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DIY Stompboxes => Building your own stompbox => Topic started by: earthtonesaudio on January 21, 2008, 10:10:06 PM

Title: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on January 21, 2008, 10:10:06 PM
Hey y'all.  The basic info on how to do this is floating around out there, but I thought it would be nice to have a pretty photoessay available for all.

This covers the mods for adjustable delay time, infinite repeats, and increased wet signal from the "Mix" knob.  Plus a solution to the extra pot placement.


The infinite repeats mod: a big ol' blob of solder between that SMD resistor and the leg of the cap sticking through from the other side.  Other DIY sites recommend shorting a different resistor (visible above and slightly left of the tip of the screwdriver/pointer) but I felt that one took too much travel out of the stock "repeat" knob.  This one still gives infinite repeats, but you get better control over them.
(http://lh6.google.com/ashroyer/R5VYmajDGkI/AAAAAAAAADg/WQmvhvXP3fo/IMG_0759.JPG?imgmax=576)

The maxed out wet signal mod: short the resistor between lug 2 of the "mix" knob and that big metal pad.  I used a piece of wire.
(http://lh3.google.com/ashroyer/R5VYsqjDGlI/AAAAAAAAAEA/bbI_8LerG_A/IMG_0760.JPG?imgmax=576)

And the real point of all this mess, the adjustable delay time mod: remove the resistor between pin 6 and ground, and replace it with a pot to ground.  I soldered one lug (center lug I think) to pin 6 and the other to that big ground point below and to the left of the top left screw.  Like Dano says, put some strain relief on those wires, or they will snap off. Immediately.  :icon_eek:
(http://lh5.google.com/ashroyer/R5VY4KjDGmI/AAAAAAAAAEQ/0HHwMazmuCU/IMG_0761.JPG?imgmax=576)

Here's where the other "how-to's" have been lacking: delay time pot placement.  I took my trusty Dremel with the 1/2inch sanding drum attachment and slowly ate away at the corner of the battery tray and the footswitch lever arm apparatus.  It took lots of grinding, then checking clearances, then grinding again, etc. until I was satisfied with the result.  Make sure you can depress the switch button and that it actually turns on and off.
(http://lh5.google.com/ashroyer/R5VZGKjDGnI/AAAAAAAAAEU/WKhpNndHtn0/IMG_0764.JPG?imgmax=576)

Clearance issues: the pot pushed the footswitch lever too far down, so I put in a spacer to raise the switch board.  Cured the problem of "always on" or "always off."
(http://lh6.google.com/ashroyer/R5VZJajDGoI/AAAAAAAAAEc/5YJADXhpmr0/IMG_0765.JPG?imgmax=576)

Put it all back together...
(http://lh6.google.com/ashroyer/R5VZNajDGpI/AAAAAAAAAEk/KEtgQpHMRsk/IMG_0766.JPG?imgmax=576)

Still works? Good!
(http://lh4.google.com/ashroyer/R5VZQ6jDGqI/AAAAAAAAAEs/ZQ7CSpawCv8/IMG_0767.JPG?imgmax=576)

Make your own knobs from fallen twigs and branches.  Never take from a live tree, because in the next life you might be a tree. 
(http://lh5.google.com/ashroyer/R5VZUKjDGrI/AAAAAAAAAE0/aMb55IWQFYY/IMG_0769.JPG?imgmax=576)

Here's where I got the basic ideas:
http://experimentalistsanonymous.com/board/viewtopic.php?t=1094&highlight=fab+echo
http://www.beavisaudio.com/Projects/FABRack/
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: 12milluz on January 21, 2008, 11:17:29 PM
Thank you so much! I'm going to try this! :D

BTW, I love that knob, what an original idea!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: widdly on January 21, 2008, 11:24:42 PM
now you should go play some Bach...hahaha sorry I'll go stand in the corner now
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: disarrayed on February 15, 2008, 09:21:35 PM
Thanks a ton for these photos.  They really helped me along on my first mod.  I just did the 100% wet and infinite repeats mods tonight.....wow.  Some crazy sounds come out of that thing now.

I'm hoping to get to the store this weekend to grab some parts for the delay time mod and maybe a re-house.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: theundeadelvis on February 15, 2008, 09:30:32 PM
Hey are you located in Bloomington? I've seen your pedals at Roadworthy!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Processaurus on February 15, 2008, 09:44:04 PM
I bet one could get one of the tiny 9mm Alpha pots  (http://www.smallbearelec.com/Detail.bok?no=693) Small bear sells (which I talk up a lot, I guess) in the vacant "gable" between the other two pots.  There are maybe one or two film caps in there, but they relocated to the bottom of that pcb.  Or I bet it could go on top, around the "B" in FAB.  I just feel bad hearing about all the dremeling going on.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on February 16, 2008, 02:22:28 PM
Hey are you located in Bloomington? I've seen your pedals at Roadworthy!

I sure am!  Yup, those are my pedals.  Have you played them?

I bet one could get one of the tiny 9mm Alpha pots  (http://www.smallbearelec.com/Detail.bok?no=693) Small bear sells (which I talk up a lot, I guess) in the vacant "gable" between the other two pots.  There are maybe one or two film caps in there, but they relocated to the bottom of that pcb.  Or I bet it could go on top, around the "B" in FAB.  I just feel bad hearing about all the dremeling going on.

I saw one like that.  If you relocate the caps to the other side of the board, there's room for a small pot to fit on top, with the knob coming out of the "A" right in the middle.  It looked pretty slick.  The one I saw used one of those small/thin pots like Crate uses in their amps.  Very low profile, but they have a fragile look to them.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: darwin_deathcat on April 07, 2008, 06:25:42 PM
Hey, I did basically the same mod, but with a different pot mounting technique. I drilled a small hole (in the middle of the "A" in the "FAB" sticker") and pulled the pot wires through them. I had a small PCB mount pot (almost identical to the ones already in the FAB), and I hot glued it in the "center" pot location (you know how all the FAB chassis have three places for pots whether they have three or not). I basically covered all exposed wiring and solder joints with hot glue, and then used some nail polish on top of that to get a similar color match. I made a YouTube video, check it out: http://www.youtube.com/watch?v=It8WOGPxOoQ

Cheers!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on April 07, 2008, 08:55:48 PM
Cool!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: theehman on April 08, 2008, 09:31:42 AM
Hey are you located in Bloomington? I've seen your pedals at Roadworthy!

I sure am!  Yup, those are my pedals.  Have you played them?

You're in Bloomington?  I'm in Bloomington!  I don't sell any RonSound stuff in town, though.  A lot of my sales are international.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on April 08, 2008, 10:22:06 AM
Another Bloomingtonian, cool!  PM sent.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Rawkgod on November 14, 2008, 07:37:23 PM
Thanks EarthsTone I actually just got a FAB echo and am  excited to do this.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on November 14, 2008, 09:47:35 PM
Cool!  Good luck.


By the way, these are so cheap that I got 2, and so of course I had to mod the second one as well.

(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=36278&g2_serialNumber=1)

This one has adjustable delay time, infinite repeats (but not the other mod for increasing repeat volume), and a LED/photocell in parallel with the delay time pot, brought out to a 1/8" jack for external LFO or manual delay time.  Oh yeah.
I had to relocate the through-hole caps to the other side of the board, but it was still a tight fit.  Worth it though!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: darwin_deathcat on November 18, 2008, 12:53:12 AM
I like how you place the pot... I wish I'd thought of that! I keep having my delay time wiring connection break. It's so hard to get a good solder connection to thos SMD pads. I'm actually thinking of rehousing the thing in a roomier box so I can make sure that I can get proper "strain relief" on that connection! Cool job man!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: jacobyjd on November 18, 2008, 08:56:27 AM
All of these crazy Indiana people....sheesh...it's an epidemic :)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on November 18, 2008, 09:37:28 AM
I like how you place the pot... I wish I'd thought of that! I keep having my delay time wiring connection break. It's so hard to get a good solder connection to thos SMD pads. I'm actually thinking of rehousing the thing in a roomier box so I can make sure that I can get proper "strain relief" on that connection! Cool job man!

Yeah, I actually drilled a couple extra holes in the PCB to allow placement of a wire tie which I used for strain relief for the connecting wires.  I might rehouse mine eventually because I find the footswitch a bit awkward.

I think if you use one of those 9mm pots like Zvex uses, you could put the pot on top without other modifications, but if you use a full size one, you really have no choice but to relocate the components to the other side of the board.

All of these crazy Indiana people....sheesh...it's an epidemic :)

Haha, yep!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: drewl on November 18, 2008, 09:43:05 AM
That's great, how long a delay time does it have?
I've been thinking of doing something similiar to my $20 Arion delay....maybe even mounting it in a metal case if I like the sound.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on November 18, 2008, 11:39:55 AM
I used a 100k pot for the delay time and I'd say the usable time tops out a little under 1 second, but it probably will go up to maybe 1.5 seconds.

The longer delay times are increasingly distorted, sort of low-fi sounding.

[edit]
And I should point out that while longer delay times won't hurt the chip, decreasing the resistance from pin 6 to ground to zero is not a good idea, because it can potentially harm the chip.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: moertz on November 20, 2008, 03:00:23 PM
hey, i did my first mods with the help of your description so thank you very much for your encouragement! everything worked out great apart from the infinite repeats mod. i only got it to make a few repeats that blend out very quickly. so i also shorted the other resistor as described in the experimentalists anonymous forum's post but nothing changed. it has both resistors shorted now and still just a few repeats. i also tried random bends with a nice result so i'm already very happy with it but i really would like to hear more of the lofi repeats.
do you have any ideas why mine dind't work out the same? i alredy re-tried it multiple times and think i'll just buy another one to see if i get it working on that..
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on November 21, 2008, 07:16:15 AM
I'm not sure why that isn't working for you.  If you could post a high-resolution, very close-up photo that might help. 
Also the answer to a couple more questions may be helpful for de-bugging:

-Aside from the obvious fact that you can't get the infinite repeats, does the "repeats" knob work as usual?  Meaning, can you turn it down to get just one repeat, and then turn it  up to get a few more repeats?  Or, has its function been entirely compromised?

-Is the solder bridge contacting anything else that it should not touch?  Look very closely.  It's easy to slip with a big soldering iron tip, especially when working around surface mount components.


Hopefully you can get this working 100%.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: moertz on November 21, 2008, 04:50:38 PM
ok this is the closest i got with my camera http://www.bilder-hochladen.net/files/8t1j-1-jpg.html (http://www.bilder-hochladen.net/files/8t1j-1-jpg.html). the repeat knob works as usual with one repeat when i turn it down but just about four when i turn it up. the fourth is already barely audible. it is limited to one repeat only when i remove one of the two solder bridges. i don't know what else could be contacted by the bridges .. i also resoldered them multiple times. i thing i'm buying another fab echo anyway so i'll see if i get it working then. do you think it's possible that it just doesn't work on some?
thanks for the quick help!
 (http://www.bilder-hochladen.net/files/thumbs/8t1j-1.jpg) (http://www.bilder-hochladen.net/files/8t1j-1-jpg.html)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on November 22, 2008, 02:07:09 PM
Hm... Not sure why it's not working.  Other than the fact that I left my 12k resistor in place, and shorted the 4.7k instead, it looks alright.  My best guess is that one of the two solder joints is not complete.  Try and test for continuity with a meter and see if there's any high value (>1k) where there should be a short.  It's easy to make a cold solder joint when re-working something.  Those tend to make strange problems.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Ssmit on March 13, 2009, 01:42:35 AM
Thread Resurrection!

So I took my Fab Echo apart to do the infinite delay mod, and maybe plot out the delay time knob positioning, and I found out I have a different "delay module" board layout than most of the pics posted; the PT2399 chip is on the TOP of the board (the pot side). I'll try get some pics up tomorrow, but for now, I'm just going to leave it alone (wouldn't want to break anything  ;D). So, is anyone else have this revision?
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Ssmit on March 13, 2009, 12:20:31 PM
Bottom
(http://i215.photobucket.com/albums/cc254/seansmit/Bass/IMG_5989-1.jpg)

Top, with PT2399
(http://i215.photobucket.com/albums/cc254/seansmit/Bass/IMG_5991-1.jpg)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Ssmit on March 15, 2009, 03:06:28 PM
Anyone? I'd really like to get this done :P
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: krellmusician on April 06, 2009, 01:13:19 AM
Just did two of the three mods (infinite repeats and mix; delay time pot will be added tomorrow) and I'm not sure if I might have done something wrong.  The mix pot is acting more like a pure wet level control, that is, I hear no dry sound at any setting of the control.  To be honest, I don't remember exactly what it sounded like stock, but I know that I used to get an output with the mix control turned all the way down.

Any ideas?  Or am I just imagining things?
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on April 13, 2009, 08:27:41 AM
@ Ssmit: Locate the resistor coming from pin 6 of the pt2399 and going to ground, remove it and replace it with a pot for adjustable delay times.  For infinite repeats, take a look at the datasheet: http://www.datasheetcatalog.org/datasheet/PrincetonTechnologyCorporation/mXyzsyzt.pdf
And notice the 50k pot under the "Echo Application Circuit" schematic diagram.  The 50k pot corresponds to the "mix" control on you delay unit, and the 18k resistor attached to the wiper of that pot is what keeps it from doing infinite delay/self oscillation.  Reduce the value of the corresponding resistor on your Fab Echo (anywhere between zero ohms and 10-12k should do it) and it should work.  HOWEVER, the circuit might be slightly different (instead of the 18k resistor attached to the wiper, a similar value may be in series with lug 3 of the 50k pot) so take a good look, draw a schematic from what you have, and you'll be able to make a better decision from there.  Good luck!


@ krellmusician: That sounds like something's wrong.  I think at minimum, the mix pot should either let full "dry" signal and no "wet" through, or maybe mostly dry and a tiny bit of effect.  I'd look for solder bridges first.

-Alex (Earth Tones Audio)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Ssmit on April 30, 2009, 07:28:19 PM
@earthtonesaudio: thanks! I'll be getting to it soon (have a lot on the go at the moment)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on April 30, 2009, 07:53:47 PM
There is a fairly easy way to do a true 100% wet/dry mix but the one draw back is you lose the bypass function. If you are true bypassing it then this is no big deal.

Any interest ?

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on May 30, 2009, 07:42:46 PM
There is a fairly easy way to do a true 100% wet/dry mix but the one draw back is you lose the bypass function. If you are true bypassing it then this is no big deal.

Any interest ?

Andrew

I would be interested. I just got one of these and want to mod it. Thanks in advance
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on May 31, 2009, 05:14:17 PM
I'll take some pic later to outline the mod.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on June 10, 2009, 08:40:32 PM
Sorry for the late response. Okay here we go.

Wet / Dry Mix Mod

The Fab Echo does not have true bypass but instead switches the delay signal in and out and leaves the clean buffered signal always connected. To disable the clean signal from always passing cut the trace between the jumper connection and the SMD resistor:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod1.jpg)

Note: An easy way to cut the trace is with a sharp knife. You can test to make sure the trace is cut by measuring with your meter.

To get the clean signal connect a wire to the jumper connection on the board. This is a good place for example:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod2.jpg)

To get the wet signal wire a connection to the wet side of the mix pot on effect board:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod6.jpg)

Note: Do not forget to turn down the pot attached to the board otherwise it will interfere with the mod.

Connect the clean signal to one end of a 100K linear pot. Connect the wet signal to the other end. Connect the wipe of the pot through a 1uF capacitor and a 33K resistor.

Go ASCII graphics:

Code: [Select]
Clean
   |
   |
   |
   P    1uF      33K
   O----|(----/\/\/\/\----Board
   T
   |
   |
   |
  Wet       

Connect the wiper to the orange capacitor at this spot on the board:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod3.jpg)

You now have a 100% wet / dry mix pot. If you want you can decrease the 33K for more output then put a volume pot on the final output of the effect as a level control.

Since the clean signal is disable the bypass function will not work anymore. If you want to force the pedal into effect mode all the time then perform this mod.

Always On Mod

Cut the trace at this point:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod4.jpg)

Connect a wire from the switch's board connection to the resistor:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod5.jpg)

The pedal will now always be on. You can install a true bypass switch.

Enjoy.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on June 11, 2009, 05:25:45 PM
Thanks,
This is very nice of you. Step to step instructions together with photos!!!!!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on June 11, 2009, 06:32:20 PM
Thanks,
This is very nice of you. Step to step instructions together with photos!!!!!

No Prob. Let me know if you need anything else.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Br4d13y on June 12, 2009, 10:23:59 PM
wow. i got one at the gc for 5 buks used yesterday, and did the delay time pot mod

this thing has longer delays than my dd-3?! and the slightly lo-fi breakup at long delays sounds way kool!!

this has a place on my pedal board, im just mystified that a dano, other than my fish n chips, is there!!!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: lolalola on August 27, 2009, 09:25:52 PM
Aaaaah, I want one! Anyone want to sell me one? Puh-lease???? I so do not have the brain capacity to make one, so if you're bored of yours, please email me! x
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: lolalola on August 27, 2009, 09:29:08 PM
Aaaaah, I want one! Anyone want to sell me one? Puh-lease???? I so do not have the brain capacity to make one, so if you're bored of yours, please email me !
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Quackzed on August 27, 2009, 11:53:23 PM
you can get the fab echo on ebay for a reasonably low price...  :icon_neutral:



Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: DjFrontBum on October 07, 2009, 01:59:10 PM
wotto, just got 1 from CPC/Farnell for Ģ26 including UK delivery,
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AudioMime on October 16, 2009, 12:06:26 AM
Indeed, I got one at my local music store for 15  dollars.

Well I found this out while I was roaming through the pages, and I remembered I got one for christmas a year ago.  So I whipped it out and unscrewed it. So far I was able to take off the first board, but the second board with the pots is really annoying to get out. Any suggestions to get the knobs off?

BTW this is a pretty cool mod for a really cheap echo/delay. Thanks you guys.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: mueller on October 16, 2009, 12:45:55 AM
Is there a simple way to add an FX loop to this pedal?

Not worrying about fitting in the jacks,etc. I would put it in a different casing.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: earthtonesaudio on October 16, 2009, 11:12:13 AM
Any suggestions to get the knobs off?

I just used pliers.  It's fast, but it will scuff up the knobs (I didn't care).  If you want to keep them "pretty," you could put something (like rubber) between the pliers and knob.

Is there a simple way to add an FX loop to this pedal?

This would be possible, but tricky.  The schematic is very similar to the echo base, so you could take a look there for inspiration.  But the hard part is that the Fab Echo board is very compact and mostly surface mount, so it's very difficult to attach extra components. 
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on January 11, 2010, 07:28:27 AM
Resurrecting an old thread but I was playing with my Fab Echo today and I was wondering about the following:
Is the dry signal kept without A/D and D/A conversion or it also goes through the A/D and D/A conversion?
Just curious.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Processaurus on January 11, 2010, 08:52:12 AM
These Princeton chip based designs are implemented much like an analog delay, so that means not only an analog dry path, but analog regeneration as well.

This is an interesting chip because it uses 1 bit sigma delta A/D/A conversion, which a totally different process from regular digital audio.  Rather than a pixelated, stairstep the audio looks more like a connect the dots, vector image.  Ironically an analog delay with its slow sampling rate would resemble a typical digital audio output closer than this type of conversion.

http://www.diystompboxes.com/smfforum/index.php?topic=31886.msg219966#msg219966 (http://www.diystompboxes.com/smfforum/index.php?topic=31886.msg219966#msg219966)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on January 22, 2010, 03:01:53 AM
Is the dry signal kept without A/D and D/A conversion or it also goes through the A/D and D/A conversion?

The dry signal gets passed through the buffer/mixer opamp and mixed with the delay signal so there is no A/D/A action. To switch the effect off they just disconnect the delay signal so the dry signal is always going through the opamp. Its not true bypass.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: E-mol on March 02, 2010, 11:22:12 AM
Hey.

I have tried to do the mod of the delay time, but now there isn't any effect at all. Sounds like pass through. I have followed the guide in the beginning of this thread, plus the ideas about cold soldering, and missing connections. Nothing had worked. A possibility could be that number 5 and 6 (on the photo) have more ohms than my meter can measure.

I have tried anything I can think of, but I'm pretty new to this modding stuff, so that's no guarantee  ;)

I have addet a photo of my circuit board as it looks now. Hope it can help :)

(http://emilharder.dk/print200.jpg)
Bigger picture here:
http://emilharder.dk/print.jpg (http://emilharder.dk/print.jpg)

I hope there is light at the end of this tunnel
Thanks
E-mol

Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Mark Hammer on March 02, 2010, 12:00:05 PM
In situations like this, I often suggest the person get an old toothbrush and some methyl hydrate and scrub the solder flux off the board.  When the traces run close to each other, sometimes the flux reflects the light in a way that makes it hard to say if there is an accidental solder bridge or if the solder joint is a good one.

The problem may well NOT be any of the above, but at least you can scratch "solder bridge" off your list with confidence because you had a good and unobstructed look.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: E-mol on March 02, 2010, 12:10:22 PM
Thank you hammer :)
But after I had assembled the pedal it all works :)

I don't know what the problem was but.. the tunnel wasn't that long.. ;)

Cool mod - maybe I get addicted to this stuff :)

Thanks
E-mol
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Top Top on May 06, 2010, 01:44:17 PM
Did  this mod last night. I almost didn't do it because the fab echo actually sounds kind of cool even though it is very limited. I figured $15, I will go for it. I am really glad I did.

I re-housed the pedal into a new enclosure to make room for the knob and because I plan to add an LFO possibly for modulation eventually. Clipped the switch wires and hooked them up to a momentary spst pushbutton (any will do).

It actually sounds pretty sweet. I used a 100K pot. You do start to hear some clock noise at the longer settings, but the delay itself still sounds ok - a little grungy, but ok... It sounds really good, smooth, up to that point. Each repeat is colored in a nice way. Very dub sounding.

You have to really watch out with those SMD resistors. If you touch one with your soldering iron, you can pretty much kiss it goodbye. I don't know if you were supposed to remove the resistor (by the cap leg) for the infinite repeats mod, but as soon as I touched it, the tiny thing stuck to my soldering iron - so small I almost  couldn't see it on there. I just bridged it with a solder blob, and it works... so... no complaints but a close call maybe... wouldn't want to touch any that you weren't sure about... I used some hot glue in a couple places for the stress relief on the wire for the delay time mod pot... that's that...
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: aleister on September 06, 2010, 02:54:08 PM
I just did the 3 mods on my fab echo and all I can say is WOW!!! This pedal is a total beast now. Sure when you max out the pots you do get osscillation but there are so many great sounds to be coaxed out of this baby now.       Now when I went to do the second mod, wet mix, I also had the problem of the smd resistor come right off and stick to my iron. Then I tried a blob of solder with no success, then I clipped a short lead and tried to solder that on and it wouldnt take. Now this was my first time messing with smd components so I am thinking I am screwed but I sit back and take a second and realize that both ends where the smd resister was connected to thru hole components so I got a .47 ohm resistor and connected it to those joints. So with 30 minutes work and less than a buck in compnents I have a kick ass delay.  I got mine new off ebay  for 18 bucks shipped to boot!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: clamup1 on October 01, 2010, 12:24:33 PM
i thought i messed mine up with the ocillilation. but im glad i didnt. great mod
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Renegadrian on January 19, 2011, 11:56:26 AM
So the wet signal comes out from the pin with that arrow. So I have to desolder the pot and take the wet from there, then take the clean fron the oter board and connect the wiper to that cap on the sw board. right?!

My goal is to make it true bypassable as a standard pedal - even get rid of the sw. board, in case I'd add the tl072 part with a daughter board! but keep the switching as usual!



To get the wet signal wire a connection to the wet side of the mix pot on effect board:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod6.jpg)

Note: Do not forget to turn down the pot attached to the board otherwise it will interfere with the mod.

Connect the clean signal to one end of a 100K linear pot. Connect the wet signal to the other end. Connect the wipe of the pot through a 1uF capacitor and a 33K resistor.

Go ASCII graphics:

Code: [Select]
Clean
   |
   |
   |
   P    1uF      33K
   O----|(----/\/\/\/\----Board
   T
   |
   |
   |
  Wet       

Connect the wiper to the orange capacitor at this spot on the board:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod3.jpg)

You now have a 100% wet / dry mix pot. If you want you can decrease the 33K for more output then put a volume pot on the final output of the effect as a level control.

Since the clean signal is disable the bypass function will not work anymore. If you want to force the pedal into effect mode all the time then perform this mod.

Always On Mod

Cut the trace at this point:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod4.jpg)

Connect a wire from the switch's board connection to the resistor:

(http://img.photobucket.com/albums/v515/TheToneGod/delay_mod5.jpg)

The pedal will now always be on. You can install a true bypass switch.

Enjoy.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on January 19, 2011, 06:32:01 PM
So the wet signal comes out from the pin with that arrow. So I have to desolder the pot and take the wet from there, then take the clean fron the oter board and connect the wiper to that cap on the sw board. right?!

My goal is to make it true bypassable as a standard pedal - even get rid of the sw. board, in case I'd add the tl072 part with a daughter board! but keep the switching as usual!

I don't need to desolder the pot although you could. Just set the pot to zero so the wiper is grounded out. No soldering needed. Other then that just follow the diagrams and the solder points with the arrows and your good to go.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: joelindsey on January 25, 2011, 04:27:58 PM
Just as a heads up to you folks who might have a hard time placing the pot out of the way of the lever arm. I just bought a new one of these, and it looks like Danelectro got rid of that entirely with the newer models. Instead there are two springs directly under the actuator. That frees up a lot of space. 

(http://farm6.static.flickr.com/5137/5387984579_248cd62c88_z.jpg)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Renegadrian on January 25, 2011, 05:28:13 PM
clever move - lever (re)move(d)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: The Tone God on January 25, 2011, 06:34:24 PM
The batch I bought awhile back are like that. Simpler and cheaper I'm sure.

Andrew
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Renegadrian on January 26, 2011, 10:20:55 PM
FINALLY REHOUSED (http://www.swingandsoda.altervista.org/pedals/index.php?cmd=image&sfpg=RmFiIEVjaG8gcmVob3VzZWQvKjI3LjAxLTA3LmpwZypjYjQwZDM2MWM2MWFhNGE5OTc4YTkyODE3NmIxMzAwNQ)

switch is a momentary dpdt - I had some work to do to make the boards fit the box, like sanding off excess pcb!
Added pot for the time, it it very similar to a rebote minus the feedback crazyness and the mix mod hasn't been made, so wet level isn't that high - good effect anyway, 20 euros shipped is ok!!! I had fun doin' this!!!

Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: ThunderShowers on June 05, 2011, 08:20:19 PM
REVIVAL: Sorry guys

If I want to use a Roland ev-5 to control the feedback, I would use a Stereo jack across the pot, orrrr?
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: steampunkistof on October 05, 2011, 06:34:05 AM
Hi,

Great mod! But I have messed up the pcb pretty bad.
I have a question.

(http://farm7.static.flickr.com/6094/6213481817_23abc98549.jpg) (http://www.flickr.com/photos/68286908@N02/6213481817/)
xcgsdfgd (http://www.flickr.com/photos/68286908@N02/6213481817/) by steampunkistof (http://www.flickr.com/people/68286908@N02/), on Flickr
Are these points connected?
I have stripped the path running from the cable (right upper circle) to the zero resister so I have no way of knowing. I have a suspicion that it is connected under the white line around the cap (thats also gone on my pcb).
Can somebody check

PLeaase :-\

BY the way ignore the red arrow ( it was already there). I dont mean that resitor haha
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: muffinman on October 15, 2011, 04:52:53 PM
Just wanted to add that I'd had one of these for years- came free with something (like a mag subscription?-can't remember) but never used it as that slapback is so - well I reckon everyone knows... did the infinite plus feedback , wet volume and put in a 250k for the delay time. MONSTER for glitch madness and catch and mutate loops. Many thanks for the info and great pictures.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: elmo7sharp9 on April 15, 2012, 06:51:59 PM
Saw one of these for 10GBP,
rushed home to check if it was moddable,
found this thread, bought the delay and did the 3 mods.

I used a 100k log pot for the delay time, with a 1/4" socket in parallel, for a 100k expression pedal.

On shorter delay times, the expression pedal gives me manual flanging.

Wet-only use with the expression pedal is hilarious :icon_biggrin:.

Thanks for the photoessay!

The only unanswered question is...
why did they market a pedal with such a vital parameter missing ???
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on May 17, 2012, 04:33:49 AM
Thanks for all of the great information on this mod. I've had my echo for a while and wasn't too impressed with it.  It's a lot more functional now. I did the three mods. I took some photos since I am installing switches for the infinite repeat and wet mod:

I decided to try this ribbon cable I got very cheap at Fry's. It's 28AWG and works really well for SMD work. Most if us have a few of these from old computers. You can make your own 2,3,n pair leads:

(http://i1160.photobucket.com/albums/q485/jdansti/621f524e.jpg)

Here are the two wires for the infinite repeat switch.  I used hot glue for strain relief:

(http://i1160.photobucket.com/albums/q485/jdansti/920b3a5e.jpg)

Here are the two wires for the wet switch mod:

(http://i1160.photobucket.com/albums/q485/jdansti/5354cc62.jpg)

Here's where I removed the resistor for the delay mod:

(http://i1160.photobucket.com/albums/q485/jdansti/611da767.jpg)

My first attempt to solder the pot lead to pin 6 for the delay mod. Got a nice bridge between pins 6 and 7:

(http://i1160.photobucket.com/albums/q485/jdansti/dbb79937.jpg)

Fixed the bridge, but still had to clean flux and a little solder off of the surface of the board to get it to work:

(http://i1160.photobucket.com/albums/q485/jdansti/a748d76c.jpg)

Here's a look at the board after soldering all of the leads:

(http://i1160.photobucket.com/albums/q485/jdansti/16404d81.jpg)

Works great!  I'll post some pics of the pot and switch installation after I finish. Thanks again!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: CodeMonk on May 17, 2012, 05:00:02 AM
I did this mod for myself a few years ago, then did it to several more FAB Echos for a local music store.
The thing I did different than what I have seen others do with those mod is to use a 9mm 100K pot for the time ( Smallbear has them).
100K gives you about 1200msec of delay time (IIRC).
Although once it gets past around the 80k mark or so, it sounds, uhm, not so good.
I would drill 3 holes in the PCB (which trashes 2 traces, but a few jumpers fixes it, no problem) lined up with the other pots.
Hot glue and some super glue hold it in place quite well.
This, IMO, makes it look so much better, as there is an unused gable there.
Makes it look like it came that way from the factory.

I don't have the pedal anymore, and I don't have any pics :(
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on May 17, 2012, 11:21:26 AM
I did this mod for myself a few years ago, then did it to several more FAB Echos for a local music store.
The thing I did different than what I have seen others do with those mod is to use a 9mm 100K pot for the time ( Smallbear has them).
100K gives you about 1200msec of delay time (IIRC).
Although once it gets past around the 80k mark or so, it sounds, uhm, not so good.
I would drill 3 holes in the PCB (which trashes 2 traces, but a few jumpers fixes it, no problem) lined up with the other pots.
Hot glue and some super glue hold it in place quite well.
This, IMO, makes it look so much better, as there is an unused gable there.
Makes it look like it came that way from the factory.

I don't have the pedal anymore, and I don't have any pics :(

Thanks.  I see that unused gable. That's pretty tempting.  I just don't know if I want to rearrange the board for my personal use. It looks like I can install a 16mm pot to the left or right of the PCBs.  There are indentions there that look designed to take a component.  I'll have to ruminate on that one  ;).
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on May 18, 2012, 03:07:01 AM
Here's my method of installing the pot and switches.

This is where the pot is going to go:

(http://i1160.photobucket.com/albums/q485/jdansti/1bcfa877.jpg)

I removed the ring shown in the previous photo:

(http://i1160.photobucket.com/albums/q485/jdansti/c5784b89.jpg)

Test fitting the pot. I'll trim the legs later:

(http://i1160.photobucket.com/albums/q485/jdansti/3a5c9f94.jpg)

Drilled holes for the switches and test fitted them:

(http://i1160.photobucket.com/albums/q485/jdansti/160bf79b.jpg)

Notched the PCBs to make room for the pot. Had to be careful to avoid traces:

(http://i1160.photobucket.com/albums/q485/jdansti/155bad30.jpg)
(http://i1160.photobucket.com/albums/q485/jdansti/acfb5c28.jpg)

Here's everything wired and installed:
(http://i1160.photobucket.com/albums/q485/jdansti/552a9866.jpg)

All back together. The switches move up and down, not forward and backward as it might appear.

(http://i1160.photobucket.com/albums/q485/jdansti/53d8c7fe.jpg)

The only trouble I had was this circuit seems to be sensitive to leftover flux on the board. It stopped working for a while and I spent several hours troubleshooting. As a last resort, I decided to take some alcohol and scrub the board. It magically started working again after that.  It could be a coincidence but it's the only thing that seemed to work. Anyway, I really like the sounds I can get out of it now. Thanks to everyone who contributed to this mod!  I used a lot of information from here.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: pinkjimiphoton on June 28, 2012, 11:02:08 PM
i messed mine all up...broke pin 6 off the 2399. scraped away with a dental tool, and just barely got a little wire on the close to microscopic nub.
phew.

still can't get feedback...one slap, that's it.

but...i put a 16mm 100k pot from tayda below the bottom board... a bit of dremel work, and i whacked a hole fright thru the a in FAB. just fits.

THAT part works great.

don't like the shorted resistor for the level, it has some pretty nasty noise when cranked...tho fuzzy echo at a really short delay with just one slap almost sounds backwards.

now i've gotta get the feedback thing happening.

but the pot location i thought may be useful for someone in the future...peace!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on June 29, 2012, 01:25:26 AM
i messed mine all up...broke pin 6 off the 2399. scraped away with a dental tool, and just barely got a little wire on the close to microscopic nub.
phew.

still can't get feedback...one slap, that's it.

but...i put a 16mm 100k pot from tayda below the bottom board... a bit of dremel work, and i whacked a hole fright thru the a in FAB. just fits.

THAT part works great.

don't like the shorted resistor for the level, it has some pretty nasty noise when cranked...tho fuzzy echo at a really short delay with just one slap almost sounds backwards.

now i've gotta get the feedback thing happening.

but the pot location i thought may be useful for someone in the future...peace!

Hey Jimi, if you really want some fun, why don't you replace the SMD 2399!  Just kidding.  :)

I like the idea of putting the pot where you did.  If I can pickup another cheapo I'll give it a try.

My brother in law and I were upstairs messing around with my modded echo a couple of weeks ago while the girls were downstairs doing girly stuff. He was playing while I was tweaking the knobs, and the amp was a little louder than necessary.  ;)   I turned on the infinite repeat switch and then slowly rotated the delay knob towards shorter delays and it sounded like a freaking alien spaceship taking off.  Then I quickly turned the delay all down and it sounded like a gigantic explosion!  We were laughing our *sses off. My wife didn't think it was so funny, though.  >:(
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: pinkjimiphoton on June 29, 2012, 01:42:56 AM
screw smd!! pia!!! gawD!!!

lol...i decided, when the %^#^&#^ wire broke off the %^^#^%$% pin that i was gonna just literally take it apart. so i did. it is unsalvageable.

i'll use the casing for something useful, like a fuzz or something. i finally got the repeats working on it..

shaky hands and smt don't go together. good for vibrato, bad for fly turds. one slip of the iron...like, a millimeter... and wango. another resistor (i think) stuck to my iron.

i'll leave the hard stuff to the guys who can get it...not me. i'll build something bigger.

sucks tho, cuz this thing sounded great with the 100k pot..very echoplex-y. i may buy another to try and get it right...someday. i don't know why, cuz, i gotta crapload of delay pedals, rackmounts, even a pair of echoplexes..

i don't like to admit defeat, i guess. and i'm a total gear whore. PAS, brother, PAS.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on June 30, 2012, 09:45:26 AM

i don't like to admit defeat, i guess. and i'm a total gear whore. PAS, brother, PAS.

I know the feeling. Sometimes I wonder if I'm OCD... :)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on January 25, 2013, 04:56:11 PM
(http://i1160.photobucket.com/albums/q485/jdansti/552a9866.jpg)

I'm using this photo to ask a question regarding a new mod. Not exactly a mod, more of an add on.
I'm adding another circuit AFTER the Fab Echo, using the existing box. I wanna have this new circuit hardwired to the output of the Fab Echo. It will always stay on (The new circuit)!
So, I wanna tap into the 9v + of the Fab Echo to power the new FX board. I wanna tap into it before any current limiting resistors in the circuit. What is the best place? Can somebody point it at the above photo? I also want to disconnect Fab Echo's output from the output jack and connect it straight to the input  of the new circuit board.
Then I will take the output of the new fx board and wire it to the existing output jack. Which pin of the output jack in the picture above is the tip?
Last question, should I connect the ground wire of the new FX board to the unused pin of the output jack or somewhere else.

The output jack traces in the photo are the ones on the lower right side.
Thanks a lot in advance!!!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on January 25, 2013, 11:54:42 PM
>So, I wanna tap into the 9v + of the Fab Echo to power the new FX board. I wanna tap into it before any current limiting resistors in the circuit. What is the best place?

This might be a difficult because you have to deal with the battery and the power jack. Since the power jack switches the battery in and out of the circuit, you can't just tap off of one or the other unless you plan to only use one or the other.  We really cant tell just from the photo.  We'd need to look at a schematic.

>I also want to disconnect Fab Echo's output from the output jack and connect it straight to the input  of the new circuit board. Then I will take the output of the new fx board and wire it to the existing output jack. Which pin of the output jack in the picture above is the tip?

I haven't looked at those jacks in a long time. You should be able to use your meter to check for continuity between ground and the terminals of the output jack to answer this question.

>Last question, should I connect the ground wire of the new FX board to the unused pin of the output jack or somewhere else.

All of the grounds should be connected to each other. When you finish the mod, be sure to check for ground continuity. Do this by placing one probe on a ground connection and use the other probe to check every one of the other ground terminals and ground board connections. Don't move the first probe to another location while doing this.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on January 26, 2013, 05:55:30 AM
OK, here is the same picture but with all the connections labelled: This should make it somewhat easier to trace things.I marked the 220uF cap and diode traces surrounding the 9v jack. I assume these are for polarity protection (?). So maybe they could give an extra clue about the ground path. Thanks again!
(http://img818.imageshack.us/img818/7494/552a9866.jpg) (http://imageshack.us/photo/my-images/818/552a9866.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: slacker on January 26, 2013, 08:23:53 AM
Battery negative will be going to jack ring so that's jack 1, jack 3 seems to be connected to the same place as the Cap negative so that looks like ground so that's the sleeve. That leaves jack 2 as the tip, looks reasonable as there seem to be components connected to it.

On the DC jack, it looks like 9v  1 is connected to the same place the cap negative and jack 3 so that's ground, 2 looks like it goes to battery +, so 3 must be the connection to the DC jack positive, so that's where you want to tap off your 9 volts.

If you have a meter you can check all this pretty easily. lug a lead into the input jack and test for continuity between the tip and jack 2, if you get it that's the tip connection. Same with the sleeve and jack 3. You can check the DC jack the same way plug a lead in and test for continuity between the outside and 9v 3.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on January 26, 2013, 02:38:58 PM
Thanks slacker!
I thought that was pretty much what was going on but I couldn't confirm it. My multimeter is broken so I went with whatever I could trace by looking at the pcb and thought I should ask the knowledgeable guys here for confirmation and advice.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: gogul808 on January 27, 2013, 07:29:09 PM
hehe bought one of these coz it was cheap and modded it similar to the last post with the pictures (except I used 3 100k pots ) it was all working well until the switch(the old style version that is on the power board pretty much fell apart ! don`t ask me how I dunno lol   :'( )
Anyhoo , as the the soldering and prelim sound test indicated that it worked before my switch gave up the ghost I was wondering If anyone could please tell me how the 4 solder joints underneath the switch housing would correspond to a dpdt switches wiring ?as I will prolly re house it in a new chassis
For my 1st pedal mod i`m chuffed It works ,and is a pedal I would use ,once i get a dpdt switch in it !  unlike before it was modded (the switch I blame on cheap shoddy design ^^)

all the info in this thread was great , including the warnings about how easy to fudge up the teeny tiny resistors .
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: AM on January 28, 2013, 03:04:51 PM
It worked! Thanks again gents!
I desoldered the output jack, and bent the output pin so it doesn't touch the Dano's circuit anymore. I hard wired the output of my new diy board on that pin.
I soldered the input of my diy board to where the output jack pin used to be soldered. Then I soldered the other two pins of jack back on the Fab Echo's circuit board.
Soldered the ground wire of my diy board on pin 3 of the output jack.
I soldered the 9V+ wire of my diy board right on the diode so I could take advantage of the polarity protection circuit that is already installed on the Dano.
Worked really well and I'm very happy with the final result.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: bizbiz on February 24, 2013, 12:43:07 PM
Hi all,
Like many others I lifted the resistor right off the board when doing the infinite repeat mod.
Does anyone know the value of that resistor?  The only schematic I came across said 100k, though someone else mentioned it is .47ohm
Would like to replace that resistor and add a momentary switch inbetween cap
Kinda new at this and really excited to get that guy workin.
All other mods worked great, thanks to this thread!
 :)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on February 24, 2013, 01:39:56 PM
Probably not 0.47R. I assume the resistor vanished into thin air or the carpet when you removed it ;), but if by chance you still have it, place it on the sticky side of a piece of masking tape and secure the tape to your bench sticky side up with a couple more pieces of tape. Now you can measure the resistance.

If you don't have the resistor, solder a couple of leads to the pads where it was and connect those to a pot with some clips. Start with a the snallest pot you have and adjust it to see if you find a spot that works. If it does, then being careful not to turn the pot shaft, remove the clips and measure the resistance across the same two lugs where you had the clips connected.  You want to remove at least one of the clips when you measure the pot resistance because the board could affect your reading if you don't.

If the first pot doesn't work, try the next size up and keep experimenting until you find a resistance that works. Heck, it might be interesting to see if a pot here might give you desireable results.

After you figure out the resistance, just place a regular resistor of the approximate value that worked on one lug of the switch. Hope this helps.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: bizbiz on February 27, 2013, 03:36:43 PM
I assume the resistor vanished into thin air or the carpet when you removed it ;), but if by chance you still have it, place it on the sticky side of a piece of masking tape and secure the tape to your bench sticky side up with a couple more pieces of tape. Now you can measure the resistance.
 
Heck, it might be interesting to see if a pot here might give you desireable results.

. Hope this helps.



Thanks JDanski!
Yes, the resistor was lost in a poof of smoke as it ascended off the board  :icon_biggrin:
After measuring pot resistance to find the right value, it became obvious that keeping the pot in there vastly expands the feedback time from whats included stock, so i left it..
This is it packaged:

(http://i147.photobucket.com/albums/r319/mbizon/DSC_0119.jpg)
(http://i147.photobucket.com/albums/r319/mbizon/DSC_0120.jpg)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on February 27, 2013, 08:10:43 PM
Cool!  You accidentally found a new mod! Nice box too! I like the white plate. I've got some cigar boxes that will have to have similar plates! 8)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: J0K3RX on February 27, 2013, 08:34:23 PM
bizbiz - Very cool!!  :icon_mrgreen: I may have to get one of these delays now after looking at this thread?

Speaking of cigar boxes, have you all seen the cigar box guitars and amps? The guitars are kinda a big thang and have a big following...

Here's one of many sites
https://www.cbgitty.com/cubecart/index.php
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: gpizzolato on March 09, 2014, 11:46:10 AM
Very old topic but very detailed and very inspiring!

I modded a FAB Echoa few weeks ago, based on the info found here. I just made a few things differently and added more controls as follows:
- Traditional SPDT switch inside FAB Echo enclosure for the Mix Mod
- Added a stereo jack for the foot controller

Controlled by the foot controller:
- Infinity repeats mode controlled with a momentary switch
- Two selectable Delay time pots (dpdt push-button switch)
- Modulation effect using an oscillator (dpdt toggle switch)
- Factory mode (another momentary switch)

Sound sample/video here:
http://youtu.be/vomqV3gZEgg

I hope you guys like it! Cheers!
Gui
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Renegadrian on March 09, 2014, 12:29:05 PM
Ciao e benvenuto! (I assume you are italian)

it really is a fun thing to do, not so useful as we had joyos or chinese delay pedals cheaper than the FAB in those last 2 years...
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on March 09, 2014, 01:44:05 PM
Great job!  Sounds great!  What is that black enclosure?
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: gpizzolato on March 10, 2014, 03:43:02 PM
Ciao Renegadrian!
Yes I'm third generation Italian born in Brazil. It's a shame I don't speak Italian though.

I agree, but I have to say that now that I'm living in Canada almost everything in the Handmade world is more expensive than what I can find in the market. It ends up being just for fun anyways. Back in Brazil it was the opposite, imported goods were so expensive and the components so cheap that it was better to build.
I know this is somehow "off-topic" but I have been reading your comments and checking your schematics for a while and they are always extremely good. Anyways, I have been building handmades for a long time even though I don't have a background in electronics, if you have some time check my youtube channel for my other pedals, specially "The British Tone" which is basically your "Tube Star" running at 80V, and the "Emerald Amp" which is a hybrid amp based on the Twincaster.

Cheers!
Gui
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: gpizzolato on March 10, 2014, 03:47:41 PM
Hey John,

The black enclosure is from a "Infinity Play - Dictation assistance USB foot controller" :)
I bought this in a thrif-store for about $3 a while ago. It comes with 3 separate momentary switches but I just kept two of them.

Cheers,

Gui
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on March 10, 2014, 09:02:56 PM
Cool!  I'll have to look around for one.

BTW I'm half Italian (Sicilian) and half Cajun.  Does that count?   ;D
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: JakeVP on May 16, 2014, 10:54:33 AM
Just finished my modding and re-housing of this echo. This thread was very helpful! I have decided NOT to go with the always on and wet/dry mods, because I wanted to keep this thing somewhat "glitchy" to supplement my TC Flashback X4.
Thanks for all the help- heres a photo of the finished re-housing:
(https://scontent-a.xx.fbcdn.net/hphotos-prn1/t1.0-9/10376938_10203116945421225_214672618374106367_n.jpg)
JAKE
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on May 16, 2014, 03:43:47 PM
Love the enclosure, knobs, and international symbols!  How did you do the symbols?  It looks like they're burned into the wood.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: JakeVP on May 16, 2014, 04:04:27 PM
The symbols were done on 1/8" baltic birch with a Universal Laser Systems 40 watt laser.  The knobs were done by hand with (From left to right) walnut, hickory, and maple
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: Jdansti on May 16, 2014, 07:44:14 PM
Cool!  :icon_cool:
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: clipman3 on May 24, 2014, 11:43:54 PM
REVIVAL
 ;D
Not sure if anyone else ha done this yet, but I added tails to my echo. Just solder pins 3&4 together on the right-most IC, the one that does the switching, on the bypass board. Picture below

(http://i1288.photobucket.com/albums/b485/AlexRGuitar/Cut.jpg)

Now, I'm not sure if it's because of this mod or because I seriously messed up the area around pins 3-7 when I was doing it, but I now have A LOT of hiss when the effect is bypassed. Not quite sure why, but I was tired of messing with it tonight lol. Proceed with caution

I'm also not quite sure if this is the best way to go about this. I didn't investigate too far, but it seemed this IC controlled the bypass switching of the pedal. There were 5 wires (two inputs) going to the delay board, as well as a few FETs that I'm suspicious of, so I'm thinking there might be a better way to do it.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: aonascimento on August 23, 2014, 08:32:16 PM
I tried going for the mod but something went wrong and I canīt say what it is.

No wet signal, just the bypass signal... even with the pedal on. Is that possible that I screwed with the PT2399?

(https://lh6.googleusercontent.com/zgiy8ywe6BFfAb9xLCZLwBfDdZ71SaNW0P6dEm2bIuqtd8hjh1bxKHMJz8bI6JOUjnN5H042k2U=w1893-h804)

Through the image it seems that the wire is touching PIN7 but itīs not.

Any clue?
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: aonascimento on August 24, 2014, 11:38:31 PM
Image url broken...

(http://drive.google.com/uc?export=view&id=0B_kWs9vfWcJwZVBrV2dvWkdqZEk)
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: magic attic on November 23, 2014, 03:19:08 PM
Very old topic but very detailed and very inspiring!

I modded a FAB Echoa few weeks ago, based on the info found here. I just made a few things differently and added more controls as follows:
- Traditional SPDT switch inside FAB Echo enclosure for the Mix Mod
- Added a stereo jack for the foot controller

Controlled by the foot controller:
- Infinity repeats mode controlled with a momentary switch
- Two selectable Delay time pots (dpdt push-button switch)
- Modulation effect using an oscillator (dpdt toggle switch)
- Factory mode (another momentary switch)

Sound sample/video here:
http://youtu.be/vomqV3gZEgg

I hope you guys like it! Cheers!
Gui

What makes the self oscillation footswitch work? I'd love to see a step by step.
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: 72Telecaster on August 06, 2015, 10:57:01 AM
Bumping this old thread -

Just did the time pot mod - glad I bought 2 of these; after frying the first (resistor trace and pin 6 of the PT2399  :icon_eek: )I dove into #2 last night.  I made sure to goop the wire right after I soldered it so it'd stay in place, which helped a lot.  I used a 100K linear pot, with wiper to pin 6 and pot lug 1 to ground...

It sounds great ! ...up to about 9:00 on the time knob (maybe 250-300ms?), where it then develops a wonky modulated sound and a loud thump percussion.  Any clue why this would be ?  From previous posts it seemed folks were getting close to 1ms before "freakout" ha.

Any help would be appreciated!
Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: fraser on April 24, 2016, 02:05:17 PM
hope im not committing a faux pas by bumping this thread-

did the mods and loved it.
have a problem when setting the repeats pot to a single slap-
gives me a high pitched squeal.
in my attempts to correct this, i modded it until it was broken, then fixed it.

first i broke pin 6 off the pt2399, just like pinkjimi did-
wasnt enough hair there to resolder, so i ground into the chip casing with a dremel and got enough exposed to make it work.
first time i ever tried that- was worth the cost of the pedal right there, though i couldve selected a cheaper victim.

also added a high cut switch and cap off the mix pot.
works nicely.

all was good.

then i tried to reverse the feedback mod, thinking that might be the cause of the squeal.
managed to wipe a resistor off. then another.
replaced them with 1/4 watt resistors and epoxied the whole mess so i cant screw it up anymore.

still have that high pitched squeal with the repeats pot backed off-
a minor irritation.

built a modulation board that sounds great with it, so ill dig further when i attempt to stuff that in there.

Title: Re: The $20 delay (Fab Echo mods photoessay) 56K warning!
Post by: blackcorvo on July 27, 2017, 12:41:39 PM
As this is the most referenced topic in regards to mods for this pedal, I thought it would be good to post about it here.
I have added the time control to my FAB Echo, and I love it! I thought I'd want to do the other mods, but I'm happy with just this one.
I simply soldered two wires in place of the resistor on pin 6 of the PT2399 (at 3AM, and I managed to NOT destroy the pads!), and ran them to a 100k Linear potentiometer, which I installed on the empty spot on the pedal:

(http://i.imgur.com/4vibG6d.jpg)

The pot I used came from a fried Danelectro Honeytone (which will become another project, very soon). These miniature potentiometers work very well for this purpose.