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, March 17, 2015

EarthQuaker Devices Ghost Echo

The Ghost Echo is a nice little reverb unit, and uses the Belton BTDR-2H-L digital reverb module, as well as a PT2399. I'm not going to lie, this layout gave me some issues (at one point it made DIYLC crash). Even had to use a jumper (which annoys the heck out of me, as you may have picked up on). You won't be able to squeeze it into a 1590B, but a 125B should be a good fit. The Belton brick can be mounted directly to the board from the solder-side.

Here's what EQD's website says about the effect:

Vintage spring reverb emulation capable of providing a little atmosphere all the way through to vast depths in one tiny box. The attack control sets the delay of the initial pick attack on the wet signal only. When playing staccato this registers as a slap back type echo hitting the reverb but when playing fluid lines it adds a massive depth and “fattens” up the sound. The dwell control is a fine tune function that enhances the decay and the depth controls the intensity of the reverb.



Update: If you're having a hard time getting unity volume, try replacing the 10k resistor of pin 9 of the TL074 just above the 2.2uF cap with a 17k resistor (or something close to that).

60 comments:

  1. I tried the PCB layout and I'm having some issues- the input is very heavily gated and farty. BUT I can hear the echo from it... and that sounds pretty good.
    The only part replacement I made were the lm7805- I swapped them with some 78L05 I had laying around... but I dont think that could be the problem.
    What do you think?

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    Replies
    1. Yeah, the 7805s shouldn't matter at all. I'm no expert when it comes to trouble shooting, especially with a circuit this complicated. I'd double check your ICs. I think some PT2399s can be somewhat flakey. Though, I kinda doubt that IC is what's giving you trouble. I was going to suggest you ask over on the FSB thread, but I see you already did. Hopefully more knowledgable folks over there will chime in.

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  2. Has this layout been verified? I wonder if I just need to start over from scratch... which is no problem so long as theres hope in that the layout is verified.

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  3. Replies
    1. cool... I'll just make a new one from scratch and report back. Thanks for your help!

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  4. Hi,

    I found mistake on the PCB. Input first 1M to ground second 1M to 4V5 (Depth3) not to ground.

    sound ... almost like spring. I use BTDR2H - middle, bud in my opinion must be long

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    Replies
    1. Thanks for the catch, Marcin. The layout has been updated.

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  5. Built and it sounds great but I've got a slight volume drop. Any ideas?

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    1. Additionally I"m not getting that slap found at 2:55 in this video: https://www.youtube.com/watch?v=mmTpSX2cd9o
      The dwell is extremely subtle

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    2. Not sure why you'd get a volume drop. I'd post over on the FSB thread on this circuit and see if better minds than mine can help you trouble shoot. It's not quite my forte, especially with circuits as complicated as this.

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  6. Hello man i would like to do this pedal and i have read the comments and i dont know if it´s
    100% verified or not
    So hope you can help me!!!

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  7. I would say it's verified. The layout it good based off the schematic from FSB. The comment above about the volume drop is the only one I've seen like it.

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  8. Hi i just read in the fsb thread and the sabrotone vero layout of this one that changin the r5 that has the value of 10k in this layout is the one that is in series with the 470r you can solve the problem incresing it about 17k http://www.sabrotone.com/?attachment_id=3884 i know it is spam but it could help someone

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  9. Is LM7805 the same with 78L05? or can be replaced by it?

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  10. 10nF and 22nF near PT2399 should be 1nF and 2,2nF

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  11. there are differences between btdr 2h l and btdr 2h m?

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    Replies
    1. Yes. The L is longer delay time than the M. Personally I prefer the L.

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  12. Is the TL 074P an CI in DIP or SMD?

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  13. Hello, how are you? I've been looking schematic. There are two errors 10n and 22n are actually 1n and 2n2, correct? Anything else my unit also has a loss of volume. what can I do? Grateful

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    Replies
    1. I replace the 10n and the 22n, and it's working great; the wet signal is now more present with the "death" at max. (sorry for my bad english)

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  14. Verified!
    I made it and sound good.
    But I got some high frequency noise too.
    And Dwell has no change
    Any idea please?


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  15. hello, i don't have any reverb in the output
    does anybody has voltages for the ics?
    I used an audio probe and notices I don't have audio on pins 13, 14 and 16 of the pt2399, is this normal?
    thanks

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  16. i used an audio probe, i have audio at pin 15 on the pt2399, but not on pins 13, 14 or 16.
    maybe it's a pt2399 problem?

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    Replies
    1. You need to check the data sheet of the ic and see what those pins do.

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  17. Just want to say that I tried replacing R5 with 17K like suggested above and I've got unity volume.
    Maybe this should be put out as a recommended mod

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  18. Hi !
    I just have finish my pedal, sounds go through, when IN sound go through too, but no effect happens.
    I do have taken out my BTDR2H, sound still go through when IN..
    COuld the BTDR be dead?

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    Replies
    1. As well I use a TL074N instead of a TN074P..

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    2. BTDR-2 could be bad, but it could just be a short as well. Check for shorts and use an audio probe on it if necessary

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    3. Hi dtgehrin and all. I have the same problem. See 7805 near BTDR. GND of 7805 is not grounded. So Belton is not powered by +5V on pin 1, and pin 2 (powered gnd of Belton) also isn't grounded. On this verified layout:
      http://www.sabrotone.com/wp-content/uploads/2013/08/GhostEcho.gif
      7805 is gounded with 100nF. Is this something with AGND <-> DGND? Would you explain? Thanks:)

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    4. It is an analog/digital ground thing. I would try jumping the digital ground (brown trace) to the analog ground (green) and see if that gets things going.

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    5. Thank you for reply. Bridge from GND to pin1 done - BTDR is powered by +5V, board checked lot of times. But still nothing. I spend much time on this. You have done great project - probably some short on my pcb. Would send me some list of voltage points?

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  19. hello, good day from mexico the capacitors of 22n and 10 n are incorrect, I veirifiado in the scheme and should be of 2.2n and 10n, it is also better to lower to 15k the resistance of 22k in dweel to make it more responsive, with the capacitors that are shown in the layout will only get a distant reverb that does not mix or exceed the original signal

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  20. Hi. There is a mistake in the layout. The 1M resistor from the pin 3 of the TL074 goes to nowhere in the layout of the upper left.

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  21. Hola desde Colombia, que versión del pedal es?

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  22. Hi, can someone confirm if the change they mention is correct? change capacitors 22nf and 10nf by the values ​​2.2nf and 1nf? What modifies do this?
    (Hola, alguien puede confirmar si es correcto el cambio que mencionan? cambiar capacitores 22nf y 10nf por los valores 2.2nf y 1nf? Que modifica hacer esto?). Gracias!

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    Replies
    1. I have already built it, I confirm what has been verified and it works perfect! the correct values ​​are 2.2nf and 1nf. Also use a b5k potentiometer on Detph and operate.

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  23. I just Built this and for about 2 days been trying to work out why it didn't work. The 22nF and 10Nf isn't changed on the above schematic.. i only just read these comments and have been pulling my hair out over it finding you guys have figured it out about 2 years ago lol.. nice build anywho. thanks

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    1. I say this and something has shorted after 1 day of using it.. Are these belton brick accutronic thingys easy to blow/short? I think mines dead, circuit seems fine just getting no sound at all now, works fine switched off. replaced the IC's and then rebuilt the whole board and still doesn't work with all mostly new components barr the brick. :(

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    2. Check your voltage regulators, make sure they're the right way around, and know that the large 7805's (the TO220 style) have the OPPOSITE pinout that the 78L05's have.

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  24. Someone has the schematic please?

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    Replies
    1. http://www.freestompboxes.org/viewtopic.php?f=7&t=8136&hilit=ghost+echo
      here you go

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  25. Verified after 3 points below.
    1. replacing 10nf and 22nf to 1nf and 2.2nf.
    2. swapping 1 and 3 lug for depth pot
    3. connecting 1m from pin3 of 2399 to pin5 (layout at bottom left is incorrect).

    Thank you very much for sharing. I like it very much.

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  26. Friends! your work is fantastic! Having assembled this scheme, I had to suffer a little in the setup.
    Be sure to put a 17k resistor to adjust the volume. In order for the pedal to be really easy to control with the Dwell, the 22k resistor needs to be replaced with 8.2k. This will make the entire handle range effective.

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  27. I'm just curious, does anyone know why they use 2 voltage regulators? Why can't both the pt2399 and BTDR run on the same 5V source? Would a single regulator not supply enough current or is it just about reducing noise?

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    Replies
    1. I've wondered that too. It's probably for noise reduction. My initial thought was that the 78L05 regulator can't put out enough milliamps to power both the stand alone PT2399 and the 3, PT2399s that are in a Belton brick. But a single 78L05 should put out 100 mA and according to EQD the draw of Ghost Echo is only 80mA. So it's probably not that unless they used some lower output regulators.

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  28. Hey there, I am kind of new to building pedals. Was wondering what goes into the holes marked BTD2RH? Thank you

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    Replies
    1. That's a Belton reverb brick. BTDR-2 is the model number

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    2. Would it be possible to use the Medium BTD2R instead of the long? If so how would it affect the sound?
      Thanks for your site, I built my first pedal (TS808) and it worked amazingly!

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    3. Yeah absolutely. It would have less overall reverb, but with the PT2399 pushing it I doubt you'd notice it all that much.

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  29. Is there any good reverb except equinnox which dont use btdr?

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    Replies
    1. Check out the Ersatz Verben:

      https://effectslayouts.blogspot.com/2015/06/ersatz-verben.html

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  30. Thank you very much for the layout. I built this pedal and yes, there are some mistakes on it:

    1. Depth control worked for me reversed, I needed to swap the pot leg connections 1 and 3, as mentioned above.
    2. Checking the schematic from diystomboxes the 10nf and 22nf capacitors just below PT2399 should be 2.2nf and 1nf, also mentioned in previous comments.
    3. The schematic shows 10k resistors, not 17k. When I try this value, what I get is a horrible feedback loop that makes the pedal unusable, so I kept the 10k value.

    All things considered, I would say its verified although the Dwell control doesn't seem to work for me. Not very perceivable to say the least. I will check the schematic further looking for any other bug.

    Again, thank you very much

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  31. I changed that resistor to 16k or something like that. Apparently, it works quite well in some ranges. My depth potentiometer is B5k instead of B2k. When I put dwell on maximum and add alot of depth it starts generating. As long as I work in the depth regime up to 2k it is fine. I am trying to figure out if it is a design issue or it can be fixed without changing anything.

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