Saturday, 24 March 2012

Tanabe Zenkudo

With a name like Zenkudo it should be pretty obvious what this one is based (very closely) on.  It's a great sounding circuit though and at least Mr Tanabe hasn't (as far as I know) said it's a totally unique product based on 2 man-years worth of R&D or other such nonsense like some of the other boutique companies have claimed about their ripoffs innovations (Mr J and Mr F, put your hand up if you recognise yourself in that statement).  Tanabe has also added what I suspect many will find a useful feature with his Landgraff Dynamic Overdrive style clipping selector switch to add a few extra flavours.

Still I must admit that I'm glad I spent my money on the Hermida original and supported the real innovator behind the circuit.  Especially after seeing a gutshot of the workmanship in this one!

The rotary switch (or a DP3T switch if you can find one) will allow you to make an exact copy including different LED colours based on clipping selection, but if you are happy to miss out on the bells and whistles then you could do exactly the same thing with a 3 position SPDT toggle switch.  Gain 1 to centre lug, and then the other 2 lugs connected to Sw2 and Sw3 shown in the layout.  Then the centre (off) position will give you the "Dumble" clipping, one position will give you the "Zenkudo" clipping with the mosfets and germanium diodes, and the other position will give you the "Marshall" clipping mode with the 3 red LEDs.  Of course you won't have the trendy tri-colour LED but all the sounds will still be there. 






82 comments:

  1. IvIark,

    I'm looking for a nice saturated OD with plenty of gain...which of the layouts that you have done would fit this description or come close? The Amp Eleven I built from your layout seems to be close to what I am looking for, but I am curious what else you might suggest.

    Thanks,

    Kellet

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    1. My favourite overdrives are the Timmy and Zendrive, they're great individually and make a really great stacked pair for high gain. It's all down to individual tastes but there's something about the Zendrive voicing that I find particularly appealing.

      If you've already done the Amp11 then the Zendrive (or Zenkudo/Gain Stage Red) maybe a good choice. Have you seen the demos of the Zendrive and derivatives on youtube?

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    2. Thanks for your input! I haven't heard the Zendrive, but I've read reviews...I will build it up and check it out.

      Overall I am pleased with the Amp 11, and the Timmy is good as well but a little light in terms of gain for what I am looking for. I figured the two would sound very similar, but the lovepedal has a lot more saturation and gain which I like. As a side note, is there any simple way to increase the gain of the timmy (ex swap op-amps)?

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    3. Did you make the Timmy with a 1M and the Amp 11 with a 500K Drive pot?

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    4. Yup...should I change the pot value on the Timmy?

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    5. Well that's surprising, which is why I asked the question. The gain is calculated using the drive pot in the equation, and with all the other components being equal it would mean that the Timmy should have twice as much gain as the Amp 11. Of course there are other components which obviously affect it, maybe the 510K versus 1M to vbias makes a significant difference here. It may take a bit of experimenting

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    6. Any chance you could post a layout for the Zendrive? Obviously no rush, but I certainly like your layouts over the others.

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    7. I did a couple of months ago! :o)

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    8. Ah ha! Found it! I was searching "Zen" with no results, had to key in the entire "zendrive." Thanks again!

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  2. Purple Plexi? deffo high gain and has a nice whiff of Marshall in there..

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  3. Has anyone ever seen the layout for the Dumkudo? I play a strat and would love a little extra gain! The Dumkudo sounds incredible!

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    1. I haven't seen a schematic for it,but going off the Zenkudo I wouldn't be surprised if it was a 4 knob Mosferatu with the Zenkudo's diode clipping options.

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  4. Hi again,

    I just builded the Hotcake and now i want to build this one.
    It seems like i can't find any pot specs on your layout?

    Mr. Bo

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    1. Ha, how did I miss that off?! I'll update the layout now

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  5. I can't get how to wire it without the tricolor led.....

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    1. If you use an SPST 3 position switch and imagine the the lugs looking like this:

      1
      2
      3

      Take Gain 1 to lug 2, and take Sw2 and Sw3 on the board to lugs 1 and 3 (doesn't matter which). Then in one position the mosfets will be in circuit, in the other position the diodes, and in the centre position neither

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  6. Mark what do you think man, this thing or just the zendrive. i really do love the zendrive sound and i am kind of old school when it comes to, for lack of a better term "knock offs" not trying to discredit the zenkudo by any means. realistically im not someone that needs a lot of options on an overdrive pedal. i pick od's for what they are, not what they try to be, if that makes sense. its not like youre going to change your pedal on the fly from dumble to marshall clipping anyway. might have just answered my own question on which to build haha

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    1. I have an original Zendrive and it's one of my favourite pedals so I may be biased! :o) But I'd like to build the Zenkudo too just to see what the extra options are like with the Zen, although I have a feeling that once I'd played with the various settings, it'd stay in my favourite Zendrive setting for the rest of its life!

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  7. yeah although this one does look really interesting, i dont need all the bells and whistles. by the way, whats your take on the metal film vs carbon comp resistors. you think there is a real tone difference?

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    1. To be honest mate I'm on the fence about it. I've made effects with both that have sounded different but I couldn't say for certain that is because of the physical properties of the resistor or just tolerances. I often hear from engineer types (and I don't mean that in a derogatory way, I'm an electrical engineer by trade, but I'm talking here about someone who will put the numbers in a datasheet before anything they hear with their own ears) that the only thing a carbon comp will add differently is noise, but I don't know what form that noise takes, is it just white noise or some non-linearity in distortion? I've built lots of effects using carbon comps and have never found them obviously noisier than effects I've built with metal film and the best Muff I've ever owned is all carbon comp (Pink Flesh). So although I've heard differences, I couldn't attribute that specifically to choosing one type over the other, but I'll continue to use both in the future.

      All I'll add to that is that none of the most sought after vintage effects will have a metal film resistor anywhere near them and the carbon comps and carbon films in some of them are still creating great tones 40+ years after they were made. That alleviates any worries I have about anything I make with similar resistors drifting enough to make the effect unusable like some may suggest. And whilst it doesn't answer the question, it does emphasise that great sounding effects can be made by something that some people will tell you is a waste of time using.

      Don't get me wrong I'm not saying that you SHOULD be using carbon comps, just that you shouldn't dismiss them just because someone says so. You can get carbon comps for around 11p each from Rapid, and so it would cost you about £2 total to try them out in a TS808. Not exactly going to break the bank and DIY would still be cheaper than buying a Digitech Bad Monkey or Behringer pedal. I've still got thousands of MF resistors that I'll use all the time, but for me particularly with dirt pedals, sometimes it's nice to experiment with something different.

      Now don't get me started on caps! :o)

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  8. haha its good to get a first hand honest opinion on the subject. When I was first starting out (and this was only a few months ago realistically) i ordered like 4300 metal film resistors basically all the values i could ask for (for the most part) for like 30 bucks so just couldnt beat it. i do want to get my hands on some carbon ones though.

    from what I was told, boutique pedal makers used whatever was cheapest. well maybe thats worded wrong but you know what i mean, whatever was more cost effective and things like carbon comps just stuck because of the obsession with the boutique. either way, all of my builds which have used metal film sound good so no complaints! you are indeed right though, caps are a totally different story haha but no matter who i hear from, the panasonic ecq's and topmay box caps seem to be held in the best regards. so ive done my best to stick with them where i can.

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    1. Everything I've ever made with MF resistors sounded great as well, so there's certainly no need to go for anything else unless you're trying to satisfy some internal OCD craving (like I must have) to tweak. When things have turned out better, whether those improvements are down to the constituent material or just the fact that a 490K resistor actually sounds better in that position than a close tolerance metal film 470K resistor doesn't even matter to me. To bias that transistor exactly, maybe sometimes a drifted value is exactly what you need, and maybe sometimes it isn't.

      To be honest it's mind blowing all this stuff, if you went through all the permutations of what could be improving your effect pedal, your head would probably explode :o)

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    2. haha completely agree, sometimes i think what makes a pedal so unique and something that even a clone cant replicate exactly probably comes down to the tolerances of the components. maybe a resistor is a 470k but it really measures to a 469k, and thats what makes the magic happen. maybe not so literally but you know what i mean. the quest for the perfect tone is an infinite one. but its the journey, not the destination that really matters :)

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  9. I can't source the rotary switch; Can it be done with separate SPST/SPDT switches ? Please post diagram for that. Thanks.

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    1. If you use an SPDT 3 position switch and imagine the the lugs looking like this:

      1
      2
      3

      Take Gain 1 to lug 2, and take Sw2 and Sw3 on the board to lugs 1 and 3 (doesn't matter which). Then in one position the mosfets will be in circuit, in the other position the diodes, and in the centre position neither

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    2. Is this a on-off-on switch?

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    3. No, it selects from the different clipping options.

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    4. So you jump a wire from the gain pot to the switch? Or...?
      I really can't get it to work.

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    5. And can the led wire be omitted?

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    6. Yes if you're using the SPDT switch then the LED wire can be omitted altogether if you don't want any LED indication. Or if you do want just a regular on/off LED rather than the multi-coloured option provided by the rotary switch then wire the LED up to your 3PDT stomp as you would with any other effect.

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    7. One thing I would say is that I'd suggest sorting the effect out before worrying about the diode switching. It will work fine without that switch and so the important thing is getting some sound out of it first.

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    8. I have sound, but no differences...

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    9. Have you wired the switch like this:

      http://i76.photobucket.com/albums/j6/IvIark_2006/DIY/Zenkudosimpleswitch.png

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    10. No, but i took it from gain 2..........!
      Thanks again for your enourmeus patience with goofers like me ; )

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  10. Hmm.. is the only difference the clipping options, or is there something else going on in there? Looks to me that placing different clipping options to the original would suffice...
    +m

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    1. If you use the 4 pole 3 position rotary switch then it is doing a little bit more, but nothing audible. Only two poles are used, one to change the clipping, and the other to change the colour of the tri-colour LED for indication of which mode you're in. That's why you can get away with just using a 3 position SPDT switch if you're not bothered about indication.

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  11. I give up on this sucker. It is my second attack on this one, and it never really worked out. I get very little sound out of it.

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    1. Just put it to one side and I'll double check through everything. In the meantime take a front and back pic so I can have a look

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  12. That's very kind of you, but i have already disassembled it and will make me another Zendrive with the bits. Everything else from you have been working out so far, and i am thankful for that. I guess it wasn't for me to have a Tanabe zenduko ; )
    My buffers, hotcakes, lovepedal cot50 and my zendrive is a gift from you and Harald that works perfect and will go on the road and in the studio with me.

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  13. Oh oh oh! After i disassembled this thing, i found the fault....
    Then i reassembled it again with way greater results! But i still can't make the switch happen. It stay with one sound whatever i try.

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    1. Are you sure you've got that top cut in above Q2? If that wasn't there (or if there was some unwanted bridge) then no matter which position the toggle was in, both the mosfets and the LEDs would always be in circuit other than in the centre off position.

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  14. The cut is fine. In your text you say: "Gain 2 to centre lug, and then the other 2 lugs connected to Sw2 and Sw3 shown in the layout", and in the drawn example you say "gain 1". Which is right?

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    1. I didn't, I said "Gain 1 to lug 2". Basically gain 1 is the common, then the switch decides whether the signal goes through the mosfets or the LEDs. Check with a multimeter that you're getting continuity where you should be getting continuity. Also have you got the diodes in the correct way, from left to right (cathode) up - up - down

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    2. I try that. Not to rap, but here is what you said in the text:

      "The rotary switch (or a DP3T switch if you can find one) will allow you to make an exact copy including different LED colours based on clipping selection, but if you are happy to miss out on the bells and whistles then you could do exactly the same thing with a 3 position SPDT toggle switch. Gain 2 to centre lug, and then the other 2 lugs connected to Sw2 and Sw3 shown in the layout. Then the centre (off) position will give you the "Dumble" clipping, one position will give you the "Zenkudo" clipping with the mosfets and germanium diodes, and the other position will give you the "Marshall" clipping mode with the 3 red LEDs. Of course you won't have the trendy tri-colour LED but all the sounds will still be there."

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    3. Aah right I thought you were talking about my comment below the main post. It's definitely Gain 1, I think I must have been thinking about the IC pin number when I was typing that because it's from IC pin 2.

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    4. It is really strange. It will absolutely not change effect, no matter how i try to wire it up. And the cuts are fine. Strange. I have a 3 position spdt switch and all. Gain 1 from the board to centre lug of switch, then jump it to the pots first lug.

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    5. Post a front and back pic of the board.

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    6. Did turn those fets. Still nothing happens . Well i guess i can live with the dumple option. It seems to me that it is what i have. Is this verified?

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    7. I don't think we can call it verified until we know the clipping is working. Looking at it, the clipping certainly seems to be doing everything it should, connecting between pin 1 of the IC and the Sw1 and Sw2 connections on the board which they definitely are. I'll build this next to try to confirm it.

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    8. Looking forward, and again...thank you!

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  15. Cross this one of the unverified list too, clipping works fine. Slight volume drop with 1n34a clipping but I would expect that. I used a dpdt on/off/on switch with a bi-colour led on the second pole so i get red/no light/green as an indicator, not quite all the bells and whistles but some at least :-). Now i need to build a zendrive to compare the 2, if the zendrive is better than this i`ll be blown away, this is a feckin fabulous overdrive.

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    1. Ha I'd built this too but hadn't tested it yet. Thanks for verifying mate

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  16. Sorry to bring in a question so late. Just populated my board and getting ready to wire it up in the enclosure. Since pin 4 of the IC is jumpered to the bottom row, I am just using what is labeled as "vol 1" as my ground connection to the jack since it is closer than the ground wire on the other side of the board under the input wire. I will just run a wire from lug 1 of volume to ground as I usually do. That gets rid of one board wire. Question is, instead of using the 2M on the board and vol 2 wire from the board, can I just solder a 2M resistor between lug 1 and 2 of volume pot ( 1 will already be connected to ground ) and then run lug 2 to output? Seems equivalent and gets rid of another board wire.

    Also, is it correct that board wire labeled "Gain 1" connects to gain lug 1 and then connects from there to middle lug of 3 position single pole on-off-on switch?

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    1. Sorry I missed this Tim but the answer is yes to all of the above. No problem soldering the resistor across the volume pot and yes, Gain 1 label on the board, Gain 1 lug of the pot and switch common are all connected together.

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  17. Mark

    Thanks for the reply. I went ahead and built it the way you had it set up since I wasn't absolutely sure. Going to build a second one eventually with a 1M volume pot to get a little more gain.

    I used the indicated 4558 originally in the layout. Didn't really like the sound of it. In my last Zen drive build ( which I foolishly sold to a friend ), I used the alternative suggested in FSB - OPA2134. I tried that here and I like it better. Sounds a little smoother ( for lack of a better term - I guess the corollary is that the 4558 sounds a little more "raw", if that is what you are after ). I also have an OPA2604 that I am going to try to see if there is any sonic difference. The OPAs are a bit more more expensive than the 4558 but well worth it in my estimation....

    BTW, for anyone else building this, I used the 3 position SPDT switch for the diodes as indicated above. Works great.

    Thanks!

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    1. Yes I've got a few of the OPA* opamps too and a few expensive ones by Analog Devices like the AD797 and the AD712 which I think was used in the Zendrive. It's always interesting to swap and change and see what you like best, and another good thing about socketing the ICs is that you can share these expensive ICs between numerous pedals if you want to and just put it in the one you want to use! :o)

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    2. Oh and by the way it'll be the Gain pot you need to increase, not the volume. I assume you meant that but were typing on auto pilot like I do all the time! :o)

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  18. Oh - just noticed you already suggest the OPA2604 in the zendrive layout here. ( Looking back through all the overdrives for a new build )

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  19. I did mean the gain pot. Thanks for correcting though in case someone else read that and didn't know what I meant ;). I'm at work so autopilot is fully engaged....heh

    I do need to pick up an AD712 - not one of my normal suppliers carry them. Guess I'm going to have to venture out of my comfort zone.

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  20. Finally got around to swapping the OPA2604 for the OPA2134. Much better. Little gain bounce plus it just sounds like there is a little more there harmonically. I was a little "meh" about this pedal before but now I'm pretty happy with it. 4 bucks well spent. Now I may throw one of those in my Timmy and see what happens...

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  21. I just built this- wasnt sounding right so I flipped my jfets and now its sounding MUCH better. dont know if it's just the 2n7000's I have or what... but mine definitely need to be flipped from the orientation shown here. if you're not getting enough gain, try this

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  22. also, i really dont like the middle position or the LED Clipping on this circuit. I'd just like to convert it to a standard zen drive. Do I just need to remove the switch and connect gain 1 to where "sw2" wire goes and add another diode? (I already used bat 41's)

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  23. Hey guys, just built this one and have a few questions.

    1. I've sent the "LED -" straight to the LED from the board but this means the LED is always on, and I'd prefer to use it as an indicator, can I just send the same lead from the LED with a CLR resistor to the usual spot on the footswitch?

    2. Are the board mounted clipping LEDs supposed to light up? I assumed the longer LED leads were the + and built it that way. There just doesnt seem to be much sonic difference between green and red "modes". Blues is very noticable.

    3. The entire effect sounds "fizzy" to me (sort of a fizzy short decay on the notes - not a nice long sustain). I've used the OPA2604 opamp. All in all it's made the build a little dissapointing compared to the zendrive. Any help would be appreciated.

    4. I used 1N34A's from mammoth, these were both very fragile (managed to break 2 just by bending the leads gently!), and much larger than the tiny 1N34A's from Pedal Parts Plus. Any problems with using these larger ones?

    Thanks heaps for all the help in advance!

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    1. If you look at the notes it says you connected LED- to the LED common cathode after stomp switching. If you connect it directly then as you say, the LED will always be on. So that wire goes to the stomp, the other side of the switch (when the effect is on) then needs to go to the common cathode (or cathode if you're just using a single colour LED).

      The board mounting LEDs may light up, but that isn't the important thing. They are being used as clipping diodes and will perform that task whether the LED illuminates or not.

      I haven't played with this circuit so can't comment on the fizzy thing, but it is essentially a Zendrive and so it's not what I would expect to hear. Have you tried any other opamp?

      Any diodes will be fine, but I suspect the larger ones are the real 1N34A's. Sometimes smaller diodes which look similar to the 1N4148 silicon diode are sold as germanium, but I suspect these are just schottky diodes with a similar forward voltage to germanium.

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    2. IvIark, I had to use 2 x 1m resistors wired together to make the 2m resistors, hopefully this wouldn't be the prob?
      I'll try a couple of the regular opamps and see if it changes things. Thanks for the quick reply!

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    3. I got the fizzy decay but only in the Zenkudo mode, and with gain maxed or close to maxed ( the middle position with no clipping diodes ). The other two modes were fine ( think I used Bat41s instead of the 1N34s ).

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  24. Just a quick update, tried the NE5532 opamp today and same results... still fizzy decay on all clipping modes. I'm going to rebuild this I think cause I really want to get it working. I just don't know enough to work out what might be causing it. This is the first build where I've used single sided 3M tape to back the finished board. Anybody had any probs using it? I just assumed it's not conductive...

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    1. Oh, one last quick question, I've ordered some 3PDT mini toggle switches in a On-OFF-On configuration, could I use these for the LED/Clipping switching, and if so how?

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    2. You can use it to switch the diode clipping options by just using a single pole (although it would be a bit of a waste) but you can't do the multi-colour indication. For that you would need a rotary switch or a DP3T toggle switch.

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  25. Quick question on this one. If someone was looking for the gain of the dumkudo pedal, would just bumping up the gain pot value to something like 1 meg work or would there be more changes necessary?

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    1. Increasing the gain pot to 1M will certainly increase the gain, but whether than is the only difference between the Zenkudo and Dumkudo I really don't know.

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  26. Gotcha, thanks. Think I'll pop one in there.

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  27. How would you wire the DP3T then? Sorry for this question, but I never came across this Switch :)

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  28. Hi IvIark! Thanks for the blog, I have made some other effects and they are great,, but I have one problem with the Zenkudo. The Marshall mode is not working, it sounds exactly the same as the dumble mode.
    I have tested all the connections and the position of the 3 leds and they are all good, continuity all around. The only difference can think of is that my LEDs are red 5mm ultrabright red instead of the 3mm ones. Can it be the problem?
    Thank you in advance

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  29. I was looking at the schematic and I was wondering about D6 near where the 9v starts in the circuit. I noticed it's not on your layout.
    http://1.bp.blogspot.com/-_oTKcGpVRMg/T2MVDgJ4f6I/AAAAAAAABG0/i_DPH2YS8Pg/s1600/Zenkudo.GIF

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    1. That's a parallel polarity protection, which is almost always omitted from almost all layouts. Mainly because it's destructive protection method without a fuse. It has zero impact on the tone.
      +m

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    2. Cool, thank you for the info and the quick response!

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  30. Aright, so I got it all wired up last night and tried it out, but nothing really happened. When the pedal was on, with the volume all the way up, it was very close to the pedal being off. The modes didn't sound any different, and the tone, voice, and gain knobs did nothing. The only knob that did anything when the pedal was on was the volume knob, so it's basically acting as a very fancy volume limiter. I tried a swapping the op-amp, but made no difference. Any ideas?

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    1. I tested the board for unwated connections and it was all good... Can anyone try to help shed some light on this?

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