Members fishfartz Posted May 28, 2006 Members Share Posted May 28, 2006 i remember an older thread about the fab-echo where CountZero posted this: The cost to mod the pedal for adjustable delay time is the cost of a pot and some wire. The echo is based around the PT2399 digital delay chip, which is used in a number of DIY pedal designs already. The delay time in the chip is controlled from pin 6 of the chip via a resistor to ground. Currently, there is a fixed resistor to give the short echo sound. A 100k pot in there should give you up to 1 second of delay... however, anything beyond 600ms will start to get lo-fi (this may be your thing)** ** Theoretically. I haven't done the mod yet, I'm waiting on the pot to arrive. has anyone tried anything like this? i was thinking of giving it a shot but not sure where to start. what i mean is literally im not sure which chip is the one in question and so on. this pedal is not as bad as folks say IF the set slapback time relates to the tempo you are using. however since songs often change tempo there should have been at least 100 ms worth of changing options on this pedal. i dont find it any more of a tone sucker than "common" digital delay pedals on the market....i just find it almost useless without a time control. so does this post above make sense? id be willing to try it with a little help from some of you tweakers here. im pretty handy soldering and have messed with pedals in the past, i just need to know where to start and what to do Link to comment Share on other sites More sharing options...
Members freeridstylee Posted May 28, 2006 Members Share Posted May 28, 2006 This should help. Just replace the existing resistor coming off of the 6 pin with a 1k and a 50k-100k pot to ground as shown in the general guitar gadget's pt80. lemme know how it comes out Link to comment Share on other sites More sharing options...
Members fishfartz Posted May 28, 2006 Author Members Share Posted May 28, 2006 i appreciate the reply - i see a few chips in the echo but nothing that resembles a resistor (forgive my ignorance) ill try and get a close-up pic and post it, maybe you could circle the spot im supposed to work with. ive fixed broken/non working pedals before by only by experimenting Link to comment Share on other sites More sharing options...
Members fishfartz Posted May 28, 2006 Author Members Share Posted May 28, 2006 i kind of see in your diagram what im supposed to do now - its a tiny space, it looks like if i lay the soldergun there the whole chip will melt. would it be easier to just cut the old resistor and then place the new one there? so the 1k resistor takes place of the one on pin6. so i put the new 1k resistor there and what lug on the pot do i solder the other end? am i even in the ballpark here? Link to comment Share on other sites More sharing options...
Members 3vcos Posted May 29, 2006 Members Share Posted May 29, 2006 So do these little delays sound any good? Thats a hell of a good price if I can mod the delay time (I've got those parts at home already). So are there mods for feedback,etc? Thanks,Tim Link to comment Share on other sites More sharing options...
Members bieke Posted May 29, 2006 Members Share Posted May 29, 2006 there's this mod Link to comment Share on other sites More sharing options...
Members bieke Posted May 29, 2006 Members Share Posted May 29, 2006 self oscillating mod Link to comment Share on other sites More sharing options...
Members 3vcos Posted May 29, 2006 Members Share Posted May 29, 2006 not the dan echo the fab echo (the fab echo costs $15 new!) Link to comment Share on other sites More sharing options...
Members fishfartz Posted May 29, 2006 Author Members Share Posted May 29, 2006 Originally posted by 3vcos So do these little delays sound any good? Thats a hell of a good price if I can mod the delay time (I've got those parts at home already).So are there mods for feedback,etc?Thanks,Tim they suck a little tone but not too bad for a digital delay/slap. i think it sounds OK, especially when you factor in the price. i think most of the folks who get turned off by them buy them not realizing just how limiting no time control knob can be. its great if you just need a simple quick slap for rockabilly type echoes, i think thats what this pedal is geared towards. but the moment you even think about adjusting the time is a when you start to think nasty thoughts about this little pedal you can get that waterfall echo effect by maxing the feedback, but not into oscillation. overall id say its OK, it sure eats batteries and willl darken your tone a tad - which again is great if you play bright rockabilly - no beef there. but its not totally transparent so keep that in mind. ive heard better and worse when it comes to digital. id really like to mod it for a time control. Link to comment Share on other sites More sharing options...
Members fishfartz Posted May 29, 2006 Author Members Share Posted May 29, 2006 Originally posted by freeridstylee This should help. Just replace the existing resistor coming off of the 6 pin with a 1k and a 50k-100k pot to ground as shown in the general guitar gadget's pt80.lemme know how it comes out OK i found the chip and followed the pin - is the resistor that tiny tiny square right beside it? thats about the size of a brownies dick! (anyone seen the movie "willow"?) so i replace that and then add a pot, and then ground the pot to what? sorry about the questions but im not sure if that tiny thing is what needs replaced and where to ground the new pot. if that tiny square is the resistor cant i just melt it with the iron and solder the new resistor to the melted one? Link to comment Share on other sites More sharing options...
Members freeridstylee Posted May 30, 2006 Members Share Posted May 30, 2006 well if theres anyway you can clip both sides of the small ass resistor (and i know it's crazy small, thats how they keep the cost down) then solder wires going to a 1k resisor and a pot then you'll be good. if its too small to do that, then somehow get rid of it, exacto knife it out or something. then salder directly to pin 6, then pot/resisor then to a common ground (try the input or output jacks). I havn't really seen the pedal so i can't say anything 100%, but thats the best way to go about it. let me know if it works out Link to comment Share on other sites More sharing options...
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