Octaver Clone

by zeta55

Krister's Pearl OC-07 Clone Build

This is the first octaver for gaussmarkov.net. If you have a steady soldering hand, or are seeking a challenge, this is a good one: a Pearl OC-07 clone. I used SMD ICs and a two-board arrangement to get everything (except a battery 🙂 ) into a Hammond 1590B. My build is pictured above; you can see the daughter board standing vertically at the bottom of the enclosure.

Because I laid everything out in Eagle it seemed natural to make everything available on gaussmarkov.net. Check out my website if you would like to see my small tube amp projects. And see my original posts on Aron’s diystompboxes forum: search for posts by zeta55 with the word “pearl” in them. You can find more discussion and some sound clips there.


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16 Responses to “Octaver Clone”

  1. gaussmarkov said:

    Krister just pointed out a mistake that I introduced into board 1: a missing trace from C23 to R34. I just fixed it.

    If you are building this with a project file dated before October 21, then use one of the component’s leads to make the connection. If you’ve already built it, then use a left over lead to patch in the trace.

    Posted 21.10.2007 at 2:02 pm

  2. zeta55 said:

    I noticed that IC2 on the board2 schematic and layout calls for a TL074. In my pedal I have a LM324 in that position. If it matters I don’t know.

    Posted 23.10.2007 at 11:23 pm

  3. gaussmarkov said:

    Finally … I changed IC2 to an LM324. I apologize for the delay.

    Posted 15.11.2007 at 10:01 pm

  4. js said:

    Does anyone have a DIP layout or pcb? I realy don’t like to hand solder SMD chips and i’m no expert in Eagle 🙂

    Posted 01.08.2008 at 2:53 am

  5. diego said:

    is the pcb layout in the photograph the same of the project? i’m curious because the position of the components in the photo is different from the layout…

    Posted 05.02.2009 at 4:15 pm

  6. zeta55 said:

    diego, you’re right. The projekt files were edited after my first build. There were a few corrections made.


    Posted 07.02.2009 at 2:49 am

  7. diego said:

    Is there a bigger version of this project? with ICs of normal dimensions?


    Posted 16.02.2009 at 11:39 am

  8. Mário Calegaro said:

    Maybe you can give some tips… I own an original OC-7, and his octave up doesn´t work anymore… Any advice? Have you seen this before? Thank you and congrats!

    Ps.: I´m an eletronics technician that doesn´t work with eletronics since the trainee passage.

    Posted 09.11.2009 at 3:06 pm

  9. Elliot said:

    Hi, I’ve been looking around trying to find a normal layout (without SMD) due to me trying this (gauss) layout multiple times and failing every time…
    I found people talking about Mundy’s layout, and I’m wondering if anyone knows where I could find that. I found some dead links, but other than that-Anyone have any suggestions?
    Thanks so much!

    Posted 21.03.2011 at 8:16 pm

  10. André said:

    Hi! Just built this really nice circuit (used a madbean pcb), but I am getting bleedover signal when I set everything to 0.

    There are no wires over or under the circuit board, and the FX I/O are shielded.

    It is not really loud, but quite fuzzy.

    I used the audioprobe to check a few points, and when I touch lead n.3 of the clean vol, which would be the first thing to be amplified according to the schematic, I am already getting those signal in the mix.

    Tried chaning the pots values just to see if that would make a difference, but nothing.

    Does anyone also had a similar problem?


    Posted 22.04.2012 at 6:31 pm

  11. André said:

    Well, not only in 0… it is there all the time, but it gets less perceivable as the octaves and direct volumes are increased.

    Posted 22.04.2012 at 6:32 pm

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    Posted 16.12.2012 at 12:34 pm

  13. ko said:

    Hi, cool site, thx!
    Where can i see a video of how it sounds with this PCB (maybe you have sounds/videos of octaver placed on a photo above)?

    Posted 22.07.2013 at 2:44 pm

  14. Petr said:


    great site, thanks. I build mine OC7 recentlly, but I have few problems and don´t know what to do with it. At first it seems that first and second low octave pots doesn´t work at all. When i put all pots to the left (minimum), there´s no signal going through, but when i turn upper octave to the right, signal starts to go through and when normal is at minimum lvl, signal is almost clear with small fuzz in the background. I used your scheme and same parts, no substitutes, I checked circuits 3 times, but couldn´t find anything, any ideas? thanks

    Posted 05.03.2014 at 6:07 pm

  15. Petr said:

    I realized that I used old part list and instead of LM324 for IC2 I put there TL074D, so I´ll buy today LM324 and swap them, I´m rally curious if it will change something

    Posted 06.03.2014 at 7:46 am

  16. Petr said:

    Ok, so it looks like it wasn’t just different IC, there were few small shorts, had to use magnifying glass and some cold solders, but I have 2 problems now, effect works, but norm pot , there’s almost no difference between full off and on position and almost at all strings between open string and fifth fret it doesn;t tracks well, here’s an example https://soundcloud.com/burdin84/oc7-problem is it normal or some problem?

    Posted 11.03.2014 at 1:28 pm