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Thursday, February 19, 2015

Jen HF Modulator

Jen was an Italian electronics company that produced a lot of OEM stuff for other companies (Vox, Gretsch, etc.) as well as marketing their own line of effects. For instance, the HF Modulator was the same effect as the Gretsch Playboy.

This effect is a ring modulator and sounds fantastic with a fuzz pushing it. The original unit used 2N5172 transistors (which have BCE pinout), but I've laid this out for more common 2N3904 or 2N5088 transistors (that have CBE pinout). I've also added pulldown resistors, polarity protection, and power filtering.




Here's the schematic if anyone needs it. Most of the ones online have the tone section wrong.



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17 comments:

  1. UnknownMarch 18, 2015 at 7:23 AM

    Hey is this verified yet?

    ReplyDelete
    Replies
    1. dtgehringMarch 18, 2015 at 12:20 PM

      Not yet that I know of, but it should be fine. Give it a shot!

      Delete
    2. UnknownAugust 15, 2020 at 4:18 AM

      I made this today

      It turns on
      But just make a little Boost
      No effect


      Any help?

      Delete
  2. UnknownSeptember 4, 2015 at 4:29 AM

    Just finished.It works fine)

    ReplyDelete
    Replies
    1. dtgehringSeptember 4, 2015 at 9:01 AM

      Thanks for verifying!

      Delete
    2. UnknownAugust 15, 2020 at 2:53 PM

      Made this today

      It turns on
      But just make a little Boost
      No effect


      Any help?

      Delete
    3. UnknownAugust 17, 2020 at 12:43 AM

      Made this today

      It turns on
      But just make a little Boost
      No effect


      Any help?

      Delete
  3. UnknownOctober 13, 2015 at 6:32 PM

    On the PCB layout the capacitor across B C on Q1 is marked 2.2nf and on the schematic below it is marked 220pf. Swapping out for the 220pf reduced volume drop.

    ReplyDelete
  4. UnknownJanuary 4, 2019 at 11:07 AM

    So all the same!
    Capacitor near Q1 should be 2n2 or 220p?
    In different sources in different ways!

    ReplyDelete
  5. MulekickerJanuary 30, 2020 at 11:04 AM

    I'm glad I looked at this. I did a vero build that Anders has on his site with a 2.2nf and the volume is low. Will swap out for a 220pf.

    ReplyDelete
    Replies
    1. UnknownAugust 31, 2020 at 12:51 AM

      I did it

      Don't get modulation

      Justo the tone knob works

      Any help?

      Delete
  6. UnknownAugust 15, 2020 at 4:17 AM

    I just Made this today

    It turns on
    But just make a little Boost
    No effect


    Any help?

    ReplyDelete
  7. TrevorAugust 17, 2020 at 10:06 PM

    The PCB layout is missing a pad for the 3.3nf cap at input.
    easy enough to drill and extra but you might want to correct for clarity.

    ReplyDelete
    Replies
    1. UnknownAugust 31, 2020 at 12:58 AM

      Can You make ir work?

      Mine just work tone knob

      Don't get modulation

      Delete
  8. ChernyshevOctober 16, 2020 at 7:01 PM

    Only tone knob works, no modulation.What does it mean "Most of the ones online have the tone section wrong"?
    How to set up a nonal section and what could be a mistake? Apparently, the users above have the same problem, please explain! Sorry for my English, I'm from Russia.

    ReplyDelete
  9. Dave BJanuary 5, 2021 at 4:54 PM

    Works beautifully - here's a little demo how it sounds: https://youtu.be/t9FFN2GWlYE

    ReplyDelete
  10. gnavalesiAugust 5, 2021 at 6:10 PM

    Just finished! Just two changes to the schematic:
    The 2.2nF cap should be 220pF
    Q3 is inverted compared to the FSB schematic. C and E should be swapped.

    ReplyDelete