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 13, 2015

DOD 280 Compressor

The DOD 280 was DOD's first compression pedal made in the late '70s through the '80s. A great sounding compressor, this fairly simple circuit uses an LDR and LED combination (in the form of a VTL5C2) to compress the signal. This one's laid out for on board right angle PCB pots, mounted from the solder side as per usual). I've added polarity protection and power filtering, as well as an input pull down resistor. You can use a VTL5C9 or CLM6000, or a good ol' 1M dark resistance LDR and an LED in heat shrink in place of the original VTL5C2.




at
Labels: , ,

22 comments:

  1. MaurusAugust 9, 2015 at 10:50 PM

    Verified, works!

    ReplyDelete
  2. AnonymousSeptember 12, 2015 at 11:58 PM

    If I'm gonna use it and it'll stay always on, I don't need a switch anymore, do I?

    ReplyDelete
    Replies
    1. dtgehringSeptember 13, 2015 at 8:50 PM

      In theory, I guess you wouldn't have to build it with a switch. If it were me though, I would at least install an on/off toggle switch (DPDT). Or at the very least test it with your rig before boxing it up.

      Delete
  3. fredNovember 19, 2015 at 7:36 PM

    hi, brother.is the real image size to transfer in the pcb?

    ReplyDelete
    Replies
    1. Effects LayoutsNovember 20, 2015 at 12:09 AM

      Use the one in the Transfer Image Library. See the tab at the top of the page. It'll be in the DOD folder

      Delete
    2. fredNovember 20, 2015 at 10:24 AM

      thanks!

      Delete
  4. Dennis KriggerMay 12, 2017 at 11:23 PM

    it works, but the compression pot is reversed

    ReplyDelete
  5. fdAugust 8, 2017 at 12:18 AM

    shouldnt pins 1 and 2 of comp pot be tied together instead of 2 and 3?

    ReplyDelete
  6. AnonymousNovember 2, 2017 at 7:13 PM

    You forgot the 3M Ohm resistor in parallel of the LDR, in original DOD they use this 3M Ohm resistor to create a variation above 1M Ohm, for minimize the current daw.

    ReplyDelete
    Replies
    1. Effects LayoutsNovember 3, 2017 at 10:13 AM

      The schematic I used had a 1M resistor in parallel with the LDR (which is just to the left of the IC). Seems like there are some variances between schematics floating around the net. Feel free to use a 3M instead.

      Delete
  7. AnonymousNovember 4, 2017 at 1:29 PM

    I made a test, with 3M our 3M1 the current in LDR is very lower, at 1M the current state is high and the LDR heat very little.

    ReplyDelete
  8. SnishNovember 5, 2018 at 2:31 PM

    Lo hice pero no anda, me re calienta el diodo, lo probé si estaba al revés y también con otro diodo para ver si eso era el problema, pero no lo era. ¿Cómo lo puedo solucionar?

    ReplyDelete
  9. FlaconsiusAugust 15, 2019 at 10:28 PM

    This comment has been removed by the author.

    ReplyDelete
  10. Pablo G.February 1, 2020 at 10:28 PM

    I'm looking to build this comp but for use in a rack mounted bass preamp. If you don't mind me asking, can I power the circuit with 15v instead of 9v? I'm worried about feeding the LED 15 volts. Should I put an additional resistor before the cathode?

    2. I'd like to have a second LED as a panel indicator of the compression level. Can I put a second LED in series with the octocoupler?

    3. If I'm gonna use this comp with a bass, which component values would you recommend change?

    Thanks a lot in advance.

    ReplyDelete
  11. MatiasSeptember 8, 2021 at 4:40 PM

    Hi, I'm trying to build this circuit. Does anyone have pictures of the physical assembly of a working unit? Thanks a lot

    ReplyDelete
  12. UnknownJanuary 1, 2022 at 11:42 PM

    Hello, my name is Nicolás ... I have a question, it may not be that the difference between the pedal to the amp and the guitar directly to the amp is not noticeable? It happens that I simply change Q1 for a 2n222

    ReplyDelete
  13. FernandoApril 10, 2023 at 7:58 AM

    Is possible to use a 4558 or TL072 in place the LM358 ?

    ReplyDelete
    Replies
    1. Ricco SeixasMay 23, 2023 at 7:22 PM

      This comment has been removed by the author.

      Delete
    2. Ricco SeixasMay 23, 2023 at 7:25 PM

      Work with tl072,4558,ne5532, in my pedal used 5532 ,have great sound,low noise and sound clean!!!

      Delete
  14. Rafael MatosJune 28, 2024 at 10:07 AM

    I got mine working a first but now it is sounding like a broken fuzz, I've changed the ic and pots and still got this problem. Any advice?

    ReplyDelete

Subscribe to: Post Comments (Atom)