This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, February 26, 2019

Lovepedal Zendrive 2

The Zendrive 2 is a big box version of the Zendrive, using a 12AX7 internally. Sadly the tube is only being used for clipping, replacing the BAT41 and 1N34a diodes in the small box Zendrive. But according to reliable sources, it sound very good, with some harmonic mojo happening. Other than the tube clipping, there's only a few value changes from the small box version. Schematic for reference.



25 comments:

  1. Thanks for posting this, David. I've never looked at this circuit before and, yeah - a little bit of a let-down to see that the tube is only in there for clipping. I guess I really wanted some extra magic tube mojo going on.

    Any which way... if it sounds cool, who cares what's in the box?

    Funny, though. I was just reading a thread where some real cork sniffer types were going back and forth about which NOS tubes they get the best tone from in this pedal. I guess if you paid $400-$500 and waited on some kind of list for over a year for it, you'll find a way to hype up the mystique.

    Personally, I have a Telefunken 12AX7 that was taken from one of Jimi Hendrix's Marshall heads, blessed by a Navajo medicine man, and then stored for 50 years at an energy vortex in Sedona, AZ. (At least, that's what the eBay seller told me, and he has 100% A++++++ feedback so it must be true).

    That tube is going to do wonders in my build! I'll update as soon as I have results.

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    1. "he has 100% A++++++ feedback so it must be true"

      Hahaha best comment I've seen in a while.

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  2. feeding 9V to heaters will short tube life, should be use 9AU7 or any doble triode with 9v heaters, I bet they sound better with that tube, providing less or more current for the heaters is not appropriate.

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    1. More current(A) is ok, less current is no working; less voltage(V) is ok, more voltage will blow the filament. 12AX7 is 300mA i think, and 9V to 13V is ok. Less than 9V will not heat.

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    2. yes you are right, I made a mistake about definitions, I was trying to explain about volatge a not amperage, btw, is 300mA for that tube, I can't understand why feed below 12v those heaters, I know is conected for clipping and not for usual tube use.

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  3. Hello, do you haver the schematic? May you share It please

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  4. I guess it will work with a TL072 or a NE5532. Would a 12AU7 work as well?

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    1. some users claims that his Zendrive uses NE5532, u can use any doble troide with 9 pins that bleongs that type of tube, in this case the tube is not working a tube, is replaceing the diode clipping section.

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    2. Hello everyone, I realize the exact clone of bk butler, and I must say that it is beautiful, this zendrive 2 compare it with my clone tube driver is back light years as sound, here is a link of the pedal that I realize, obviously the graphics are different , the one in video is for illustrative purposes only

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  5. hi everybody!
    thanks for another great layout!
    buildt it last night with the values in the layout and it works like a charme!

    greetings from austria
    bluesanderl

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  6. any value between 51pf and 220pf for CX?

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    1. That's my schemo. The reason why I wrote 51p to 220p is because different op amps, tubes, and most of all guitars, will all react slightly differently with this circuit. Depending on how much "ice pick" you want/can endure, adjust this cap accordingly. Use your ears to define the ultimate value for you.

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    2. Thanks for chiming in, Dino, and thanks for all your contributions to the DIY community!

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  7. i build one but not work. i do pedals every day and i believe i did not know how is the pinout of tube.
    what is the reference point for starting counting on the pins?

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    1. i used bs170 inverted and 5532 like op amp but i belive that not is the reason to not work

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    2. https://www.amplifiedparts.com/tech-corner/12ax7-tube-diagram

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    3. oh guy, i do inverted tube pinout! thanks a lot!

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  8. Looking at the drilling template, it appears that the tube is to be mounted through the top of the pedal enclosure. I am looking to rather put it inside a 1590BB like in the original Hermida Zendrive 2. Is there a pcb available that I could print out and use for the 12AX7 tube? Also How are others attaching the tube to the circuit board provided here?

    Thanks

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  9. I built the circuit and it work, only not with the tube in. I connected a 9 pin socket to the board per the layout, tried 3 12AX7 tubes, what could be the problem here? The socket and tube pin outs match up. I did connect pins 6 & 7 together, and 1 & 2, 4 & 5 with the same lead wires, is that right? Any insight here would be greatly appreciated!

    Thanks

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  10. It works, the drawing is good. I built a few pedals from the drawings here. Thanks for them.

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  11. I build this pedal and it works, but when I take the tube out it has far more gain and sounds more like the videos... I wonder if this is normal

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