Fab echo.. With crazy "sweet spot" !!!

[LoFi-Ninja]

Yep I've bended on of these after seeing a thread I think it was on EA forum.. What I haven't seen is people talking about this pedals sweet spot.. Maybe because it's abit hard to find, so you need an extra pot for fne tuning.. Anyways it is CRAZY ! It's unbeliaveable what a monster this pedal can become! You wil see in the vid.. Let me see your CB fab echo please!

http://www.boutiquemusicinc.com/e-store/images/Danelectro/D4FAB.gif

This is what it looks like now
http://www.flickr.com/photos/lofininja/3337879889/

Utube vid with circuit bent keychain dub siren (please read the description)
http://www.youtube.com/watch?v=ZQczbda5Uos

Self oscillation ambient noise
http://www.youtube.com/watch?v=qtKVa_-1V64
PS: Why can't I link directly to the pics ? They won't show with [/img][/img]

[3rdness]

Yup these things are cheap and tasty!

[Circuitbenders]

You could get those delays for £3 each from CPC a few months back when they had their sale on. I bought about 5, i'm not sure if i have any left though.

[volg4]

hey, i saw this post and bought 2 of these!
been bending one, gonna do the other and re-house them, hopefully with an lfo and patchbay...

nice work!

[Simon]

Yeah, that one looks like a trip Thru time, I wonder how it sounds?. The thing is I did some simple CN work inside two synths that I have which I believe there's a thread about in this site and I found some connections where I get a completely clean sound... with a you know what. Does this Fab echo sound clean or is it just noise?(the thing is my puter won't view youtube)
Thanks
Simon

   

[Dylan]

In my earlier days of bending when I would just lick my thumb and put it on the circuit board, I found that Danelectro pedals had some awesome bends. The Daddy-O overdrive pedal has some sweet theremin style sounds in it.

[manufactured zero]

I stuck one of these into a yamaha pss140 recently. The data line mods were mildly interesting but with a pitch mod and one of these fab echo's stuck in there it became instant power noise in a box. The fact you can wire it up to process the keyboards internal sounds or an external source made an otherwise ok keyboard into a beast.

Here's what i did to mine for anyone wanting to do one. (sorry about the image quality, my phone camera is buggered)


A good project for the novice to get into with no hassles. And a some impressive results for half an hours work and £20 or so.
The 470k pot brings the pitch WAY down into clciking, dirt and disjointed noise as the delay cycle becomes longer. If you don't want such extreme depth a 100k is just as good.

[SineHacker]

I have a DanElectro Slap Echo, not the same as the fab echo and a real piece of shit as it stands, I wonder if it will yield similar results

[SineHacker]

poo i killed it I found some sweet mods, repackaged it (this took some time), stupidly used some superglue to keep the two boards in place. I tested it in the new package and found the audio was crackling and behaving oddly because of some poor soldering on the surface mounted chip, upon closer inspection i managed to break the leg off the chip. happy days :

[Gordonjcp]

Do you know what the chip is?  Sometimes it's possible to grind back the packaging of the chip and solder a fine wire onto the stubby bit.

[SineHacker]

it's a surface mounted LT2399s - I will definitely try to fix it, i need a solder remover also if i'm going to achieve anything here.

By the way Gordonjcp, after reading about 100 posts with you stating 'find datasheets on your ic's' I started doing it recently and it's significantly improved my bending experience 

I thought about trying to find another LT2399s to replace the one on the board, but it seems near enough impossible if you're not going to bulk buy them, however I did find the LT2399 (dip version) on ebay really cheap from hong kong and if you find and download the data sheet it pretty much explains how to build your own delay, it states on the sheet that you can only get like 380ms of delay though, so I was thinking of reverse engineering the fab echo to try and build my own from scratch.

also in my web wasting, I came across the FE-7 which seems to be a pretty self contained reverberation effect ic - it has some preset settings and you can control some parameters like decay with pots, also you can hook it up to a computer and program your own effects, I think it works like a phasor and some similar delay-based effects. Will post back on here with project results

[Gordonjcp]

it's a surface mounted LT2399s - I will definitely try to fix it, i need a solder remover also if i'm going to achieve anything here.

Yup.  Braid is good.  Don't worry about the chip if it's definitely fried, just carefully cut the legs away with very very fine snips or gently with a scalpel, then use solder braid to suck up the solder and snipped-off legs.  You'll need a steady hand, a good light, and a fine-pointed soldering iron.

When you go to stick the new one down, solder a diagonally-opposite pair of legs (pin 1 and pin 9, or pin 8 and pin 16 for a 16-pin chip - the latter are good because they're often power pins on logic ICs).  Get the chip square on the pads and flat on the board, and then solder up the rest.

By the way Gordonjcp, after reading about 100 posts with you stating 'find datasheets on your ic's' I started doing it recently and it's significantly improved my bending experience 

Yup.  There's a reason why I say that ;-)
It's often worth looking on the manufacturer's site for other chips that they have.  Sometimes companies will send you samples of all kinds of wee chips that do stuff like voice playback and sound effects.

I thought about trying to find another LT2399s to replace the one on the board, but it seems near enough impossible if you're not going to bulk buy them, however I did find the LT2399 (dip version) on ebay really cheap from hong kong and if you find and download the data sheet it pretty much explains how to build your own delay, it states on the sheet that you can only get like 380ms of delay though, so I was thinking of reverse engineering the fab echo to try and build my own from scratch.

also in my web wasting, I came across the FE-7 which seems to be a pretty self contained reverberation effect ic - it has some preset settings and you can control some parameters like decay with pots, also you can hook it up to a computer and program your own effects, I think it works like a phasor and some similar delay-based effects. Will post back on here with project results

You might find the same chip under PT2399 by Princeton Technology.  They definitely have things like sound effect chips.  Another company to look at is CML.  They do mostly chips for radio, tone generation and decoding five-tone beedlybeep, CTCSS, DCS and so on - but one interesting one is a frequency inverter for scrambling audio in cordless phones and walkie-talkies.  I can't remember the name offhand but at work tomorrow I'll dig it out of the workshop manual where I spotted it.  CML128 or maybe CMX128, I really can't remember.

[SineHacker]

sorry PT2399 and PT2399s is what I meant, yeah Princeton Technology, it's the chip that's doing most of the work behind the fab echo and a lot of other delay pedals I think.

the main problem is the PT2399 is thinner and longer than the PT2399S, all the pins correspond however, I will try and leave enough of the legs behind so I can just wire the replacement up methinks

I'll see if the other Danelectro echo pedal has a PT2399s in it as well, that may be another solution - I wouldn't shed any tears over hacking that piece of junk 

[Gordonjcp]

Somewhere I have a tube of ten PT2399s that I bought off eBay and never did anything with.  I should really make a batch of PCBs.

Any interest in a PT2399-based echo kit?

[the_zombiest]

I'd be interested Gordon.

I've been playing around with the pt2399s for a couple of weeks and they're great. If you could commit the schematic to a PCB it would save some crippling veroboard work.