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