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, March 6, 2017

Death by Audio Echo Dream 2

Gotten a lot of requests for this one. I've put it off because the schematic that's out there isn't exactly straight forward, not to mention it's 7 pots, 2 switches, 3 ICs... You get the idea. Anyway, I wanted to keep this 1590BB friendly, so all the pots are board mounted... except one (Blend). Six out of seven isn't bad, I reckon. haha


38 comments:

  1. i was waiting for it

    This one is very strange actually, XR definitely lacks voltage to operate correctly, when powered by 9v it does not generate any wave. Better power it with 18volts, but it may overheat 5v regulator...

    Anyway, magnificent job, as usual.

    ReplyDelete
    Replies
    1. I'm looking at the 78L05 datasheet and it looks like the max input voltage is 35V. I'm by no means an expert on reading datasheets so I may be wrong about this...

      Delete
    2. Yep, Ian, you are right.
      My bad.

      Delete
  2. Sweet! This is one on my bucket list, I was thinking about doing the Vero version, but wiring 7 pots offboard... Ugh. Thanks man!

    ReplyDelete
  3. TL072 would work in place of MC33172P?

    ReplyDelete
  4. Do you do the drilling templates in Eagle?

    ReplyDelete
  5. Just to let everyone know, there had been issues at the tagboard forum with powering this effect at 9v. the xr2206p chip's says on it's datasheet that it's operating voltage is from 10v to 26v, so a lot of people had reported that the modulation section was not working when using 9v batteries or power supplies. They recommended just making a simple voltage doubler and powering it at 18v!

    ReplyDelete
    Replies
    1. Those charge pumps give me endless grief :\ Though the klon clone I made from a layout here works fine.

      Delete
  6. oops i didn't read that first comment :p

    ReplyDelete
  7. This comment has been removed by the author.

    ReplyDelete
  8. DBA released the Micro Dream recently! It seems like a (twisted) stepson of the Echo Dream. I'll be waiting that layout for sure! Haha

    ReplyDelete
  9. hi excellent layout but remplacement of XR2206P?? please thanks so much

    ReplyDelete
    Replies
    1. Sorry, Esteban; there isn't a replacement.

      Delete
  10. Fuzz knob isn't doing anything on my build. Everything else is peachy. Too tired now to troubleshoot, if anyone has any ideas, let me know.

    ReplyDelete
  11. 4 wires must be connected to sw1
    but layout has pads only for 3

    ReplyDelete
    Replies
    1. One of the pads goes to 2 lugs of the switch. You don't really need an extra pad. Just run a wire between lugs 3 and 6 and a wire from there to the board.

      Delete
    2. No, there should be at lest 4th wire.

      There is no point in using 2 contact groups in DPDT with 3 wires and 1 jumper like this: http://i.imgur.com/m92ka6l.png - it makes no sence, jumper between 3 and 6 does literally nothing ;-)
      Even if you place it between 3 and 4 or 3 and 5, it will still do nothing since pins 2 and 5 are not connected to each other.

      Delete
    3. I'm with you now. Yeah, there was a 10k resistor from the voltage to switch pins 4 & 5. Updated the layout and it should be good now. Thanks for catching that.

      Delete
    4. So you switched the 4.7k resistor to 10k and have the former LED+ going to switch 1, 4 and 5 correct? Was there any other changes?

      Delete
    5. Other than moving the LED resistor over to the left, no.

      Delete
  12. Hi all!

    I've just finished the DBA Echo Dream using this layout and I have some troubles:
    1. the Fuzz pot do nothing (no fuzz)
    2. the Depth pot have a little effect (and it never goes to 0 for unmodulated signal).
    3. the overall volume is under unity
    4. the switch 2 acts strange in a position

    I tried MC13382 and other op-amps instead MC13372, with no luck.

    Anyone built it succesfully?

    Thank you very much!

    ReplyDelete
    Replies
    1. Same exact problems that you had. I gave up on trying to figure it out.

      Delete
    2. I will try to recheck the PCB as soon as I will have some time...anyway, the schematic from FSB is a little unclear to me...and I have limited electronic knowledges.

      Delete
    3. What voltage are you running at? I am using a 555 charge pump and wondering if the 18 volts might have fried something in the chain? Also, what voltage are your electrolytic caps rated at?

      Delete
    4. I'm running it at 18V (a Dunlop power supply), because I used electrolytic caps rated at minimum 25V. As I read on other forum, it must be OK

      Delete
  13. I found first mistake in the schematic from FSB: the 220nF is only 220pF!!! The value of 220nF for a cap in a feedback loop of an op-amp is ridiculous and kills all signal. In the hand drawn version the cap is 221, but in the redrawed version it becomes 224.

    Now, the Fuzz pot acts OK and the overall volume it's OK when you set the Fuzz pot at 8-9 o'clock (which is normal, because the Fuzz pot is esentially a gain pot).

    Anyway, the Depth pot has almost no effect and the switch for the sine waveform sounds horrible (for the rectangle waveform sounds nice).

    ReplyDelete
  14. I found a mistake in the layout: the SW1-2 must go to pin 2 of the Depth pot (instead of pin 3, as is). Now the Depth pot works OK, but I am not sure if SW1 works OK or not (it sounds a little strange for my taste on the sinewave side).

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
    2. Also try to have your input connected to the second pin of MC33172P and see what that does to the overal volume. Without the 1 MΩ that goes to ground and with the 10K resistor after the 1uf (neg side of the electro) to ground!

      Delete
    3. Actually The junction there (10K , 10K ,10K pos side of 1uf electro) supposed to be ground!

      Delete
  15. I believe that both 220nf and 47nf are wrong and in their place must be 220pf and 470pf....although in tagboard and effects the 470pf is connected with the in pad!

    ReplyDelete
    Replies
    1. AND, after comparing the two layouts(yours and tagboard) i found out that in series with the 470pf there is an electro that goes in series with a 10K which goes to ground!!Other than these two i haven't found anything more. Maybe i 'll investigate further as i lay mine on the breadboard when my parts arrive.

      Delete
  16. Hello everyone, today I finished mine with the suggested changes of the two capacitors, sounds great.
    Just have a problem, you hear the clock, I do not know if it's echo or modulation, any suggestions?
    It's a fantastic pedal, thank you!

    ReplyDelete