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.

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.



17 comments:

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

      Delete
    2. I made this today

      It turns on
      But just make a little Boost
      No effect


      Any help?

      Delete
  2. Replies
    1. Made this today

      It turns on
      But just make a little Boost
      No effect


      Any help?

      Delete
    2. Made this today

      It turns on
      But just make a little Boost
      No effect


      Any help?

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

    ReplyDelete
  5. 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. I did it

      Don't get modulation

      Justo the tone knob works

      Any help?

      Delete
  6. I just Made this today

    It turns on
    But just make a little Boost
    No effect


    Any help?

    ReplyDelete
  7. 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. Can You make ir work?

      Mine just work tone knob

      Don't get modulation

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

    ReplyDelete
  10. 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