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.

Wednesday, October 26, 2016

Demeter Compulator

Here's a really nice optical compressor from Demeter. It offers vintage studio compression that's very transparent and a fairly simple simple build as well. The trimpot sets the gain of the compressor's preamp stage. If the signal is distorted, turn down the trimmer till it's clean. Here's the schematic for reference.


36 comments:

  1. Great! I never used a Vactrol, but can I replace it with a VTL5C2?

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    1. Not sure if the C2 will work as the specs are different from the C10. You could experiment with different LEDs and LDRs.

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  2. Oh boy, how I miss having spare time to build some stuff for myself and verifying your layouts hehehe. Nice one!

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  3. Do you have a source for the vtl5c10?

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    1. You can get them off eBay, Newark.com, couple other suppliers. Just google the part number.

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  4. Which the softwere you use to make these layout ? Thx , greetings from Brazil !

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  5. Can I use a vtl5c1 instead of vtl5c10? They're similar? And has anybody verified this?:)

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  6. It is verified.I socketed expensive vtl5c10 just in case of my bad build.
    Also socketed 1uf cap to try another value.

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    1. I have added DPDT switch to go between 1uf film and 22uf electrolytic.

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  7. I can't find Log 20K pots but only W-Taper or Lin. How can I do instead?

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  8. bro, may i change the lf353 to other common dual op-amp?

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  9. Can I use, 1N4007 in place of 1N5817 diode? Thanks Man

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  10. I think there's no 47uF capacitor in original Demeter Comp. Why did you add it here?

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    1. That's for power filtering. I include them in all my layouts.

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    2. Thank you. And also verified.
      Photos:
      http://pl.tinypic.com/r/b3lthu/9
      http://pl.tinypic.com/r/w8pabo/9

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  11. What is the correct combination for LED + LDR? To find this vactrol? Will it be that dull blue works? Tanks

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  12. Hi i am very interested to make this one !! look like the diamond comp !
    By which ic could i replace the lf 353 ?

    I already made a diamond compressor but I would like to make another with a real PCB made by myself but I can not find the layout! I have progressed a lot in the finishing and quality of my pedals, that's why I want to do it again ...Will you interrest to do it? I can give you a donation for it! It's my favorite comp guitare !

    Franck

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    1. Donations are always welcome :) I'm actually already working on the Diamond Comp.

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    2. Whoa your are the best ! i go donate now !!!!

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  13. Please just tell me me if i can replace LF 353 by TL 082 ?

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    1. Don't know off the top of my head. They're both dual opamps, so I would think it'd work. You'll have to to compare the datasheets.

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    2. ok thx ! going to see it …

      Thx for all man ! your work is great !

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  14. Whaou !!! really nice comp !!!! work very good !!!!

    just a question : the resistor variable de 10K must be at 1,1 k without 9V ? (between the lug 1&2) ?
    What is the incidence or result if the value is not ?

    Could you clear me a little beat ?

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  15. I have built another one with a combo of an ultra-bright 5mm green LED and a LDR with 400K ohm dark resistance. Also added a LED in parallel with the combo LED as an external indicator. It works well.
    The trim pot lug1 and 3 should be reversed, I think.

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  16. Built this comp, sounds pretty nice, but I'd swapped polarity protection diode with 100 ohm resistor for lowering noise level. Thanks for the layout!

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  18. Hello, I have a little distortion when I play the E chord; I try to replace 1uF until 10nF, nothing 's change. I change op amp with TL072, nothing's change too. Is it my op amp (LF353P) who is wrong? or the VTL5C10 (aliexpress)?
    Best regards
    Franck

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