Wednesday, 23 February 2022

Tim Escobedo Harmonic Jerculator

 Tim Escobedo's take on the rare Harmonic Percolator. Simple with no mojo parts in sight. 



33 comments:

  1. Very cool. I’ll try it tonight.

    ReplyDelete
  2. Verified. Quick build. This would be a good 1590A fit. Just need a couple 9mm pots. Thnx dogg.

    ReplyDelete
  3. Says 5 links, but appears to be only 4.

    ReplyDelete
  4. Hey fuzzhead... got another if you are interested... Tronix DS710 distortion...
    http://www.geocities.ws/teleman28056/pictures/ds-710_sch.jpg
    http://www.geocities.ws/teleman28056/pictures/component_list.txt

    ReplyDelete
  5. Hi!Thanks!!If you find the time pedalpcb has released the schematic of the Jackson audio amp mode... Cheers!

    ReplyDelete
  6. Слава Україні! Героям слава! Ми переможемо! Будемо паяти фузи, грати музику!!!

    ReplyDelete
    Replies
    1. Totally!
      Are you safe Zzoyd?
      Is ther anything we can do?

      Delete
    2. yes, we are ok, Kiev! Thanks!

      Delete
  7. The whole world is praying for you guys ZZOYD.

    ReplyDelete
  8. This comment has been removed by the author.

    ReplyDelete
  9. Im new to Vero pedal bulding and I just finished the board ( first one!). Can anyone guide me on how to wire this up? I have all the parts but I'm a little confused about where the in and out from the board are among other things like why there are only 2 lugs mentioned on each side. I'm so close I can taste it! I just need help. Thanks in advance!

    ReplyDelete
  10. So if you are looking at the potentiometers with the shaft pointing up and the lugs facing you, from left to right, they are 1-2-3 - apologies if you all ready know this - just trying to be thorough. So the input wire goes to lug 3 of the harmonics pot. And you take the output wire from lug 2 of the balance pot. If you haven't got one all ready, I suggest searching YouTube for videos about building a circuit tester box. This way, you will only need to build the circuit with Input, Output, 9v and ground in order to test it and not have to wire up footswitches or jacks without knowing if the circuit works. Good luck!!! -Chris

    ReplyDelete
    Replies
    1. Also - if you look at the comment just above yours, you will see that input may actually go to Harmonics 2, not 3. If this is the case, you can swap Harmonics 2 on the board for lug 3 of the pot.

      Delete
    2. Sorry for being meticulous, but I'm looking at the 3dpt wiring schematic and it has led - at the top left lug, input jack (i assume positive?) going through lug 2 jumped to bottom right lug 9, ground goes to lugs 4, jumped to 7 and 8, and output jack goes to lug 6. what I'm confused about in this schematic (assuming this 3pdt I'm looking at from skreddypedals is correct) lug 3 is labeled BOARD OUT and lug 5 BOARD IN. but I don't see a board "out" or "in" on this vero? So, in your explanation, is lug 3 "board in" off harmonics? if so what would board out be? Also, even if I build one of these circuit tester boxes the vero still doesn't have an in or out? Sorry if these are super obvious questions I'm just a beginner in the dark with all this! I'm used to building on PCBs and daughter boards (i've got a million daughter boards if it's easier to use one of them with the 3pdt for this board!). Ialaso don't have the materials on hand to build a circuit tester but I pinned the trannies and diodes just in case and worst case scenario I can start over since there are like 5 caps and 4 resistors

      Delete
    3. Input or "board in" is the unused lug on the harmonic pot, output or "board out" is the unused lug on the balance pot.

      There seems to be some discrepancy between the drawing and what folks are saying in the comments as to just which two lugs of the harmonics pot need connect to the board and which one is the input/board in. The drawing says lugs 1&2 connect to the vero and input is lug 3. But Tom, who commented just above yours, claims that lugs 1+3 connect to the vero and that input is lug 2.

      So honestly - you are probably going to have to try both ways and see which one works. Before doing any layout that is marked verified, I've found it is best practice to read all the comments, as tedious as it can be, very carefully because there is often something that you might need to know.

      Delete
    4. Thanks for clearing that up! I rally appreciate it! I'll try the correction first and go from there. Thanks for taking the time to explain it to me :)

      Delete
    5. I wired it all together but alas nothing happens. I get the guitar signal whether it's on or off but no effect. The LED turns on with the switch, and when I turn the pots I hear crackling noises until all the way off and then I hear screeching? I tried flipping around the transistors cause why not but it didn't change anything so I put em back the way they were. "Maybe" there's a noticeable change in the tone of the guitar? a volume and tone drop? but just a little bit. Any ideas where I went wrong? I'm pretty good at soldering and all my connections are correct there's just no fuzz effect.

      Delete
    6. I always scrape between tracks with a utility knife before I even test a circuit. So try that. I like to shine a flashlight through the board to look for solder bridges. It's a common issue with these builds. Make sure all of your components are properly placed. It's easy to overlook something. And finally check that your transistors are oriented correctly. You'll find the issue.

      Delete
    7. Thanks! I'll keep at it and post back once I figure it out :)

      Delete
  11. Just to clarify, I’m looking at the schematic I saved from the original Tim Escobedo Circuit Snippets many years ago, and Lug 3 goes to the Input jack and Lug 2 goes to the Circuit input?

    ReplyDelete
    Replies
    1. Brian's right. From what I can find of schematics for the Jerculator that are floating around online, the pot lugs may not be numbered per se, but they all look like input goes to Harmonics lug 3, then lugs 1+2 get wired to the board.

      Delete
  12. It's probably my mistake. I never saw a schematic. Harmonics just adjusts input impedance like a FF Contour control. I built a stock Percolator with a diode lift that I'm in love with and don't use the pocket percolator much these days. Sorry for any confusion.

    ReplyDelete
    Replies
    1. No worries, Tom. This is what the comments are FOR!!! To work out stuff so that everyone learns!👊

      Delete
  13. Hi all... I have found that this circuit sounds much better when Q2 is flipped to that it is CBE from top to bottom.

    ReplyDelete
    Replies
    1. I'm sure what everyone here really needs to know is whether or not the pedal enclosure constructed of legos has anything to do with that tone? 🤪

      Delete
    2. Well, if people don't know that LEGO makes pedals sound better, then. Pfft!

      But, seriously, I think that tranny is reversed. ;)

      Delete
    3. I think that this version of the Percolator is based on the Albini version which has more of an overdrive character. I really like it but it doesn't have that blown out Fuzz Face quality that a "real" Harmonic Percolator possesses. For starters, it doesn't use diodes. But I prefer the diode lift anyway.

      Delete
    4. Try replacing the 2N3904 with the Percolator's 2N3565.

      Delete
  14. If you look at the schematic the emitters are tied together with the 22uF going to ground, the layout represents this, I think that the orientation of the trannies is confusing your eyes?

    ReplyDelete
    Replies
    1. Nope. With the 2N3904 in this configuration, there is some mild oscillation when you hold a note (almost goes octave-down). With the 2N3904 turned 180 deg, it's a nice smooth fuzz.

      Delete
  15. Original Schematic: http://www.jiggawoo.eclipse.co.uk/guitarhq/Circuitsnippets/hj.gif

    ReplyDelete