Wednesday, 25 January 2012

Hermida Zendrive

Another popular pedal and rightly so, this is a great sounding overdrive.




Geiri's video of his Zendrive build with AMZ MiniBooster in the same box.  Thanks for the vid mate:





BUY A KIT

229 comments:

  1. Hi Mark,
    Verified! Nice sounding little box, smooth compression and great drive. The only problem is that the volume pot at about 90% makes a sudden boost. Tried both lin and audio pot. I used OPA213 but that can't be the cause i guess. If you have any idea, please let me know as I can't wait boxing it! :-)
    Thanks.

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    1. Thanks for verifying Krik. If the taper doesn't seem right with linear or log, then reverse log could well even things out a bit. Only problem is not many people are stocked up on reverse log pots.

      You could always give it a try by making a reverse log pot out of a higher value linear and resistor.

      Have a look at The Secret Life of Pots:

      www.geofex.com/article_folders/potsecrets/potscret.htm

      or this calculator:

      http://www.diystompboxes.com/analogalchemy/emh/emh.html

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    2. Easier still is to wire a log pot up backwards. The gain control will work in reverse... ie turn to the left = more gain. Now you don't have to buy another pot but it will work like a c taper. Just turn it in the opposite direction.

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  2. Finished this build and it sounds great! It's late so I haven't gotten to crank it yet, but I can't wait to campare with the Amp11... Either way I can say I am happy with my OD options at this point. Thanks for the layouts!

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  3. quick question for you. i was thinking of building this one, but looking through my parts i don't have any 2M resistors on hand. i do have 1.8M and 2.2M, so i was wondering if i could safely sub one of those values in place of the 2M? thanks again for all your help.

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    1. Yes either value would be fine, it's an anti popping resistor so you could even use a 1M as many other builders do

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  4. I'm guessing this is based off the Sabrotone vero? The Gain knob is wired backwards in this schematic. Gain 1 and Gain 3 should be swapped. :)

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    1. None of my layouts are based on anyone elses. It's much easier to follow a schematic than trying to decypher someone elses interpretation first. We could well have done them from the same schematic though, but thanks for the heads up, I'll update the layout now.

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    2. No you didn't :) (or i printed it out before you did)

      Boxed this up today and it's really just perfect, warm and smooth overdrive.

      Thanks again Mark!

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    3. http://mirosol.kapsi.fi/varasto/boxes/zen.JPG
      +m

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  5. Done. One of the best OD I've ever played. I used 1n4001 as D1 and D2 and 1n34a as D3 and JRC4558DD IC. who said this baby doesn't have much gain on tap? This one is now a keeper for life, it sings at both low gain and high gain. EJ,Carlton and Ford is no longer an impossible tone to get....:) . And I think the the layout has been corrected because my gain pot works fine as it should. Cheers. Keep up the good work mark....:)

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    1. Yes this is my favourite too. The Timmy ran it close and is definitely more versatile but the Zendrive sounds so pleasing to my ear that it's the winner for me.

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  6. What does the voice knob do? I built one (and I love it!) but the voice knob doesn't seem to make any difference to my ears. I'm gonna double check if I wired it correctly though!

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    1. Voice controls the frequency response before the clipping stage between two set levels, so ccw should be fatter, cw should be brighter and with slightly more gain. Tone is your conventional tone control after the gain stage with a greater range.

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    2. Sorry to keep asking for about this and that. I'm wondering what could be wrong with the voice knob on my zendrive. I've gone through a few videos on youtube where I can hear quite the difference between the voice settings. I can't hear those changes when I turn the knob on mine. The board is laid out correctly and the knob is wired correctly, otherwise there wouldn't be any sound coming from it, right? If I were to disconnect the voice knob, the pedal would stop working?

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    3. Oh man, I just labeled the enclosure the other way around. The voice DEFINITELY works but the tone doesn't do any difference so I need to check that out.

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    4. Hee hee. In answer to your question about the Voice control anyway, yes the circuit would still work fine without it. It's just a variable pre-gain filter and not necessary for the effect to work (although it may not sound as good). Tone is a lot more simple though, just a 50K pot in series with the signal path to create a low pass filter (along with the preceding 10K resistor) with the following 3n3 cap to ground. Depending on the position of the tone pot, it will start rolling off highs starting anywhere from 800hz and 5khz. So you should be getting plenty of range from that pot.

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    5. Thanks for the details. It's weird, I had a look into the pedal and I can't seem to see why the tone isn't working. The pot might be dead. I'll try swapping it out for a new one.

      Cheers!

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    6. if i want to skip the voicepot, is removing the 10k to voice 3(and the voicepot itself ;) enough?

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    7. I don't quite understand what you mean by removing 10K as voice 3 connects to 1K resistor - while voice 1&2 are connected to 100nF cap.

      But if you really want to remove voice control, you could just use link or any resistor ranging from 1R and 10K between the voice wire holes. Link would mean that voice remains in CCW position and 10K would be for CW. I don't know if the circuit will work at all if the wires are just snipped.. Link (or resistor) will be safer thing to do.

      In my opinion, the voice control is very good for this circuit and i personally wouldn't recommend omitting it.
      +m

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  7. Just finished my build and it's working well--for the most part. For some reason i don't get any volume at all until the volume is at 90% or higher, and at that level it's still pretty much only at the same level as the clean signal. The volume knob is also affecting the LED somehow...At 0%, the LED is fully on...then as you turn it clockwise, the LED dims just a bit..then is back to full brightness at 90% clockwise or further. As far as i can tell the Gain, Voice, and Tone controls are all working properly. Perhaps a bad volume pot? Or do i have something crossed somewhere?

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    1. You have a ground bridge somewhere. I once installed the vero to the bottom of a case with particular two sided adhesive tape. Yup. This one wasn't exactly non-conductive...

      Check if your pots are wired right and there's no connection to the case. Other than that, knife through all the gaps in vero.

      Your symptoms tell me that there has to be a ground leak/bridge somewhere around there.
      +m

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  8. Just got it all working...My wiring wasn't super neat (or at least not as neat as i'd like) to begin with, so i just stripped everything out, made sure all my traces/vero gaps were clean, and wired everything carefully...All working well now, no LED/knob interaction, and sounds fine to me. The volume pot is a bit scratchy, but seeing as it won't be moving while the pedal's on, that shouldn't be an issue. Thanks for the help!

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  9. This is an awesome overdrive! Thanks Mark!!!

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  10. I am almost done with this, but have probably dumb question: How do I figure out which direction the op amp chip faces?

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    1. My guess is that it faces up as I think I remember reading that op amps get V+ at the top-right pin, which would correspond to the 9V row in the diagram here.

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    2. There's a notch drawn on the top side of the opamp.. So that means that top is the shorter side with the notch or dimple.
      +m

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    3. Thanks mirsol! I just realized I couldn't see the notch in the diagram above, because I was looking at on an iPhone.

      If I want to replace the ceramic caps with tantalums, how do I figure out which way the polarity goes?

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    4. Ceramics? What caps do you mean? I would only use ceramic for 100p.

      But the other non-polar caps on the borad.. Left hand side 470n, negative to input (,or down). 100n, negative to Voice 1&2 (,or up). 3n3, negative to ground (,or down). Right hand side 470n, negative to 1K output resistor (, or up). That 100p should be negative down...
      +m

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    5. Thanks mirosol! I am making a run to Jameco this afternoon, to get some low-value ceramics.

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    6. Get multilayer ceramics or mylars instead of basic ceramics. Ceramics produce unwanted noise when they are in the signal path. 100pF here is on the feedback loop, so that doesn't matter too much if it is simple ceramic.

      Also, check the mylars at taydaelectronics.com - They are cheap and good.
      +m

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  11. Hi everybody!

    First I will just say that i LOVE this site! Good work with it!

    Then, i built this one, and it's great, but I may like it even better without the transistors (which i first forgot to socket). What do the mosfets do, really? Drive the diodes harder for more gain? The overall volume is at least as loud witout them...

    And, i used one bs170, as i only had one 2n7000 on hand. Will it make a difference?

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    1. Those are for clipping, along side with the diodes. It's sort of like "shaka braddah" clipping described here:
      http://www.generalguitargadgets.com/richardo/distortion/index.html

      So the board will work just fine without them. Omitting those will just change the texture/colour of the clipping.
      +m

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    2. And if you use 1 x BS170 and 1 x 2N7000 that would be fine but the BS170 will need rotating 180 degrees to the orientation shown for the 2N7000 in the layout.

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  12. Love this pedal. it has a really great mid range without over doing it. Here is a pic:

    http://i1273.photobucket.com/albums/y413/glenncohen/_DSC0087.jpg

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    1. Sorry only just noticed this one, looks excellent!

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  13. Built this tonight, but only got to test it at low volume
    Sounds really good ,cant wait to blast it tomorrow
    Had to use a 2.7M resistor instead of the 2M will it make a difference ?

    Thanks again Mark for all these great pedals & a new addiction :-)

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    1. 2M7 will be fine, as it is so called pulldown resistor that is used to prevent popping sound from the footswitch.
      +m

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  14. Thanks Miro
    Cranked it up & its soo nice, But I'd love it to have just a little more gain!
    Any way of doing this ?

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  15. just as a note the two cuts on rows 1 and 3 show in different columns (9 or 10) on the cut guide and the schematic. I understand this has no effect on the circuit however if you are using the cuts as landmarks for placing your components it can be a little confusing.

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    1. Thanks for the heads up, layout corrected

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    1. never mind found the issue, I was using a 500 ohm pot instead of 500K

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  18. Okay, got the Zen working on my bench, but I am now boxing it and confused about how to route the Output to Volume 2, when using this Beavis stompbox wiring diagram: http://www.beavisaudio.com/techpages/StompboxWiring/

    Specifically: the Zen has Output going to Volume 2, but the Beavis instructions have Output going to Lug 9, on the stompswitch.

    Please help as soon as you can! Made this circuit for a friend, who is coming over shortly, and I can't finish without this answer.

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    1. The output of the board is actually the volume 3 wire which obviously goes to the volume pot. Then volume lug 2 is the actual final output which goes to the stomp switch.

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    2. Sweet--works great!

      Trying Landgraff Mo'D next :-)

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  19. Hi Mark,

    Could you make a tagboard layout for this one?
    I prefer te work like that?
    If you got better things to do, I'll understand that :^p


    Grtz

    R

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    Replies
    1. My friend Pawel already did an excellent layout here:

      http://www.turretboard.org/?p=50

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  20. Very nice pedal!! Thanks Ivlark! I have only one problem, an oscillation when I use power supply. What can I do to eliminate it?

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    1. You could try increasing the 100u and 47u caps, and maybe add a low value resistor such as 47 ohms in series with the 9V from the adapter. But it may be that you just have a noisy power supply that will be difficult to keep quiet, and so may need to get hold of cleaner supply or conditioner.

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  21. Is there much difference in sound between the AD712 and the OPA2604?

    I can't seem to find an AD712 at a sane price - they are about £6/ea on ebay.

    Tayda have the OPA2604 for $2.94.

    Are there any other equivalents which will sound very similar?

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    1. http://www.rapidonline.com/Electronic-Components/Ad712jnz-High-Speed-Amp-82-0455

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  22. Built this one a while ago, here are a few pics. Sorry, no gutshots as it is extremely messy. :)

    http://bit.ly/ZgN63C
    http://bit.ly/XhfZt7

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    1. Wow that is stunning! Great job! Can I ask how you did that - is it etched?

      I've just built the Zendrive - its the best sounding overdrive I have, but mine doesn't look half as good!

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    2. Thanks man!

      Yes, it's etched and this was my first ever etch. I've only done two after that (see Wampler Black 65 comments, don't have pics of the third one) because it's really messy and time consuming. I have a small child and a small apartment and some things are just too much hassle.

      There is plenty of etching info on the interwebz but I'll gladly answer any questions you might have if you want to do your own etching.

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  23. Hi there,

    Is it possible to get some more top (crisp) out of this little box? I miss the last "zing".....

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    1. Really? I've built a few of these and I always find it easy to get it nice and crisp using the voice and tone together. You know that the voice sets if it's distorting at a lower or higher frequency, right? The higher the frequency, the sharper and crisper it becomes.

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    2. Yes, i mean it. I think the voice knob is a bit too mid toned. I would like to have something that opens it up in the very top frequency. (10-15 khz).
      Other than that it is a very nice unit.

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  24. HI,

    Built this circuit yesterday evening. Everybody raves about this overdrive, so I had to build it to give a try. Very few parts and straight forward build in a few minutes.

    Wel, have to admit that the result is amazing, and now I can understand why this pedal is so highly considered.

    Will get boxed for sure :)

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  25. can I use BS170 instead of 2N7000? They are very similar or not

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  26. HI!
    can i use BAT42 instead BAT41?

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  27. Hi Geiri, IvIark,
    Does anyone have the diagram/layout/schematic of the outstanding pedal, "The Invader" Zendrive build with AMZ MiniBooster in the same box"?

    I have a great friend who is helping on my build. This will be a gift for my son.

    Question, how can you email someone on this blog?

    All the best.

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    Replies
    1. Hey there, that's a pedal I built. You wrote to me on my YouTube account. It's just a Hermida Audio Zendrive with an AMZ Minibooster in front. Both layouts are from this site. Good luck!

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    2. Geiri,

      Could you our someone help me with a Zendrive question about reading the schematic Input jack and how to take that info and use it for a breadboard. This is my first build.

      finom1@gmail.com

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    3. This comment has been removed by the author.

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    4. I see below that you are breadboarding this? What info are you missing?

      If it's only the input jack (and I'm assuming the output as well :) ), just take the jack tip to the wire marked "input" and sleeve to any ground point on your breadboard. Likewise with output.

      Is that what you meant?

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  28. Where is everyone buying there parts?

    If you wanted more of a Mid boost what needs to be done?

    Thank you Geiri, Mark,
    I am new at this and I am going to try to build this on a solderless breadboard with help to learn what to change to voice it. Any advice?

    Thanks again. finom1@gmail.com

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  29. hi did someone used AD 823 AN cause for many people is the best sounding ic , thank you very much michael

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  30. I was wondering if electrolytics are marked with the negative or positive?

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    Replies
    1. The negative is the little light blue "-" on one side of the cap

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    2. Thanks, that was quick. I also see somewhere that the pots have been included in the drawing, I just like to assemble and therefore likes to have in with a silver poon. Any chance of having the wirers drawn up here?

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  31. My Audio demo. I used all exact components and the AD712 chip

    http://snd.sc/17rXqbH

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    1. OK, now I KNOW I'll never ever ever ever be posting clips of my "playing".

      Ever.

      Ever.

      The hat's off, man...

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    2. Damn Vince! That's some soulful playin'.

      Just got my AD712 in a shipment on friday. Now I'm even more keen to throw together another Zen Drive ( sold the first one...).

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    3. I cringe every time I listen back to a demo I've recorded, partly because of my crappy playing, partly because of my crappy recording technique. You seem to have nailed both Vince! :D

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    4. I've used a OPA2604 in a couple of Zendrives now with excellent results, never tried the AD712 but it'd be nice to do a side by side to see if there's much difference.

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    5. Madferret

      I had both OPA2604 and OPA2134 in my original. I really liked the 2604. I've just always wondered if the AD712 made any difference. I'll socket the build and let you know if I hear any difference.

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    6. Haha... thanks for comments ;o) ... years of nagging women and being stone broke helps.

      It would be good to hear any differences between the chips. I got mine from eBay at 50 for £42. Not a bad price and they were really fast delivery.

      http://www.ebay.co.uk/itm/50PCS-AD712JNZ-AD712JN-IC-DIP-8PIN-NEW-mjL5-/181067258666?pt=LH_DefaultDomain_0&hash=item2a28731b2a

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    7. Great demo mate, sounds just like my original

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  32. I see on some other boards you have drawn up the pots as well, any possibility on this here?

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    1. Is that really necessary? With this picture and wires being numbered, you shouldn't have any problem wiring it up.

      http://4.bp.blogspot.com/-Eu1vuXVH3UM/TzGNIkeLuAI/AAAAAAAAAlM/h7re0CGH6A8/s1600/Pot20numbering.jpg

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    2. Ok, thanks, didn't get that the numbers referred to the lugs on the pots,.

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  34. I was wondering if anyone would care to have a look at theis> http://www.flickr.com/photos/97574148@N04/9057052097/

    I get sound through, but not anything when effect is activated.

    Thanks.

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    1. Hi, the board could be shorting out against the case, maybe put some electrical tape along that wall? Also some of the soldering around the DC socket looks like it could do with a little touching up, I'd reflow that and maybe trim the remaining wire so there's no chance of it brushing against anything else.

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    2. Hi and thanks. Now I ge sound through, but the gainpot is not working, I've checked mos things now. Any idea?

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    3. Is the pot working at all? When you measure voltage across pins 1-2 or 2-3 and turn the knob, is the value changing?

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    4. All the pots are working. Tone and volume seem to be working the sound as well

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    5. Well that's interesting. If the actual pot is working yet you hear no difference in sound when turning it, then I'd venture to say that it is separated from your signal path.

      Check this out (dunno which schematic Mark used but all Zendrives are alike):

      http://www.nxgeneration.com/index.php?topic=1235.0

      Check for continuity between pot/resistor ends and mosfet/diodes. The only way for it to not affect the sound is if its somehow disconnected from the rest of the feedback loop.

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    6. Short between gain 1 and 3 would explain it.
      +m

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    7. It certainly would and it would come up on his continuity tests. He said that he took a close look at the pot so I looked elsewhere.

      It's not easy to see on his picture but the actual pot doesn't seem to be shorted.

      Rivermen, I can't see because of the transistor, but is your gain1 (orange wire) soldered to gate or drain?


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  35. the orange one is soldered to no 3 tag.

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  36. Sorry, also to the drain as in the drawing.

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  38. Been using a Timmy for a year & just built this- I'm torn. Only want one OD on my board and the Zendrive sounds rad with humbuckers. Maybe I'll built a bigger board...

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  39. Build that is, not "built".

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    1. The Timmy and Zendrive are my two favourites. I suggest making a double pedal in a 1590BB box with them both in (Zendrive first), then you don't have to miss out :o)

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    2. Good point, but no 1590BB needed, just a 1590B is enough, so you develop your build skills :)

      BR

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    3. Dude! B With 2 stomp switches and 8 pots?... :P
      +m

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    4. After the Musket and the Megalith, I believe it doable, 8 pots, a toggle switch + 2 stompwitches. Wanna bet? :P

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    5. Possibly, just possibly doable, definitely, very definitely fucking crazy tho'.

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    6. Don't want to bet on it, but i'd sure like to see it :)
      +m

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    7. I would love to see that!

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    8. I put this into a 1590bb along with a Timmy and have an effects order toggle. Has anyone had any issues with the pedal squealing? of course I have to max the drive and volumes + have the trebles cranked... massive gain that way and really not usable however is that normal? LOL
      otherwise this is a fantastic combo! I can dial in some great settings that I can use in a band. :-)

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    9. Yes this is one of my favourite combos. As far as oscillation goes, I'm not too surprised to be honest. One thing that can often cause oscillation is crosstalk between close input and output wires, especially in higher gain circuits, and using an order switcher means that you're immediately putting input and output wires over and around each other for both circuits.

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    10. hmmmm... I may remove the order switcher then and clean up the input and output wires and wire everything with some shielded wire.
      I like the Zen into the Timmy better and the order switcher now is moot...

      thanks!

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    11. Yes it's always Zen into Timmy for me too. The Timmy has the better EQ so it makes sense.

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    12. Got it!
      I took out the order switch... since I prefered a Zen> Timmy and rewired everything with some good shielding guitar wire for all the inputs and outputs...
      AWESOME pedal now... in fact you know you have a winner when you plug it in and the next thing you know... a good hour has past and your still jamming going WOW! hehee
      soon as I get my graphics done and she is all pretty, I shall take some pics for your collection lvlark

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    13. Nice one Leo, look forward to the pics

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  40. Great idea! 1590BBs though... I already have a clarinot, uglyface, tremulus lune and tri-vibe (to be boxed) hogging space. Who am I kidding? I have more boxed pedals than I could ever step on in a band.

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  41. doable if using 9mm pots for sure! mixed with a bit of luck and carfeul drilling haha.
    any ideas on the taper the first comment is about? or are the orignal pots ok as well as the type of taper?

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    1. used the noted 500k LIN and imo the taper is just fine, nice sweep.
      great sounding overdrive really, will make one for myself real soon to!

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  42. Built it a month ago and works great, "just like on the videos" LOL. If there's something about this circuit I'd change would be having a little more gain though... but it's (also) great the way it is. For me, it's almost like a TS but improved in so many aspects (more dynamic, better tone control(s), less compressed, better low-end response)... probably not a TS anymore then. Thanks Mark!

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  43. Finally got around to building a zendrive and I highly recommend it after building many ODs.

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  44. I just built one after getting it as a present from my girlfriend. Can't get any sound out of it...

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  45. Hmmmm... Wonder if I did something wrong with the switch... I found a lot of different wirings for truepass and they don't look the same...

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    1. You should probably try out the board before putting it in to the box. The switch may be one, but there could be other issues in there. AS for the bypass switching - just choose one and go with it. They all do exactly the same thing, while they may be different. Some use different poles for different purposes.

      Once you've got the switching right, follow the basic debugging procedure by triple checking component placement, possible shorts between the gaps and so on.
      +m

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  46. this pedal really deserves its reputation, its a sweet sounding box, i cant imagine another OD pedal knocking this one off my board but if anyone has any suggestions im always open to try more. Thanks for vero

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  47. Hey, thanks for this layout..
    Just wondering, if I was to put it in the same box as the AMZ Mini Boost like in the video, can I just run both boards 9V+ to the jack, or is there some better way to wire the power?

    Cheers.

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    Replies
    1. never mind.. found your post on how to do it! :)

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  48. How would you go about getting more volume from this? the 1k resistor going to lug 3?

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  49. Just finished building this and playing around with it. So far it is by far my favorite pedal I've built. Now all I have to do is house it in the same 1590BB as the Timmy I built. (IvIark says it's great, so I have to do it)

    The only issue I had was not soldering in all of the IC socket pins. Apparently it's important to ground the IC...who knew? Thanks for the fantastic forum/blog everyone..IvIark and Mirosol, you are killin it!

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  50. finished this, can't seem to get what everyone is talking about... is there a particular setting at which the 'dumble-ness' of the pedal kicks in? The Sweet honey seems to be much better, together they are pretty badass,

    Gonna try building the Timmy to box w the Zendrive in soon, if Mark does it - it must be magic, they guys can have ANY pedal on earth, so if he uses it, it must be good. Mark and Miro, ever thought of working at TC (or any of the other brands) or starting a Boutique pedal line of your own?

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    1. I feel the same way about the Zen. It's not bad in any way, but it didn't convince me that much.

      About boutique... http://fyaelectronics.com/
      +m

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    2. I could never get the right sound out of it either... even after my Timmy. But then, I'm not really a lead player - I can hear that it might be good for soloing, but I use my timmy for crunchy chimey stuff, and I'm looking for something to take that a bit further.. going to try a morning glory (either before or after Timmy)

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  51. Hi,
    I just finished the zendrive as well and I really like it !
    With the gain at @ 11 oclock -great for blues and picking single notes in chords.With the dirt piled on ,pinch harmonics are easy.
    An easy one to build as well.
    I wrecked it though ,on my 2nd and last coat of clear coat there wasn't much left in the rattle can and it sprayed air bubbles all over the face of it. :-((((
    Ah well,it is only a stompbox and it still sounds wicked !
    Thanks.

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  52. Now that Lovepedal is building the Zendrives, they are using the LM833 chip. It is assumed that this is the correct chip (original Zen had chip # sanded off).... Just FYI for anyone building this.

    G

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    1. It's the NE5532. I had been using the OPA2604 swapped it and justand there's very very little difference between them in this circuit.

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  53. This comment has been removed by the author.

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  54. Hi - I bulit this today and it fired up right away. I do seem to have a problem with the gain knob, however. When I i turn the knob I get more gain and higher volume until I reach 12 o'clock then the gain decreases until it reaches minimum gain and output when the knob is turned fully CW. The minimum and maximum settings on the knob are basically identical.

    I'm thinking that I have some kind of grounding issue. But can anyone help me out?

    ReplyDelete
    Replies
    1. Problem solved. Turns out I accidentally switched gain 1 and 2 when making connections to the board:-( Now the pedal works perfectly and sounds really really good!

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  55. I tried this with mo luck. Ive used BS170's, 1n60 diodes and a mix of chips. 4558, TL072 . Ive gone over my board and everything looks fine. I get slight sound but only if i crank my master volume up all the way. Sound is faint though. I have checked for bridged and bad solder. Ive checked the orientation of my Transistors. Can anyone give me a heads up? Please

    ReplyDelete
    Replies
    1. Measure the DC voltages between all IC pins and ground and post them here

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    2. Also did you rotate the BS170s 180 degrees?

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  56. These are my voltages using TL072

    1- 9,41v
    2- 0,97v
    3- 0,98v
    4- 1,45v
    5- 8,06v
    6- 6,70v
    7- 0,40v
    8- 0,00v

    ReplyDelete
    Replies
    1. Can you just check the pin numbering you've used, the IC is numbered like this:

      1-----8
      2-----7
      3-----6
      4-----5

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    2. And on the IC the circle is next to the 1 pin, or if yours has a semi circle at the end, it is between 1 and 8

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  57. And yes ive checked the pinout of the BS170 according to data sheets. I believe im correct

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  58. Sorry should be right now
    Pin voltage

    1- 9,41v
    2- 0,97v
    3- 0,98v
    4- 1,45v
    5- 0,00v
    6- 0,40v
    7- 6,70v
    8- 8,06v


    ReplyDelete
    Replies
    1. You've got something very wrong there. This is what I would expect the voltages to look like:

      1 - 3.5 to 4.5V
      2 - 3.5 to 4.5V
      3 - 3.5 to 4.5V
      4 - 0V
      5 - 3.5 to 4.5V
      6 - 3.5 to 4.5V
      7 - 3.5 to 4.5V
      8 - 9V

      To me that looks like you've mirrored the layout with pin 1 being 9V, and pin 5 being 0V.

      When you look at the layout that mimics looking at the top of the board at all the components. The copper is on the reverse, and so the cuts you need to do on the copper side are the mirror image of the bare board shown in the layout.

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    2. For visual reference look at the way Timmy's build looks compared to the layout in the build guide, and the way he has to mirror the cuts on the tracks: http://tagboardeffects.blogspot.co.uk/2012/04/vero-build-guide.html

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  59. Ok hold on. I take my veroboard, size it and then put it on my table copper facing up. Then i do my cuts as i see them on the image. Should i have the copper facing down and do the cuts? So that when the copper is facing up the cuts will be mirrored compared to the image???

    ReplyDelete
    Replies
    1. The view you see is the top of the board and so the copper tracks and cuts you can see are as if looking at an xray. That is why some people like Timmy mark the cut positions up on the front which then matches the layout position and gives them a visual marker yo put something through the marked holes and do the cuts on the copper side.

      So yes, all cuts are mirrored when you turn the board over onto the copper side. It isn't the ideal way to display it but it makes more sense for people to see the positioning of the components correctly when placing and soldering and mirror the cuts on the reverse, than to show the cuts correct and have to mirror the components.

      The bare board layout shown is a bit of a compromise simply so you can see cuts and links that may be obscured by components. If I mirrored the bare board so the cut layout looked correct for when you were doing them on the copper side, then the links would be the wrong way around and so require mirroring when placing on the front of the board and then soldering.

      So to do the cuts either mark up the front of the board like Timmy shows in the build guide, or do what I do, download IrfanView which is a freeware graphic editor, and simply press "H" to do a horizontal flip (or use your own favourite graphics editor of course if you prefer).

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  60. Omg... How thick could i be. Ive been doing my boards backwards. I thought i was doing it right because i did small one knob fuzz and naga viper. Obviously with luck mirrored they would still work. Thanks bud. Appreciate the help. From South Africa :)

    ReplyDelete
    Replies
    1. There's no problem doing it with transistor layout because they're in a single row and so the connection can be made from either the right or left sides, with an opamp it's obviously different, the inputs and outputs don't match up symmetrically and you have supply and ground connections to consider.

      Don't worry about it though, you're not the first person to do it and you won't be the last and there is a bit of ambiguity because of how the layouts are presented, but like I said, it's the compromise that makes the most sense with all things considered.

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  61. Well im rebuilding the circuit now. Will send u my result as soon as im done

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  62. Wanted to let you know that it works now. Thanks for all the work and help with debugging! Appreciated

    ReplyDelete
    Replies
    1. Excellent, glad you sorted it. Can I just confirm, did you use the new smaller Rev3 layout with the blue diodes or the older version?

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    2. Yea used the version with blue diodes. Had plenty og gain. So i replaced the 500 k lin with 100k and still had enough gain to throw around. Sounds great

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    3. That's great thanks Leon. I was pretty confident it was good but the new one hadn't been verified, so you've just done it. Cheers :o)

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  63. To anyone considering this pedal, BUILD IT! Just finished it up today and it's great. I'm really impressed with the response to pick attack. It's a great pedal. Very versatile.

    ReplyDelete
  64. I built this one and the sound is terrific. I do have an issue ONLY WITH POWER ADAPTOR (with battery works completely silent) when cranking up the knobs past 3 o'clock, mainly with the gain and voice. With the guitar quiet , when the knobs are past 3 o clock I start getting a high frequency hiss that get's very noticeable with the knobs at their max. I measured de IC voltages (AD712) and they are in line with the ones posted above. All is grounded and all ground at 0 v. I used an audio probe, and can hear the hiss coming from the IC pin 1 or from the transistor that connects to it (not sure which comes first. I The other transistor was quite, so I swap them but I still go the hiss form the one connected to the IC pin 1, so thought that maybe something wrong with the IC but the voltages are right...

    Is this normal?? I't kind of annoying and I end up using the battery instead of the adaptor, because it just sounds so good an quiet that way... Any ideas?

    Many thanks. BTW, great site, just finished building the RC booster too!

    ReplyDelete
    Replies
    1. If it helps, here are my readings (power supply is 9.33v):

      AD712:

      1- 4,66v
      2- 4,66v
      3- 3.16v
      4- 0v
      5- 4,62v
      6- 4,66v
      7- 4,66v
      8- 9.33v

      Q1
      E 4.33v
      B 4.66v
      C 4.66v

      Q2 (where I hear the noise)
      E 4.5v
      B 4.66v
      C 4.66v

      Appreciate your comments.

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    2. Your voltages looks fine, but if the effect is silent with a battery and noisy with a supply then it suggests strongly that it's just a noisy power supply. The only other thing that it could really be is maybe a cold solder joint on the supply cable from the DC adapter. You've proven that the effect can work silently and so the cause of noise must be elsewhere.

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    3. Thanks. I resolder all 9v points and also some other solder joints that were not silver shiny... still the same. Lacking any other options, so I'll give my stubborn head a rest and let it go.

      Thanks for the help!

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  65. I finished up a dual build tonight, Zendrive & Timmy. The Timmy sounds great, the Zendrive a bit dull. The controls all seem to be working on the Zen, but I don't get unity volume until the volume control is at 2 o'clock, with the other controls at noon.

    All part values I used are as shown on the stripboard, except I used a NE5532P.

    Here are the voltages using a 8.75V battery

    NE5532P:

    1- 4.18v
    2- 4,13v
    3- 3.95v
    4- 0v
    5- 4,13v
    6- 4,16v
    7- 4,16v
    8- 8.45v

    Q1
    D 4.16v
    G 4.16v
    S 4.06v

    Q2
    D 4.09v
    G 4.09v
    S 4.07v

    With the diode setting on my meter, I get 0.6v between S & G,D on both 2N7000s and 1.2v between G,D & S.

    I now understand why so many people like the Timmy, but the Zendrive I just built isn't cutting it. I have to believe there is something wrong with my build.

    Can someone let me know where you get unity volume on your Zen and for those of you who have built both the Timmy and Zendrive, with volumes maxed, is your Timmy much louder than the Zen? And is your Timmy livelier sounding?

    Thanks,
    Mike

    ReplyDelete
    Replies
    1. Change the Volume to a B100k for more volume in the Zen and drop the 3n3 cap to a 2n2 or even a 1n to make it brighter...

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    2. Swapping the volume to linear did the trick, thanks Vince! Now the Zendrive volume matches by guitar volume at 10 o'clock, where before it was 2 o'clock. After fooling around with the controls a bit more, I decided to keep the 3n3 for now.

      https://lh4.googleusercontent.com/-MXukCoKt4Fg/VBPwP7JoJ9I/AAAAAAAAAOA/zOlF0JUwGwM/w417-h510-no/IMG_20140912_221601_962.jpg

      https://lh3.googleusercontent.com/-mYqOlguOweg/VBPwSp14HZI/AAAAAAAAAOI/ywudZMrPq70/w361-h510-no/IMG_20140912_221649_193.jpg

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    3. That looks fantastic. They make a great pair!

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  66. Hi Mark, I am wondering if at some point this year you updated the layout? I built two of these boards last November (2013) and boxed one. The second board I am just now getting around to boxing, but I don't know where any of the wires go because my board and components dont exactly match the current layout. It's close, but not the same.

    Could I have built these two on an older layout? Do you still have it possibly? The boards I have are 16x12 if that helps??

    I would really appreciate any info you have on this. Thanks!
    Jason

    ReplyDelete
    Replies
    1. Yes I updated it, the first layout was annoying me for some reason :o)
      I think this is the version you want

      Delete
  67. Hi Mark! I begin this pedal, and I'm wondering if it's possible to add a switch (2pdt) to select between 2 modes of clipping (The 3 BAT41 vs 2 3mm LEDs).? How do you do this ?

    Thank's !

    ReplyDelete
    Replies
    1. It won't be the easiest thing to add because of the number of components used for clipping with the mosfets and diodes. Id probably suggest using a small piece of vero as a daughterboard with the clipping options on it, and then use the switch to determine which are in circuit.

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    2. Maybe it's esiest to switch between, D1 + D2 and the leds ?

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    3. D1 & D2 are only clipping one half of the waveform and still have the mosfets in series with them. To separate the standard clipping from the opamp you need to remove the clipping components off the board and do something like this.

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    4. Actually instead of connecting to IC pin 1 it's probably going to be easier to just connect to Gain lug 3, unless you prefer making the connections on the board, in which case connect both wires to IC pin 1 and the Gain 1 wire to IC pin 2

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  68. I love this pedal. It is awesome!!!!

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  69. This comment has been removed by the author.

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  70. Hello there Mark!
    Newbie here...I put this together...used your offboard wiring diagram...And the 100uf cap xploded. It was crazy! I've heard of it happening but ya I'm a convert. Gonna use my full body gear with gas masks now every time I plug one in for the first time. Anyways, I'm pretty unsure what is going on. I look over everything many times. It is amazing how stupid this stuff makes me feel sometimes. By the way I want to say thanks for this great site! You rock...hopefully someone can help thnx...
    Ty

    ReplyDelete
    Replies
    1. That is the power filter cap and it is expected to blow up if it is wired in reverse. Negative lead goes to the bottom row, which is ground.
      +m

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  71. Ok! So I'm not grounded somewhere. I used two mono jacks because I'm not using a battery. Would that be my problem?

    Thnx!

    ReplyDelete
    Replies
    1. no man.that's no problem using mono jacks. you could post your voltages and photos if you can't debug it by yourself at some point. i'm sure we could give you a hand if we have all these.
      are you sure that you've soldered the right way the 100uf cap as miro said? you might have also burned something else too...maybe you should change your ic too for a new one. hope you'll make it!good luck

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  72. Hey there great site!!!
    I'm a newbie and figuring out debugging. I built a probe and a test rig. I am not clear on when you test (rock it) it before you box it. Do the pots need to be soldered on the board to test or can it be tested without them connected? Thnx so much!!

    ReplyDelete
    Replies
    1. If you use pots with pins like the ones from Tayda you can push them into a breadboard which is what I usually do before soldering. You will almost certainly get noise but you just have to ignore that and just check the pot it doing what you expect it to. The noise shouldn't be there once soldered and boxed.

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  73. Hey there!
    Still working on it. Just a quick q's. It says volume 2 to output. Does this mean solder a wire to lug 2 and that is you output? Thnx!:)

    ReplyDelete
    Replies
    1. Yes. Volume 2 lug is the final output of the circuit so that's what you take back to the stomp switch

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  74. Ok...that's what I thought...
    Now the ic is getting smokin hot! Any ideas? Thnx:(

    ReplyDelete
    Replies
    1. Most of the time when ICs get hot you have a short somewhere. Go through all the things mentioned in the fault finding guide above to make sure holes are cut cleanly, there are no unwanted bridges between tracks, no bad solder joints, parts are placed correctly etc. Don't just assume you have done everything right, double and triple check everything critically and look for places on the board which look suspect.

      If you measure the voltage on the IC pins that should give you a good clue.

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  75. Hey there!
    Just wanted to say thanx for all the help. Coming in cold, lots of things to learn, kept on going and finally got some pedals going. I had a male 9v dc jack wired backwards. I made this to run a test probe as I live in an RV out in the boonies. Feel like an idiot but living and learning. Once again big thnx!

    ReplyDelete
  76. I finished this one up today as part of a dual pedal and was trying out the mod where you replace the 3n3 cap with a 33n cap and to me the mod is pretty sweet, however I think the 33n is a tad too dark though and will try out some other values like a 22n or even a 15n cap.
    Great layout as usual and this pedal loves my STRAT!
    Thanks!

    ReplyDelete
    Replies
    1. Yup
      33n is way too dark, going with a 15n on a DPDT to toggle between 3n3 and 15n
      Awesome pedal!

      Delete
  77. Where can I add a switch to short the circuit for clipping?

    ReplyDelete
  78. I'm about to build my fourth Zendrive clone according to your vero. Thanks for your work. My problem is that I'm down to just one BAT41. Is there a more common diode I can use as a substitute?

    ReplyDelete
    Replies
    1. You could try any type you have, but 1N4001 and 1N5817 should sound pretty close.
      +m

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  79. First of all, great site, great layouts! Zen was my number 5 from here and it's awesome. I had to box it together with Timmy after all I read here and that was a fantastic choice!

    I still have some trouble though. I get about +1V DC on the input wire when Zen is on, and the first in the chain, resulting in some scratchy noise when I move the volume pot of the guitar. I checked solder joints, parts placement, micro shorts and still have no idea. One hint might be a slightly low voltage (2.85 V) on pin 3 of the NE5532AP I use but I don't know what to conclude from this. All other pins are very close to 4.00 V (except 4 and 8, of course). So are DGS of Q1 and Q2 which I have chosen to be 2N7000 and BS170.

    I would be very grateful about any clues!

    ReplyDelete
    Replies
    1. Input wire connects only to 2M pulldown resistor (to ground) and a 470n input cap. This means that if you have any voltage in the input wire, your ground isn't properly grounded or the input cap is bleeding the voltage. Voltage on the input explains the guitar pot behavior. You need to figure out where the voltage comes from to fix it.
      +m

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    2. Thanks miro, the cap is the problem, I think. The ground is dead zero. Having been desparate for 470nF caps that I didn't find I used Tantalums here, and hence I learned they are polarized - the hard way I guess. I guess the input cap is fried, resulting in some leaking voltage. I will get new ones on Monday and replace them...

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    3. That explains everything. The downside for tantalums is that they tend to short out if they get reverse polarity. You'd have issues with any polarized cap reversed in that position. Aluminum elcos just blow up or stop working. Like i said, that'll explain the low voltage on pin 3 too. What's the closest value you have? 1µ? 220n? Try either one. Just note that whatever you use, in case of polarized cap - positive to pin 3 and negative to input wire.
      +m

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