Thursday 14 February 2013

ZVex Super Hard On - Compact Layout

Request.  The vero version of this that I already posted included axial caps, this keeps the size down by using all radial caps and will be more handy for someone wanting to add a small boost board to another effect for instance.  Includes details for adding a master volume pot.






Geiri's build of this layout in A box:

186 comments:

  1. Lug 1 and Lug 2 of the volume pot to output ehh?

    ;-)

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  2. Reducing the board width removes the cut at row 2 hole 5, does that need to be elsewhere? or is it good as is? Thanks

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    1. There has to be a cut between the 5K1 and 10M so just put it anywhere between the two.

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    2. Hey guys, a bit of a noob question, but does that mean that you can make the cut anywhere on the board as long as it is in between the 5k1 and the 10M resistor? I have this build finished, but getting hum when the effect is engaged. The pot volume works, so i know it isnt too far off being complete.

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  3. Well, even though it isn't a new layout, you can call it verified but with the master volume. Sounds like an SHO

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  4. I had a weird dream last night. Before I went to sleep, I checked the e-mail from Guitar FX Layouts where it notified a new layout for SHO.

    So in my dream, I opened the same e-mail and there was a new layout for SHO and it apparently was "the new updated super correct version" where it had A LOT of resistors, the 9.1v Zener had three pins (looked like a transistor) and it had two of them. There were two "capacitors" that looked like oversized opamps with about 18 pins or something.

    Man dreams can be weird!

    This is my shinfo of the day (=shitty info)

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    Replies
    1. Aahaha! Maybe you build just a bit too much these days:D
      +m

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    2. Ha ha, I was just going to say the same thing. You need a holiday man!

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    3. Haha probably! Funny how during the dream, it made sense and was perfectly normal!

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    4. .....oh God, it'll be sleep soldering next! ( cue the music from psycho) eek, eek,eek, eek

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  5. SHO was my first build about a year and 1/2 ago. Badly soldered the few parts together, badly soldered it into a crappy enclosure with a spst switch and......it worked! An amazing moment. Now, about 50 pedals later.....not dreaming pedals....yet ;)

    Geiri - your demos kick ass. Nice playing man.

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  6. Is that the best you got? ;) I did a 9x7 without even trying... http://hotbottles.wordpress.com/2012/03/29/building-a-z-vex-sho-clone-from-scratch/

    I know you don't like vertically mounted resistors though, so it doesn't count ;)

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    1. No, my smallest was 7 x 5, also with no links and 2 cuts, but I'd never dream of building it! :o)

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    2. Could this be used for bass? With what kind of modification eventually?

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    3. I would just up the input cap for 220n.
      +m

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  7. Build it in about 5 min. Worked perfectly. I am a really big fan of this site. I check it almost daily!

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  8. How do I make this but with the original "2 Outputs" ?

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  9. Also what is "Gain 1-3"? The other SHO schematics don't have that...

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    1. The second output just daisy chains off the first, and Gain is Boost or whatever Vex calls it on this pedal. There's only one control and that's it.

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    2. so gain 1-3 would coincide with the Boost Pot lugs?

      also for the second output is it better to split off with two wires from the board to each jack OR run a single line to OUT1 and jump it over to OUT2?

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    3. also in your experience do you think i could fit 2 outputs in a 1590A or would i need to bump it up to a 1590B?

      for reference i want 1 IN, 2 OUT, 1 clear shaft illuminated POT, 1 switch, and DC jack.

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  10. I built it with a dpdt switch fot the output cap, the stock 10µf and a 2,2µf for less bass. Sounds great

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    1. I try this, but i didnt hear any difference

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  11. Quick question... I'm building this (Second pedal I've built), and have run into some problems. Basically when I plug it in, I get almost no volume. It's just very barely there in the background, very dark sounding as well. When I was building, I didn't have a 5k1 resistor, so I swapped in a 4k7. Could that be the cause of my problem? I've tried both transistor orientations, new caps, etc. Any help would be great!

    Charlie

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  12. This works great, thanks for the layout

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  13. I don't have any 9V1 zener diodes :( any viable replacements?? Thanks!

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    Replies
    1. Have you got any other zeners like 12V or 15V?

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    2. all I've got are 1N34A, 1N4739, 1N914, 1N4148, and some assorted LEDs :/
      maybe radioshack has them.

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    3. The 1N4739 IS a 9V1 zener :o)

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    4. Hello Lvlark! You mentioned 12V or 15V if not having 9.1V zeners. I've ordered 9.1V zeners, but got Tesla KZ706 instead. These are "9.4-11.6V" 10W Zeners. Are you sure I can use them? Thank you in advance!

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  14. I just finished this project (first build). It works, but there is a slight, but noticeable white noise when the pedal is engaged. I built another and boxed it up to see if maybe I just did something wrong in the first build but the noise / hiss is still there. Any ideas where to start looking here? I did use a pretty cheap ceramic disk input cap - is that a possibility? Thanks for any info. Love this site - great stuff on here!

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    1. Well me too. In my pedal the noise is evidently from the circuit, as it is there even with nothing connected to the input. The pitch of the noise gets higher when turning up the boost. Did I fry the transistor with static, maybe?


      Also, I cant seem to get the led to work, as it only flashes while disconnecting the power cable as the pedal is on?

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    2. There are a few known build reports with this layout... Your behaviour could basically be with the power source.. Does the noise appear with both, a battery and a wall adapter?
      +m

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    3. Got my problem solved, thanks for the help Miro. Apparently, the noise was caused by my mistake in soldering the led. As I got the led working, the noise vanished.

      The noise in my box wasn't actually white noise, but a pulsating one. Googling for white noise and super hard on, I found this:

      http://zvex.com/phpBB2/viewtopic.php?t=4801&sid=effa07280ab6583c7072d1732a0cdf56

      So basically a low level of white noise should be expected.

      Now to choose a pot cap...

      https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-ash3/166722_10151527997339617_330642585_n.jpg

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    4. Thanks for the link. Actually, i wondered if it might be just a normal level of noise. Live, you would never notice it.

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  15. Built another one, and ended up with the same problem. Pulsing noise, the pitch of which rises with the gain.

    It appears that this design is very vulnerable to high voltage. I was testing the circuit with a 10v, not a 9v PSU, and the noise disappeared as soon as I changed to a battery.

    Just a heads up to anyone trying to get by with the PSU available at home.

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  16. Done! More than excellent :)
    http://www.flickr.com/photos/95025812@N07/8657477991/

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  17. I have exactly the same problem as cmengel above (9th March).
    I've checked out the layout a dozen times and changed the transistor, and resoldered all the connections and there are no unwanted bridges between the tracks - and always get the same quiet, muffled output.
    Any ideas as to what's causing it?
    I notice that this layout has an extra 1meg resistor over the previous larger layout, is that significant?

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    Replies
    1. Ever figure it out? I have the same problem with my first build.

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  18. I ordered parts for this build yesterday and can't wait to get started. It will be my first build.

    One question though: I ordered a 1N5239B diode. Mammoth has is listed as a 9V1 Zener. Is that correct? I guess I probably should have asked before I ordered.

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  19. i built this and the LED comes on but as soon as the pedal gets switched ON theres no sound. when its off there is sound. any suggestions?

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    1. It could be any number of things and all we know so far is that your led wiring is ok, that you have power and that your true bypass is working.

      Pending further information (I suggest building an audioprobe and testing your circuit), I don't have much other than your regular "knife your gaps, check the components and placement, check wiring, check for cold joints" advice.

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  20. I'm having the same problem as the guy above. I've rewired it once already and about to rewire again. I used an audio probe and sound is really faint coming out of the transistor and the pot.

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    1. i found out that the problem was that the board wasn't getting any power. i disconnected the DC jack and just wired everything straight to a 9volt battery snap.

      multiple pedals i built with these dc jacks (http://www.mammothelectronics.com/4SJK-101DCXT-Round-External-Nut-DC-Power-Jack-p/600-1000-xt.htm) all had the same problem, either i'm wiring them up wrong or i somehow got a bad bunch of dc jacks

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    2. While it's not impossible to get the bad batch, it's not very likely that ALL of them are equally faulty. Take your DMM on continuity setting and see what's happening to pins when you plug the dc power plug in and out. If you are using both dc and battery and the dc jack is doing your switching, it's all too easy to get confused during wiring.

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  21. I was thinking of adding this circuit to a couple different drives, is there any way I could put a toggle switch in to control what circuit fires first?

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    1. Go to this link TattMunney, scroll to bottom of the page for the last diagram and notes...http://www.beavisaudio.com/projects/Looper-Switcher/index.htm

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  22. Can this be built without the "Gain" pot and just the "Master Volume"? I dont have a reverse 5k Pot, but i do have a few 100k's handy...

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    1. Sure. Just replace the gain pot with a fixed resistor of the value of your choosing from within the pot sweep. Socket the resistor and see what sort of fixed gain you like for your setup.

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  23. If I wanted two LEDS (As in Geiri's demo video above) how would I go about this?
    and would I be able to do the same on other pedals?
    (I don't know if it makes any difference but I have built this with the additional master volume)
    Thanks in advance,
    Matt

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    Replies
    1. Check this out.

      http://www.instructables.com/id/LEDs-for-Beginners/step7/Wiring-up-multiple-LEDs-in-series/

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  24. The picture link didn't work. Just Google image 'LEDs in series' and some picture diagrams should come up.

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  25. just finished putting this together, but theres a high pitch squealing in the background kind of like feedback. when you move the knob back and forth is sounds like a theremin. other than that it works fine, sounds like all the SHO's ive heard. any suggestions on a fix? already checked all the obvious things, this my 12th or 13th build.

    http://youtu.be/oIg1XUWsC7A

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    1. nvm, when i ordered everything i bought the "audio grade" electrolytics, i didnt realize they were bi polar I flipped them around and the noise went away. sounds great now.

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  26. Hi,
    A quick idea I intend to use for a post OD booster, for solos...
    The plan is to add a column or two to the right, and rearrange the link and the mosfet to add space for an extra 4k99 resistor from source to row 3, which is conveniently enough empty. Take the end of that extra resistor (row 3) to lug 1 of a stomp switch, gain 1&2 to lug 3 of that stomp switch, and finally lug 2 to row 1 (ground).
    The idea is to switch between the fixed resistor and the pot, which would result in switching between (an approximate fixed) unity gain and a higher gain set with the pot, for rythm/solo settings, so the SHO would always be on.
    Let me know what you guys think... :)

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  27. Just built this... I love the sparkle / thickening it has on my sound. There is a distinct hum though, which won't be a problem live, but for recording, is not great... though I should add that I left out the 47uF and I used a 4.7k Log wired backwards (gain knob goes anti-clockwise).. will try and add that 47uF when I can pick one up in the next couple of days, see if that helps any.

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    1. oh, and I used a radial film cap for the 100nF

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    2. nope... hum is still there with the 47uF and correct pot... hmm... ideas?

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    3. Mine hums as well, its only really noticeable if I crank it past half way. I just try and keep mine turned down so I get the sparkle, plus its always on with my little C600 and if I want to boost the amp I will just use my peppermill or spark boost. Maybe its just the nature of the beast?

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  28. Hi, this is my first build and Ive got a problem (most likely noob problem). When its not engaged the signal passes through but once engaged there is no sound. When i turn the gain pot higher it starts to make some random noise and the inside of the pot starts emitting light (short circuit?)... I checked inside and it got a bit burned... Not sure what could be causing this since I double checked the wiring and everything. Any help would be appreciated

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    1. Try replacing the pot, and make sure the parts you are using are rated for higher than 9v.
      Cheers
      Dave

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    2. Thanks, I will try that! I am awaiting the components to arrive and I will report back as soon as I get it done.

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    3. Well changed the pot and a faulty resistor and the thing worked! Thanks for the help!

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  29. Further up the thread there is mention of replacing the gain pot with a fixed resistor... stupid question but would that go where the two gain pot wires are?

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  30. Here's a quick demo of my build:
    youtube.com/watch?v=9cyGwSArgb0&feature=g-high-u

    Lots of fun!

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  31. Hi there,

    Love this site :) I've got a noob question for the caps...am I right to assume that the light blue dash in the dark blue ring = negative if I use polarised caps?

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  32. That's great. Thanks for a speedy reply :)

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  33. i used a 5k linear but it doesn't do anything the effect just sounds like it's dimed all the time

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  34. Hi! I'm just buying components to make this little thing. Does anyone know about the BS170P (ZETEX) ? It cost almost 30 times the price of a standard BS170, does it worth it ?

    Thanks in advance :)

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    Replies
    1. I've never used a Zetex BS170P in a DIY project only Fairchild, but I have played an original Super Hard On and can say quite honestly that they sounded identical to me. Some people may be able to pick certain nuances that they preferred out of one or the other but I'd quite happily put money on it that they couldn't tell which was which in a blind test consistently.

      The SHO is a very good boost pedal, but paying 30x more for a Zetex mosfet won't make it anything else, so personally I wouldn't. Especially when Fairchilds are still available at reasonable prices, from trusted sellers and to be honest, I have no doubt that the premium for Zetex is because it was a UK company where you will always pay over the odds for components.

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    2. Ok thanks, i'll buy the BS170. And thanks a lot for that blog, lot of really helpfull intells! :)

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  35. Can someone explain the purpose of the 100k to ground at the output of this and some other circuits I've seen around? I thought it might be some sort of voltage divider since there was no volume pot but then on the Dragon Fly Sparkly Boost it has a 100k to ground and volume pot. Second guess is to tame some high end or something. Hmmm...

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    1. That's a pulldown resistor, mainly to address the switching pop. And also limiting the output to suitable level. For example, if you have 100K resistor from output to ground, upping it for 220K should give out a bit more volume. This may also affect the frequency responce in some cases.

      Output volume pot acts in the same way. Sometimes there is a 100K resistor in parallel to 100K pot, which means that the volume pot value is in fact 50K (two 100K resistors in parallel) with a custom taper. Linear 100K turns into 50K log with that configuration.
      +m

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  36. Hi, i'm a noob builder :L and i have a problem. When i turn the gain pot (i have 5k log NOT rev log) there 's a noiz. Why? :P

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    Replies
    1. That's feature of the design. The pot is hot-biasing the MOSFET, so there is bound to be scratchy noise when the pot is turned. This is the reason why the original unit has a text "crackle ok" next to the knob.

      Logarithmic pot will give you very poor control. All the boost will come out at the very end of the sweep. You'd want to swap it for linear or reverse logarithmic.
      +m

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    2. Or you could wire the gain pot backwards, 1 to emitter, 2 and 3 to ground. It'll work the opposite way but at least the taper will be correct.

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    3. thanks for help guys. also i would like to ask if it's normal that there's a noise (like screaming) when the gain pot is not fully turned.

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    4. actually sounds like cicada :)

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  37. Can a 1M0 replace the 1M resistor?

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    1. Absolutely :) A 1M resistor strictly speaking is 1.0M and for ease of writing and to make things clear the letter is often used to replace the decimal so 1M0 = 1.0M or 2.2K = 2K2 and so on. Enjoy.

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    2. Great...thanks for the info!

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    3. This comment has been removed by the author.

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  38. One more question! If I have a polarized cap for the 100n, which way should the negative face?

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    Replies
    1. The negative side will face the input wire. The positive will face the gate of the mosfet transistor. :)

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  39. Hey there.

    I've just put this together and hooked it up to my test rig and I'm getting a horrible mosquito like whine along with the audio signal.

    I've reflowed all the joints and checked for solder bridges and everything seems fine. Does anyone have any idea as to what may be causing the unwanted noise?

    Thanks

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  40. Can I chuck a 1N4001 in place of the zener?

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  41. Hi Mark,

    in the last couple of weeks I've tried everything to get sound from this pedal without any result, changed all of components three times, reverse the position of bs170 but nothing.

    Now with a 2n7000 works without any problem. O_o

    Do you know why?

    Thanks in advance.
    Marco

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    Replies
    1. Hey Marco. Did you make new boards each time or just de-solder and re-solder in new components? Cause sometimes it's the dumbest things that cause the issue, like the tiniest of solder bridges, or a cold solder joint that looks good. If you soldered in your transistor it could have fried. I know how frustrating it must have been, we've all got builds that it too 2, 3, 4, or more times till it worked, but awesome that it's working.

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    2. Last time in new board but nothing (all times the transistor was over a 3 point strip), was all ok, just changed bs170 to 2n7000

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  42. Mosfets are sensitive to static discharge and can be damaged pretty easily

    You probably just had some damaged BS170

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  43. Hello people,

    I don´t know how to do this but I think it could be a little simple: I want to create a SHO with another pedal and I think the valve caster could be a good choice. I read that the valvecaster doesn´t have much distortion on the output signal, so if I put the SHO before the valvecaster I could obtain a valve caster with more distortion ? My doubt is if this union could be dangerous.


    Here is what I'll make...

    http://migre.me/mzJMB


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    Replies
    1. Hey Alambike. I don't know much about tube tech but the way I see it, this is the same as running a SHO pedal before a Valvecaster pedal and I can't see why it would be an issue. Otherwise I would just build another simple pedal with better/more usable distortion like a COT50 and hit it with a SHO. Have fun :)

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    2. that's not a problem, it's super easy to do, and no danger at all. there's no difference in the wiring if you were going to run a boost in front of any other pedal. in fact under the offboard tab mark has a wiring guide for putting a boost in front of another pedal.

      http://2.bp.blogspot.com/-J3EhMIZQLck/UH6a8ZnzSFI/AAAAAAAADHE/ewTfTXuvTYA/s1600/!Offboard+Wiring+with+switchable+pre-effect+booster.png

      just remember, since the boost board isn't shown, you need to connect the input and output wires from the SHO to the boost switch in the correct locations, and it doesn't show the a 9V wire going to the boost, so don't forget that.

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    3. Hello Johns, in this case I don´t want to use two 3PDT switch pedal, I only want to introduce the circuit in "serie" with other.

      I think to make by this way:

      http://migre.me/mAFRQ


      What do you think about it ?

      Thanks

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    4. yes man that's right. i did it a couple of times too for pedals with low output, but i always put sho after the main effect..i don't know why but anyway...your wiring is ok.

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  44. I can't see the link you posted, it tells me it's wrong, but what I posted is exactly what your asking for. You said you want to have a boost that you can turn on or off in front of another effect, specifically a SHO in front of the valvecaster. What I posted is not a selector switch (a/b box), as you wire everything in one enclosure. The two stomp, switches control the boost and other effect independently, and they are wired in series (boost then effect).

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    Replies
    1. Never mind the link now worked. The way I understood you was you wanted to control when the boost would be introduced to the circuit, not have it on all the time. I just saw your wiring diagram in the link, and if you want it one all the time that will work perfectly. If you want to be able to turn it on and off then follow what I posted.

      Let us know how it turned out. I know I've been thinking about building a valvecaster, but have heard it's really dark, so hopefully this might help.

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    2. Hello Johns,

      Thank you, so I thought to control the SHO with its Pot (Gain 5K rev log). When I don´t want the influence of the SHO I put the Potentiometer at zero. The question now is if even this pot at the zero the SHO will influence in the sound of the valvecaster.

      Is there another way to turn on or off the SHO instead using the 3PDT. For example, could I connect one SPDT switch (ON - ON) between the effects. In the position 1 the signal goes only to the Valve Caster, and in the position 2 the signal goes to SHO and after to Valvecaster.

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    3. the SHO basically a buffer/booster, and will influence the signal is the pot is at 0. what you could do is use a DPDT switch instead of a 3PDT switch, you just need to leave off the part of the wiring on the SHO switch for the LED.

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    4. In this case the DPDT will not influence in the sound of the other effect ? How could I plug the cables in the DPDT ?

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    5. if you use the DPDT switch instead of the 3PDT, just follow the wiring as you see it with the 3PDT, but ignore the column on the far left, the one with the LED wiring. this should give you the ability to turn the SHO completely off or on, but not have a LED indicator. the effect will bypass like normal.

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  45. Got a weird thing with my build of this. I'm using a 5k rev log pot but it does two things; most of the range is in the last 1/4 turn and also seems to be working backwards. Any ideas? My first thought is that the pot is mislabelled 5k lin but any other ideas?

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  46. Switch the 1st and 3rd wire around on your pot.

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  47. I have a couple of questions, both of which are probably exceptionally dumb:

    1. I can't source a 5k reverse log pot so thought to make one by putting a 1k resistor across the outer lugs of a 5k linear pot as per this website: http://www.geofex.com/Article_Folders/potsecrets/potscret.htm. However, the diagram for this method is for the pot being used as a voltage divider. Is how the pot is being used for this build?

    2. I've just soldered the board and realised that I've done it backwards, i.e., the board is populated correctly shiny side up but is a mirror image of it on the non-conductive side. Is this any issue? All polarised components face the correct way.

    Any help for the newbie greatly appreciated.

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    Replies
    1. hi there!
      1)i would just stay with the 5k lin...!but yes you can play with pots too.
      my way to get a "something like 5k log" pot would be a 10k resistor in lugs1 and 3 of a 10k lin pot. using 1k as you say will give you something like 0.8k pot.

      2)that's something that happens to beginners...and it's good that happened in such a small board without ic. now you won't have any problem as long as you got the orientation of transistor right. but keep in mind the right way for you next build!

      good luck!

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    2. http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/anti-log-reverse/5k-ohm-c5k-5kc-anti-log-taper-potentiometer.html

      Rev log definitely gets the best sweep for this circuit...
      +m

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    3. Tayda to the rescue with a 5k rev log potentiometer, along with socketing the transistor as, yes, I did have the transistor back to front on my already back to front build. Consider this build well and truly idiot proof!

      Also, I've incorporated it into a send/return booster looper so that multiple pedals can get the 'more' footswitch in series, just like the Box of Rock.

      https://dl.dropboxusercontent.com/u/91723417/booster-looper.JPG

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  48. Many thanks for your advice. On second look at the circuit and Secret Life Of Pots, it looks like the pot has a two terminal connection and is being used as a simple variable resistor.

    I'm going to keep the 1K resistor over lugs 1 and 3, and remove the bridge between lugs 1 and 2: a parallel circuit should be made with CCW 5K ohm - 1k ohm; and CW 0 ohm - 1K ohm. If that fails there's always Tayda!

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  49. A few layouts require two ground connections, usually because there wasn't space for a link without making it wider than will fit in a 1590B. In those instances just daisy chain the ground connection

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  50. Just omit the 3PDT stomp switch, and wire the input and output on the board directly to the input and output sockets.

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  51. Post a high res front and back pic of the board and we can see if we can spot anything obvious

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  52. hi kevin.i can't find anything strange in your board.it looks good to me. take a razor and knife between stripes to be sure about unwanted briges.
    do you use a test box?if not how do you test the board?do you make the right links with aligator clips?are all grounds connected?(guitar's wire ground,board's,amp's,9v supply??)

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  53. Thank you for this build it works well. Here is a picture of my board.

    http://s1383.photobucket.com/user/denfox1/media/20150126_051955_resized1_zps60b4de6c.jpg.html?sort=3&o=1

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  54. Could I change the potentiometer by a fixed resistor ? For example, I only need to put a 4K resistor (if I want more drive) between the ground and the S of the Q1 ???

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    Replies
    1. Even better, if you could find a way to implement a trim pot in there you'd have full control and then you could just set it and forget it.

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    2. Good idea!! But the question is how to exlude the potentiometer and put a resistor or a trim pot. In the case of the resistor I think the correct way is only connect the resistor in the ground to the S of Q1, but I am sure !!

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    3. Sorry, I mean "I am not sure !!!!"

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  55. Hello - thank you for a great site. It seems that I have been building the SHO due to a project (without any knowledge about how well estimated circuit it seems to be) which uses the SHO as input buffer. The result was great though some noise appeard most significant when you dial the gain pot. But i'm pretty satisfied and considering building a stand alone version and was wondering about if any components in the circuit may be critical for a good result?

    By the way the project I refer to happens to be a great solution to put in front of the OCD overdrive (which I build way back) to eliminate the annoying oscilation which seems to appear.

    Thanks
    Lauter

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  56. Great layout! Here's my almost semi-finished pedal, I may do an etch in the near future, as a nice finish :) It's a 1590A, with two 16mm pots (GAIN + VOLUME), the closed cheapest stereo jacks from Tayda are well suited for this enclosure! Still a tight fit, haha!
    Here are the links for your library Mark, cheers:

    http://s304.photobucket.com/user/H_A_M/media/DIY/SHO/SHO%201590A%20wknobs%20-%20unfinished_zpsbe822042.jpg.html

    http://s304.photobucket.com/user/H_A_M/media/DIY/SHO/SHO%201590A%20-%2016mm%20knobs%20-%20unfinished_zps5bd953f9.jpg.html?sort=3&o=1

    http://s304.photobucket.com/user/H_A_M/media/DIY/SHO/SHO%201590A%20-%20guts_zps0e384918.jpg.html?sort=3&o=2

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  57. Having a slight issue here...

    I've built two of these now, both are boxed up and good to go, but both have the white noise other people have mentioned. When they're engaged, there's a slight static-type noise. I can't imagine I made the exact same mistake on both. After troubleshooting the first and realizing everything was correct, I just made the second, but my results are exactly the same. I've tried various power supplies, several bs170s, various plugs in my apartment, and a couple different 9.1v zeners, but it's always the same thing.

    Any ideas on what my issue might be? Is it just the way the circuit is, or have people made them with zero noise?

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  58. This pedal smokes! Thanks for the layout.

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  62. So this is all fine and well but can someone PLEASE post how to wire the pots and the adapter and the switch and the jacks? THANKS

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    1. There's posts everywhere on off board wiring. Read through the step-by-step guide on this site to get your bearings. Take your time.

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    2. I really need to see pictures. Like actual pictures of how this looks when everything is laid out before cramping it all into the enclosure.

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  63. Will a 1N4148 work on this build?

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    1. The zener diode is there to protect the transistor. A 1n4148 won't do the same job. Some people have had a good outcomes replacing it with a red led (also a type of diode) but zener is probably the best bet.

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  64. Could I use this circuit with the master volume for bass? For example to get a clearer and more open sound when playing with a pick.

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  65. Yeah you could but I would probably put a larger cap on the input such as 220n so you don't lose any bases frequencies going into the boost. :)

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  66. First of all thanx for sharing
    I built it yesterday.
    it sounds very transparent making my guitar shine through this , very responsive but turning the "crackle ok" past 12 o'clock it's getting very loud making impossible to crank it at home .
    is that normal?

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  67. thanx for sharing!
    I built it yesterday. very transparent and tone comes out with great clarity.
    setting the "crackle ok" over 12 o'clock the pedal becomes very loud so that I can't crank it at home. is that normal or I did sth wrong?

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    1. Hey Andy

      Totally normal. It's a boost not an overdrive. So the more you turn the knob the louder it gets and the harder it'll drive ya amp. And it's a loud one.

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  68. thank you both for responding so quickly
    take care

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  69. I have an old Boss FV-100 volume pedal with a bunch of space inside, and I'm planning to build one of these into it. I think I'd like to incorporate the master volume into the expression pedal too. Here's what I'm thinking:

    Install a 50K dual gang pot on the expression pedal. One gang is used for the volume pedal circuit. 3PDT switches between the passive volume circuit and the SHO—when the SHO is on, the volume circuit is bypassed. Wire the second gang of the 50K expression pedal pot in series with with another 50K pot, and the two of these together work as the master volume.

    Would this work OK?

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  70. I have 1N4001, 1N4148, and 1N914 diodes. Will any of these work?

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    1. Plenty of people have used 1N4001 and there are some designs using a red LED as well. There is still a lot of discussion about whether these really are or are not as effective as the zener in protecting the MOSFET but I have used both 1N4001 and red LEDs for about 5 years and nothing has blown up yet.

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    2. the zener is there to protect the MOSFET, as you pointed out already. while people have substituted it for other diodes, i can tell you that you increase your risk of blowing the MOSFET up simply by plugging in the input cable. the original had 2 diodes, 1 from 9V to gate, and 1 from gate to ground. these were very unstable, which is why it was replaced with the zener.

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    3. I completely agree with your thoughts Zach and you are spot on. Just for the home DIY pedal builder, who doesn't have any zeners on hand, I don't personally think the increase risk is enough to warrant sitting around waiting for a zener to get shipped to me (in my case it takes 14 days to get here). If it blows up, I'll just build another one. If you are buidling for others or selling them, absolutely put a zener in there. It's the lowest risk.

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    4. agreed it's up to the builder, but for me i would rather build it so i can rely on it rather then risk it. MOSFETS are very finicky and sensitive. with the price of replacing the MOSFET vs the price and waiting for a zener, i'd wait. especially with the super hardon.

      it's known, even with the zener to blow the MOSFET, in fact for a long time, not sure if mr vex still does this, but he would send replacement MOSFETS when they blew on customers. what's messed up is that 9 times out of 10 it wouldn't sound the same after the replacement.

      i remember seeing a music doc and the tech for queens of the stoneage mentioned it, cause when recording josh's blew, they got the new MOSFET for vex, changed it, and the whole effect sounded different and it fucked up their recording.

      even though have a company and sell, whenever i build something for me, or to sell i want to be able to rely on what i build. when i hit that switch it has to work or all the time building it was for nothing. just my humble opinion.

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    5. Not only did I love the Queens of the Stoneage story, but I really respect your humble opinion. You're one of those let's get it right the first time people and we could use more of those. I fall into the let's just get it done and hope for the best... it can also be my failing. Happy building bro!

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  71. Just built and boxed. Such a great boost!

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  73. Hey, total noob here. Looking to make this as my first build. I wanted to do the 2 pots, but am unsure how to wire this. Any help would be amazing. Thanks guys.

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  75. Hey does any one know what going on with my? Just bult this and I'm only getting any output when I change the orentation on my transistor but it's very quiet. If anyone could help me that would be great

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  76. Hi guys ! I have made this circuit 3 or 4 times and have a poping noise when switching it on.. More or less.. I have tried different resistor led values, tried this thing : http://www.muzique.com/lab/led.htm But nothing works..

    Do you have the same issue? An idea?

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    1. An LED is not always the problem. Check this link, many ideas there: https://www.diystompboxes.com/smfforum/index.php?topic=117611.0

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  77. hey guys, i installed this into a box with a timmy and i'm getting some hiss only from the SHO side, any advice?

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  78. yeah, it's my 3rd try with this one, i've built at least 10 of them in the past, never had this issue. any help would be appreciated!

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    1. do you guys think i'm pulling too much power from the dc jack or something? i rewired it again and can't figure anything out. like i said, the timmy side is fine, just the SHO side is giving me hiss.

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    2. You got hiss even with a battery?

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    3. i dont have room for a battery on this build, so i didn't try it. i've built this combination of effects a bunch of times, i'm not sure why it would be hissing so bad.

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    4. If this last SHO you built work fine alone it means maybe it's well built.

      I would like you try to power up the combo with a battery just to see if the hiss is stille there. Could be something power filter problem. In case you have a pair of thing to fix that.

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    5. Yes! Battery took the hiss away, but how can I use an adapter?

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    6. If the hiss (is it like a whistle, a squeal?) come from the power supply you should try to add in line to the 9v a 47R or 100R resistor, or in alternative a 1N5817 diode. Verify if this solve the problem.
      If it works you can mod a bit the layout. It's not so nice, but you can do it.
      Move a stripe down the 9v wire and add on this stripe one side of the resistor/diode and the other side where there was the 9v wire.
      You can follow the new track of the 9v: from the wire, across the resistor/diode and then where it was in origin.
      Make just a new check of short circuit after this new solders.
      Another alternative is add simply the 47R/100R flying resistor between the DC jack and the 9v wire. Probably this is the easiest way to see if this trick works.
      Let us to know if you make this pedal work fine. ;)

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    7. ok, tried all 3. resistors didn't help. the 1n5817 took the squeal away when the effect was turned up, but as you turn it down, the squeal comes back. WTF?

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    8. Do you mean with the SHO engaged it works ok and when the sho is bypassed there is the noise? But you got the squeal with the whole pedal in bypass or just with the Timmy engaged?
      Anyway I think the power supply is the reason it squeal, check both the boards, and check if both have at least a 47uF from 9v to the ground, or the 1N5817.

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    9. timmy - no noise, engaged or not
      sho - noise only when engaged, and goes away when c5k is all the way up, noise increases as the c5k is turned down.
      both boards seem to be fine. the effects both work perfectly, just have the squeal in the sho.

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  79. I finally built the SHO circut, but I also got the squeal problem. I tried to insert in line to the 9v a 47R, a 100R, a 1N4001, a 1N4007 and a 1N5817, but nothing solved the problem.

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  80. I built one of the compact layout with the volume knob and the volume works as expected but the gain knob doesn't seems to do anything at all.

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    1. Found my issue, misplaced one leg of the 1uF electro by a row, moved it and all is well.

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  81. I built this but have a high Screech coming thru at all times ( obviously harder to hear when the boost is at full) no solder bridges to be found. any ideas?

    Many thanks

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    1. I tried replacing the 47uf cap with another 1N4148 diode as I found a few schematics that had 2 diodes, but still has a screech. Could the screech be from the 47uf cap was only rated at 16V?

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  82. where can I find schematic for compact layout?

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  83. I made this pedal with the extra volume knob and works great, but I used a Bat41 diode will this make problems in the future? thanks

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  84. For anyone is curious, you can use 2.2meg in place of both 10meg resistors. I don't know if that's already known, but I tried it and it works just fine.

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    1. Yes you’ll just get a lower input impedance but the effect will work fine

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