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Step 2: The Schematic

My schematic is largely (read: almost entirely) based upon Casper Electronics' EchoBender pedal, which is in turn largely based on Tonepad's Rebote 2.5 Delay pedal, which is in turn, more or less, based upon the example schematic in the PT2399 datasheet. Having breadboard all three, I personally can not hear a significant difference in sound between the Casper Electronic version and the one on Tonepad, which some people say is superior sounding (the one in the datasheet just sounds flat). The nice thing about the Casper Electronics version is the inclusion of a feedback pot, which gives a really full sound to the echo effect.

The things that I have changed are a few mildly significant resistor and capacitor values. The biggest difference is that I have removed the "long delay" distortion pot. This potentiometer is basically forcing the chip to under-sample the input to create a longer delay and, in my opinion, doesn't sound very good. If you like under-sampled, long-delayed, audio, by all means throw in a large (1M) potentiometer in series with the delay pot. As you may have also inferred from this, the longer the delay, the less clear the output signal; so be warned that even the "short delay" starts to degrade when cranked up all the way.

For redundancy sake, I have redrawn the schematic. I have put three image notes on my schematic to indicate parts of the circuit that have changed. The schematic drawn by Casper Electronics is much more clear and I recommend you mainly go by that one.
I experienced a lot of distortion at the output, what are causing this??
<p>What type of distortion? It could be so many things, it is impossible to say. </p>
It just sounds like I have a drive pedal after the delay pedal. No matter how much the gain knob on my amp is turned down, there will still be the same amount of clipping.
<p>My guess is there is something wrong with the wiring / components related to the opamp. It's hard to say without being able to see / debug it.</p>
<p>Thank you for helping me!</p>
<p>hello, is any way to make it with two inputs and outputs? i mean to make it stereo...</p><p>Thanks!</p>
<p>are those potentiometers linear or logarithmic? thank you</p>
<p>I believe I went linear with everything. </p>
<p>Not including the case, the pedal totals up to $28.91 when you buy parts off ebay (with about 800 extra transistors :) ) Not bad.</p>
<p>How about make a tuner next time?:)</p>
<p>GOOD JOB,,,,I LIKE THIS</p>
<p>will be hard but i will do it!</p>
<p>hi, is the feedback infinity? how much millesecons are the time? thk</p>
<p>Hello Randofo , I am very new to all this What Voltage are the Capacitors used and will 1/4 w metal film Resistors do the trick? .. sorry if that sounds dumb</p>
<p>Haven't looked at all 69 previous comments to check if someone caught this - but you have a terrible mistake in your last step. The heading should be &quot;Plug and Pray.&quot; Otherwise, nice if incredibly anal job. Much as I love tools, not getting a laser cutter anytime soon. </p>
<p>Like this pedal, thanks for sharing..I have a blog for guitar and pedals too. welcome to visit: <a href="http://www.guitarever.com" rel="nofollow"> www.guitarever.com</a></p>
<p>Hi are the potentiometers linear or logarithmic?</p>
<p>Nice Job, Pretty Pedal. It looks like you spent a good deal of time working on both the electronics and the object. Some day I should be so focused&hellip;</p><p>Question for you: I think I would like to use this IC PT2399 for a non-music project, from what you have considered do you think it would be pretty straightforward to make a circuit that is 100% wet (so just passing though the audio with a delay - no feedback, no repeats, ) with 200 or more msec delay? And adjusting the delay a la 0, 50, 100, 200, etc msec? Controlled with a micro controller? Feel free to answer any or all parts. </p><p>And again congratulations on the pedal - You Made That !!!</p>
<p>You would need some circuit or chip which can change the resistance to the delay pin via a microcontroller.</p><p>Once you figure that out, I do not see why the rest should not work.</p>
Hello! Great instructable! Can i use this pedal for a bass or it is only guitar compatible? Thank you in advance!
Thanks. That's awesome. :D
Does the IC need programming? <br>Didn't see anything much about it on here so I wasn't sure. <br> <br>Great instructable, by the way. <br>I was thinking of using this as a resource for my A Level project. :)
It does not need programming. The cheap is designed to perform this function.
chip
what is the capacitor value after the 1k resistor coming out of pin 14?
what programme do you use to open the files?
I used Corel.
having trouble finding a power jack with cut off. help please :) thank you!
This one looks like what I used: <br />http://www.futurlec.com/DCPower-ChassisMale.shtml <br /> <br />I don't remember exactly. You should be able to maybe find something at Radioshack.
where abouts did you order the parts from? i cant find the casing, the rubber sheets or the cork
The case I got from Small Bear, the cork I got from a local craft store, and the rubber came from McMaster.
Hi im delighted to find this project as i needed something for my end of year project for college, just a few questions if you wouldn't mind answering: what type of capacitors are these? e.g panasonic, aluminium? and do i definitely not need an arduino board? also, would you recommend using the full casper schematic or did you make your own for personal reasons or because it was a better layout as such than the original schematic? Thank you!
some are ceramic and others electrolytic. Usually, the dividing point is 1uF. <br /> <br />You can use theirs. I changed a few parts to my liking, but nothing too significant.
I really need your help. Your work is awesome and it'll be very much helpful to me. I'm sorry but can you put up some of your conclusions in doing this product since you're the one who've made it. I just really need it for my research. Please be kind to me. Hehe. I'll appreciate your feedback. Thank you. =)
What sort of conclusion?
What kind of lazer cutter do you have/recommend?
I have been using an Epilog. I don't have much experience with others, so cannot recommend them.
You have the whitest foot that I have ever seen.
It's almost as if I am wearing a white sock.
Inconceivable!
only my comment for this project is only the capacitor uf. has indicated. but the voltage does not. so it can be over voltage the IC and it won&quot;t work properly.. please reply me as soon as possible thanks.....
can you send to me the full schematic ??<br>thanks in advance
See the links above for more information about the circuit.<br /><br />Resistors are 1/4 watt. Capacitor voltage does not matter much... try 16v+
how many volt does cap have ??<br>what watt is the resistor.
What's the cap symbol with no indicated value after the 510k resistor? And where do you use that SPST you mention in the parts list?
5 - 10pF. You can probably even leave it out.<br /><br />The SPST switch I was using as a power switch. You can probably use stereo jacks instead of mono such that when you plug in a mono guitar cable have the extra stereo connector complete the circuit by making the ground connection.
oh! I thought &quot;better diagram&quot; meant the one you drew but with better quality. I just wanted to have a better picture of your own diagram, even tho you said that it's almost entirely based on casper one, I still wanted to look into it with its all details. I can't recognize some parts of your version of diagram because of low quality of file, even if I save it on disk and then zoom it, then the quality gets worse and I can't see clearly for example cap marks or any other detail... I'm a beginner amateur electrician so I need to study diagram carefully to get it. please let me have your version of diagram with better quality and sorry for causing so much trouble!
<br /> Let me know if you still have questions.<br /> <br /> <a href="http://www.instructables.com/files/orig/FCJ/EBN8/GA1BGINA/FCJEBN8GA1BGINA.jpg">http://www.instructables.com/files/orig/FCJ/EBN8/GA1BGINA/FCJEBN8GA1BGINA.jpg</a><br />
could you please update &quot;better diagram&quot; link? thanks!
link updated. for redundancy:<br /> <br /> <a href="http://cdn.makezine.com/make/blogs/blog.makezine.com/upload/2009/10/build_an_experimental_echo_pedal/Echobenderrev02.jpg">http://cdn.makezine.com/make/blogs/blog.makezine.com/upload/2009/10/build_an_experimental_echo_pedal/Echobenderrev02.jpg</a><br />

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Bio: My name is Randy and I founded the Instructables Design Studio. I'm also the author of the books 'Simple Bots,' and '62 Projects to ... More »
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