Tuesday, 27 September 2016

Electro Harmonix Octave Multiplexer

Here is a layout for a classic pedal.
I've drawn 2 versions: Vintage and Modern.
There are 2 layouts for the Vintage: with and without output boost.
I've added a boost to the Modern layout to avoid volume loss.
You can find the original FSB thread here.
16/01/2017 Layout updated! I've changed the vintage layouts because there were some errors in the schematic.
Thanks to Barcley for pointing out the corrections that I needed to make!





58 comments:

  1. WOW! Alex you are unbelievable. Thanks. Man my build list is getting big. Respect!

    ReplyDelete
  2. Hi Alex. Thanks for some great layout once again. I build the modern one but I have some problem, I can't make it works. I tried to check my build but I wasn't able to find errors (it's maybe on my side but I didn't find). I also tried to change IC's and trannies in case of faulty one but nothing better. Any help would be very appreciate.

    Here is my voltage :

    5457 / D 5.44 S 4.62 G 4.66

    5459 / D 3.5 S 3.5 G 0

    4013 / 1/ 5 2/ 3 3/ 0 4/ 2,5 5/ 0 6/ 2,5 7/ 0 8/ 0 9/ 8.63 10/ 0 11/ 2 12/ 8,67 13/ ABOUT 7 14/ 8,72

    LM324 / 1/3,5 2/ 3,5 3/ 3,5 4/ 8,72 5/ 3,5 6/ 3,5 7/ 3,5 8/ 4,13 9/ 3,9 10/ 3,8 11/ 0 12/ 3,9 13/ 3,9 14/ 4,1

    4558 TOP / 1/ 7,35 2/ 3,5 3/ 3,5 4/ 0 5/ 4,17 6/ 3,5 7/ 2,3 8/ 8,73

    4558 BOTTOM / 1/ 1,5 2/ 3,5 3/ 3,5 4/ 0 5/ 3,8 6/ 3,6 7/ 2,6 8/ 8,72

    To finish, pics of my build :
    http://dl.dropboxusercontent.com/u/9520625/20161001_112634.jpg

    http://dl.dropboxusercontent.com/u/9520625/20161001_112718.jpg

    Thanks a lot for all your work

    ReplyDelete
    Replies
    1. Hi Thomas.
      Did you compare the layout to the schematic?
      I think it's ok but I won't be able to check again until Monday.
      I'm not able to see all the cuts from the pictures but I assume you already double checked everything.
      From your circuit picture, I think both transistors are reversed. Have you checked the pinout?

      Delete
  3. Thanks for the comment. I checked cut and pinout..
    I placed the tranies by respecting letters but I tried to reverse them without success.
    I tried to look at the schematic also but I don't hAve the knowledge to understand. I just know building.

    ReplyDelete
    Replies
    1. Hi Thomas!
      Had a look again and there were a couple of mistakes:
      from the 2n5457 Ground there is a 1M resistor that should go to ground, one row below (it goes to Vref on the previous layout).
      The 100n cap at the bottom right corner should be removed.
      I've already changed the layout.

      Delete
  4. OK, thank you I will test that and keep you updated. You were right on my pics trannies were reversed. I remove them to test them and put them back quickly (and badly to make the test).
    Not sure to have the time tonight but tomorrow it should be good.

    ReplyDelete
  5. OK I made the change and.... it's working. The modern version is verified. Thanks a lot for giving us another great layout).

    ReplyDelete
    Replies
    1. Cool! Thanks Thomas!
      Does it sound like the original?
      Is the JFet boost helping with volume loss?

      Delete
  6. It sounds very nice. I don't really know the original but from what I heard on the web it's close, maybe a bit more artefact (not on every setting).
    The boost help a lot, you can even have a volume boost so it's perfect.
    Thanks again for your work and the help you gave me.

    ReplyDelete
  7. IMO it's a bit misleading to talk about "volume loss". I own the reissue and modern XO version, plus a former bandmate has a vintage specimen. None of those have volume drop issues. Like johnk says in the FSB thread: "I found that it could use a bit more output so I added a Jfet boost to the output with a volume control". Boost afterwards isn't a bad thing and adds to usability. But nevertheless, the original is an octave pedal and always performs at unity level, no matter the source instrument. Adding a JFET stage and volume control are extra features that are not essential.
    +m

    ReplyDelete
    Replies
    1. My bad.
      Drawn the layout a while back and forgo why the boost was there.
      Glad it work though.

      Delete
    2. Damn i sound mean :) That was not the intention.

      I'll be building one soon(ish) too. And super great work man!
      +m

      Delete
    3. You are a mean! :)
      Don't worry.
      At least now people know the Vintage version without the boost should still work without any problem.

      Delete
  8. Verified the vintage with the boost. Sounds close to the YT vid but doesn't seem to track quite the same. Mind you those vids on YT make everything sound amazing.

    ReplyDelete
    Replies
    1. Thanks Gavin!
      Which video have you watched?
      The ProGuitarShop's above the layouts?

      Delete
    2. PGS videos always sound perfect (different from reality).
      You should check some videos of the "Vintage" version.
      Don't know if they've been modified later for tracking issues.

      Delete
  9. hi alex..im so confused about number of the switch, any switch pinout images for this...im newbee..sorry for my bad english.... thanks

    ReplyDelete
    Replies
    1. Hi Agus.
      "Regular" Switches are always numbered the same on this blog:
      SPST:
      1
      2

      SPDT
      1
      2
      3

      DPDT:
      1 4
      2 5
      3 6

      3PDT

      1 4 7
      2 5 8
      3 6 9

      You can check Storyboardist page here:
      http://effectslayouts.blogspot.fr/p/general-layout-notes.html

      Delete
    2. oke,thankyou very much for suggest... i will try it....

      Delete
  10. Did anyone successfully build the vintage version (the one without boost)?
    Mine doesn't work and I can't quite figure out why :-(

    ReplyDelete
    Replies
    1. Hello Ozzy,
      ICLM324 parallel with the IC4013 has a lot of mistakes to the original shematics.
      1. The diodes D1 and D3 should tourn poles
      2.The connection betwen 2-13 should be discontinued
      3.Make to bridge 1-13 pin
      4.Bridge 10-6 should be discontinued
      5.Make bridge 10-7 pin
      Everything else is fine althoug there is a slight disagreement with some components.

      Delete
    2. Hi Barcley.
      There are no mistakes.
      The layout is identical to the boosted one and that's been verified.
      This is the schematic:
      http://www.freestompboxes.org/download/file.php?id=27474&mode=view
      LM324 is a quad op-amp and pins numbering can be swapped around to suit the layout.
      Please, next time, if you think there are any mistakes point them out to the person that has drawn the layout.
      That way we can explain all the possible changes we have made or correct the mistakes if there any (of course is more than possible, we are human).
      That way we'll avoid confusing people.

      Delete
    3. Thanks so much for your reply, Alex! Please can you check my wiring here, as I am not sure if I am doing it correctly?
      https://drive.google.com/open?id=0B8HeRqgTRGTCODI4WUpxTFYxSzg

      Delete
    4. Hello Alex,
      I do not want to convince you
      But you're wrong
      It is possible that you have misunderstood
      I guarantee what you publish
      All that I announce the first try.
      So this scheme octave Multiplexer(Vintage70`s)
      If you want to see for yourself, so try.
      My works perfectly and I am very satisfied.
      Oh yes, and I replaced the FET transistor with a J 201
      And finally, I do not intend to confuse people but to help advice, thank you.

      Delete
    5. Hello Alex,
      I do not want to convince you
      But you're wrong
      It is possible that you have misunderstood
      I guarantee what you publish
      All that I announce the first try.
      So this scheme octave Multiplexer(Vintage70`s)
      If you want to see for yourself, so try.
      My works perfectly and I am very satisfied.
      Oh yes, and I replaced the FET transistor with a J 201
      And finally, I do not intend to confuse people but to help advice, thank you.

      Delete
    6. Now I am really confused...
      Alex, please, could you check my board if you can see anything suspicious? Thanks a lot again!
      https://drive.google.com/open?id=0B8HeRqgTRGTCeUYyblVRSkk5RUE
      https://drive.google.com/open?id=0B8HeRqgTRGTCcGRjM1hfTzVEYW8
      https://drive.google.com/open?id=0B8HeRqgTRGTCbTk0bFJJblpmMnM

      Delete
    7. Hey Barcley!
      Sorry but I didn't understand what you've meant with
      "I guarantee what you publish
      All that I announce the first try.
      So this scheme octave Multiplexer(Vintage70`s)".
      Of course I could be wrong and any help is more than appreciated.
      What I was saying is that the vintage layout (with or without the boost are pretty much the same) has already been verified by Gavin and I trust his judgement.
      And I wasn't sure the schematic was correct until that moment.
      I have to relay on other people verifying them, I can't build all the layouts I draw.
      If you write a post addressed to Ozzy where you say that half layout is wrong and that there are parts missing people are gonna get confused because the layout had already been verified.
      And that doesn't mean you are wrong!
      If you address a post with your suggestions to "me" first, I would be more than happy to check them because none of us like to keep wrong layouts on the blog.
      That's what I was saying.
      Which schematic did you compare the layout to?
      This:
      http://www.freestompboxes.org/download/file.php?id=27474&mode=view
      or this:
      http://www.freestompboxes.org/download/file.php?id=26589&mode=view ?

      Delete
    8. Hi Ozzy!
      Can you add those pictures to the Debugging section of the forum with a description of your problem and ICs and JFet voltages?

      Delete
  11. Hi Alex
    I did not say that half of the schedule is not true.
    I'm pinpoint what is not good.
    I'm staying in their assertion.
    Maybe you did not understand me, my bad English is the reason, I'm sure.
    http://s514.photobucket.com/user/midnight_liberation/media/EHOctave_Multiplexer_1975.gif.html
    The first data schema for the vintage version is 99% of the match.
    Exscept apart from what I said.
    Check and see.
    I have made vintage version as the blog (not good).
    With my correction works perfectly.
    I have not invented anything new, I just applied logic.
    When something is not good, find the problem.
    Thank you for writing,I'm here if you need to clarify anything.

    ReplyDelete
    Replies
    1. Ok. Now I understand.
      I thought you've made your changes based on the schematic from FSB!
      Never seen the one you've used!
      What I don't understand is how the layout have been verified.
      Hey Gavin! Is the layout you've built working properly? (Apart from the tracking. I think the tracking is not as good as the newer versions anyway)

      Delete
    2. Mine never sounded what i expected so i think its in the debug pile at the moment. The sound and tracking were weird in not a good way, if i remember correctly. What exactly is the problem? Maybe i can try a fix.

      Delete
    3. Hi Gavin.
      I've thought it was working.
      Barcley has found a different "corrected" schematic:
      http://s514.photobucket.com/user/midnight_liberation/media/EHOctave_Multiplexer_1975.gif.html
      Try his suggested changes:
      1. The diodes D1 and D3 should tourn poles
      2.The connection betwen 2-13 should be discontinued
      3.Make to bridge 1-13 pin
      4.Bridge 10-6 should be discontinued
      5.Make bridge 10-7 pin

      Delete
    4. Thanks Alex. Don't know how missed the five steps by Barcley. I'll try and give it a go later. Have to run some errands first and fix my guitar hanging slat set up to the wall.

      Delete
  12. http://topopiccione.atspace.com/pjimages/EHOctaveMultiplexer.sch.gif
    Here is a link with two JRC4558 instead LM324.
    Link in the previous message with two LM324.
    I hope that now everything is clear.
    Greeting.

    ReplyDelete
  13. Hi guys,
    I've solved the problem,In 5 easy steps,and for me it's finished.
    I'll be satisfied if I helped someone.
    If someone wants my advice, I'm here.
    My pleasure.

    ReplyDelete
    Replies
    1. Hi Barcley, many thanks for helping me out. I will try your 5 steps and will report back with the results.

      Delete
  14. Ok, applied the changes mentioned by Barclay and its sounds much more like it should. Before it sounded like two signals out of phase, but i just wasn't sure if it was correct or not. Now its definitely correct. Cheers Alex and especially Barclay.

    ReplyDelete
    Replies
    1. It's crazy but mine doesn't work even with the above changes applied. Only hum comes out (sounding same like when touching an unplugged input jack). Please, can you recheck the layout once more? My ICs and JFET voltages are as follows:

      JFET 5459
      D - 4.3
      S - 4.3
      G - 4.6

      LM324 (upper one)
      1 - 4.3
      2 - 4.3
      3 - 3.8
      4 - 9.3
      5 - 3.8
      6 - 8.6
      7 - 0.6
      8 - 4.3
      9 - 4.3
      10 - 3.8
      11 - 0
      12 - 4
      13 - 4.3
      14 - 0.6

      LM324 (one next to 4013)
      1 - 8
      2 - 0.9
      3 - 0.9
      4 - 9.3
      5 - 0.9
      6 - 0.9
      7 - 0
      8 - 0
      9 - 0.9
      10 - 0
      11 - 0
      12 - 0.9
      13 - 8
      14 - 0

      4013
      1 - 9.3
      2 - 0
      3 - 0
      4 - 0
      5 - 0
      6 - 0
      7 - 0
      8 - 0
      9 - 9.3
      10 - 0
      11 - 0
      12 - 9.3
      13 - 0
      14 - 9.3

      Delete
  15. Hi guys,
    I'm glad that I helped a little.My greetings to Alex and Gavin,cheers.



    ReplyDelete
  16. Hi Ozzy
    Some voltages are not good.
    5 steps should only be used LM324 parallel with the 4013, not on the first above!
    How you apply?
    I'll give you my voltages but you must be a mistake somewhere.
    Also I see if your input voltage is above 9v,and that after passing through the diode D4.This shows that you do not have stabilized voltage 9v.My power suplie is exactly 9v after diode D4 8.39v in all integrated circuits.Although I think that this is not a real problem at your place but this is the basic thing.Application L7809 in power suplies.
    The following message sending these voltages.
    Check once more,do not give up man!

    ReplyDelete
  17. Hi Ozzy, i was just starting to measure my voltages when i discovered that after the pedal is on for a bit my voltages right across the pedal drop.Plugged it in and i lose the octave effect. It seems i may have an additional problem with my build. If i can figure it out and get it working properly i'll post the voltages for you.

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

    ReplyDelete
  19. J FET 201

    D - 4.19
    S - 4.20
    G - 2.60

    LM324(upper one)

    1. 4.20
    2. 4.20
    3. 4.17
    4. 8.39
    5. 4.17
    6. 4.21
    7. 4.20
    8. 4.20
    9. 4.20
    10. 4.13
    11. 0
    12. 4.15
    13. 4.20
    14. 4.20

    LM324(parallel with 4013)

    1. 7.11
    2. 4.13
    3. 4.20
    4. 8.39
    5. 4.20
    6. 4.20
    7. 0.02
    8. 0.015
    9. 4.20
    10. 0.02
    11. 0
    12. 4.20
    13. 7.11
    14. 0.03

    4013

    1. 1.70-2.50
    2. 3.20-4.10
    3. 0
    4. 0.03
    5. 0
    6. 0.015
    7. 0
    8. 0
    9. 4.90
    10. 0
    11. 3.40
    12. 4.90
    13. 2.50
    14. 8.39

    With these voltages works perfectly.
    If you find a mistake you made,I'm not sure it will help you a lot.

    ReplyDelete
  20. Thanks, Barcley!
    btw what vero layout did you use? The one that Alex had posted here originally?
    I rechecked everything and still didn't find what's wrong. Any tip where to look please?

    ReplyDelete
  21. Ozzy,yes, I used the schedule which is set Alex,with 5-step changes.The first schedule.It is now taken care of and you can see it.I will try it by your voltages to find something.You check under the scheme on the blog, now with the changes.Look at my voltages,Look at my voltages,where there is disagreement regarding check components.Lm324 upper one,pin 14 must be the same voltage as pin 13.Chek capacitors 22n which connects them.The same voltage must be on pin 6.Further,Lm324 parallel to 4013,the quad-opamp output pin1,7,8,14,must be a voltage.Check it out and diodes D1 i D4.Fet transistor is eccentric.That's what you've got brum is proof your signal goes to ground.Monitors signal from the start and the end.That's all I can do this.I hope that you will succeed.

    ReplyDelete
    Replies
    1. Great tip, Barcley. It finally works!!! Somehow I managed to miss a hair-thin bridge at one of the cuts.
      Thank you guys so much for helping me out! I truly appreciate it!

      Delete
  22. Congratulations Ozzy,
    we're here to help.
    Greeting.

    ReplyDelete
  23. hello guys...i've just finish to build, but there's a tremendous volume loss, even with pot volume all turned up...i changer just one thing: i put 2n5458 instead of 2n5459 (hard to find)...could it be the problem? i've build the modern one, is it verified?
    thanx

    ReplyDelete
  24. ok, solved it: it was just a solder bridge!
    an information: i used MPF102 insted of 2n5458, and it works better!

    ReplyDelete
  25. Hello alex where is the resistor clr for?
    And what it is

    ReplyDelete
  26. CLR= Current Led Resistor, i presume
    so, it should be between 2K2 and 4K7 (at least, these are what i use)

    ReplyDelete
  27. Hi guys. I also plan to build a clone of this pedal. So I found PCB in Sprint-layout format here. http://www.komitart.ru/guitar/716-sobiraem-effekt-octave-multiplexer-electro-harmonix.html

    ReplyDelete
  28. Sorry mates. but were are Sw1-4 and Sw2-4 connected to? I made it, i didnt connect Sw2-4 and Sw1-4 nowhere and the signal passes through, every knob does something... but it isnt remotely close to octave effect :P (i meesed up somewere)

    ReplyDelete
    Replies
    1. Nowere... thats were they connect to. :)

      Delete
  29. I have some problem with the modern+boost version. (Is it verified, it isn't?)

    I replace the 2N5459 with a 2N5457.

    I have a big pop engaging and disengaging the circuit. I see just one 1M resistor in the boost section. Do I need of a pulldown resistor?

    Someone can tell us the right voltages of the JFET boost.

    Thanks!

    ReplyDelete