MXR DISTORTION + <<error>>

[9V]

man, i am so frustrated, and greatly pissed off right now...

the distortion does not come in, and the green led light i've got is, blinking like (blink blink blink...and so on) and the sound is only the silence, with tappa tappa tappa...

i got the wirings perfectly, and ic socket now re-done..

anyone who can help me?

[zener]

have you tried the audio probe? It will help a lot.

Most of the time, an audio probe and a DMM is all you need to check what's going wrong.

The audio probe is on the debugging page.

[petemoore]

But shipping would negate any helps, and it's quicker for you to debug it.
 What are the opamps pin voltages?
 What kind of OA are you using?
 Green light? No real need for a green light with a DIST+ debug.
 Connect ground and output hot to amp, and inject thumbuzz starting from the amps input, then working your way back toward the center of the circuit...first the 'inside of the DC blocking cap following the signal path and touching it [a probe connected to you, your guitar or keyboard and ground signal generator of some type]...where the signal gets 'lost' look for a miswire.
 Post the pin voltages and the problem may quickly become reduced in scope.

[9V]

as you might have guessed i am a beginner,


and i have no clue what you guys just said,

i will look into the debugging page thanks

and petemoore, what do i have to do it look for a miswire?

[petemoore]

A DMM=Digital Multi Meter...is really indespensable for debugging and building...if you have one of these...
 Connect the black DMM lead to ground. set the DMM for DC volts [20v range].
 Then take the red lead, and toubh it to pin 1 of the opamp, take a voltage reading of pin one and write it down.
 then repeat this procedure for each of the other Opamp pins.
 Type the readings of voltages from opamp pins 1-8 here.
 There's a signal path throught the circuit. it starts at the input cap, the opamp has + and - inputs, and it's output are part of this path.
 If your amp works, plugging in a cable and putting your thumb on the other end should cause a buzz sound. Use this thumbuzz [signal injection method] or hook up some kind of signal generator...guitar keyboard...oscillator...you'll need to make the ground connection from the generator to the circuit tho...that's why I use the kwik/dirty thumbuss method.
 You trace through, starting from the output...listening for the buzz or input of your choice when it's connected.
 First test that the amp makes the buzz your thumb produces, then connect the circuit ground input and output to the live amp, and check for 'thumbuzz' at the hot connection of the output...working your way to the center of the circuit, injecting on the inside of the output cap, then follow the signal path farther...and keep checking to see if the sound still comes through or is lost.
 More than likely the signal is lost in the circuit somewhere...and when you find that problem, you're 1rst step is done.
 The second step is finding a solution...

[Fret Wire]

What schematic did you use? Did you use their PCB or did you make  your own? What wiring layout and switch did you use? Did you use any substitutions for components or their values? What IC? What type of pots-value and taper?

[petemoore]

I' d lose the switch and jacks to debug a circuit, as isolation/elimination of variables seems to be the way to find problems. I always debug before adding the bypass switch or jacks....I use the jacks of the test jig.
 I just use the board, offobard pots and battery clip, and make the input output and ground connections with a test jig.
 Test jig is: a metal box, with 2 mono phono jacks.
 then an open top cardboard box or plate, fastened on top [for setting the circuit on]
 Connect an alligator clipped wire to the jacks ground, connect two more testclipped [alligator clip on one end of a wire] to the input and output hots from the jacks [individually of course], and poke holes and feed them through the cardboard so they're right there.
 I found one of these to be a real timesaver, and makes finding and fixing circuit porblems much easier and quicker..

[9V]

i used extactly the one in the generalguitargadgets?

so petemoore, i should use my thumb to look for a buzz around everything i've got off and on the pc board? right?

if there isn't a buzz on a diode or output jack etc.., then that is the problem?

plus, i don't even know the terms, are you suggesting me to get a DMM or Make my own?...
and what is an opamp? is it IC socket?

man... i am pretty dumb eh?

sigh... i would just like to give it up, and just play guitar....

btw.. i've got a weird 3pdt on/on switch..now is that a problem?

[petemoore]

You Are not Dumb...You ARE learning!!1
 Opamp in the DIST+ is a 'single Opamp'...as opposed to a dual...you'll need a single OA, or you can use half of a dual OA.
 The triangle on the Dist+ schematic represents a single OA.
 An OA [opamp] socket must be used, trying to solder an opamp in will very likely kill it. If you've soldered it in...get some desoldering braid, solder it out, and install an 8 pin IC socket [RS..Radio Shack has them].
 The thumbuzz method is just the 'handiest' [pun intended but really is] signal injector...and I debug all the time using it. All it does is...produce the sound of your thumb on the end of a live amplified input cable.
 To test what a thumbuzz should sound like, plug in a cable to your amp, test that sound comes from the amp...push your thumb across the tip of the cable...you Should hear a buzz sound....now..
 You connect the live hot cabel to your effect...ground and output hot' connections made...touch your thumb to where the hot tip of the cable is connected...[I use a metal probe like a screwdriver shank]...you should hear the same buzzsound...that means the signal path has extended past the jack.
 Then...follow the little wires or the schematic, and follow the signal path farther into the circuit...if you experience that the buzz can make it all the way to the input...and sounds amplified...your circuit is problable working...but.
 If you experiance that the signal [buzzsound] is lost...say you make it past the DC blocking cap at the output [far right of schematic, just before the vol control]...but no farther 'in' [you hear no sound when injecting at the opamps output] your problem is probably very near to where the signal path is broken...one side buzzes, the other side nothing...look right around there for a miswire.
 DMM=Digital Multimeter...invaluable tool for debugging...if mine became disabled, I'd get another before building or testing anything.
 You should be able to come across a PDG [or great for debugging purposes and other..] DMM for around 40$ N/P..no problem.
 Tell me if you have one...otherwise get one...worth every penny IMO. Indespensible for circuit builderz.
 Once you get one, test for DC volts...it should come with directions.
 Anyway, once set for the proper range, and the DMM test leads plugged into the proper DMM jacks...and turned on...you should be able to measure the battery voltage of your 9V battery, and should read something near 9vDC. Then your DMM is ready to..
 have the black lead connected to circuit ground, and take readings from the opamps 8 pins individuall noting the readings in DC volts..write those down and post 'em.
 I suggest brousing/reading links etc. there's a vast resourse of info... you'll have to sort through to find the info you Don't have and learn from that.
 I saw one recently titled something like building with opamps...very good reads for those new to opamps...I just can't tell you where it is now.
 Anyway you should see if you can get readings from circtuit using the DMM.
 Be sure to read the instructions that should come with the meter...very information in that..

[Jason Stout]

btw.. i've got a weird 3pdt on/on switch..now is that a problem?

I don't know, but...the question is,

Are your jacks and switch wired properly?

This is the starting point, after you confirm that the jacks and switch are working you can then begin with the circuit board.

To test your jacks and switch wiring (the quick and dirty way,) take a piece of wire and connect one end to the circuit_board input (the 0.01 μF capacitor,) connect the other end to the circuit output (The middle tab of the volume potentiometer.) Make sure you are plugged into your amp, if you can both, hear your guitar and turn it on and off with the switch, your jacks and switch are wired correctly.

This can be done in a matter of minutes; all you need is some wire!

Let us know what you find.

[Jason Stout]

9v wrote

and what is an opamp? is it IC socket?

An opamp (operational amplifier) IS the IC (integrated circuit) that goes into the IC socket, the circuit will not work without the opamp.

[jimbob]

I been there before many times..Still am. Ive built tons of different effects and yet i cant seem to get a microamp working or a easyface..haha  seriously. O well, theyll go on the back burner while i build something 3 X more complicating-all perf. Have a beer, or whatever, move on to something else and come back to it in a week. This should be for fun/relaxation.

BTW- i originally built the dod-250, changed it to the mxr dist +. I had a similar problem..and it was the opamp choice. If i recall the GGG site give you the choice of LM741 or JRC741 or LF351. I think there are others that can be used as well. I have a jrc 4558 if i recall,,its been a while. This was one of my 1st builds as well and i was ready to call it quits--someone? i dont remember who reminded me this should be for fun.

Good luck

[petemoore]

I'm attempting the second Shaka Tube in as many days...[actually 3 days now nogo]. First one I'm using the pots and tube socket from..dohh
 I'm also working on my second million dollars...
 The first ones didn't work out.
  Still trying...but have run into power supply issues...I think the wall wart half died... :cry: ...
 But I'm learning about tubes    !!!
 Today just isn't the day I'll get it going.

[9V]

thank you guys so much for help me out again,

alright i'll give it a try in about a week or so, AFTER reading everything what you guys said here, again, testing the circuits, reusing the wires, as for DMM (i might have to do without it)...

for using your thumb? do you test the components as well, on the soldered side or the side on the top?

oh yes btw, my output ground (thumb tseting)..has a big buzz, so that's good, but the funny thing is, the two connections, out of one, has no buzz, so mabye that is my first problem? haha...

and i can't find 3PDT FOOT SWITCH anywhere, from here,.. stupid radio shack don't carry anything (but ican';t order..)

i might even buy that book called (DIYstomp..somthing) by Craig..something...

well, thanks again, if you got anymore tips i can use, post it here please, it would be greatly appreciated, thanks!!

[Peter Snowberg]

3PDT switches are hard to find so if you're not buying big volumes, your best bet would be to order one from Aron. See the top post in this forum for more.

I think the book you're refering to is "Electronic Projects For Musicians" by Craig Anderton. It's a little dated in some ways, but the info is still 100% useful. I would highly recommend it!

Best of luck!
-Peter

[petemoore]

Definitely look at skills you need to know, and see if you can find some stuff relating to this ... look at GEO, I printed out a Rangemaster Article long ago, and had reads to try and comprehend ever since, but  :idea: s started popping off right at the start...read through and get what you can from there.
 There is no current at ground, anything connected to ground will be 'dead' sounding.
 For current to flow you need a circuit, ground is the reference voltage, 0 in this case, the jack/plug tip is what the signal flows through. Ground must be connected to make a circtuit.
 At the top of the page is FAQ, and check into all the links, at this point, gaining elementals is easiest by using the reads!!!...you may have to sort through ...lol... a little, but there's an enourmous abundance of reads...trick is finding the terminology and basic current flow...I think there are tutorials on exactly this available from the aforementioned reading suggestions.

[9V]

thanks petemoore, but still one thing puzzles me, what is a blinking LED light mean? and also what does 3PDT ON/ON NON-FOOT SWITCH (flip kind)
mean? does it mean that it has no off?

[Jason Stout]

Your led is blinking because:

i) You are passing a very low frequency ac current through it.
ii) You bought a blinking led.

I'd bet on the blinking led!  

Do you have the package it came in? I think Radio shack sells about 4-5 different led types, one is the blinking type.

How did the switch test go?

I wrote:

To test your jacks and switch wiring (the quick and dirty way,) take a piece of wire and connect one end to the circuit_board input (the 0.01 μF capacitor,) connect the other end to the circuit output (The middle tab of the volume potentiometer.) Make sure you are plugged into your amp, if you can both, hear your guitar and turn it on and off with the switch, your jacks and switch are wired correctly.

This can be done in a matter of minutes; all you need is some wire!

99% of the population wouldn't even try what you have already done , so don't be afraid to ask questions or tell us what you have tried; i.e. "I tried to connect "wire X" to  "point Y" and this happened" Everyone is learning here, even the "Gurus!"

[9V]

thank you for help me man i appreciate it.

for them wiring test, my guitar can be off and be on without that test, but i'm pretty sure there is a reason behind the test?

and yes my mother thinks i am quite insane for making an electronic device! he he..


but how about the switch?? does that matter?.. i think i need more tips on them ic socket putting in method, it's a MESS! heh..

thanks

[petemoore]

Pencil tip soldering iron is also highly recommended for doing perf builds.
 I'ts really sort of an art, heat exposure times [the tip to metal contact timing]...you need to get all the metals to be bonded up to temp.
 Planning how the wires approach, so as to leave room for the iron access around the OA connections.
 Don't solder IC sockets with the OA in...you'll good chance burn it. Same for diodes and transistors, when you need to solder these directly in, use a test clip between where the iron heat will be applied and the body of the component as a heat sink.
 Look at the nodes, where more than one connection is made so as to better layout, and make all the connections at that node neatly.
 I like to drill holes in the board, usually sized for two or thrree wires to go through for the wire to go through, this relieves movement and stress on your solder joints/wires that connect offboard parts like pots, battery clips....all offboard wiring.