Earthquaker Devices - Ghost Echo  [traced]

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Re: Earthquaker Devices Ghost Echo [guts]

Postby induction » 16 May 2013, 19:40

Sounds like the PT2399 locked up. Does the regulator or the chip get hot? Does it sometimes work if you disconnect the power supply for five minutes? If so, try putting a 1N4001 (or other Si diode) between the regulator and the +5V point on the chip. If that helps, you have one of the many dodgy PT2399's in existence. In some cases the diode is a permanent fix, but if the chip is already fried it won't help at all and the regulator won't get hot anymore. Try swapping the chip and monitoring it for similar problems. I buy several PT2399's for every build I plan to use them in for exactly this reason.

Of course it could be something else entirely.

Good luck.
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Re: Earthquaker Devices Ghost Echo [guts]

Postby Shepherd214 » 15 Aug 2013, 17:59

That looks so different compared to the earlier version I have.

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Re: Earthquaker Devices Ghost Echo [guts]

Postby Govmnt_Lacky » 15 Aug 2013, 20:30

Shepherd214 wrote:That looks so different compared to the earlier version I have.


Not really all that different.

Just a smaller layout to accommidate the smaller box :thumbsup
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Re: Earthquaker Devices Ghost Echo [guts]

Postby destro » 16 Aug 2013, 16:01

I've seen three different versions of this circuit, two different big box versions and then the small box. No huge changes between them, but there are definitely component differences...like the 1n914 diodes (seen in that pic) and the use of 2 78l05 seen in the small box.
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Re: Earthquaker Devices Ghost Echo [guts]

Postby DonDougie » 09 Oct 2013, 17:49

I built this one with Harald Sabro's layout and it sounds great, very eerie and atmospheric. Now when I tested it out of the box, something was shorting and I only got the wet signal coming through, which would be a neat feature to have.

So, does anyone know where to add a kill-dry switch to this circuit?
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Re: Earthquaker Devices Ghost Echo [guts]

Postby induction » 09 Oct 2013, 20:07

Try removing the leg of R3 that currently goes to the output of the input buffer (g1 on the vero) and attaching it to Vb at c3 or f15. If that works, you can use an SPDT to switch them.

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Re: Earthquaker Devices Ghost Echo [guts]

Postby DonDougie » 09 Oct 2013, 23:38

induction wrote:Try removing the leg of R3 that currently goes to the output of the input buffer (g1 on the vero) and attaching it to Vb at c3 or f15. If that works, you can use an SPDT to switch them.


This works perfectly, thanks!
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Re: Earthquaker Devices Ghost Echo [guts]

Postby lars-musik » 14 Oct 2013, 22:13

I just finished my Ghost Echo but either I’m deaf or the dwell knob is too subtle for me or I’ve made a mistake. All three answers are quite possible. I tried to put in a parallel 39K to R22 (22K) push that resistor down to 14K to test John’s solution at Sabrotone’s (http://johnkvintageguitars.homestead.co ... Layout.png) but I still can’t hear any changes when I turn the knob. Anybody got the same problem? Or could anybody try to explain what I am expected to hear so I could persuade myself that I in fact do hear it?
Thanks a lot in advance and thank you all for that great project!
Cheers, Lars

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Re: Earthquaker Devices Ghost Echo [guts]

Postby DonDougie » 15 Oct 2013, 14:05

lars-musik wrote:I just finished my Ghost Echo but either I’m deaf or the dwell knob is too subtle for me or I’ve made a mistake. All three answers are quite possible. I tried to put in a parallel 39K to R22 (22K) push that resistor down to 14K to test John’s solution at Sabrotone’s (http://johnkvintageguitars.homestead.co ... Layout.png) but I still can’t hear any changes when I turn the knob. Anybody got the same problem? Or could anybody try to explain what I am expected to hear so I could persuade myself that I in fact do hear it?
Thanks a lot in advance and thank you all for that great project!
Cheers, Lars


The dwell control IS subtle and fine tunes the length and thickness of the decay (in the words of EQD). Start with full depth, dwell off and attack off and play some open chords. Now manipulate the dwell knob from low to high and you should notice the decay getting fuller and a little bit more pronounced the higher you go. Depth full sounds more washy and intense, like additional echoes getting mixed in.
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Re: Earthquaker Devices Ghost Echo [guts]

Postby lars-musik » 15 Oct 2013, 15:07

Thanks you for the explanation. I just put a 50K pot instead of the 5K for the dwell to adjust. With the 14K as R22 it was able to get into pretty harsh self-ocillations, putting me to rest that I wired everything accordingly. Obviously the early versions of this pedal in the larger enclosures were able to do that, too. Have a look at that video (from approx. 2:30 min): http://www.youtube.com/watch?v=BQkD69vcnX8
Maybe a 20K for R22 and 25K-pot produces a hearable dwell for less subtle people like me.
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Re: Earthquaker Devices Ghost Echo [guts]

Postby claytushaywood » 18 Jan 2014, 21:28

i'm into the 25k pot 14k resistor for the dwell pot... much more useable range of sounds. what about increasing the attack pot for longer delay times?
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Re: Earthquaker Devices Ghost Echo [guts]

Postby claytushaywood » 19 Jan 2014, 02:15

i went ahead and changed the attack pot to 25k to get a longer initial delay time. adds a lot more versatility to the effect at the expense of a little bit of fine tuning- which i thought was way too fine throughout this pedal. i highly recommend increasing the dwell and attack pots to 25k to get more versatility out of this circuit

EDIT: I tried the kill dry mod mentioned above and it does work. its not really a completely 'wet' verb though, probably due to the fact that the pt2399 is passing a sort of 'dry' signal with its repeat. know what i'm saying? i guess because of the pt2399 giving delay in the circuit your always going to have that "dry" delay repeat with the verb following it- i'm putting dry in quotes because it is a repeat of the pt2399 but its not verb'd out completely.

now to get more mix. I tried increasing the depth pot to 25k, and it seemed to give me a little bit more depth in the mix, but it also made it clip and distort in a minor way. Is there anyway to get more depth out of this without redoing a lot of the circuit? i've been comparing this circuit to the deep blue delay and the culture jam box of hall to see what's different between the delay and reverb sections. but its not getting me very far in my newbness, maybe decreasing r5 and r6 and increasing the depth pot to say like 25k?
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Re: Earthquaker Devices Ghost Echo [guts]

Postby claytushaywood » 25 Jan 2014, 20:36

so i'm getting less than unity volume when the pedal is engaged. Which 1M resistor are you supposed to change to 470ohm to fix the volume issues?

Does sabrotone's layout have this fix?

also i'm looking at the vero layout at sabrotone and comparing it to the schematic it looks like there are some mistakes.

do you number the legs of the TL074 differently than you number the legs of the pt2399? like are the first and last pins at the top? and pin 8 would be at the bottom right of the tl074? because if that's correct it seems there are some problems with that layout... but i cant consider myself an authority enough to call out something on being incorrect.

any helpo is much appreciated!
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Re: Earthquaker Devices Ghost Echo [guts]

Postby DonDougie » 04 Feb 2014, 11:16

claytushaywood wrote:so i'm getting less than unity volume when the pedal is engaged.


I have the same problem. The layout seems to include the fix, but there is still a very noticeable drop in volume/gain when engaged. It's unuseable like this, which is a shame because otherwise it sounds really good.
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Re: Earthquaker Devices Ghost Echo [guts]

Postby lars-musik » 04 Feb 2014, 14:42

Did you use the (updated) sabrotone layout? Then there's no need to change anything. R17 ought to be 470R. It's the one closest to the output. In the first schematics back in this this threat it was identified as 1M. R17=470R=unity gain. If it is not, something else is wrong.
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Re: Earthquaker Devices Ghost Echo [guts]

Postby tcc » 08 Jun 2014, 15:10

Hey guys, I used Sabro's layout to build the Ghost Echo twice. With both I had the following problems:

1) insanely loud popping when stepping on the stomp button
2) sometimes the effect starts to crackle and swoosh and make unhappy sounds

With the first build I managed to fix this and it is working perfectly now, although I'm not entirely sure how I did it anymore (has been some time). I think the crackle/swoosh had something to do with the vero/parts on the vero touching the enclosure; the popping maybe was due to the vero being squeezed against the stomp button. I checked these things with the second unit numerous times, and sometimes the popping is less bad, but then gets worse again. The swooshing and crackling seems to just come and go, when it isn't there the effect sounds just as it should. I checked the wiring, parts, bad solder joints again and again, and I also I checked for solder bridges on the vero like 5 times (using a carpet knife).
So I was hoping someone else had one of these problems and figured out where this comes from? I'm pretty desperate on this one as the unit worked great and I gave it to a friend, and then it started acting like this. Could the crackle come from defective parts like ICs or transistors? Could it be broken cables? Something with the power supply?

Well, any help or hints appreciated!
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Earthquaker Devices Ghost Echo PCB HELP

Postby HellRaiser100 » 31 Jan 2015, 14:21

Hi :) Can someone make a PCB layout from this ?
I'm to stupid xD


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Re: Earthquaker Devices Ghost Echo PCB HELP

Postby ~arph » 27 Mar 2015, 17:08

Try and learn, try and learn... :secret:
In the quiet words of the virgin Mary: "Come again?"
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Re: Earthquaker Devices Ghost Echo PCB HELP

Postby storyboardist » 27 Mar 2015, 20:19

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Re: Earthquaker Devices Ghost Echo [guts]

Postby Boba7 » 30 Jun 2015, 23:19

Hi!

So I built a ghost echo clone with a pcb from fuzzdog pedal parts.
I checked and made no mistake.

Si it fired up directly and sounded directly great except for the low volume.
I changed r5, went up to 17k (instead of 10k), to achieve unity gain, but doing so, I felt the delay was too loud and the reverb not enough.
So I put back a 10k and tried different values for r17 (last in series before output). But here even with a jumper accross instead of the original 470r, the volume is still low.

If anyone has any idea what to do, it'd be great!! :)

Maybe using 15k for r5 and r6 and try different values for r17?

Any help is much appreciated!

Cheers!
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