Thursday, 4 July 2019

1981 Inventions DRV

PedalPCB's schematic, info and pcb available here.
This is a buffered effect.
For true-bypass, leave out Sw 3 and connect the rest the usual way.


44 comments:

  1. Thanks for posting this one! I've been wondering what all the fuss is about with this pedal. Time to find out...

    ReplyDelete
  2. Wohoo nice! Adding this one to the build list...

    ReplyDelete
  3. To use max1044 or 7660s, Do I only need to omit the cut between 1 and 8?

    ReplyDelete
  4. Awesome. I've been hoping this one would drop!

    ReplyDelete
    Replies
    1. I've gotta ask: why make a Vero when PedalPCB boards are so cheap? Not being critical, I've built my share of both and this site is a fantastic resource. but when I can get a PCB for $10, It's a no-brainer for me.

      Delete
    2. Veroboard are even cheaper! :D
      Of course we can buy PCBs for our pedals, but using veroboard or protobard layouts, I guess, make the work more "homemade". It's a part I love.
      And with veroboard I can modify easily the layout and add or cut some parts of the circuit. I did it more than once.
      This is my modest opinion.

      Delete
    3. I'm with you there. Simple mods I'll make on the PCB, if I can get one. When I want to get more ambitious with the mods, or build an original design, then it's Vero for sure.

      Delete
    4. I think most of the fun for me at least is making mods and making the circuit your own! That's what makes vero so great for me at least. That plus the exchange rate + shipping for me to Australia is horrendous haha

      Delete
  5. Does anyone know what general design this is based off of, if any?

    ReplyDelete
    Replies
    1. Rat-inspired apparently.

      Delete
    2. Well, it's and hard clipping, and tone section yes, that is Rat inspired.

      Delete
    3. it doesn't have the same slew rate compensation that a RAT has, but the hard clipping and tone control are a lot like it, yeah.

      Delete
  6. I've just checked this against the schematic before building, and everything looks good, except for C9 in the schematic, which is written as 22n, but here is 2n2. Also if you're using a MAX1044 or ICL7660 you can just omit the cut between pins 1 and 8 of the LT1054. Thanks!

    ReplyDelete
    Replies
    1. I guess you're right about the 22nF. Thanks!

      Delete
    2. No worries, I'll wire this one up in the coming days and hopefully we can verify it soon!

      Delete
    3. Well spotted! Used the wrong cap. That's been fixed

      Delete
  7. you can tag this one. i like it, but think the hype is maybe a little overkill. i'll put it on my board and play a couple hours and i'll know better then!

    ReplyDelete
  8. you can verify it. sounds pretty good

    ReplyDelete
  9. Hello I am quite new to this and don't recognize the CLR in the bottom right of the circuit, can you please tell me what that is.
    Thanks

    ReplyDelete
  10. Hi Steve. The CLR is a current-limiting resistor used to adjust the brightness of your LED. Too small and you'll go blind looking at your pedalboard, too large and you won't be able to tell that your pedal is "on". Depending on the efficiency of your LED, something like 3.3K to 10K should work, but you should try it on a breadboard before soldering the resistor.

    ReplyDelete
  11. Anyone else had a high pitched whine noise with this effect when switched on? The overdrive itself works, but there's a very high squeal when not playing. Only difference was use of a max1044 (left the cut out between pins 1 and 8) to above. The noise stops when in bypass. This is before I have boxed it using a test box on a 3pdt switch (left the switch 3 connection off too). Any help would be much appreciated. Thanks, Ian.

    ReplyDelete
    Replies
    1. hey Ian, Make sure you've got the 'S' variety e.g. 1044scpa or others, as the chips without the 'S' will emit a high pitched noise, as you've described.

      Delete
  12. Thanks for that, think that will be my issue, much appreciated.

    ReplyDelete
  13. if you compare with this scheme there are differences in the operational pins:
    https://effectslayouts.blogspot.com/search?q=1981

    ReplyDelete
  14. Would the switch 3 on the board be the output if rewiring for true bypass?

    ReplyDelete
  15. Hey, I am trying to learn a lot, and I'd be stupid to say I'm not scared to ask the basic low-knowledge questions, but:

    I understand the difference between eletrolytic capacitors and the other ones, but, what is the difference between the capacitors with the boxes, and the ones that look round? I am assuming they are made of different materials. My best guess is that some are film and others are not, but, if anyone could help, I am trying to source parts for the first time and really don't want to order the wrong components, as money is tight. I am ordering through Tayda, as they have been very reliable for me with other projects

    ReplyDelete
  16. The effect works very well! Thank you for posting it!

    But ...
    I'm having a high pitch when there's nothing conncected to the input jack and the effect is even on ON or OFF. That sound appears when the Drive and the Volume are at 12 o'clock and it goes up if I push the volume. So the more Volume I go more "high freq" noise I got.

    If I try to connect the guitar (on the input jack) then the noise dissapears even the effect is ON or OFF.

    I'm using a 7660S IC.

    Any suggestions?

    Cheers,
    Jaime

    ReplyDelete
    Replies
    1. Maybe linking the input jack to ground while nothing is connected.

      Delete
    2. Seems normal - mine is the same with LT1054. Its probably the buffered bypass and bleeding noise into the output.

      Delete
  17. Hi, thanks for this layout. I have built it, sounds cool!

    ReplyDelete
    Replies
    1. [img]https://scontent.flhr4-1.fna.fbcdn.net/v/t1.0-9/70978473_10156258610375870_737583229187391488_n.jpg?_nc_cat=101&_nc_oc=AQmLV0N1zL2kSu4fPCcf4QhrFtsAvSmmibQ00EoXIdq75LeYVZ9d15hwZFqiYDhTHBw&_nc_ht=scontent.flhr4-1.fna&oh=d88d9e4b33e3eecda82fd02b220c9568&oe=5E36D82F[/img]

      [img]https://scontent.flhr4-1.fna.fbcdn.net/v/t1.0-9/69878693_10156258610410870_7961117213400760320_n.jpg?_nc_cat=101&_nc_oc=AQnGBJzRtzxvU9II8S8AU0pMa_NoS6zbd1d3c1URpTXEp7DphUdEt5F8w4lmyKN9tuQ&_nc_ht=scontent.flhr4-1.fna&oh=db36357771410edacf508754cd6f9981&oe=5E01E7F1[/img]

      Delete
  18. Is anyone else getting this warning message when they try to access the forums section? I'm using Chrome browser.

    "This server could not prove that it is guitar-fx-layouts.42897.x6.nabble.com; its security certificate is from asciidoctor-discussion.49171.x6.nabble.com. This may be caused by a misconfiguration or an attacker intercepting your connection."

    ReplyDelete
  19. Where is the OUT on the board if I'm doing it true-bypass? Tried it at Sw 3, but didn't work.

    ReplyDelete
  20. What is going on with all the spam atm?

    ReplyDelete
    Replies
    1. Some f'd up flood. I'm cleaning it up as we speak... These come from time to time.
      +m

      Delete
    2. Seems the amount of it isn't slowing as i hoped. Did some cleanup and reporting of the user accounts today. Hope i'll find the time to keep the comments clean in the future too.
      +m

      Delete
  21. This comment has been removed by the author.

    ReplyDelete