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.

Monday, July 18, 2016


Here's a cool variation on the MXR DynaComp. Apparently it's well loved by Rickenbacker players for adding even more Byrd-like jangle to their tone. It's laid out for board mounted pots and you should be able to squeeze it into a 1590B.


  1. Hey, can I request a layout via donation button on the bottom left?

  2. Hi , can I request a Multiplex Echo Machine from 1776effects?

    Thanks a lot!

  3. I presume the CA3080 ic works fine in this?

  4. I'm getting a strange oscillating fuzz sound. Theres no sound at all until I hit the strings hard and the suddenly it will come on with fuzz sound that continues steady on the decay but cuts in and out as the signal dies. Is this bad envelope ripple.

    I've measured the transistors.
    C: 8.82
    B: 1.14
    E: 1.28

    C: 8.73
    B: 0.08
    E: 0

    C: 4.4
    B: 0.53
    E: 0

    C: 4.4
    B: 0.08
    E: 0

    C: 8.83
    B: 4.4
    E: 8.2

    1: 0
    2: 2.2
    3: 2.2
    4: 0
    5: 3.6
    6: 0.08
    7: 8.82
    8: 0

    I've checked polarity on all the capacitors and triple checked the transistor orientation.

    Any ideas?

    1. Have you tried going through it with an audio probe?

  5. I think the pins 2 and 3 are reversed in the one schematic I saw for the Jangle box. I compared it against the ross any dynacomp. I am going to try to swap them on the board to find out.

  6. I had a problem with low output. Couldn't figure out why. Compared Ross and Dyna schems and thought the pinout might have been issue. It was not. I put it back the way it was. Then doing some checkin on DIYstompbox forum, reading using 2n5088 in the Rodd and since I built the Ross and it worked great, I swapped out the 2n5089s with 2n5088s. Bingo! Got the gain that was missing. The layout is good. Another great job!

  7. I had the same problem with a very low maximum output (not really usable). I tried changing the individual CA3080 and the transistor type with a range of different med-high gain NPN silicons (2N5088/2N5089/MPSA18/etc...) to no effect.

    As a variant of the MXR DynaComp/Ross, I wondered about:

    (1) The 10K resistor to ground (pull-down) shown above on the Gain 2 to output trace, as there is typically nothing present here in the DynaComp/Ross, except possibly a 1M or greater (an 'anti-pop' precaution?)
    (2) The 92K resistor to Gain 3 and which would effectively set a minimum resistance for the Gain control, as this is only 10K in the DynaComp/Ross?

    Then I found the RIC schematic 'E1' on the net, which appears to represent a JangleBox circuit as fitted in the guitar, but without the Attack potentiometer, so Attack resistance would be effectively fixed at the minimum value of 33K. Here, there is a 10K resistor to ground, but it is placed after the 92K resistor and before the guitar's 'Master Volume' 250K potentiometer.

    So I tried first lifting the 10K to ground between the Gain and output and replacing it with a 1M1. I now had a good output level. I then replaced the 92K with a 9K2 and as expected it increased the Gain range further and it did so without introducing any notable extra distortion. If I get time then I plan to reinstall the 92K and add a pull down 10K to ground between the 92K and Gain 3 and then compare.

    A last note, the 'E1' schematic also shows the polarity of the capacitors. If this is to be followed and you are using polar capacitors, then the 2u2 between Q2 emitter and the 92K resistor will need to be reversed (+ive towards the 92K), all the other capacitors orientation match the layout above.

  8. I forgot. Re: Hannah Grace comment (admittedly nearly 2 years old, so this may academic now):

    I have had the same problem (no sound until you hit the strings very hard, then distorted notes with a rapid decay) in several Dyna Comp based compressors. I found that in all cases just a change of CA3080 solved this and produced a fully working compressor.

    Usually, I had to change out an Intersil (i) marked unit for a Harris (H) or RCA marked CA3080. Moral of the story, do not use Chinese supplied Intersil branded CA3080s in a Dyna Comp or variant, or at least try several different individual CA3080s from different sources before giving up on the particular PCB.

  9. Agree with TJM. Replace the 92K with 10K for more output. 92k seems an odd value but was probably actually measured as 9.2K when reverse engineered. I replaced out to ground with 1M too.
    Good compressor with a good bright tone. Also I didn't bother with the switch. Sounds good as it is.

  10. Hi, has anyone built one of this Janglebox? Mine does not emit any sound, I checked welds and components several times but without result. I also tried TJM's suggestions but it doesn't work. Can anyone give me some information? Thank you.

  11. Hi Max,

    Mine worked fine after I changed the value to the two resistors as outlined above.

    As you have checked the layout and component values, the only further suggestion I can make is make sure your IC is an 8 pin DIP operational transconductance amplifier (OTA) like the CA3080. I have now invested in an IC tester and found that some Chinese sourced ICs marked as CA3060 or LM3080 were not even OTAs, but cheaper standard single op-amps like the LM741 (different method of operation/different pinout, or simply just dead. On closer examination you could usually see evidence of replacement of the original IC markings (top of the IC body a different colour/texture to the bottom, top of the legs clean and shiny the rest of the leg tarnished, etc...). If you can then test with an IC 'borrowed' from an already working Ross/Dynacomp style compressor circuit.

  12. Hi Tjm, i have build a new janglebox starting from a veroboard project and the same IC CA3080 work fine. My build work fine except some radio interferece when switch is on the dark mode (!). Maybe tantalium capacitors can solve this problem. If Effectlayout project is confirmed verified and fully working i try to build this again. Thank you for reply ;-)

  13. Hi, new build, new components, new pbc same result: no sound :-(

  14. Ok, I checked the whole circuit again and the components look good. The integrated circuit has been replaced (CA3080E) and however retested on a Janglebox in a veroboard project and works perfectly. At this point I am desperate and I believe he will have to abandon the project. The capacitor of which TJM speaks (the 2u2 between Q2 emitter and the 92K resistor) is in the right position as shown in the figure or must be rotated (tried this solution anyway)? link for janglebox in veroboard i build and work perfect