Friday 5 September 2014

Test box 2.0

We always recommend trying the boards out before soldering everything in to the enclosure. Main reason being that if you have an error on your build, it's about a hundred times harder to find it inside the otherwise finished build. Like Madbean says - Build it, Rock it, Box it. There is a reason for that order. One could, of course, simply use a breadboard and/or simple screw terminals to achieve the same goal, but if you are building more than one circuit every now and then.. Well. Then i'd suggest you'd build yourself a test box. I've had a few different methods of trying the boards out before boxing, but my latest, equipped with a little more sophisticated screw terminal block was closing in on the end of the road. It was simply falling apart due all the use it had seen. So. I wanted to build myself a new one with slightly more features than the previous one. And while i was at it, i snapped a few (poor) shots of the process. A slight warning: This "photo essay" may not be detailed enough for someone who's doing anything like this for the first time. But if you know what you're doing, you're more than welcome to try something similar out. Here's my "Test box 2.0", which includes a switchable audio probe input. Let's start out with what you'll need.


Most things needed are your standard pedal parts.
  • Enclosure (i used a plastic box that can be found through Tayda)
  • 4-way speaker terminal and bolts/nuts for it (again, Tayda)
  • 2 mono jacks
  • Binding post for "banana" connector (mine isn't exactly like this, but once again - Tayda)
  • 3PDT On-On toggle switch
  • DPDT On-On toggle switch
  • 1µ polyester box capacitor (higher the voltage rating, the better)
  • Small piece of stripboard
  • 2 LEDs (i used diffused red and orange)
  • 2 1K2 resistors for the LEDs
  • Holders for the LEDs
  • A few meters of wire of your choice
  • Heat shrink tube etc. etc.
I drilled the enclosure first and started with mounting all the ingredients. Due to location of everything on my bench, i went with jacks on the left, speaker terminals on the right, DC jack on top and probe binding post at the bottom. I Placed the switches on the upper half, because it just looked like that would be a good place for them. The LED holders are below the switches. You should probably think the geometry of all the parts so that it'll suit your needs and bench.


Next up, we'll wire the grounds. The DC jack pictured here has its longer leg as sleeve and shorter as tip, so we'll take a wire from the short one to lug 2 of the DPDT switch - and from that pin to the second speaker terminal lug - and from that to input jack's sleeve - and from that to output jack's sleeve - and from that to lugs 1, 4 and 5 of the 3PDT switch. Here's picture of all the grounds connected:


Now, the small piece of vero. We're using that as a tiny daughter board for our LED resistors, just to keep everything neat. 4x5 board is enough. We'll wire two red wires to one row with two resistors and one wire for each row that has the other end of the resistor. Those wires are for the LED anodes. Like so:


Now we can wire up all the "hot" leads inside the box. To attach the tiny board to the enclosure, i used Tesa PowerBond Outdoor branded two sided adhesive tape. 3M's similar product doesn't insulate the connections, so do not use that. With slightly bigger board one could use a plastic, or even metal PCB standoffs, but i've found the Tesa tape to be sufficient solution. LEDs go their respective holders (i'm using red for bypass/3PDT and orange for probe/DPDT) and cathodes need to be soldered to lug 3 of the DPDT and lug 6 of the 3PDT. The longer free red wire goes to DC jack's sleeve and the shorter to the first speaker terminal lug.


Now we have all the grounds and supply wires hooked up. Next we'll need to solder up the signal wires. Connections are pretty much per the standard outboard wiring, but please do read this twice to make sure you got it:
  • Green wire - from 3PDT lug 2 to speaker terminal lug 4
  • Blue wire - from speaker terminal lug 3 to 3PDT lug 9
  • Yellow wire - from input jack's tip to 3PDT lugs 3 & 7
  • Orange wire - from 3PDT lug 8 to DPDT lug 4
  • Brown wire - from DPDT lug 5 to output jack's tip
All that wiring is depicted here:


We're pretty much all set, but the probe section is still missing. The box does work as it is now, but there's no use for the binding post and the DPDT switch does nothing - but light up the LED when set to probe mode. Now we'll need to solder two wires to the 1µ capacitor. Like this:


Other end of that wire is then fastened to the screw at the bottom of the binding post. The other end needs to be soldered to DPDT lug 6. I used a small piece of the two sided adhesive tape to keep the capacitor nicely in one place. Like so:


That's it. Simple and straight forward. The 3PDT bypass switch acts as a true bypass in the same manner as in any pedal. The speaker terminal connections are the ones where you'll snap in your just finished new effect board. One for supply voltage, one for ground, one for circuit input and one for circuit output. Here's a shot of the thing in action:


Some of you may think "why add the binding post for the probe?" Here's the reason - let's assume i've built a board, hooked it up to this box and it doesn't work. There's no signal passing through. We already have the ground wire for the circuit connected, so why should we rip out all the cables (excluding the supply/ground) and clamp an alligator clip to a ground point on circuit, plug the probe to the amp and start probing? For no reason. With this setup, we can simply connect a multimeter's test lead to the binding post, flick the probe switch and start probing. Even when debugging a broken factory pedal, this solution eliminates the need for a separate probe. Just connect that pedal's grounds to the ground slot of the speaker terminal and start probing.

How am i going to remember which of the speaker terminal slots is which and which jack is which? I'm probably not going to, so. I added some Dymo tape to mine...


I = Input, O = Output, G = Grounds and V = voltage in. Don't bother pointing out that the speaker terminal is upside down. It isn't. This way i can snap the wires in without having to lift the box off the table.

The idea for this box is rather simple and you should be able to add the features you want/need. Like for example - a negative charge pump and separate 2-way speaker terminal for the -9V and ground. That feature would enable you to try out positive ground circuits with the same test box. Why i'm not doing that? Because i have a lab supply on my bench and i want to be able to try the circuits out with higher voltages than just 9V. So ICL7660S with maximum input of 12V doesn't really suit my purpose.

One last thing. If you don't have a lab power supply with quick fuse, please do not test your circuits with a wall wart power supply. Even the slightest short will burn your supply or its regulator in a heartbeat. For testing purposes - solder a standard DC plug to a battery snap and go with that. You'll be able to drain a battery in ten seconds with a short, but it'll be a lot cheaper than burning wall socket adapters.

109 comments:

  1. This comment has been removed by the author.

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    1. Really useful ! Every builder needs one and that's not that expensive...
      Thank you for having shared that !

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  2. This can save me quite a few steps. Thanx

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  3. Thanks again Mirosol! Looks like i need to order some parts again. Great ideas!
    Vince
    Simplefx

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  4. You read my mind, man... I was trying to figure out how to make one of those... Great site and great layouts! Greetings from Chile

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  5. Great post.
    It is so important to have the right tools and tactics above the endless world of schematics and layouts. Breadboarding and playing the circuit before boxing it is important for troubleshooting, important for modding, and most of all, important to see whether you like the damn pedal or not. You can't really have hundreds of boxed pedals laying around.
    I prepared a basic box just like that which hooks up to either a breadboard or a vero board/prefboard. Input, output, switch, power and ground. That's all you really need.

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  6. Thanks Miro!

    The treat for me is to be able to try out circuits (taste test) quickly and easily to see if I want to do the full build.
    So many circuits look cool on paper, but simply don't work with my rig or my ears, so this will be a real help to me!

    G

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  7. Thank you Mirosol! I believe there's a small error where you say, "and anodes need to be soldered to lug 3 of the DPDT and lug 6 of the 3PDT" for the LED connections. These would be the LED's cathode wires.

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  8. great post, thank you. mine has these exact features, but witch alligator clips => sometimes it's a mess and therer are shorts... hooking the wires to the speaker terminal is definitely the way to go!

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  9. Any chance of a schematic for this build? Otherwise I may need a test box to troubleshoot my test box build :)

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    1. I forgot to say, this is fantastic and the site as a whole an excellent resource. Many thanks to all involved

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    2. You think you really need a schematic of this?
      +m

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  10. You read my mind too - I was also just assembling the parts to build on of these. I did not think about Speaker lugs instead of a terminal block, or a quick ground lug - good ideas. Thank you so much, really, for all the insight you give to us.

    We have discussed test boxes before but this one has few new features so I hope you don't mind that I ask about them. I have re-read this a few times because I am not fully sure I understood the functionality for all the parts.

    (Sorry, but I also have to say I am a bit afraid to ask "noobie" questions here now, which these are, so I hope I don't get hazed for it).

    1) The built in audio probe. Is that made to work with the output of the box which you already have connected to the amp? A great idea, but I just want to clarify I am reading this right. Also - is the audio probe LED for the probe just there to tell you that it is on or is there more to it I may be missing?

    2) The LED connected to the 3PDT switch bypass. What exactly is the reason for this? Is it just in case you need a different wiring for that switch, so the included one doesn't fit the circuit? What is an example where you would bypass the built in 3PDT?

    Another thing: when I was thinking out my box I also realized it can be a good idea just to keep several standard value pots pre-wired that you can easily connect them to a terminal block so you don't have to solder them to the circuit just to hear what they do. Just run wires from your board to the terminal block and connect pots as needed. I assume many of you already do this, but I have not seen it discussed.

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  11. Wow...Good job! We are glad to see our Dymo tape is helpful for you. Keep up with the good work. ^CP

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  12. Once again.... I would appreciate (a lot) some help on this topic: You write

    "There's no signal passing through. We already have the ground wire for the circuit connected, so why should we rip out all the cables (excluding the supply/ground) and clamp an alligator clip to a ground point on circuit, plug the probe to the amp and start probing? For no reason. With this setup, we can simply connect a multimeter's test lead to the binding post, flick the probe switch and start probing. Even when debugging a broken factory pedal, this solution eliminates the need for a separate probe. Just connect that pedal's grounds to the ground slot of the speaker terminal and start probing."

    I just don't follow - you discuss an audio probe, but is this the same thing? You say "connect the multimeter to the ground post, flick the probe test and start probing."

    Are you saying use the multimeter as an audio probe - or are you talking about probing for voltages now? I have never seen anything on how to use a DMM as an audio probe. Is this something some DMMs have that mine does not have, or are we mixing verbiage here - talking about an audio probe and a voltage probe in the same sentence? I can built an audio probe, and that was why I assumed you put in the capacitor - hence my confusion.

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  13. Okay - I just googled DMM with built in Audio Probes - don't see such a thing, furthermore I don't see a way to use a DMM as an audio probe. So, I am assuming the lead for audio probing is connected to the DPDT lug 3. Am I on the right track here?

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    1. You are not using the multimeter as a probe, only the test lead of the multimeter. Unclip 1 of the leads from your multimeter, clip it on to the binding post, flip the probe switch and start probing. To answer your earlier questions, yes the probe does work through the output of the test box connected to your amp. The probe led is only to signal that the probe is on. The led connected to the bypass switch is also only an indicator that the switch is on, exactly the same as you would do with the foot switch of a pedal.

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    2. Second. I didn't say anything about using a multimeter for anything. Just its test lead.
      +m

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  15. Sorry, I wanted to edit but all they have here is delete - so. Thank you.

    The LED for the 3PDT is also a bypass as I read it, but I do believe I understand it is there the LED, so you can test your own LED, I assume.

    I know this stuff is written up for experts, sorry to be a noob, but I pay the world back by answering noob questions in other places.

    So, the audio probe uses the amp speaker - and the ground lug can be used for either audio or voltage testing (obviously).

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  16. " Unclip 1 of the leads from your multimeter, clip it on to the binding post" - -

    OH....

    I really wish you guys could read this stuff the way we noobs read it sometimes. I never would have read this "With this setup, we can simply connect a multimeter's test lead to the binding post, flick the probe switch and start probing," and thought of disconnecting one of my probes to use as the audio probe.Especially since my probes won't connect to a binding post (they are banana plugs inside of plastic covers). I assume you guys have clips (?)

    Sorry that embarrassing myself is the only to learn this stuff.

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    1. Yes. The LEDs on the box have nothing to do with the board's LED. It's just to good to have that in there - if you have a short on the power power section of your board or something else is wrong, the LED won't light up and you know right away something's wrong.

      My test leads have standard banana plugs. Some others i have do have those plastic covers, but you could a) shorten the plastic to use them on binding posts, or b) get a standard banana plugs and swap them. Those with plastic sleeves are still standard banana plugs, even though there is extra insulation on them. Standard plugs do go with any multimeter as well.

      I did note on first paragraph that this may not be detailed enough for first timer.
      +m

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    2. Since you obviously aren't that familiar with the probe, check this out:
      http://www.diystompboxes.com/pedals/debug.html

      My version of a test box simply has that probe incorporated in easier to use manner.
      +n

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  17. Thanks Mirosol. You know questions are not criticisms of anything, it is just our limited imaginations and experience that makes it difficult to understand everything. So there is no need to think there was anything wrong. The only thing I have said about this site is that noobs will get left behind, and that I hope we are not considered "bad people" just because we ask questions.

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  18. I realized I do have banana plugs on my DMM (we beginners don't think about all this stuff). In fact, I had been looking up audio probes since a pretty long time ago. That's how I figured out you were using the "out" as the audio probe signal. I still don't know why the biggest cap (+1uf) possible is ideal, unless you are planning to poke around some AC circuits (which is possible). I have no 1uf cap that isn't electrolytic. I have a lot of stuff but I am always surprised at what may be called for.

    I actually found a spare binding post that came with my breadboard, but I also ordered one. I also have been looking at signal generators and was considering the Keen "Fake Guitar".

    In any case, I know having a good test box will make a huge difference. I'm looking forward to it. Thanks for the layout.

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  19. Awesome! Been meaning to make one of these. Thanks

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  20. Built it - and it works, everything. It powers circuits, the switch bypasses them. The audio probe works so when you power up the box there is no audio unless you find it with the probe connected to the binding post.

    I know this will sound weird coming from me - but assuming I followed all directions (which I seem to have done) you can call this "verified." - And it's great. I had no problems at all

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  22. I'm building this in an aluminum enclosure. Do I have to make sure the lugs from the speaker terminals aren't touching the enclosure? Also I want to add a sag pot. How would I wire that in?

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  23. I used a plastic box, but I would not recommend connecting that post to the aluminum if the box is grounded, because it is meant to carry audio. Basically - all you need is a way to isolate the post from the box - maybe put some plastic tape or shrinkwrap around it - and tighten it up with the bolt.

    The post does come in handy as an audio probe. I have used it. Good luck.

    If you did not use metal audio jacks, and did not connect their ground to the box then no problem, but if you have ground on the enclosure, I would not let the audio probe touch the enclosure.

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  24. Sorry - comment above appears to be related to deleted post...

    But - nothing should make contact with the enclosure (since it is aluminum) except possibly ground (and not required).

    If you do let the speaker terminal touch the enclosure you will get a short between + and - power supply - not good. You have to either switch to a plastic box, or find a way to isolate the parts the could touch the enclosure - shrinkwrap, tape, or something. Good luck.

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  25. Thanks! (Yeah, I figured out a way to attach the binding post about ten seconds after I sent that comment. No one had answered yet so I deleted it.) What about the sag pot a'la the Beavis/Z.Vex dying battery thingamajig? There's an image of how to do a standalone dying battery simulator using two DC jacks, but I can't really figure out where to insert it in this circuit.

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    1. (To be clear: WITHOUT the second DC jack. Just the one, like on the breakout box for the Beavis board.)

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    2. You can add the one that is similar to this one http://www.beavisaudio.com/Projects/DBS/index.4.jpg.

      I had to open my box to be sure, but the +9 supply goes straight from the DC jack to the speaker lug, so if you just put a pot in there it will be in the circuit permanently, so you don't want that.

      The sag works like this - you take a 10k linear pot and connect the +9 supply to the pot's number 3. Then you take 1&2 (on the pot, tied together) and run a lead to the +9 point of contact for the effect.

      But since you don;t want it in there full time - you would need to add a 2p2t switch so you could send the +9 directly to the speaker lug - or send it to the pot. One way would be sag on, the other off. You would then run two leads to the speaker lug (+9 out) - one directly to it, the other through the switch to the pot (lug 3) and then from 1&2 tied together to the speaker lug.

      Alternatively - you could put two DC jacks in your box and make one of them the "Sag Input" and the other non-sag. Run the first directly to the speaker lug, run the second to the pot (lug 3), and then 1&2 tied together to the speaker lug. Then just use the input you want - with or without sag.

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    3. From above "You would then run two leads to the speaker lug (+9 out) - one directly to it, the other through the switch to the pot (lug 3) and then from 1&2 tied together to the speaker lug."

      Both leads come off the switch - one directly back to the speaker lug, the other to #3 on the pot.

      Delete
    4. There is absolutely no need to add a switch to a sag pot, it is a variable resistor, hence when it is turned fully clockwise there is zero resistance and the circuit acts as if the pot wasn`t there, so you get the full voltage output of your power supply, as you turn the pot back you introduce resistance and lower the voltage, why would you need a switch?

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  26. I will stand corrected - thanks for your help

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  27. Cool, thanks for the responses. However, I'm confused about where the other wires go.

    1. The stripboard has one wire running to DC+ and one running to speaker lug.

    2. I bridge the 1 and 2 of the pot and run that to the DC+. I run the 3 to the speaker lug.

    3. What do the two wires coming from the stripboard go to? Would I just need one of them (remove one) running to the speaker lug along with the 3 lug of the pot?

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  28. It is simple now as long as the pot is out of the circuit when fully clockwise. I would just disconnect the lead going to +9V out (speaker lug) and connect that to lug 3 of the pot. Then take the lead from the bridged 1&2 and connect that to the same speaker lug from which you just disconnected the wire.

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  29. Thanks again for the info.

    So I built this thing. Didn't work. It was pretty ugly inside, lots of burned wires and such, so I cut it all out, desoldered everything and rebuilt it from scratch. Looks much better, but I'm still getting zero voltage when I check the positive and ground at the DC jack.

    I'm new at this and I have no idea what to do. How does one find a short or a bad solder connection?

    One more thing: I put heat shrink around the speaker lugs so that there's no direct connection to the enclosure. But the jacks and switches are both touching the enclosure. That's okay, right? I mean, I'm not supposed to isolate them with plastic washers am I?

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  30. I checked all the ground connections on the 200 ohms setting. I get 1.4 at the speaker lug, 3.2 at the input sleeve, 2.3 at the output sleeve, 2.2 at 3DTP-1, 4.2 at 3DTP-4, and 2.6 at 3DTP-5. So that means the problem is NOT with any of the ground connections, right?

    How do I check the positive side?

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    1. the ohms settings are for measuring resistance, you want to check the grounds for continuity, you may have a setting on your multimeter for this, it emits an audible signal when 2 points are connected. check that all grounds are connected to each other. What setting are you using to measure the voltage at the dc jack, if you are getting 0 volts at the dc jack lugs then you are either using the wrong setting, your dc jack is faulty, or you haven`t got a power supply plugged into it.

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  31. The only thing you have to worry about touching the enclosure is conductive metal. Jacks are okay because the part that touches the enclosure is supposed to be grounded anyway - the switches should be plastic in the areas that between the enclosure and the lugs - so no worries there.

    How does one find a short? Get a meter with a "continuity check" - something that makes an audible noise when current is passing through it. Then check the places that are NOT supposed to be connected to make sure they are not.

    Those small ohm readings are typical for ground - you should be OK.

    What worries me is 0 voltage at the DC jack. Double check that you connected the correct lugs to + and -

    - (ground) is the one that has its own angle (perpendicular to the other two) and has a flat part on the base. + is only the lug furthest away (below) from that. The one between them is the "ring" of the DC jack, and it does not carry any current. You do not use it in this box.

    - = ground
    | = ring (nothing)
    | positive +9

    If you are getting no voltage at the DC socket you need to check your supply - and then make sure you have the jack wired correctly.

    BTW: I am a newbie myself, and the builder of this box actually said he did not recommend it for newbies. I was able to figure it out by carefully blowing up the pictures, trading wires and by reading his notes very carefully. If you are new to basic concepts like continuity testing, you won;t get much help here - sorry.

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    1. "If you are new to basic concepts like continuity testing, you won;t get much help here - sorry."
      Why would that be? Why do you persist in the notion that newbies don`t receive help here, or they are ignored. This is a fantastic community with hundreds of extremely helpful members, however you seem to assume that because a newbie question goes unanswered or is answered in a manner you don`t fully understand, then this is some sort of elitist community where newbies are not welcome. Nothing could be further from the truth. As I have stated to you previously, the vast majority of people frequenting this blog started here as complete newbies and have reached varying levels of expertise, expertise that was attained by researching whatever they needed to know wherever they could find it. This blog (again as I`ve mentioned before) is a layout blog, not a one stop electronics tuition blog, however most people here will help if they can, but you need to remember that most folks will only really spot a request for help if they see it in the recent comments list, or they happen upon it while looking for something themselves. There is no staff here scouring pages looking for people requesting help, if a question goes unanswered it is most likely because it has gone unseen by someone who has the answer.

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    3. i can't agree with dexxyy more. i myself have started out as a "noob" and due to the help and support of many of the people here, as well as researching and learning things on my own, i have been able to modify and create my own pedals, as well as make layouts, and have/try to provide as much help as i can to others. to the point where i try to come on at least once a day to see if there's something positive i can contribute by helping someone, or making a layout, or even just making some silly stupid comment that i think is funny.

      i have been biting my lip about this for a long time now, but i can't not say anything anymore. comments like this has to stop, as the more i see it from you (motterpaul), i feel like its creating a negative feeling. if you don't get an answer you like, then look for it yourself, and learn. i seen in nearly every post on the forum and many of your posts here saying something to the extent of "i'm just a noob, blah, blah, blah," then something negative. i'm sick of it. i'm sorry you don't get individual attention and people holding your hand to teach you everything, or some how pass your their knowledge through osmosis, but just stop complaining about it. sometimes you need to research things on your own.

      not every question gets answered, but people try to help as much as possible. there is still the first question i asked on here unanswered under the russian green muff post. i had to figure it out myself, which isn't a big deal. i had to search online, in different forums like DIYSB or FSB, or even other places, not to mention different books i've read on electronics and building effects. you can't expect everyone to just GIVE you answers, you will have to do some work on your own to find answers.

      sorry for the rant, this just really grinds my gears. i've said it before and i'll say it again. comments like that are insulting to myself, and i would assume others, that have helped you and are hear to help others.

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    4. I`m not trying to be scathing but I had explained this before, it seems this was mis-construed. Looking at the tabs at the top of the page there are sections for offboard wiring, an explanation showing how to connect switches, pots, led etc. A comprehensive build guide showing a tried and tested method of building a layout, this methodology applies to every layout. A component section with info on most of the passive components used in builds, nothing for discretes or offboard components but anyone who has the time and/or inclination can feel free to add this at any time. A fault finding guide with a basic guide to finding most common faults, doesn`t include audio probing (I will do a tutorial for this next week when I return from holiday) there is even a layout section showing how to make your own layouts from schematic. Then there is the general forum.
      That, for me, is a pretty comprehensive list of help and education, all this on top of the 800 odd layouts not including the contributions of others in the forum section (many of whom learned how to do this via the layouts section)
      No, there is no soldering 101, we presume you can solder when you get here or learn elsewhere, no there is no detailed tutorial on operating your brand of DMM, we presume you read the instructions it came with or learn elsewhere. There are no tutorials for painting/finishing your enclosure, there are many methods of finishing.
      As stated before this is not a complete start to finish pedal building tutorial, but it is pretty comprehensive. If some of the very basics are not found here then research them elsewhere and come back and enjoy building some great pedals.

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  32. My DMM is this one: https://www.reliableparts.com/product/Digital-Multi-Meter-1477068/Electrical-Terminals-and-Wire-Nuts#

    It has the diode icon, which should be continuity, but there's no sound icon next to it (as the ones I've Googled have) and when I use it, no sound comes out.

    By the way, I fixed the box anyway! It seems that the issue is the bolts holding the speaker terminals. I removed the metal ones and it worked. I then went out and bought some nylon nuts and bolts and they also short it out. (How is that?). So I superglued the terminals to the box and now everything is just dandy.

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    1. glad to hear you got it working man. i took a look at the 3 DMM's i have, including a fluke and 2 cheap-o ones from harborfreight, and the continutiy test setting on mine looks like waves, or to be more descriptive like the wi-fi symbol on an iphone turned sideways. all it does is go "BEEP!" real loud if there's continuity.

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  33. I really apologize for any comments where you feel I have come across that way, but I honestly don't mean any disrespect for anyone and I certainly don't feel like I have a sense of entitlement. All I can say is this - it is very easy to misread a person's intent in postings like this, and I think you are misinterpreting things I write as opinions that in fact I do not hold or even mean to imply.

    To say I have a sense of "entitlement" would mean I have been disrespectful to people for not helping me. I don't think this is true. In fact, I have at specific times asked for "help" in ways that are far more specific to the circuits here and when I received help I have been very grateful. But MANY other times I have rather been told in no uncertain terms that this is not a place for hand-holding - these very words coming from the people who started this site; so after hearing it from the top brass a few times, I accepted it as fact "that is the way it is." Especially when they said it would be a drain on them doing what they want to do - spend time working on their circuits. I fully understood and accepted that.

    You know - I get the feeling I can't win here. I was in one board one day where someone recommended to me that the best way to get help here was to tell people my playing style and the sound I like, so I said I was in two bands (to describe what styles I play) and then described my equipment (to show what kind of tone I like). With the very next post someone accused me of bragging and said no one cares what kind of stuff I do or have. Geeze, wasn't i just asked?

    In other words - I have a sense of humor, but I keep getting the old switcheroo here. Someone will ask me a question, which I answer, and some time later someone comes in and reads a comment I made to one person, and it might be a month old, and instead of looking at it in the context of the conversation I was having - they choose to take it out of context and read me the riot act.

    Dexxy - you were explaining to ME why help can be hard to get here. I understood what you were saying. Was I rude to you in my response? NO. So, why are you now accusing me of being rude when I just told this person the same thing you told me - that there are not always a lot of people here to give you help - especially when it comes to the most basic things? Was it the tone of my voice? (that's a joke, this is text).

    If one thing has been made made clear to me here it is this - asking for specific help for the betterment of helping people trying make the circuits in this site is acceptable (IE: do you think a different value for "X" might make this sound better?"). But asking basic questions like "is it okay to have the ground on the jacks touch the case?" is generally a defensible reason to tell a person to go do their research. Those were the ground rules I was given. And I was just repeating what I had been told.

    I hope I have made myself at least a little more clear. I have met some very nice and cool people who always seem to see where I am coming from. But at the same time - I have also met people for whom I have nothing against, but who have chosen to use my post for chumbait for reasons I really don't understand.

    Bottom line - I hate arguing in message boards, so if you think I am being argumentative, please just remember that - I hate arguing in message boards. Its one of my least favorite things in the world. So, if you think that's why I am here - bottom line - that is not an accurate notion.



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    1. You know - I get the feeling I can't win here. I was in one board one day where someone recommended to me that the best way to get help here was to tell people my playing style and the sound I like, so I said I was in two bands (to describe what styles I play) and then described my equipment (to show what kind of tone I like). With the very next post someone accused me of bragging and said no one cares what kind of stuff I do or have. Geeze, wasn't i just asked?

      Um, actually no-one asked you, you just came out with it, and I was only pointing out that gear does not matter - if you like the sound of something then great - if you don't then try something else.

      It's this kind of constant passive-aggressive karate that is rubbing people up the wrong way.

      As you say youself - you hate arguing on message boards - after having an arguement!

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  34. John... I am especially sorry that you see my posts that way because I am in awe of your knowledge. I KNOW I am a blunt person, but that is just the way I was raised, including my days in the music business. It's off topic, but I just quit a band because we had a lead singer who could take NO criticism at all. Our first gig he was crowding me all night long, but I didn't say anything to him that night because I did not want to throw him off. I had been with the band four years, it was his first gig with us.

    The next week after the gig I said - "I would like to talk about something - some of your stage moves were really cramping my style" They were, but I thought that if I could just talk about them we could work it out and move on.

    His answer to me was "no one has ever said anything so rude to me in my entire life." And then he proceeded to think of every rude thing he could possibly think off to say to me including totally off the wall comments like "and your mother is ugly."

    My point is that not all that "sounds" like criticism is truly criticism - not in my mind - and seeing things as criticism and responding accordingly does no one any good. Asking questions or making suggestions is not being rude in my book. I am an inquisitive person who believes that asking questions is how you learn. HERE IS A GOOD EXAMPLE - I have stated the problems I had in learning this stuff several times. That is all on me - no one else's fault. But some people here seem to think I am blaming them for my mistakes. The only reasons I have stated the problems I personally faced is so I can enumerate some of the typical things a noobie might encounter - and hence help you help us. I am just trying to help, not complain.

    And being a noobie my only choice is to state it, or risk coming off sounding like a know it all (which I know I am not).
    I can be impatient, yes. I did live in New York for many years, and I am 60 years old, those things are probably reflected in my attitude. I have a lot of life experience, and like a lot of old farts, I tend to ask complicated questions. But also like a lot of old farts, I have a lot of respect for people of knowledge and accomplishments - especially when they help me achieve my personal goals.

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    1. dude, this is my last intended comment to you about this, if i have to i will reiterate it again. but i don't think you get what you're doing that's upsetting people here. so let me try to explain it another way.

      it's not that what you're saying is coming off as criticism or appears as if you're being rude, but you are and consistently make blanket comments about many of us that are big parts of the community. you don't mention people by name, and just same something like "you wont get help here if you ask _________," is saying no one here will help you if you want something. it's no different then if i said new yorkers are rude assholes. are some? yes, are all? no. you're lumping us all in to a category that isn't true, and it's super passive aggressive, which pisses a lot of people off.

      yes, there is no hand holding here, ie: someone will not take the time to walk you through a build. if you want to know how to build an effect in particular you follow the same guide as you would for any other build, which is why there is a tab at the top mark "build guide." if you need to know how to wire a stomp switch there's a tab for that labeled "offboard." there is a basic level of understanding that you need to have in order to build an effect, let alone anything that involves electronics, that you won't get help with, like grounding, soldering, positive and ground connections, etc. there are some things that you need to learn on your own, and you can do that by researching online, or reading books on electronics, or even reading posts on forums like DIYSB or FSB. i have this same issue with my 15-18 year old students. they expect me to tell them everything, not that they may have to do some learning on their own in order to understand what i want/need them too. i would not expect that from someone of your age.

      btw, i grew up in NJ, and have lived in NYC as well, and that's not an excuse, nor is your age or that you're a "noob." i may be one of the youngest members here, but there are a lot of guys here as old and older then you that seem to be able to get it. i'm glad you have respect for those with more knowledge the you about certain things, but you need to be receptive to the help, and listen to what they have to say.

      with all that, i'm done with this discussion/argument. i will stand up for anyone that's part of the community, as myself and many others have gone from "noob" to someone that contributes and has made this community what is is. which is a helpful, receptive, and welcoming place for people that want to build effects. but, i'm not going to keep going over the same crap about your actions over and over with you, it's not worth my time and energy.

      Delete
    2. and just to be clear. just because you feel you're not giving a warm welcome, don't make it out that "noobs" are unwelcomed.

      Delete
  35. Danny - glad you got the box fixed - really. I know it was not an easy project, and that it required some sleuthing to finished because the post was never intended to be a "how to do it" manual. So, it appears you do have some skills after all.

    The next step is using the audio probe - which really does work quite well. It helps you find shorts.



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  36. It's a fine line for the things one must figure out by him/herself and the things that are complicated enough to seek assistance for. It is more than ok to ask for help, and as probably all of the readers know, there are very high number of active readers who can and will offer help when needed. Even myself and Mark do that a lot too. Nevertheless. One must be open to think, read and learn by oneself. We can't do everything for others, no matter how much we want to. By the tone and content of the questions, everyone can clearly see who are willing to do some of the thinking, and footwork, by themselves.

    This blog has been here since february 2010 (Seems like we'll have our 5th birthday soon!!) and i've been one of the administrators since november 2012. All the way from the beginning, this blog has been very reader friendly and we as administrators have done a lot to keep it that way. We do not want any flame wars here and we will hold on to our zero tolerance policy on that subject. All the other being-a-dick-towards-anyone-behaviour is also not tolerated. This has been, and still is, a very nice and welcoming place for builders from zero experience to those who are running legimate pedal businesses and creating their own designs.

    As a rule of thumb - if you don't have anything positive to say, don't say anything. There are other forums for letting people know that you feel bad. This is not one of those.

    I can't empasize this enough. Everyone needs to learn these things by themselves. We offer a lot and ask nothing in return. If we had a dollar for each time there has been a comment like "where is the output", we would be rather rich. This is one of those things we (or anyone else for that matter) can't help you with. It clearly says "volume 2 to output" on the layout. One must figure out things like this by themselves. One needs to learn how to use his/her DMM by oneself. No one can help you with that. How long can one be a newbie? Depends. How much work is this person putting in it by him/herself? More one does the footwork for oneself, the more valuable his/her notes become for the whole community.

    My 2 cents. And this stops now. One more whine and i'll delete all the comments on this post.
    +m

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  37. Great Miro! I've just started building a breadboard and might include your "probe-on-a-switch" idea. Thank you.

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  38. Made a point of building this test box today to save myself a lot a head scratching. Many thanks Miro. It maybe a good idea to have this as a menu header if its not already so people know its there. Now to build some more pedals.

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  39. I wanted to have something like this since I read about the "Beavis box". Coincidentally, I had gotten that same plastic box from Tayda to use for a prototype, and then this post came up! Finally, having finished my test box I have to thank you Miro for sharing - the probe idea and using that 4-way terminal was great. My box works perfectly. I wish I had something like this 2 years ago when I got into this pedal-building hobby.

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  40. Nice idea. I have a question, probably the answer has been made several time but I can't find it; How do you set the vero on the box ? how to anchor the vero in the box and be sure that the back (solder side) won't touch the box made of aluminium ? thanks !

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  41. The vero stays outside the box, and connects to the terminals marked in/out.

    The box itself is made of plastic specifically so it won't conduct ground or anything else. It has to be that way, or else you have to isolate the guitar and DC jacks from the box (if it is metal).

    Every completed vero (with pots connected, but no footswitch, LED or DC jack) has four wires coming off of it: +9v DC, Ground, In and Out.

    Practically everyone here who builds a project gets to this point (of having these four wires). This is all you need to test a newly built circuit completely, but you need a platform for connecting the guitar (In), The amp (Out), and the power ( +9 and Ground).

    That is the purpose of this box. It is made to take a DC supply (or battery) and feed it to the vero circuit (and make it switchable, which is handy). It is also made so you can plug in a guitar and amp. The audio tracer is also handy, nd works as advertised.

    I still use my box (was using it today), but sometimes I also just use a breadboard - nothing fancy, I have a terminal block with guitar jacks, and I have a DC connector with wires coming off to go to the DC strips along the top & bottom of the breadboard..

    The more you do these circuits the more you see that they all require the same (or very similar) off-board connections. For that reason, there is just one article on how to do that (this is a good topic for outside research). Boxes like this are made to reproduce the standard off-board wiring quickly, so you do not have to solder up DC jacks, guitar jacks and power to every new project just to test it. It works well, too.

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  42. Thanks for these precisions. In fact I had also a question about how to set the vero in the final box made of aluminium , I mean having a strong fixing and of course not touching the box ground ! (insulating adhesive ?) Thanks !

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  43. In a metal box there are different methods - you can use plastic spacers, etc, but most people just use plastic covers on the backs of the pots and lay the vero down on those (component side up). The screwed down bottom keeps everything in place.

    Some people will glue the vero to the backs of the pots (or a piece of plastic placed between) - but in most cases the wires and plastic pot covers (pot condoms) already in use provide enough insulation to keep the vero from shorting out and it doesn't have a lot of room to move round.

    Thick tape also works as an insulator - double sided (but Mirosol mentions a brand not to use in the article above).

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  44. I used this leftover box. Not so pretty but works.

    http://imgur.com/S6cst2C,24RM5bQ#0
    http://imgur.com/S6cst2C,24RM5bQ#1

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  45. Two questions on this:

    1. This is my first time using heat shrink. I did like the pictures but am wondering do you need to soldier the wires some first or does the shrink take care of it? I twisted the LED and wire together some and then shrunk it. My LED for the 3PDT is not coming on so I am wondering if I cooked it or if it's not getting connection or if it needs a circuit plugged into the speaker terminals to work. The probe light comes on so I think I fried it with the heat gun.

    2. For the test probe. As best I can tell from the photos the test probe has a ground wire and the wire from the cap. Are they both connected at the same spot? The pole I got from Tayda has a little screw on terminal and nothing else.

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    1. 1, Yeah, you want to solder the wires together. Shrink tube really just secures it, and prevents shorts from happening. Also, I just kind of skimmed over this so I may be off base, but you need to connect a current limiting resistor between your power and LED, that may be why your LED is fried.

      2. Probe post ->capacitor->DPDT. There is only one connection to the post, no ground.

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  46. Thanks!

    My actual problem turned out to be that I forgot to wire the ground to the 3PDT.

    I have to double check the probe now. I think I wired both to it but it is working.

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  47. Very nice design. I built one of my own based on it! Thank you for your work!

    https://www.flickr.com/photos/r_jackson/23096735233
    https://www.flickr.com/photos/r_jackson/23344122919

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  48. Help!Just recently built this.Glad I finally did.
    But one thing...I have very low volume when I flip the bypass switch.I dime guitar,the amp and the pedal volume.Still pretty quiet compare to when the switch is off.Any ideas what mistake I may have made the causes this?

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    1. Check all your ground wires are in the correct location. If you have to turn everything up, I'm willing to bet you've either missed a ground or grounded an input/output are what you're actually hearing is crosstalk. If still no joy, post some hi res pics. Good luck

      Delete
    2. Just FYI: I found out on mine that the +9v output is still "live" even when bypass is flipped which in many cases will keep a circuit from working. If your circuit bypass suddenly works if/when you pull out the DC power plug then what I said above is probably the case (you can also measure it with your multimeter).

      This may just be my error, but I thought I built mine according to spec. Obviously this is not really a good situation (always having it juiced up) so I have gotten used to not using the power bypass switch - I just take take the DC plug in & out.

      If you look closely there is probably a better way to wire the switch so +9 is switched off when bypass it hit.

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    4. I would like to add, however, that I still use this box all the time. In fact I just spent 2 hours with it troubleshooting my chorus - using the audioprobe which works great.

      If I would chaange any three things it would be:

      1) Fix the "bypass" so +9 is turned off

      2) reverse the guitar and output jacks - because most pedals load on the left. When you turn the box around so the four in/out circuit terminals are in front - the guitar/amp jacks are reversed so the guitar is on the right.

      3) I would also put the in/out jacks on the right and power on the left, only because it often seems a lot of circuits have to power input on the right, not the left, so you end up crossing wires.

      Delete
    5. I think there's a misunderstanding here. One switch is your standard TB switch which switches AC signal only, just like almost every layout you will see here. The other switch determines whether the output of the TB switch or an Audio Probe goes to the output jack. DC is never turned off here or on most other layouts. If it was it would probably make a big pop sound.

      I just posted my upgraded Test Box in the forum and included a wiring diagram. I've used different connections than Miro but it's functionally the same.

      http://guitar-fx-layouts.42897.x6.nabble.com/Stripboard-Breadboard-Interface-for-beginners-td5260.html

      Delete
    6. Ciaren, I really like your idea of incorporating an oscillator in the box. Since it needs power, I think I will just put mine inside of my box and connect it to the DC source inside (and add a switch).

      With this box, if you look at this pic:

      http://2.bp.blogspot.com/-ZAOfEhI1-pE/VAm1A8ZRSGI/AAAAAAAAFJg/5tH8U-SqG5A/s1600/TB-08.jpg

      it shows the red wire going from the DC jack to the small piece of vero in the middle and from there to the terminal point to power up the circuit. I don't see it being switched off in any way. I know that is the case with mine - (The Dc is always on) but I might have made a mistake - I built it a long time ago.

      But if this person is having the issue he described, I will bet you that is the reason why.

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    7. Paul, the dc is always on on every TB pedal. The bypass switch in the off position does 3 things ( 1 for each pole) pole 1 disconnects the LED from ground (turns the led off) pole 2 grounds the circuit input (stops signal bleed through) and pole 3 connects input to output (hence bypass) There is no switch to turn the power off to the dc jack or from the dc jack to the circuit.

      Delete
  49. Thanks guys!I'll look into those suggestions.

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  50. Okay - I see your point, that I probably also have an error in my box.

    But the point is that this is a TEST box, and if a person thinks switching the bypass is enough to stop the +9v from going to the circuit - so he can switch a transistor or something, then he had better think twice, because that circuit still has voltage.

    (Miro did not write this up to be an instructable, he wrote it as an article - all I did was copy the pictures the best I could - if I were to do it now my bypass would work, but I was a newbie like the guy above).

    Anyway, I don't really mind that bypass does not work because the test box still works great. If I want to bypass the circuit I just take out the plug.

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    1. I don't think you are seeing my point and no your box doesn't have an error. The test box acts like any other true bypass pedal except it allows you access to the input, output, +9v and ground so you can attach any circuit to test it before boxing it. The bypass switch, like every other true bypass switch I have seen bypasses the signal, NOT the voltage. I don't see where you think the bypass doesn't work, or what you think you would do now to make it "work". All the pedals you have built will have voltage in bypass mode, the test box is no different.

      Delete
    2. Dex...

      I do get your point, don't worry. My box does have an error in that I don't hear the circuit in bypass mode when the DC jack is attached. That means it is not working in true bypass. If it was true bypass I would hear signal flow through the box in bypass mode.

      I looked at my box and I can see the footswitch is not wired the way I do it now. But Like I said I built it a long time ago and I did struggle with offboard wiring at first - mostly related to LEDs.

      In terms of how I would fix the box - I think it would be a good idea to disable the +9v to the circuit in bypass mode so you can work on the circuit without disconnecting anything from the box. You probably need a 4PDT to make it that way, though.

      Thanks for trying to help, but I know how TB works now, I guess I was just holding on to an old misperception because I also have some older pedals that I also probably wired incorrectly because they don't work in bypass unless you disconnect the +9 jack. But, that's OK, I don't think I need to delve into what I used to do wrong since my pedals do work in TB just fine now.

      You helped clear up my misperception - thanks. I am clear now.

      Delete
    3. Specifically, I left out the link between lugs 6 & 7 on the footswitch - just fyi.

      Delete
  51. Went back through and ran all the ground wiring again.For some reason I had went to my output jack before the input jack.
    Now I'm not suffering a volume loss,but the effect sputters out and pops.

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  52. So your test box now works as it should? If so then the box has done its job. It has found errors in your test circuit. Have you started probing? Basically, you follow the signal path probing for sound. If sound stops or gets weird then you have a problem either with that particular component or somewhere in that area.

    The probe is also great for making you look at your build in focus. Many times I've started probing and found I've misplaced a component that I couldn't see before.

    I'd suggest you move the discussion to the posts concerning the circuit you're building rather than here if your test box works as it should. Or start a thread in the Debugging section and post pics as suggested above.

    Good luck

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  53. Multimeter is MIA at the moment due to a recent move.
    Will look into the posts of what pedal I was testing and go from there.Thanks

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  54. So is it just me,or does the test box not like builds with transistors?
    Have no issue with time based effects or modulation type effects.But always have issues with fuzz and such.
    When I box them up they are fine,so I'm guessing it's either grounding or shielding?

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  55. Sorry - the box is agnostic - it will take any kind of circuit. Maybe check your grounding.

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  56. http://tahmidmc.blogspot.in/2013/01/using-sg3525-pwm-controller-explanation.html?showComment=1455258483621#c8137922455663982861

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  58. Thanks for the inspiration, this is my version:
    http://dunning-kruger-effekten.blogspot.se/2016/04/10.html

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    1. Nice! Seems like you took it a few steps further :)
      +m

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    2. Good idea to build a small amp into the box - saves on electricity and random loud noises coming from a loud guitar amp. The only thing you could add is an oscillator for audio testing.

      Delete
    3. Thanks! Paul: I actually have. The BNC connectorn named Function Generator is input for example sine wave audio generator.

      Delete
  59. Great project! I built the "Really Cheap Compressor" last night and tested it spaghetti style on the floor in front of my amp. This test-box would have made things easier. Definitely will be my next project.

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  60. I Guys, total Dutch noob here. first of all great site & idea's and explanations, loving it!

    I build this test box, which seems to be working but I was wondering, how do you get a Lab-power supply to power the box ? Did you solder a wire with a DC 'pin' to the lab power to connect it to the DC 'in' on the testbox?

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  61. This comment has been removed by the author.

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  62. Another noob question, sorry. What happens if I use a polarised electrolytic for the 1uF probe cap?

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    1. That works as well. Positive connects to probe, negative to output.
      +m

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  63. Does the probe cap have to be 1u or can u use 100n or any other value u have to block DC

    I'm just wondering why it's 1u

    Cheers great wee project btw

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    1. No matter what value you have. Just had 1µ on hand.
      +m

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    2. Thanks for posting this, Mirosol! After 4 years, I finally built this, and it worked on the first try. This will be great for testing new builds and diagnosing failed builds as well.

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  64. Thanks for this build. Just getting into building and this really helped me work through issues with my Sunface BC108 build. I also rolled up the Germanium Transistor tester into the same box. Thanks again

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  65. Great build mirosol, thanks. One question tho, and it may sound stupid, but is this wired for DC centre negative or positive? Only reason I ask is that I couldn't get the LEDs to light up so was fiddling around tryin to figure out why. I connected my battery snap to the DC input jack and then accidentally touched the battery on the opposite connections and the LEDs lit up. If anyone could clarify this for me, or tell me what I've done wrong, that'd be great thanks

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  66. It should follow the Boss standard which is center negative, outside positive.

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    1. "LEDs go their respective holders and cathodes need to be soldered to lug 3 of the DPDT and lug 6 of the 3PDT. The longer free red wire goes to DC jack's sleeve and the shorter to the first speaker terminal lug."

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  67. Yeah, sorted it now, thanks mate. Turns out I am a total idiot 😂. Had the LEDs wired backwards. That's not the worst part. I had taken them out before to make sure I had them wired round the correct way and put them back in cos I thought I had it right. Feel like a bit of a mug now. Anyhow, lesson learned. Thanks again

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  68. Hi Guys,

    I built this yesterday but I ran in to the following problem.
    I have a guitar in the Jack in & Amp in the Jack out, The 3PDT switch is called "Switch", the 2PDT is called "Probe":

    in through bypass mode the guitar is heard through the amp, but when I flip the switch the sound is gone. When I connect the in and out lugs with a jumper cable, No sound is beeing heard ?

    Any ideas ?

    I tested al the grounds for continuity. And also when the switch is on, I put jumpercable directly from the guitarjack in to the amp out but still nothing is heard ?

    can't wrap my head around it ?

    Maybe anyone has een idea ?

    Thanks in advance,
    Danny

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