Earthquaker Devices - Ghost Echo  [traced]

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Re: Earthquaker Devices Ghost Echo [guts]

Postby Boba7 » 01 Jul 2015, 18:14

Ok so after getting in touch with the guy from Fuzzdog pedal parts, I tried different values for R5 and R6. I finally found a setting that works really well for me: R6 is 4k7 and R5 10k (same as stock). A lower R6 means more wet signal, which I wanted. :)
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Re: Earthquaker Devices Ghost Echo [guts]

Postby Motter » 01 Jul 2015, 18:45

:lol: Somebody made a pcb for this? I feel so flattered.
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Re: Earthquaker Devices Ghost Echo PCB HELP

Postby audioguy » 14 Jul 2015, 02:17

I tried the layout from Storyboardist and I'm having some issues- the input very heavily gated and farty. BUT I can hear the echo from it...
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 guys think?
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Re: Earthquaker Devices Ghost Echo PCB HELP

Postby apollomusicservice » 15 Jul 2015, 08:05

audioguy wrote:I tried the layout from Storyboardist and I'm having some issues- the input very heavily gated and farty. BUT I can hear the echo from it...
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 guys think?

At first you have to check proper voltage supply on pin 1 of PT2399 = 5V.
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Re: Earthquaker Devices - Ghost Echo

Postby ratrod » 16 Jul 2015, 20:30

The LM7805 pin out is In- Ground- Out ..... the 78l05 is oppisite out- ground- In
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Re: Earthquaker Devices - Ghost Echo

Postby Boba7 » 20 Aug 2015, 14:01

Hi, just a quick question: do you think changing R18 (last resistor to ground before output) would affect the overall volume of the circuit?

I've changed R5 and then R6 to get unity gain, but feel it has also affected the sound, the balance of the circuit.
Or is R5 realy only affecting the overall volume?

Thanks a lot for any information!

P.S: just realized my input cap is 1u when it should be .1u, but I was told it doesnt have anything to do with the volume drop.
Cheers! :)
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Re: Earthquaker Devices - Ghost Echo

Postby audioguy » 23 Aug 2015, 02:37

Rebuilt with storyboardists layout and Im getting reverb... but nothing like the demos. The Dwell doesnt do much at all. I adjusted from 22k to 15k (no 14 on hand) as noted in Sabrotones post and got a bit more from it, but still NOTHING like the demos. Has anyone built one from storyboardists layout that sounds like the original demos?
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Re: Earthquaker Devices - Ghost Echo

Postby Boba7 » 23 Aug 2015, 15:19

Have you tried a different value for the Dwell pot? Mine is 25k with R16 12k and it made a huge difference.
(I bought a pcb for it, not using the sabrotone layout)

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Re: Earthquaker Devices - Ghost Echo

Postby audioguy » 23 Aug 2015, 21:26

Boba7 wrote:Have you tried a different value for the Dwell pot? Mine is 25k with R16 12k and it made a huge difference.
(I bought a pcb for it, not using the sabrotone layout)


I dropped in a 20k and no audible difference. Where did you buy your board Boba7?

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Nocentelli (07 Sep 2015, 21:40)
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Re: Earthquaker Devices - Ghost Echo

Postby Boba7 » 23 Aug 2015, 21:31

I've been thinking of a couple mods that could be done to the Ghost Echo. I don't know much about electronics, I've just built 4/5 pedals and modded a couple more, so I'm just gathering ideas from different readings over the internet!

1 - Shorter minimum delay time:
In order to reduce the minimum delay time, it'd be possible to replace R19 (1K from pin6 of the PT2399, in series with the attack pot) with a smaller value (100r) and add a latch up protection like on the Little Angel chorus circuit : http://jmkpcbs.com/wp-content/uploads/2 ... -Angel.pdf (the whole part that goes out of pin6 of the PT2399). Except with the attack pot (10k, 20k for longer delay) in series with the 100r resistor.
I haven't tried it yet, but I don't see why it wouldn't work.

2. Tone control :
I'm wondering if the tone control from the Tenebrion/Box of Hall could work.
https://dl.dropboxusercontent.com/u/285 ... ildDoc.pdf

In the Ghost Echo there's no resistor in series between BTDR pin5 and the depth pot, so I don't know if it should be added.
Since BTDR pin6 isn't connected, it'd be easy to just connect to lug3 of the depth pot through a pot (with a grounded cap from lug2), exactly like on the Tenebrion/Box of Hall tone section.

3. Decay control :
Just using the Ghost Echo layout/schematic with a BTDR-3H and adding a decay control should work, right? I don't think I'll do it cause I don't wan't to buy another brick, but if it was a new build it could be interesting!

Keep in mind I'm really just beginning in electronics, and merely following instructions so far, so those mods might not be possible or desirable!

If anyone has any idea about them, it would be greatly appreciated! :)
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Re: Earthquaker Devices - Ghost Echo

Postby Boba7 » 23 Aug 2015, 21:33


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Re: Earthquaker Devices - Ghost Echo

Postby andregarcia57 » 19 Mar 2017, 01:31

Anything else my unit also has a loss of volume. what can I do? Grateful
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Re: Earthquaker Devices - Ghost Echo

Postby Visualdistortion » 07 Apr 2017, 18:30

I made the "Perf and PCB" layout. Found that Depth 1 and 3 are reversed, and I compared to the original and I think it's less punchy, a bit less volume. Possibly, I will check values during the week on the original and came back if I found something different that the schematic made actually.
I wanna make it
I wanna make it wit chu
(again and again and again)

French... sorry ;)
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Re: Earthquaker Devices - Ghost Echo

Postby Visualdistortion » 22 Apr 2017, 11:58

I found nothing on it, but I've this small volume drop, but it sound exactly like the original in sound.
If someone have a solution
I wanna make it
I wanna make it wit chu
(again and again and again)

French... sorry ;)
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Re: Earthquaker Devices - Ghost Echo

Postby nunonaos » 26 Jun 2017, 17:19

can anybody give me the voltages to the ics?
another question, on the pt2399, if i use an audio probe, in what pins should I hear any audio?

I'm not hearing any reverb and at the moment i believe it's because i'm not getting output from the pt2399...


thanks
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