment where it breaks on the demo - i just can't get that to happen. A filter? Yes. And pretty nice one to add...
      +m

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    3. Now that i've played with it louder and longer, the freq pot would have some advantages if it was C50K and not B50K. The super sweet spot is somewhere around 0% to 30%, and with C-taper it could be 0% to 50%. I'm personally stuck with tayda selection on pots because of the price and the fact that i just need to have all my pots the same - having 16mm knurled/split shaft Aplhas mixed with some other - like D-shaft - is just against my religion. Everytime i use some other pot with there, a kitten dies somewhere. Minus side is that there's no 470K, 25K, nor C20K/C50K.. :(

      But. It works just fine with B50K. If one really wanted, one could use A50K, reverse wiring and call it Frequency High Cut :)

      Nice vintage circuit anyway. Very nice indeed.

      BTW.. What happened to the request page? I can't remember what i have wished for :D
      +m

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    4. Cheers for the info Miro

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  7. i have one of the systech overdrives that i bought new in the mid 70's. it has a harmonic energizer circuit in it with an overdrive. it's a pretty cool pedal.

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    1. If you get a chance can you take a pic of the board John? It would be interesting to see where they introduce the dirt, then we could get a good idea of how to make the same thing with our favourite distortion/fuzz/overdrive circuits alongside it.

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  8. Done. I used A50k and I find use of the entire sweep.. I find that the sweep has different results depending on amp/guitar, clean/drive. Tried it through sg/strat/jackson... Orange/marshall/blackstar and found sweet spots all over the place so I think it depends on the gear being used.

    Perfect for I wanted it for, Thanks again Mark.

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    1. Awesome, don't forget the pics boys! :o)

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  9. noob question: polarity on electrolytics and radial caps= does the little dash designate the positive or negative lead on your diagrams? too scared to guess and after perusing your build guide and trouble shooting guide, it never clearly says as it pertains to your build diagrams. i know the difference, i just dont want to risk burning up my caps. thanks.

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    1. The mark shows the negative lead.

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  10. That studio is right down the road from me. They smoke a lot of weed and it shares a building with a sketchy strip joint. It's a good time. Lol

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  11. could someone post voltages for chip and jfet. mine isnt working i get hiss but its not passing signal.

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  13. I found it to be a little noisy when bypassed. How would I wire it as true bypass? Run switch wire 1 to output?

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  14. I built this a while back and am getting back into it to combine it in an enclosure with the recently posted Rattle Crow. If anyone is thinking about building this DO IT. This can bring so many new dimensions out of anything you feed it. It does wonders after dirt, especially fuzz. Any way just my two cents.

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