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.

Tuesday, December 24, 2019

Grind Customs FX De Profundis Delay

Merry Christmas everyone! Hope everyone gets ample time to get some soldering done over the holidays.

Grind Customs had a lot of really great projects, but their site hasn't been up in ages and it seems they're gone for good. Their De Profundis delay was very well regarded and they offered an add-on modulation board, the PLFO. Originals had the tone control as a trimmer, but lets go for broke and have it externally. The delay board will fit in a 1590B, but with the modulation add-on I'd recommend using a 125B. Here's the original De Profundis and PLFO build docs for reference.



23 comments:

  1. Hi bro! Thanks for your great job! I have a question. Do you think the PLFO can be added to any PT2399 delay? Thanks and merry xmas!

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    1. Sorry, I have just read the attached docs :P Yes, it can be attached to any PT2399 delay. Thanks! Cheers!

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  2. Thanks, David! Merry Christmas to you... and everybody else who hangs out here.

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  3. Death By Audio Interstellar Overdriver Please.

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  4. Thanks, I'm gonna try to build it and verify this week!

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  5. The main board is verified. I'll try to get to the modulation board tomorrow.

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    1. The PLFO board needs a fourth 220k going from pin 5 of the 4558 to ground. I put this resistor above the pads for Wave 1 and Wave 3 and now the modulation board works. I used a diffused yellow LED and a Tayda LDR for the vactrol.

      Breaking the connection between the Wave 2 pad and the pot(as suggested in the build doc) doesn't seem to turn the pedal back into a regular delay. Maybe a switch at either M1 or M2 would be a better way to turn the modulation on and off.

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    2. The on/off switch for the modulation off the Wave 2 pad should work once boxed up. Looks like my heat-shrinked LDR is still seeing ambient room light and was lowering the resistance of the time pot in delay mode.

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    3. Can confirm that the PLFO needs another 220k resistor from pin 5 to ground.

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  6. This comment has been removed by the author.

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  7. Hi, i'm a brasilian guy trying to understand this schematic, i started to learn about diy pedals a recentely and would like to ask something a i'm trying to understand. How works the conection between the delay circuito and de lfo? As i said, i'm a new player in this game and seems like the m1 and m2 connections its a dead line in the circuit. Thank for your incredible job.

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    1. Você pega o pad M1 do plfo e conecta no pad M1 do circuito principal, mesma coisa com M2

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  8. Is it true or buffered bypass?

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  9. Finally finished working on this.
    Added the PLFO with a spst switch to turn it on and off.
    Problem is at when I switch it on, it goes into a modulation only mode, no delays, and definitely no modulated delays.
    I can’t quite wrap my head around why this is happening when it worked properly when I was testing.
    I haven’t boxed it yet so I know it’s not some sort of short to ground via that.
    Can anyone help?

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    1. hi, i made a plfo on the deep blue delay.
      .
      1 - if you connect m1 and m2 at pads 1/2 and 3 of time pot, you have just modulation
      .
      2 - if you connect at pins 2/3 of time pot and pin 2 of pt2399 you have delay + modulation.
      .
      Use a dpdt on-off-on for haves, < Modulation / Delay (center off) / Delay + modulation >
      .
      Increase a 1k or 2k resistor in serie with pin 1 of time, because when just in modulation if you take the pot at minimun the sounds goes out.
      .
      I'm Brazilian, my english isn't very whel.

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    2. So what can you take the ldr mate?

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    3. I just pulled out the De Profundis again and tried our Brazilian friend's suggestion for hooking up the mod board and it worked perfectly. Thanks for the tip!

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    4. I also triedthe plfo in the DBD with the brazilian friend's advice and it works great. I managed to have Mod/Delay/Delay+Mod
      As I struggled to find this information and to get there here it goes explained in a simpler way (at least for me)
      I used a dpdt on-off-on assuming:
      1 4
      2 5
      3 6
      I connected
      pot time lug 1 to 1
      pot time lug 2/3 to 4
      M1 to 2 (or vice-versa)
      M2 to 5 (or vice-versa)
      Pot time lug 2/3 to 3
      Pt2399 pin 2 to 6
      Didn’t need to change anything on the deep blue delay circuit. Just make this extra connections.
      It works great:)
      Thanks for the amazing work!!

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  10. I made it according to this layout without PLFO, it works perfect good sounds thanks!
    I would like to add a stereo out to this, could you please give me an idea?

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  11. Replies
    1. But the layout needs modification/clarification.

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  12. someone knows how to get pdf of the pcbs ? i can t find

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  13. Transfer image library > Misc. > Grind Customes De Profundis

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