Hi everybody, I am new to this forum and I hope I will get some help here. :)
This is my first project and I need some help builing MXR distortion plus.
I just went to radio shack and bought almost everyuthing that I needed to build this effect.
But I am still confused about few thing from the circuit diagram.
1. How to ground a circuit in bread board?
2. Can Mxr dist + be made in Bread board?
3. I didnt find 1n741 Ics(Op amps) so I got 1n741CN instead, does that make any diference?
1. How to ground a circuit in bread board?
Just make sure all ground points are connected on the bread board.
2. Can Mxr dist + be made in Bread board?
Yes.
3. I didnt find 1n741 Ics(Op amps) so I got 1n741CN instead, does that make any diference?
I believe it should work.
Hey Aron thanks a lot. I appreciate that.
But please remember this is not the end, hehe . This is just the begining.. Question will come out in a rapid fire mode soon.
Once again thank you Sir.
Please Ignore my stupidity, but here's another question.
How do you ground a bread board? I am not that much familiar with using bread board even though I am a second year E.Enginnering student.
Hope some one will answer.
I believe it's like 4 columns of veroboard (strip board) so just connect all the ground points to the ground row
A breadboard usually has 2 rows going left-right across the bottom, and top (maybe blue and red color). The little columns of 5 holes will then go up/down. Spend 5 minutes with the continuity function of a meter and learn how they connect together, it will save you a lot of time! It makes sense after you think about it.
IC's straddle the 'line' going across the middle of the board; there's no continuity above and below this line.
Pick a left/right row, call it "ground". Hook your - terminal of your 9v battery there...all points with a ground symbol will connect to this row ;) There's your ground for the whole circuit.
Check out the beginner's forum for lots more information. This is a great circuit, and a lot of fun, so be patient - you will be rewarded! :D
Hey thanks a lots guy. I appreciate every bit of help.
I went to radio shack yesterday and bought almost everything needed for making MXR dist plus. The guy here helped me to find all the parts but at the same time he was trying to sell stuff...hehe. SO i was like "I need lm741", and he goes "Ok here Lm741CN this should work" and stuff like that. I hope that should not be a problem.
Anyway MY question is
1.Which potentionmeter should I use?
2.I am not familiar with it, but I have heard there are different type of potentiometer like linear taper, audio taper.
And i read here in the forum most people recommend replacing 1M with 500 k and 10k with 100 K. I want to do this but I want to make sure this should be easy replacement. I mean do I have to change anyother thing to replace these two Pots?
3.And whats difference between 1n271 Germanium diode and 1n271 that are found in radioshack?
4. I found three circuit schematics of Mxr distortion plus. And I dont know which one I am supposed to follow?
can Anyone suggest?
http://img133.imageshack.us/img133/1149/mxrdistpki1.jpg
OR
http://img228.imageshack.us/img228/5526/amxrdistzp7.gif
OR
http://img133.imageshack.us/img133/2097/distplusmod406ue1.gif
Any other further help on building this pedal will be highly appreciated
Thanks
5. And one more thing. I was trying to but some cables with only one metal strip inside to connect from breadboard to ,switch,jack...etc from Small Bear Electronics. But I dont know which one I am supposed to use. I dont see any pic there. Can you recommend any from this site?
http://www.smallbearelec.com/Categories.bok?category=Wire+And+Cable
6.
I was given this switch at radio shack and I doubt about it. Since this has only two terminals. Do I need another switch?
http://www.radioshack.com/product/index.jsp?productId=2049717&cp=&pg=6&origkw=switch&kw=switch&parentPage=search
1. For absolute authenticity, a 1meg reverse-log pot is needed. Most of what that pot does, though, is not of any great use. If you are not interested in "authenticity" but primarily are interested in cranking it up and rocking ASAP, buy either a log OR linear 100k pot and use it in place of the 1meg unit shown. I guarantee it will work just fine and give you 90% of what the original will.
2. For the moment, ignore the two diodes and cap to ground near the output. You will see that what you're left with is a 10k resistor in series with the output pot. In combination, the two components act like a pot that can never quiiiiiiiiiiite reach the last 10k of pot resistance. If the output pot is 10k, that's half the resistance. If the output pot is 50k, thats 1/6 the total resistance (10k+50k=60k). If the output pot is 100k, that's just under 1/10 the total resistance . So, as you increase the value of that output pot, you essentially get to conserve more of the potential volume of the pedal. Some would suggest that using a 100k output pot provides too big of a load and will make the next device/pedal in line less sensitive to what the Dist+ can feed it, such that 50k presents the best tradeoff between increase in volume without loading issues. I use 50k and can recommend it as a good replacement for the stock 10k (which you will definitely find incapable of providing enough volume boost from the pedal).
As for the 1meg pot, because of how it is wired up (as variable resistor) at some point as you rotate it, it WILL have a resistance of 5k, and 50k and 100k, and 500k, and 1meg. The question is whether ALL of those possible resistance values are of use. Just about everything greater than 100k or so will generally NOT be of much use to a great many people, which is why the substitution of 100k for 1meg is acceptable.
Though the principle underlying this is true in many cases, it is not true in EVERY case. As you go along, you'll have a better sense of when you can or can't sub one pot value for another.
3. ANY germanium diode you can find at Radio Shack (they sell 10-packs of iN34A, I believe) is fine. Some people (myself included) like the sonic changes produced by using 1N914 or 1N4148, but diodes like the 1N34, 1N60, or 1N270 will produce the stock sound. You should hear no audible difference between any of those last 3 types.
4. The first one is largely correct, though not necessarily the most pleasing sonically.
The second linked schem is correct but incomplete and really more oriented towards folks who know what's missing from the picture.
The third linked schem is not stock but is based on the original and will produce interesting and slightly different sounds.
Anyway MY question is
1.Which potentionmeter should I use?
Like Mark says, 50k is a 'right value as Vol. pot.
2.I am not familiar with it, but I have heard there are different type of potentiometer like linear taper, audio taper.
3.And whats difference between 1n271 Germanium diode and 1n271 that are found in radioshack? Use either/try both [V little if any diffy].
4. I found three circuit schematics of Mxr distortion plus. And I dont know which one I am supposed to follow?
can Anyone suggest?
http://img133.imageshack.us/img133/2097/distplusmod406ue1.gif
I'd start with this one, for breadboard though, I'd start by getting the 'basic circuit' without the TC, bypass and Indicator..adding later as necessary
5. And one more thing. I was trying to but some cables with only one metal strip inside to connect from breadboard to ,switch,jack...etc from Small Bear Electronics. But I dont know which one I am supposed to use. I dont see any pic there. Can you recommend any from this site?[ I'm not sure I follow...link isnt' working.
http://www.smallbearelec.com/Categories.bok?category=Wire+And+Cable
6. I was given this switch at radio shack and I doubt about it. Since this has only two terminals. Do I need another switch?
http://www.radioshack.com/product/index.jsp?productId=2049717&cp=&pg=6&origkw=switch&kw=switch&parentPage=search
You'll need a DPDT for TB, or 3PDT switch for True Bypass W/indicator LED.
Aron sell's 3PDT Blue, quick ship too.
http://img133.imageshack.us/img133/1149/mxrdistpki1.jpg
I quite didnt understand the resistor being 1/6th and 1/10th the total resistence.
But in simple way, isnt the differerence between 100k and 10 k is that -
10 k lets you start your gain from less gain(clean) and as we increase the gain to max it will have the same gain as 100k but we will have less presision as we will have large range.
And 100k will start its gain from more dirtier (more gain) and as we reach max it will have same gain as 10k but since the range is less we can set out setting more precise
That was just my take?
Am I right? Correct me if I am wrong.
Thanks to "Mark hammer" and "Petemoore"
I appreciate.
@ Petemoore
I am sorry looks like the Small bear electronics site went down for few mins. It is working again NOW.
And do you have any pic of the one that Aron sell? Whats the price?
@ Mark Hammer
So that means get -
100k reverse Log/Linear pot for 1Meg (or is it 500k for 1 M?)
50k reverse Log/Linear for 10K
Right? Just want to make sure before I but it now.
Can please anyone answer my questions above? I am waiting so that I can go ahead and buy.
At the same time One more question
Do I need stereo jack? OR can I go ahead with Mono?
Get a 50k log pot for the output volume (instead of 10k), and either a 100k log or linear pot for the gain/distortion control (instead of 1meg reverse-log). Both suggestions assume you aren't trying really hard to have an "authentic to the last detail" unit.
Re: 1/6, 1/10, etc....
The 10k resistor that is connected between the output cap and the volume pot is simply more resistance that the signal has to pass through. Volume pots act by dividing the voltage. The voltage available at the wiper of the volume pot is a function of the total resistance on one side of the wiper, divided by the total resistance on the other side. The pot acts as a variable voltage divider but it is no different in function than a fixed voltage divider. Look at your first or 3rd linked schematic and you will see that +9v goes to a pair of 1meg resistors and what is available at their junction is half of 9v (i.e., 4.5v). Think of THAT like a 2meg pot with the wiper exactly halfway.
Okay, now consider that the circuit itself doesn't really care of the resistance on each side of the wiper is sitting inside the pot or outside of it. It's ALL just resistance to be divided up into the this-side and that-side portions. If we have a 50k pot with 10k of additional resistance soldered on one end, then rotating the wiper aaaaaaaaaaaall the way over to that end still will not be able to place the wiper past that juncion between the added resistor and the pot lug. You will always have 10k sitting outside the pot. So, with the wiper fully rotated, there will be 50k of resistance between the wiper and ground, and 10k more on the other side of the wiper. Add 10k and 50k together, and what you have is functionally no different than a 60k pot that can never quite reduce that last 10k of resistance to nothing.
Again, keep in mind that since the possible volume from the pot is a function of how much it divides down the voltage fed to it, zero-ohms divided by 60kohms produces NO reduction of the signal. Actually, let me change that, it's 60k, divided by 60k (=1). If our 60k pot consists of the 10k "external" part and 50k "internal", then the signal can never reach more than 50k/60k or 5/6 of its maximum value.
This principle of how-much-can-you-dial works on both ends of the pot. For instance, if you look at the schem for a Big Muff, you'll see that there is a small value resistor between ground and the ground side of the "Sustain" pot. Why is it there? So that the signal can never be dvided down to absolutely nothing. That tiny resistor assures that even when the wiper is rotated to the 7:00 position there is still just a liiiiiiiiittle bit of resistance to prevent the entire signal being divided away and bled to ground.
Note that this principle works with variable resistors (two lugs used, no division "ratio" implied) as well as voltage dividers (where ratio of one side vs other side of wiper matters). In series with the gain pot is a 4k7 resistor. Does it HAVE to be 4k7? No. The total resistance obtainable on the path, when the pot is maxed is the sum of that resistor and the gain pot (whether 1meg, 500k, or 100k or whatever you bought), and the minimum resistance attainable is the value of the fixed resistor (4k7). the gain of that Dist+ circuit increases as the total resistance on that path gets smaller. Stock, the max gain is set by the 1meg feedback resistor and the 4k7 resistor ( [1meg+4k7]/4k7 = x213). If a person changed that 4k7 for, say, 3k9 then the max gain would be [1meg+3k9]/3k9 = x257. Dropping it further to 3k3 gets a max gain of x304, and so on.
On a number of modulated pedals (i.e., those with any sort of cyclical change), the LFO/sweep-generator uses a variable resistor in series with a fixed resistor to set the speed. Using a similar principle to what has been discussed here, you could easily alter the range of speed values by changing either the pot value, the series resistor, or both. Let's say we have some LFO circuit that used a 500k pot in series with a 4k7 resistor, and you found that you had little use for most of the range of speeds. It would not be inappropriate at all to replace the 4k7 with a 10k resistor, and the 500k pot with a 250k or even 100k pot. Those two changes to maximum and minimum combined resistances would eliminate the slowest and fastest speeds from the stock circuit, and would allow the pot to have finer control of a narrower range of speeds more desirable/useful to you.
Again, the lesson is to learn to think about the total resistance or resistances involved, and use that to tailor what you want the device to do for you..
Once again Mr. Hammer comes to the rescue on this classic circuit. I just finished mine using a 1M audio pot wired backwards for the gain control.
Good luck with your build, it's a very cool pedal.
I do have one question though, what Radio Shack sells 1n34's? I have never seen them at any of my local Rat shacks here in southern california.
Scott
Firstly Salute to metal hammer. Thanks for your tremendious help.!
@ burnt finger
No I didnt find 1n34's at radio shack. SO i am going to buy it from small bear electronics.
I think I should keep in touch with you for help. ;D
At the same time which wires should I get for connecting battery,swtich,jacks?I am looking for wires with only one metal strip inside.
Are these what I am looking for?
http://www.smallbearelec.com/Categories.bok?category=Wire+And+Cable
Another question -
1>
Are LED rated? OR can I use any led for this project?
I was just trying to fiddle around trying to make LED lit.I used 1.5 battery and connected a 2.2k ohms resistor in series and tried to lit it.BUt it wont?
WHy is that?
DO I need 9v battery?
2>
I am thinking of using 9v battery outlet of an AC adapter for this project. Will it work? OR is it necessary to buy a 9v battery
I would use a 9 volt battery since this is your first test build. I guess I need to make the STORE link bigger in the future. :(
Thanks Aron for your info.
And where am I supposed to but Potentiometer that Mark hammer suggested? I looked in radio shack , small bear electronics, and other few online stores and couldnt find it.
Does anyone know some specific site?
Hmmm No body answered my question :'(
I have one more question. What type of capacitors are needed for MXR distortion plus. That radioshack guy gave me all ceramic capacitors (Beside one was taltanum). Is that what I am supposed to use? Or is it electrolytic Capacitor?
Anyone?
Well, you need know how to identify the different types of capacitors in the circuit. The DIY FAQ has a lot on this and the beginner forum has a schematic and how to identify parts/connections etc...
Any 1M pot will do as Mark pointed out. If you must have a 1M audio taper pot, you might need to order away from Mouser.com or Small Bear.
Please take the time to read the DIY FAQ (also linked above). It will help you A LOT with your project.
No one has said this, but the MXR distortion plus is NOT what I would recommend as a beginner project at all. You really would do much better trying the beginner project or a really, really simple booster.
Hey Aron thanks a lot for helping me to clear some confusion.
I went through beginners guide that helped me a lot.
But after going through Few pages of FAQ pages, few confusion still arouse.
1>
In this MXR distortion schematic can you explain how does dpdt works? In the FAQ page it says at one position it routes from input>fx> output and in another position input wired staight to output. But this mXR had led so can you explain in few line how does connection happen in either position. If possible please draw small diagram of dpdt connection in paint brush.
http://www.freeinfosociety.com/electronics/schematics/audio/pictures/mxrdistp.gif
2>
It is necessary to get stereo jack for input? or can I still work with mono.
According to FAQ page Stereo jack allows to turn power on/off with input jack. What will happenif I use mono? What would be a remedy here?
3>
According to FAQ pages capacitor from 1 uf and above should use Electrolytic caps. But I bought ceramic caps for all the caps that I needed. WIll it be a problem (beside one was taltanum).
4>
just wanted to make sure Audio taper pots = Logarithmic Pots? right?
5> I am going to buy few more things that I needed for this project from small bear electrnics . Can you please check they are the right ones
Qty SKU Description Price Total
2205 Diode 1N4148
$0.15 $0.30
1300 Capacitor Silver Mica 500V 10 pf. - 150 pf.
(10 pf.) $0.55 $0.55
2201 Diode 1N270
$0.75 $1.50
0203 Switch - Alpha 107-SF12020-L DPDT
$4.95 $4.95
1006 Pot Alpha Single-Gang Audio Taper 16mm
(50K) $1.25 $1.25 .
1006 Pot Alpha Single-Gang Audio Taper 16mm
(100K) $1.25 $1.25
0602A Jack, 1/4 in. Stereo Neutrik #NYS230
I would really appreciate if anyone would answer these questions.
new to building, but want to help where i can... ;) i believe there are 3 types of pots, log, audio, and linear. ALL can be interchanged, but the results of how smoothly you can control whatever you are trying to control will be afftected by which type you use. check out geofex.com's tutorial called "the secret life of pots" for more info.
http://www.geofex.com/Article_Folders/potsecrets/potscret.htm (http://www.geofex.com/Article_Folders/potsecrets/potscret.htm)
as for the LED, you can't have true bypasswith an LED without either a 3pdt switch or a millenium bypass circuit with a DPDT. I believe with the MXR you should use a 3pdt switch if you have on available, especially if you are gong to mount this in a box similar to the original MXR boxes (which if you are like a gajillion other people, you will be using the Hammond box that almost exactly replicates the MXR box). The extra bypass circuit would take up a little more space in an already cramped enclosure.
http://www.geofex.com/FX_images/stompsw.gif (http://www.geofex.com/FX_images/stompsw.gif)
http://www.geofex.com/Article_Folders/Millenium/millen.htm (http://www.geofex.com/Article_Folders/Millenium/millen.htm)
for more info, check out geofex.com, lots of info on creating bypasses and using LED's. other than these two options, I know of no other way to incorporate an LED and still have true bypass.
Hey firstly thanks for your help.
I went through those pics before but was bit confusing to em as I am a begginer. I am not looking for True bypass so I think i will go with dpdt.
And in that Pot article it says "Log or Audio" and Linear. So I though Log and Audio are the same type. Isnt that right?
I just now found out that for one of the 1mf capacitor with polarity shown that roadio shack guy gave me tantalum capacitor will that be fine?
And also please answer my Previous post. I am waiting for it.
Thanks
I am still waiting hoping for some one to answer :)
The skinny on capacitors is this:
Although the type of capacitor used will usually affect what type of sound you get, as i understand capacitors you can interchange any type for any type.
for example, if you get a polyester film .01uF cap, it will functionally operate the same as a ceramic disc version of the same value. However, some people prefer the sound one gets from particular types. the different materials used have different responses to the voltages, resulting in differences in sound to some ears.
be careful though. if you ever substitute an electro;ytic capacitor in place of a non-polarized cap (polyester film, metal film, ceramic disc, etc.), you have to make sure that the pos. and neg. of the electrolytic caps are facing the right way. bad things happen otherwise....
Thanks once again that helped to clearify one question.
I appreciate
here are the remaining question Once again.
1>
In this MXR distortion schematic can you explain how does dpdt works? In the FAQ page it says at one position it routes from input>fx> output and in another position input wired staight to output. But this mXR had led so can you explain in few line how does connection happen in either position. If possible please draw small diagram of dpdt connection in paint brush.
http://www.freeinfosociety.com/electronics/schematics/audio/pictures/mxrdistp.gif
2>
It is necessary to get stereo jack for input? or can I still work with mono.
According to FAQ page Stereo jack allows to turn power on/off with input jack. What will happenif I use mono? What would be a remedy here?
4>
just wanted to make sure Audio taper pots = Logarithmic Pots? right?
5> I am going to buy few more things that I needed for this project from small bear electrnics . Can you please check they are the right ones
Qty SKU Description Price Total
2205 Diode 1N4148
$0.15 $0.30
1300 Capacitor Silver Mica 500V 10 pf. - 150 pf.
(10 pf.) $0.55 $0.55
2201 Diode 1N270
$0.75 $1.50
0203 Switch - Alpha 107-SF12020-L DPDT
$4.95 $4.95
1006 Pot Alpha Single-Gang Audio Taper 16mm
(50K) $1.25 $1.25 .
1006 Pot Alpha Single-Gang Audio Taper 16mm
(100K) $1.25 $1.25
0602A Jack, 1/4 in. Stereo Neutrik #NYS230
heh, sorry. I think (here is my novice showing through) that if you aren't after true bypass, you can wire the + LED lead to a 9v+ point on the board and vice versa for the ground lead, that way whenever there is power to the board the LED would light up. however, I also think this could affect the operation of your circuit, as the voltage drain might mean necessary adjustments in the values of the other components. once i again, i recommend building a true bypass. Other board contributors, tell me if this is correct, I'm sort of guessing here. not taking into account the LED, the FAQ is dead on.
You can use a mono jack instead of a stereo on the input, but you will not get the functionality of the effect only being on when you have a plug inserted. All this means is that the effect powered on will stay on (and drain battery) whether the guitar is plugged in or not. However, it won't affect the circuit one bit otherwise. Just connect the mono jack in the same way the other jack is wired, only to the input stuff instead of output stuff.
I'm still not sure myself about the log s. audio pots thing, but i DO know that the effect will work either way. It seems like I remember seeing 3 different descriptions of pots, but maybe I'm wrong. Only been building circuits for about a week.
at a glance the parts list looks fine.
Guys Is this wire or heat shrink tube?
http://www.smallbearelec.com/Categories.bok?category=Wire+And+Cable
I was going to buy it but I am confused. I needed cable for connecting pots, jacks and other parts.
Please some one answer.
I see many products on that page including shrink tubing and wire.
I mean the first few ones.
Like
Heat Shrink Black 1/16 [.063] diam. - 1 ft.
Heat Shrink Black 3/32 [.093] diam. - 1 ft.
Heat Shrink 1/8 [.125] diam. - 1 ft.
Heat Shrink Black 1/4 [.250] diam. - 1 ft.
Heat Shrink Black 1/16 [.063] diam. - 1 ft.
1/16'' for little wires, 1ft. length black heat shrink...
Heat Shrink Black 3/32 [.093] diam. - 1 ft.
Smaller Diameter for skinnier wires
Heat Shrink 1/8 [.125] diam. - 1 ft.
Thicker
Heat Shrink Black 1/4 [.250] diam. - 1 ft.
Would be used for like guitar cable wire, you could get 6 x 2'' pieces.
So they are wires? Not heat shrink tubes?
Few more questions
1>>
How do you wire a pot. Accoring to FAQ page it says they will be numbered in schematic but in mxr dist + is not numbered . Can anyone help?
2>>
This guy has Op amp attached to the board which has parallel connection .Isnt he shorting the Opamp here?
http://img227.imageshack.us/img227/3121/mxrdistplussizedba3.jpg
The little red squares signify a cut on the copper strip so that the pins on the left and right sides of the chip are not connected together. That is the principle behind vero-board: they give some common connections by virtue of the thin isolated rows, and you the user further specify what you do and don't want connected by cutting those rows.
I don't mean to be discouraging, but from your questions it is starting to sound like you need to start simpler. That is not to suggest for one minute that you WON'T master all this stuff in a couple of months' time, but the general strategy is to point people towards projects that they can successfully build in a short time period, with a minimum of troubleshooting. Presumably, there WILL be problems along the way, regardless of how simple the project is, but they ought to be easily solvable ones, and the builder shouldn't find themselves thinking "Why on earth did I get myself into this?", while they stare at the $60 worth of stuff they purchased from here and there that isn't doing anything at all for them. During an era when you can stroll into a music store and buy a Danelectro chorus, echo, flanger and distortion pedal for about the same amount of money as what you have to lay out for your first full pedal, every extra week you wait until you get all your troubleshooting questions answered and the pedal working will make you wonder even more if it was such a good idea to leap into the deeper end of the pool.
Again, a VERY big welcome to this hobby. Just don't get yourself into anything that makes you regret that decision.
Thanks Mark , I appreciate your suggestion.
Probably that was my mistake I choose harder one than I supposed to. :)
But since I have bougght everything for this pedal. I will finish it. I sure am not going to be disspointed, even if it takes month to complete it.
I want to get into pedal designing seriously, thats the reason I choosed E . Engineerng. Ofcourse I am just a sophomore now.hehe
But still I hope guys here will help me to complete this project.
Once again cheers to everybody who has helped me till now.
Thanks.
Thi is what I am exaclty confused about.
In this picture it relates dpdt switch either connects top 4 terminal or bottom 4 terminal.
http://www.diystompboxes.com/pedals/articles/elbypass.html
and I followed how the signal flows.
But now I look in this pic. DPDT switch seems to be different. Does it conenct top 4 in one position and botttom 4 in another position?
http://www.generalguitargadgets.com/diagrams/switch_lo_dpdt_led_out.gif
Can some body explain?
Hi Izzy, welcome again :) Like R.G. was saying, going simple at first will really save a lot of headaches! Plus, you'll more fully understand why things are done the way they are!
What I suggest for you is this:
Build the MXR on a breadboard. Don't worry about the switch or LED right now...just get it on there working, to test that you understand HOW it works. That means all you need is 1 wire in, and 1 wire out (to your jack tips)...the other side of the jack (sleeve) goes to ground on the board. The +9v goes to the op amp power pin. This way, you can plug your guitar and amp in, and play with things! I've found that the switch and enclosure are the hardest parts of the whole thing, where most mistakes happen. Doing it all at once increases chances of it not working, and you not knowing why! And if you solder it up right away, you can't play with caps and diodes as easily. ;) I build each new effect this way, so I am sure of it before I make it permanent.
After THAT, then you can get a PCB or build it on perfboard or vero...and add that nice switch and LED, and get it in a box....which are challenges again!
If you have a multimeter, you can play with any of these switches to see how they work....just test for continuity on the pins, throw the switch, and note how it changed. Some bypass schems use a different way of hooking it all up, but they all work. Paying close attention to the fundamentals of audio electronics will pay off big-time later on...you certainly have the motivation! Reading electronics books and doing breadboard work is where I (and many of us) started, and is a GREAT way to learn!
Good luck!
Mike
They are two different ways of accomplishing the same thing. There are certain advantages to using the second one under certain conditions, but for most uses there is no sonic difference between them. Since you are starting out, I would say to use the first method rather than the second, simply because it is visually easier to follow, especially if you use a 3PDT and want to wire up a status LED..
@ Gibson GM
Yes Sir I will try to follow your suggestion. I appreciate your help.
Yeah and please be around I might still have some more question Even If I do the easier way like you said ;D
@ Mark Hammer
Thanks Once again. All my remaining parts should arrive in few days I will let you know If I have any more questions.
I still think you should try and make a simple circuit work on the breadboard first. The MXR is really too complicated without some kind of breadboard "layout". There are too many things that can go wrong.
Yes, I am going to do this in bread board. Infact I did it yesterday night which became too messy because of the long leads of resistor and capasitor.
I am going to do them again by cutting them. ;D
Main problem was the berad board was too small. >:(
Oh boy, you are determined, Izzy, LOL! :icon_mrgreen: I do believe you'll get it going.
I took a minute and edited R.G.'s MXR schematic (link below), removed the switching etc. so you can just follow it to get running on a breadboard easily. Quick Note, tho - I request that someone QA's this before you begin! Aron, have a look? I omitted the switch, and made battery connections direct.
Thanks.
Mike
http://i92.photobucket.com/albums/l9/generalguitar/MXRsimple.jpg (http://i92.photobucket.com/albums/l9/generalguitar/MXRsimple.jpg)
Hats Off to you!
Thanks !!!!
Yes it definately made easier to under stand.
One question though.
I am trying to use Ac adapter for power supply through 9v battery connector cable.I guess that shouldnt be any problem right?
By the way. I reconstructed it again. Might look messy but still see if you can advice anything.
This is just halfway done. Few more circuit parts should arrive soon. Then I will show you again
(http://img174.imageshack.us/img174/6586/dsc00007gr3.jpg)
hmmm he might get it going. ;)
The schematic should probably say zero volts instead of -9.
Looks ok though to me.
True, Aron, LOL...since "-9v" IS "MINUS 9 volts"....I shoulda put "- battery terminal". Good enuff for our discussion & 4 minutes editing.
Wow, Izzy, that is NEAT!!!! Much nicer than my usal Rat's Nest!! I believe you have the idea. You'll get it up and running. :icon_cool:
Using a 9v adaptor is fine, as long as the voltage, current requirements and polarity are correct. This is not a very critical circuit.
Maybe setting up the 2 jacks you'll need with wires soldered to them would be helpful...or just use jumpers if you want. I always temporarily solder 3 wires to each pot, too, for breadboarding.
It's coming right along...barring any wiring mistakes, awesome! ;D
Hi guys I finally got my remaining circuit element .
But Smallbear electronics didnt label anyone of them.
So I am having lil hard time finding out which one is which.
I got Ge 1n271 diode. But which one is positive and which one is Negetive end.
I think the one side with bigeer metal piece inside is Cathode. But I want to make sure!
On the lower end of glass its lightly dark color.
Please help me to make sure that it is cathode.
And also I had ordered 10 pf Caps. The one they sent me doesnot have any labels. How can I be sure its the one with 10pf?
(http://img353.imageshack.us/img353/3973/dsc00008gu9.jpg)
Can please some one help me here?
the dark end should be situated in the direction of the black band in the schematic. i believethat makes it the cathode.
Ignore my above post.
I tried to run it today. Damn and it didnt worked. I dont know why?
I didnt want to use bread board it makes so confusing.haha
Now how could I debug? Or can anyone see where I am doing wrong?
I tried to find mistakes but I couldnt.
I have Radio shack 20$ multi meter but I dont know how to check for continuity?
I would be so glad if anyone would look at these pics and possibly find out error? May be? ???
I am using adapter here for 9v through battery connector.
Does anyone think changing polatiry of the adapter will help?
I am scared to try that without some one gives me green signal..
I am waiting for some helpful post.
Please anyone..
(http://img237.imageshack.us/img237/1064/dsc000072wh1.jpg)
(http://img237.imageshack.us/img237/1183/dsc000082oo5.jpg)
(http://img237.imageshack.us/img237/6476/dsc00010vj9.jpg)
(http://img237.imageshack.us/img237/7237/dsc00009hh9.jpg)
Yeah and this was based on these two schematics.
http://www.tonepad.com/getFile.asp?id=4
and
http://i92.photobucket.com/albums/l9/generalguitar/MXRsimple.jpg
DAMNNNNNNNNNNNNNNNN
IT WORKEDDDDDDDDDDDDDDD
Sorry Volume was turned down before..hahahah
I am SO happy
Thanksssssssssssss to alllllllllllllll
Hi Izzy, good work! It's late here, but check what I've circled, should be 4.7K (yellow violet red, can't tell if it's red or brown in your pic). I can't see the connection for the 1M gain pot there, either. The purple wire is the feedback loop, to the 1M resistor and pF cap, right?
Red circles on 1 M resistors...these connect together; please fix. 1 end of 1 goes to +9v, the other end of both goes to ground (seems ok to me from what I can see). The 1uF cap connects to the junction of them, and goes to ground. This is your biasing setup.
With your meter, measure 9v at your power in...connect black lead to power supply ground, probe with the red lead. Set meter for "DC volts". You oughtta get 9v on the other power supply lead. Next, leaving black probe connected to ground, check the junction of the 2 1M resistors...you should get about 1/2 your supply voltage (around 4.5 V). You should also read this at pin 3 of the IC. You should have 9V at pin 4, and just about zero at pin 7. All ground points should be about 0, and all +9v points, of course, +9v. (I'm not sure if your lower row is all ground, or mixed + and ground, check those connections!).
Please post those voltages, that will get you started! And another pic, maybe edit the pic to say "input tip" "output tip" "+9v", "-9V", "to 1M gain pot" etc; that will help us diagnose the problem!
Keep it up, you're getting close...but I have to go to bed! Someone will help; I'll check back tomorrow...work on getting power to the IC, and the correct bias to the inverting input pin...
;D
(http://i92.photobucket.com/albums/l9/generalguitar/MXRtest1.jpg)
Hey, ALLRIGHT!!!!!!!!!!!! :icon_razz: Good work, Izzy...you will enjoy your new toy!!
Next, we will go over how to perfboard the thing, and connect a switch! I'm glad we didn't have to go thru too much debugging, LOL.
Happy Playing!
Mike 8)
Sure Sure. I woul be very happy if you could give me some knowledge on how to use LED using DPDT (Non true bypass).
Yeah one more thing I am getting some hummmmm
How to reduce it?
Yeah one more thing I am getting some hummmmm
*Could just be the open circuit spread over the breadboard.
Once it's covering less area, it should become less of an antenna, also inside a shielded box tends to reduce noise.
Thanks Petemore.
@ GIbsonGM
Yes Sir I checked the 4.7k resistor, and I think its red. Even though it looks like redish brown, It should be red I just checked the packet and its 4.7k.
And about those 2 1M resistor, I checked it again and I think its right. I guess the picture was confusing. ;D
I have drawn the flow on top of the pic. I think it should be right. :)
(http://img87.imageshack.us/img87/9343/dsc000082cq0.jpg)
With your meter, measure 9v at your power in...connect black lead to power supply ground, probe with the red lead. Set meter for "DC volts". You oughtta get 9v on the other power supply lead.
[/quote]
Quote from: GibsonGM on October 03, 2006, 01:19:00 AM
Hi Izzy, good work! It's late here, but check what I've circled, should be 4.7K (yellow violet red, can't tell if it's red or brown in your pic). I can't see the connection for the 1M gain pot there, either.
Ohhhh Now I see what you are saying.
Sorry , Then I think it is brown. Thats why I was wondering "why this red looks like brown to me???"haha
That mean it is 470 Ohms not 4.7 k. Damn I must be misread it while buying parts.
So whats the effect of being .47 k in place of 4.7 k??
I would love to know...
I would pop the resistor out of there and measure it with your meter (and get used to doing that, LOL)...you do have ohms, current, and continuity testing on there, don't you, Izzy? Having a lower value resistor in that particular place will just make your 1M gain pot have that much "more" effect...4.7K is the minimum value for the leg of the ckt there, and you've made it even lower. In this pedal, it will probably just not sound as good until you get your gain pot up to 4.3K. No big deal here; just change it before you solder the board up. You did it right; or it wouldn't work! I see nothing else wrong that jumps out at me.
See if you can get a big Radio Shack package of a variety of resistors...they have them in ALL the common values, 1/4watt, you won't need to buy any more for a couple of years, only like $12...I check most resistors w/my DMM before installing just for the heck of it. In some places wrong values can burn things out.
I like that you drew on your breadboard pic w/colored lines..makes it easier to answer questions!
To see what everything does in action, make an audio probe (search in forum for how to) to use with your amp. You can then test the signal path all along the circuit to see what changes are happening, esp. after the op amp before and then after the diodes! Don't probe the power supply or grounds, tho, makes UGLY noises (don't forget a blocking cap on the probe!!). ;D
Ok sir I will try to get 4.7 k Resistor when I go to radio shack.
I didnt quite get this, can you explain
QuoteWith your meter, measure 9v at your power in...connect black lead to power supply ground, probe with the red lead. Set meter for "DC volts". You oughtta get 9v on the other power supply lead.
I do have this small multimeter. But I dont know how to use it.hehe ;D
I think I should learn it.
http://www.radioshack.com/product/index.jsp?productId=2103174&cp=&origkw=multimeter&kw=multimeter&parentPage=search
See if you can find if it has connectivity test.
And I am thinking of using plactic enclosure box that I bought from radio shack
http://www.radioshack.com/product/index.jsp?productId=2062281&cp=&pg=3&origkw=enclosure&kw=enclosure&parentPage=search
It is safe to use this box for enclosure? COz one of my friend was telling me that I need to use Metal box for enclosore so that it will have ground and it can also shield the circuit. Is it true?
Quote from: Izzy on October 03, 2006, 11:06:01 AM
And I am thinking of using plactic enclosure box that I bought from radio shack
http://www.radioshack.com/product/index.jsp?productId=2062281&cp=&pg=3&origkw=enclosure&kw=enclosure&parentPage=search
It is safe to use this box for enclosure? COz one of my friend was telling me that I need to use Metal box for enclosore so that it will have ground and it can also shield the circuit. Is it true?
Many companies use plastic enclosures successfully. Sometimes even "big names". Keep the following guidelines in mind:
1) Plastic works best when it is small. That increases its rigidity.
2) Many people like to use the stompswitch to snuggle the battery against the end of the box. With plastic, you need to swing that around so that the switch is as close to the edge/wall of the box as you can comfortably manage. That will provide the added stability so that the case doesn't crack when you step on it.
3) Plastic is fine for experiments and home-playing, but not really for gigging.
4) Metal chassis DO provide helpful shielding, but the shielding can be provided by additions to the box (I buy sheets of copper shim and cut out cover plates the size of the top, secured to the chassis by the pots.) Buzz and other interference can be reduced by having short, well-planned leads to your pots, switches, and jacks, and by using shielded wire at least from the input jack to the circuit board.
Hmm so that means its better to use Metal box rather than plastic box for making it less noisy?
So which one you think will be better?
One of them is Plastic box(black) from radio shack. Another one is Tin box .
http://img107.imageshack.us/img107/9209/dsc000073gt2.jpg
I want this pedal to be very less noisy As I need this pedal for Home recording purpose.
One more question.
Which one of these board will be easier for this project?
I guess the second one right?
http://www.radioshack.com/product/index.jsp?productId=2102845&cp=&pg=2&origkw=breadboard&kw=breadboard&parentPage=search
http://www.radioshack.com/product/index.jsp?productId=2103799&cp=&pg=2&origkw=breadboard&kw=breadboard&parentPage=search
Your best bet is to get a metal box thru Smallbear Electronics, link on the link page here. $10, you get a real effect box that'll last forever!! I get the 2nd smallest size metal (NOT Hammond 1590 or whatever size). Read up on it! You will not be disappointed. Metal is easier and quieter for SURE.
Watch out for Radio Shack, my man...resistors & parts are fine to get there ( a little expensive). Meters etc. aren't very good. I can't even find any specs for the meter you have from the web site! I have a nice Extech DMM I got online, for like $50. Does a lot, incl. measuring frequency & temp, and auto-ranges. And I have an old RS meter that measures transistor gain.
Click each function on your meter, and touch the probes together. If you find a setting that goes "BEEP" when you do that, that is the continuity test ;o)
If you don't have that, use the ohm function (the Omega-sign "horseshoe", I'm sure you know)....when you touch 2 connected items, it will read "0" or ".1" or something incredibly small. Try it with a piece of wire to see when 2 things are definitely connected :o)
----get the 417 holes multi purpose, NOT THE IC BOARD!!!! I always use the 1st one you posted; it resembles the breadboard and is easier by far. ANd get a 2-pack of 8-pin DIP sockets, so you don't have to solder the LM741...
did anyone catch that Izzy called Mark Hammer "METAL HAMMER" on page 1? Just thought that was awesome....
and Izzy, you'll find that RS is not super-useful for what we do... but the DIST + was my very first project as well and I still use it! very flexible circuit, and I tried a lot of different clipping options... make sure you do that :)
@ GibsonGM
Thanks once again sir.
Actually i have already bought 417 Multipurpose board yesterday. Just want too sure that is the right one.Thanks for clearing things up.
And yes I already got IC sockets.
Now that Multimeter doesnot has connectivity thing. How sad!
No BEEPS..haha I think I should Return this multimeter.
The reason I didnt want to buy hammond is I will have to buy driller and Bits for it which will cost and extra box($10)+driller ($30-40) + bit($5)
haha So i was trying to go cheaper way. ;D
Anyway sir do you mind giving some idea how to connect dpdt swicth with LED? ;D
which one you think will be better?
One of them is Plastic box(black) from radio shack. Another one is Tin box .
http://img107.imageshack.us/img107/9209/dsc000073gt2.jpg
I want this pedal to be very less noisy As I need this pedal for Home recording purpose.
QuoteAnyway sir do you mind giving some idea how to connect dpdt swicth with LED?
The beginner project, the FAQ and the WIKI have info on how to connect circuits to a DPDT switch with LED.
Izzy,
I really mean no offense here, but you need to do some of this for yourself. All of this has been done before and is available in the FAQ, the search function, on GEOFEX, AMZ and a lot of other places. If you have people hold your hand through out the whole project you aren't going to ever learn it for yourself.
Good luck,
Jay Doyle
Thanks for your sugegstion sir.
Yes I did checked in FAQ. But I still had confusion, so I was looking for help.
I am still learning so please ignore my stupidity.
And Yes I will try as you said Sir.
But I need one rroe help, before I return this Radio shack plastic project box.
which of these box will be better for pedal?
http://img107.imageshack.us/img107/9209/dsc000073gt2.jpg
The black plastic one(Radio shack) or the Tin one?
pedal parts plus dot com has reasonable boxes... $5 for a box that would be perfect for that... shipping is cheap. a metal would be better...
Go for the metal since you want to use it for studio work.
Thanks
I will check it. But still not sure whether I am going to spend more$ in this pedal or not. Already spend $110+ for a 80$ pedal. Sounds crazy..haha
And finally I figured out how to use dpdt using LED.
But there is a significant amount of Hum?noise. How to get rid of this?
Yes I will definately go through other threads but if you have any suggestion please POst it.
Take my advice, Izzy, LOL...get a metal box from Small Bear or another suggested site. You could get the pre-drilled one, but most everyone finds it easier to get one with no holes yet, and put the jacks above the volume/gain pots (top side), not on left & right sides. To drill them, you just need a set of cheapo bits and a hand drill. You start by punching where you want the center to be with a nail, and use 1/8" bit. Then something a little larger, and so on. It's soft aluminum and I always get GREAT results using them. You're putting a lot of effort into this project...you should build it to last! I wouldn't use plastic or tin. Plastic can work, as M.Hammer said, but that's a more advanced subject (shielding). Tin will fail...takes us to #2...
2. You're likely getting some hum from lights in your house, a tv or monitor nearby...when the ckt is on the breadboard it's not shielded (just like if it was in an improperly shielded plastic box ;) It picks up any interference in the air (RF, 60Hz power hum...). Provided it is built properly, when you get it in an enclosure, the box provides all the shielding from that that you'll need.
3. You'll need a 3PDT switch (again, Small Bear) to have the LED, or a DPDT for no LED. I made mine without - I know when it's on, and it's almost always on ;) You COULD make a millenium bypass, but at this stage, a bit much to try to tackle (let's get it in the box and working!).
4. The idea with these DIY things is to get bulk parts...not just 1 cap, but a package of them, maybe even 100 to 500 assorted values. Buying individual stuff costs a lot. Same with the resistors - get a whole package, $12 at RS, instead of just a rack of 5. Get some opamps and transistors (npn small switching/amplifier type, even RS has those), pots, small tools etc. Start up cost is like $100 - $150 including a new, awesome $50 meter (Extech). That way you can build things at will, and they only cost about $10 in actual parts. Add in the box & switch, comes to like $40 per pedal. After you have made 5 of them or so, the initial $100 seems like nothing! Plus you'll use the stuff to fix your guitar, etc etc. Save your cash and buy stock!
Listen to the advice of the others on here, you can learn TONS!!!! I've made about 8 or 9 effects, and there are veterans like Mark Hammer et al. that have designed and built many more. They've learned the hard way, so we don't have to! ;)
Once again Salute to you Sir!
Thanks for another very helpfull post.
I will see what I can do with this low budget.
As per your suggestion I will try to return this chepo multimeter to Radio shack tomorrow, and most probably the plastic enclosure too. And I will see if I can get things in bulk.
And about the hum/ Noise , Is it because I am using an AC adapter through 9v batetry connector? I dont have tube light, No Tv around, One LCD monitor (Which I think doesnot cause hum). One thing I noticed was when I bring my hand nearrrr to bread board the hum/noise increased!
Yeah and I did get LED On with DPDT, even though its not true bypass it will work fine for me coz I never play guitar without distortion. ;D
Anyway here's my near final Pic, before I mesh things up with Solder. ;D ;D ;D
(http://img84.imageshack.us/img84/1693/dsc000092zb8.jpg)
One more thing to Gibson GM or anyone.
When I rotate the drive knob untill 80% the drive is pretty low and the drive start to increase after around 80% it increases really fast.
Why is that?
Is it because of this mistake? The resister circled near Opamp was supposed to be 4.7 k instead I put 0.47 k.
Could that be the reason? That is the resistor which comes before Drive Pot.
I tried with 2.2k but still it didnt changed much.
(http://i92.photobucket.com/albums/l9/generalguitar/MXRtest1.jpg)
Quote1. For absolute authenticity, a 1meg reverse-log pot is needed. Most of what that pot does, though, is not of any great use. If you are not interested in "authenticity" but primarily are interested in cranking it up and rocking ASAP, buy either a log OR linear 100k pot and use it in place of the 1meg unit shown. I guarantee it will work just fine and give you 90% of what the original will.
It's probably the taper of your drive pot. That's what Mark Hammer was getting at.
Oh no! Another article to check out! Look at the graph of the pot tapers in the article.
http://geofex.com/Article_Folders/potsecrets/potscret.htm
Thanks Sir.
I was thinking Log's graph as Reverse log's graph, so I was comparing the increasement according to it. haha
My bad.
But still the distortion sounded sudden around 80%.I will check it again.
So is LOG what most of the pedal use for Drive?
I dont know why I feel reverse log was better Option. May be I am wrong. :)
The pot needs to be a Log taper just for this project. Usually the schematic will be labeled what kind you need, but the MXR only says 1M. You don't see them very often. Mine does exactly the same thing, but I got used to it and can dial it in ok. I usually just leave it about 90% or so. If you put the 2.2K resistor in the place that needs the 4.7K, things should be just fine - in fact, if you use 2 of them in series, you don't have to get a 4.7K resistor (2.2+2.2=4.4, close enough!!).
Hum when you bring your hand near suggests a floating ground. Check everything that should go to ground to be sure it's all connected properly. It's easy to make mistakes, esp. when it does work, but just not working perfectly! A distortion pedal IS noisy, tho. Over time you'll learn what noise level is normal and what = a problem. The AC adapter may have something to do with it, yes...try a battery.
You'd do well to find someone with a credit card that will help you, Izzy, he he. That way you can order up stuff online - saves $ and you can research what you need, find out if people liked their purchases.
I returned the Radioshack multimeter today. and I bought another one from Microcenter for $25 ;D.
I think this one has Connectivity, capacitor measuring and also temperature. So I think this should be Fine.
I saw driller at Marc's for $15. It was like whole box with other stuff. Probably I will get it soon for my anotehr project.
GibsonGM dont think I ignored your suggestion, I highly appreciate it but I decided I will go with TIN for this MXR project as this is not my type of pedal. I wont be using it much. Or may be I will sell it on ebay ;D.
The main reason I started this project was I really wanted to learn how to build effects and understand what each part does to the signal. But before that I really wanted to build one to see how things work (I have a bad habbit of going backwards.). I was not expecting this one to work but fortunately it did. Surprise! ;D
Thanks to all the members that helped me so far. You guys Rock.!
I will spent some time on this mxr and try to learn and trouble shoot. In a mean time I will try to get ready for my next project Ibanez Tube screamer TS9 (This is my type of pedal ;D). I will do as gibsonGM said. I will buy metal enclosure and drill it..!!haha
I have been using Tube screamer from Boss GT6 and Digitech GNX2 before ;D. I absolutely love the tone!
Anyway, I have one question. Can I use this MXR distortion plus through Boss GT6? or in the effect chain of GT6 by using Send Return?
One of my freid told me that its not good Idea to do it because he said if DC current goes to boss GT6 circuit from this MXR it might DAMAGE BOss GT6?? Is that true?
If yes how?
QuoteCan I use this MXR distortion plus through Boss GT6? or in the effect chain of GT6 by using Send Return?
yes, yes
QuoteOne of my freid told me that its not good Idea to do it because he said if DC current goes to boss GT6 circuit from this MXR it might DAMAGE BOss GT6?? Is that true?
No, you shouldn't have a problem with dc current unless you have some kind of horrible dc offset, and even then the damage would most likely be to your ears and nerves(and possibly speakers) and not another effects unit. Most of us try all kinds of stuff in effects chains and loops, until we arrive at an arrangement and order that works for us. I've found that putting a distortion in front of certain effects can really bring them to life.
Quote1. For absolute authenticity, a 1meg reverse-log pot is needed.
500KC (rev log) for Dist. and 50KA (log) for volume are the absolute, authentic, original MXR values for this ckt.
Hey , glad you're learning so much, Izzy! Definitely a good pedal to play with, it's good to shop around to get the sound you want ;) Mine is customized to what I like, and I also use a Big Muff, Fuzz Face made with 60's Ge transistors, and an overdrive. Where are you from, man? I live in the state of Maine, USA. Some of your posts suggest to me you might be from another country (?)
To protect against any unlikely DC present on the output, measure for DC with your meter on the cable going to the amp, with effect on, before plugging it into the amp...I've actually had a breadboarded ckt with 9VDC on it! Didn't sound too nice, LOL!
hello again, I just soldered the circuit and now its not working!
I knew it!
I wanted to make audio probe but I dont have .1uf Caps now. I only have .047uf, Can I use it?
I am worried I think I damaged some component by extra solder heat may be? ?? ?
I had taken care of IC. Beside IC i did normal soldering to other component.
What could be the problem?
Part II ;)
Almost any cap'll do for the audio probe, Izzy. What it is doing in the probe is making sure that if you touch a live wire in the ckt it won't transfer the 9vDC or whatever to your amp (use on low voltage and low volume only, please, LOL). Use the small cap (or parallel a couple for more capacitance) for now and replace later with something larger (1uF, 10 uF...the small cap will make what you hear more treble is all). You start by banging a note and listening to the tip of input jack, and move farther & farther into the ckt. Where you stop hearing things is where it's messed up (generally speaking).
For this stage, debugging, find the topic "What to do when it doesn't work"...that will get you going in the right direction! Myself, I look for solder bridges, obvious goofy errors, check that the parts are oriented correctly, all jacks/power/pots are hooked up correctly. If you've got the stompswitch in already, that is automatically suspected. Next, audio probe/measure voltages at the IC. The 741 is a tough chip, hard to kill, so it's not likely to be that unless you soldered it right to the board & overheated it.
Read the article, and re-post your findings, there is MUCH information on debugging...
Thank you sir.
I had bought IC socket for IC. So 741 should be safe. I havent added DPDT switch till now.
Is there any chance caps and resistor get damaged from over heating?
I am going to try audio probe now.
Any other suggestion will be appreciated.
Very, very, very unlikely you'd have damaged the caps/resistors. They're pretty heat-tolerant. Transistors are sensitive, and IC's are too (but you have a socket, so are OK). Enough heat and anything will die, but I doubt you'd go that far, ha ha.
Check for solder bridges. Be sure the input/output wires go to the right tabs on the jacks. Make sure the IC has power. Measure voltage between ground (black probe goes there) and pin 7...you should get the voltage of the battery. That way you know the IC is live. Audio probe from input to output. Easier to do this is someone strums the guitar while you probe (I use a recording of a sine wave at 440Hz that I plug right into the input; I set the CD player volume so the output is about 100mV, just like a guitar).
The problem is simple, I'm sure, and just something you'll have to search out! The fun of DIY circuits, ha ha. ;D
Finally AUDIO Probe Solved it!!!
I found ut that two point shown in the diagram wasnt soldered ;D
But the signal through one of teh resistor still cant get through. I have tick marked the side of the resistor where I can hear signal, and I have crossed the point where I cant hear.
But distortion worker. Less hum than before.!
I checked it through Multimeter with Vdc at 20. The battery terminal of AC adapter shows 14 V :o. and all volts around IC are also 11-14v ??
(http://img523.imageshack.us/img523/7660/errorng1.jpg)
One more thing to Gibson GM or anyone.
I am sensing less gain than before. Is it because I replaced 2.2 k with 2.2k+2.2k = 4.4k before drive pot?
According to Schematics they have 4.7k.
Finally I completed it!!!
Special thanks goes to GIBSON GM , Mark hammer, Aron , adn lots of other guys who has been a great help!!!
Thank YOuuuuuuuuuuuuuuuuuuuu
here are some pic.!
here are the pic is Izzy Ish-Tortion plus!
(http://img119.imageshack.us/img119/252/dsc00011xp5.jpg)
(http://img455.imageshack.us/img455/6563/dsc00013yy7.jpg)
(http://img129.imageshack.us/img129/7885/dsc00010wz9.jpg)
Quote from: GibsonGM on October 04, 2006, 11:50:54 PM
Where are you from, man? I live in the state of Maine, USA. Some of your posts suggest to me you might be from another country (?)
Sorry Forgot to answer your question..
I am Originally from Nepal.
You might ask where's that at?
haha
Its between India and china. A land locked country. May be you have heard of Mt Everest, Buddha or A royal Macassare that took place like 3 years ago ;D.
But now I am at cleveland, ohio. Been here for 3 years . I am a permanent resident now.
I hope that answers your question. :)
Quote from: GibsonGM on October 04, 2006, 11:50:54 PM
To protect against any unlikely DC present on the output, measure for DC with your meter on the cable going to the amp, with effect on, before plugging it into the amp...I've actually had a breadboarded ckt with 9VDC on it! Didn't sound too nice, LOL!
How do I do this? One probe at tip another at sleve? or some where else?
Hi Izzy, Yes, I do know where Nepal is ;o) Very sad how the chinese came in! :icon_evil: I wish the world had done more to help...glad you are here in the U.S. now, and making neat effects! Your box looks nice, a great build! I looked at your "cross and tick"...exactly what I'd expect (the 1M resistor is blocking the signal from going off in that direction; that branch is there to provide bias voltage to the signal only and represents a 2nd current flowing in).
Less gain than before...hmm, not sure. Maybe someone else knows? The resistor value (4.4K) may have something to do with it, you can lessen it if you like...it will make effect more treble as gain increases, so you should increase that .047 cap next to it to about .22uF if you do. Playing is what it's all about!
To test a new pedal already boxed up, I just plug everything in except the amp, turn the effect on, and measure the DC voltage at the cable going to the amp...black probe to sleeve (inner part of plug), red probe on tip. It's not a major thing, but I safety test everything I plug into my nice tube amp before I use it... ;)
Going camping for the weekend in the morning - happy tweaking! :icon_cool:
Oh haha, I have been using my small marshal amp from the begining to test this circuit.hehe.
But I was scared to test this into my Boss GT6. ;D
I will do test the out put tomorrow.
By the way my adapter was showing 14 v in multimeter in Vdc when I actually had set it to 9 v. Why is that?
And how much volt should I get when I check the output cable before I plug in my Boss gt6?
I have a small marshall amp I test my stuff with too, ha ha...it would be OK if I blow it up, I just don't want to hurt the Fender! If you haven't used the MXR with a good amp, expect it to sound much better when you do! :icon_cool: Since you will measure DC output, and not AC (such as the guitar signal would be), you should get very little DC present. A small amount is ok; I typically get less than say .5V. More like .1V due to cap leakage.
Home AC power fluctuates. Actual peak can be about 170VAC and can vary during a day. A supply transformer is working with the average RMS voltage that we call 120V. Output can be higher or lower than the rating of the transformer unless it is a regulated supply. Regulated supplies put out "clean power" much closer to what we really want. Or perhaps your adapter is messed up?
A power supply is designed around a load. So, for this particular, average expected load, it would be asked to be giving 9V. When you use one with less than the designed load, sometimes you notice the voltage is higher than it "Should Be". If you exceed its load rating, sometimes you get a lower voltage, too. This won't hurt the 741 in this project; but some transistors and IC's might be sensitive to that and could be damaged some day in another project. That's why you sometimes see LM78xx series voltage regulators in a few designs.
I don't know for sure, but my hunch is that a good idea for this situation would be to install a few diodes (1N4xxx series to handle any current) in series with the + leg of your power supply. Each Si diode will drop .7V...you can use this property to lower voltage, 5 would take 14V back to around 10.5V. But not really necessary with the MXR, and will have adverse affects if you go back to a battery supply and they're in the line or use a different transformer. The 741 can handle up to 18V...your call, Izzy! I wouldn't do anything, personally, but then I don't use transformers unless absolutely necessary (don't like power needs on-stage). The Dist+ draws so little current, a battery lasts for like 8 months of regular use...