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Friday, 16 March 2012

Tanabe.tv - Zenkudo

It's supposed to do Dumble, Marshall and the original Zendrive tones - I'll tell you now; it's a straight Zendrive clone with a clipping diode switch and using the 4558 opamp instead of the AD712 op amp in the original Zendrive. More info on tanabe.tv: http://www.tanabe.tv/top/kudou/index-e.html

Here's a cheeky Mag review:

Here's a demo of the Zenkudo Vs the Original Zendrive:

Here's some shots of the PCB:

And the schematic drawn by Soulsonic:

As you can see there are a few strange inclusions with the design (it has been suggested that they were placed there at random by the designer, and it certainly looks that way!) - the 10n cap before that 2M2 resistor to ground along with the 2M2 resistor to ground at the end of the circuit in parallel with the lower half of the volume pot? Yet, as outlined in a post by PaulC these strange changes do have a small effect on the tone:

"[Quote] Greg_G wrote:
Yes. the 10nf forms a filter due to being placed before R1.. although it's set well below any fundamental tones from a guitar.

Remember, there's always a good chance with a circuit like this that the "designer" has little technical knowledge, and is just trying things and convincing himself it sounds better.
Don't think that because it's commercial it's well designed. [Quote]

You're forgetting the 470nf/470k 2nd pole. The 10nf is not isolated from these. Added up this would give you -3dB @ 41hz with the signal being down about -1dB @ 80hz. A small roll-off within the guitar range to tighten the bottom up a little. There's other ways of doing it (make the 470nf smaller for the roll-off while keeping the bleeder effect of the 2M2 resistor), but this is something you could hear."

Hmmmm, you make up your own mind - it's just a Zendrive with clipping switch and a different opamp if you ask me - Alf Hermida all the way...

Here's the freestompboxes.org thread for you: http://freestompboxes.org/viewtopic.php?f=7&t=4527


  1. What about the dumkudo?

    1. It's just a Zenkudo with more gain - I'd say just put in a 1M pot instead of a 500K pot. I'd also use the second op amp as a buffer with a bit of gain instead of buffer - see the Timmy schematic for an example of this..

  2. Wow, and these are over $300?! Looks like shit!

  3. PART 1
    09-21-2009, 08:37 PM
    Okay- my friend Phil and I have all three pedals here.

    We tested VERRRRRRRRRRY carefully with a strat and a les paul through
    a Fender Bassman 50 modded to blackface specs.

    I have a brand new Dumkudo Zendudo Twin, and Phil brought his Zendrive 1.

    We are using George L cables.

    We are fastidious listeners, and we're both around 55 years old.

    We have NO prejudices or preferences for either.
    Both are FANTASTIC PEDALS-- no question about that.
    Both would serve any user extremely well and provide STERLING overdrive at any level.

    We will just share our observations about the differences- and there are a few.

    Here we go:

    1) The only difference we can detect between the Zenkudo and Dumkudo is that the Dumkudo has higher gain then the Zenkudo. Otherwise, both sound exactly the same, and in fact use the same op amp chip. How he does this, I don't know.

    The Zenkudi does not have as much gain top end as the Zendrive.
    The Dumkudo is capable of MORE top end overdrive than the Zendrive.

    Both sides have the 3 way clipping switch selector (no this hasn't been done away with after all)

    2) BOTH Zenkudo and Dumkudo will ratchet down to virtually zero overdrive-- just that the Dumkudo has more top end distortion if you want it. Thus- both will work for any guitar- despite the suggestion that one is for a Strat (D) and the other for a Humbucker guitar (Z).

    3) The D/Z knobs essentially work in the same manner as the Zendrive.

    4) The D/Z pedals have a WIDER and more BROAD tonal variation on tap using the Tone and Voice knobs (Tone and Jali on the Dumkudo, same thing). I.e., you get more variety from the D/Z pedals in regards to harmonics.

    The VOICE knobs on all these pedals are essentially harmonic overtone filters. Turn the knobs counter clockwise, you filter out more and more harmonics-- full on, no filtering.

    Thus, the Voice knob SEEMS like a tone control- and well, it is sort of.

    The TONE knobs on all these pedals is essentially a high pass filter, thus turn completely counter clockwise, and the pedal gives you less treble and more bass appearance.

    The D/Z pedal knobs have greater latitude in what they do compared to the Zendrive.

    5) The D/Z pedal is more TRANSPARENT- i.e. it does not add midrange color when the overdrive is engaged. The Zendrive adds a bit of color/mids. Not much, but a little.

    When the Zendrive gain is fully counter clockwise, the mid boost is not apparent, but only becomes noticeable when you add gain. This is regardless of where you put the Voice knob. You can't completely dial it out.

  4. PART 2

    6) The D/Z additionally adds a three position switch that allows you to choose the type of overdrive distortion- RED= asymmetrical clipping with minor compression ("Marshall" or Tubescreamer) BLUE= Mosfet + symmetrical clipping ("Zenkudo" position - slightly fuzzy) and GREEN= no clipping (DUMBLE). The LED in the D/Z pedal changes color with the selection.

    This is a very nice feature, but will only be noticeable to a large extent when a good amount of overdrive gain is added, not on very low amounts.

    Comparatively, the Green Dumble position has no compression, and retains the most bass and changes the core guitar tone the least while adding overdrive.
    The Blue Zen position loses the most bass, while the Ren position is half way between the other two.

    7) Construction of all the pedals is excellent. The D/Z pedal has a fair amount of silicone inside to help cushion the free floating PC board which is not screwed down. I do not see that this will ever be problematic at any point, and in fact, allows a little cushioning between it and the case.

    8) We could essentially create any sound on the Zendrive with the Dumkudo, with the exception of the slight absence of boosted mids. We didn't miss that, and in fact, preferred the transparency of the Dumkudo.
    We would rather dial in more mids with our amp if we wanted it. but the difference was very very slight in any case.

    The Zenkudo was not as high gain capable as the Zendrive (or Dumkudo), not by a huge amount, but noticeably so. At the slightly lower end of drive, it performed very admirably and as well as the others. But if one had to get only either the Zenkudo or Dumkudo- it's a no brainer- Dumkudo.

    The Zendrive could not make every sound the Dumkudo could make, nor to a lesser extent the Zenkudo, because of the lack of three-way clipping selector, nor the broader range of Tone and Voice found on the D/Z pedals. Again, not a huge amount, but certainly a fairly significant difference between the pedals.

    9) The basic sound all three pedals made was essentially the same in regards to type of overdrive, tone, etc.

    10) The price of the Dumkudo Zendudo pedals, individually or in the Twin configuration (either Zen-Zen, Dum-Zen, or Dum-Dum) is higher than the Zendrive. So, for more sounds and transparency, you pay a premium. Currently, the individual D/Z pedals run over $320 each, or $560 for the twin configuration. This may even change more as the dollar loses value agains the Yen. The Zendrives can be had for $200.

    None the less, I sold my Digitech RP1000 and my Lovepedal Kanji 9 to buy my Dum-Zen Twin. I am exceedingly happy with my purchase.
    Phil is happy with his $200 Zendrive.

    11) Although the basic sound of all three pedals is the same, The D/Z pedals provide additional tonal variations that are a significant enough leap from the Zendrive so that anyone claiming it is a CLONE- is just not correct. The design may have been generated at some point from the original Zendrive formula, but it has evolved and added things, the components are different, so it is a distinctly different pedal- as a Lotus is from a Ford GT.

    There you have it.
    Neil Slade

    All three are at unity with the Tone/Voice (Jali) fully clockwise.

    I.e., with the gain all the way down, and the Tone Voice all the way up, your guitar tone is unchanged

    THUS-- these knobs act as FILTERS as you turn them counter clockwise.
    They are disengaged as you fully turn them clockwise.

    Toshihiko may describe it differently than Hermida, but what we detected with all three, is that they all did exactly the same thing.

    Tone is a high pass filter, engage to turn counter clockwise.

    Voice or Jali (Dumkudo label) is a Harmonics overtone filter, engage to turn counter clockwise.

    Yes, of course, they ARE interactive on all pedals. As you increase the amount of treble heard, this increases the high frequency harmonic overtones, and vice versa.

    People are free to disagree with us. We spent a lot of time on this, with both pedals right together at the same time. We are certain of our observations.

    As for the three way switch-- Toshihiko explained that this was only to change the clipping characteristics. This may possibly have an effect on tone- because as you clip a waveform, the auditory perception of a sound may change according to the amplitude of the wave, etc- but this is an indirect result that may or may not occur from the clipping characteristics, depending on other factors of the wave signal. The 3-way switch itself, and it's chosen position will not necessarily change the EQ of the wave, and it is certainly not the intention of the switch.

    From my listening- the Green Dumble position has more bass- because there is no compression involved in the wave clipping. The Zen position with symmetrical clipping will have the least bass, and the Red position with asymmetrical clipping will be in between the two- perhaps a more "mid" sound to it than the others.


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  7. These sound nothing like a zen drive to me. I'm the guy that "discovered" the zenkudo and dumkudo and was the first guy in the US to have them and do a youtube demo. I have no financial stake in the company. I find it a bit mean to put mr Tanabe down and assume he has no technical ability and puts parts in at random. Regardless, It doesn't matter except the way it sounds. I've had every commercial pedal that trys at that sound and I keep coming back to the dumkudo. Here's my latest demo of the dumkudo twin. I think its not even close to the zendrive. I could care less that it looks like its not well made inside. Heck, Even my favorite guitarist Pat Metheny "looks" like he can't play when you watch him. Sure doesn't sound that way though!


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