Zendrive 2

[PedalBlotter]

Sry, can't find any Layouts of this pedal.
So, Zendrive 2, what is the deal, 9 Volt with a 12ax7 Tube
Schem, Layout ? Anyone ?

Want to build it...

[iggy]

I researched this a bit ago, and couldn't find a schematic for the circuit. But there is some good info on FSB. seems as though it's a standard zendrive with the tube taking the place of the clipping diodes. I'd also like to bump this for a layout, if some one can access that information and make the change to the ZD circuit. Looks like it should be a very easy change. Sorry I don't know about tube layouts.

[Zombie11]

I'd like to bump this with the following information:

The PCB of the Zen2 is the same as the PCB of the Zen1. Remain the clipping MOSFETs and substitute the clipping diodes for the triodes applied as rectifier. Connect anode and grid of each triode and wire to the corresponding MOSFETs wiring points and wire each cathode of the triodes to the corresponding wiring points of the opamp along the Zen1 schematic. Find the 0.1 uF capacitor which is connetced from the "Voice" potentiometer to the half supply voltage point and substitute it for a 0,22 uF capacitor.
Substitute the 500kOhms "Gain" potentiometer for a 1MOhms potentiometer. Find the 100pF capacitor which is connected in parallel to the "Gain" potentiometer and substitute it for a 51pF capacitor. Wire the 9V supply to the heater pins 4 and 5.

Don't increase the supply voltage, the 9 Volts heater voltage is essential for the clipping knee voltage of the triode as rectifier.


Can some-one make a layout with this info? Zendrive 1 is a site favorite and I'd LOVE to build the zendrive 2 and we have a big shortage of easy to do tube pedals on here. THANKS!

[Zombie11]

Bumping this one as we have a alot of new layouts coming out AND this pedal is getting harder to find and floating above the 300 dollar mark if you find it on ebay or reverb

[digi2t]

As per your instructions...



I breadboarded it, and I strongly recommend going to 150pF for C7. Otherwise, the top end of the Voice pot gets really icepicky. Here's a layout;

[Claudiog]

I know it's to late but now I see the scheamtic, 9V to heaters will decrase tube's life, i'ts not a better idea to use 9v tubes? like 9AU7?

[Dex3887]

they typically run these 12.6v in series in most amps, 9v series equals 4.5v each which is less than the 6.3v
"Marshall jcm2000 run its preamp tubes at 9 volt dc( series heaters, 4.5 volt/tube.)"Cold heaters DIY stompboxes

[glasspak73]

this might be a dumb question but since the JCM 2000 runs 4.5volt on each tube wont that cause the tubes to clip sooner/faster then normal voltages? I think thats what i did with a tube circuit i built once just to get more distortion out of each stage of the circuit.If im way off here sorry im just guessing thats why i wanted to ask.thanks for your time Dex3887

[Claudiog]

I read the cold heater post, and cleared out all my doubts