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Monday, December 12, 2016

Electro-Harmonix OD Glove

Here's the Glove from EHX's nano series. Essentially, it's an OCD with a switchable charge pump. On originals the voltage switch is internal, but external makes more sense to me, so wire that to your preference. Here's the schematic for reference.


26 comments:

  1. Cool! I've been looking for this one. Looks Like I've got all parts in stock so that's a fun project for the upcoming weekend.
    Thanks for another great layout!
    I love your blog!

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  2. Replies
    1. Yes. Unless I specifically say otherwise switch are probably going to be on/on (or on/off if it's a SPST).

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  3. Can you please elaborate on the Voltage 1,2 and 3? I do not understand what it is or what it should be wired to. Thank you.

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    Replies
    1. It's a SPDT toggle switch. The numbers represent the lug numbers of the switch. Refer to the General Layout Notes tab for more info.

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    2. Thanks for your reply. So, I gather that this controls the charge pump so that the pedals operate at different voltages depending on the position of the switch.

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    3. Correct. It gives you the option to run at 9v or 18v.

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  4. Verified this today. Sounds great!

    I'm hearing a slight high pitch squeal when running in 18v mode, but I'm hoping that will go away once I box it.

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    Replies
    1. Switched out the 7660s for a 1044 and the squeal is gone. Guessing I had a bad chip.

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    2. Side note... don't order 7660s chips from Tayda. I've ordered about 5 from them and they all squeal. Their 1044 chips work fine, although they are a bit pricier.

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  5. There appears to be a mistake in the tone section. The 1uf cap negative side should only connect to the 33k/22k tone shift resistors and not lug 3 of the volume pot. This should get the tone control working.

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    Replies
    1. means you leave the lug 3 of the volume pot unconnected?

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    2. Fixed the layout. Should be totally fine now.

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    3. I made this change and it is (re)verified as working correctly.

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  6. Very grateful, Ian N. I threw my circuit to the trash last month, because I could not solve the problem of the Tone, I was very sorry because really this pedal sounds brutal, so I will do it again. Will it be possible to correct the layout?
    Thank you!

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    Replies
    1. I built the original layout before I found the error, but it was very easy to correct. Just remove the negative side of the cap from the trace going to Volume lug 3, and connect it to the trace going to the 33k/22k tone section, making sure to put it in series. I fixed mine in a couple minutes and it works perfectly now!

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  7. Hi!! i love this blog but i had a problem with this pedal,i dont have gain just a bit, i've check the circuit and look it good, tomorrow i'll be check it again but any idea what it could it be? sorry for my bad english =)

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    Replies
    1. Update: it was the input jack, now it works perfectly and it sounds amazing
      thanks!!!

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    2. Error connecting the 6.8K resistor. The lower end must be connected to pin 2 of TL082.

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  8. Gain should be A1M (logarithmic pot) http://www.freestompboxes.org/download/file.php?id=23341&mode=view

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  9. Error connecting the 6.8K resistor in the gain section. The lower end must be connected to pin 2 of TL082. This needs to be fixed! The pedal is amazing. In the PCB, I would add additional pins for unbalanced connection of clipping transistors by adding a 1n34a diode as in the OCD.

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    Replies
    1. Hello, do you know what component is FB1? https://ibb.co/2jKMPJK

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    2. Hi friend! Ferrite bead. For example BLM21PG221SN1D. https://clck.ru/TbQmZ

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    3. To prevent HF interference from spreading through the wires.

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    4. https://disk.yandex.ru/i/klxJpO82lRV-Ag

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    5. I think there's still an issue in the gain section - as shown the 220pf cap is directly connected to pin 2 of the gain pot, but I think it should be going through the 6.8k resistor to get there. In other words (E, L) is connected directly to (D, J) but it should be connected to (D, M).

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