Tube Screamer Help

[tunatuk]

I bought a Tonepad Tube Screamer, and populated it and mounted it, prior to checking it.  I was told to put pictures up, so here is the album:

http://s189.photobucket.com/user/tunatuk/library/Tube%20Screamer

I will update this thread with voltages to the IC, and to the transistors shortly.

Update:

Voltages are as follows:

IC:
1) 5.19     5) 5.17
2) 4.88     6) 5.14
3) 4.86     7) 5.16
4) .01        9.49

Q1            Q2
C) 3.29     C) 3.27
B) 3.77     B) 3.68
E) 9.49     E) 9.49

[jimilee]

Care to fill us in on what the problem is? What stomp wiring did you use? Didst thou rockit before boxit?
 

[tunatuk]

Care to fill us in on what the problem is? What stomp wiring did you use? Didst thou rockit before boxit?
 

Oops, I guess the issue might help.  Forgot not everyone reads everywhere else on the forums.

1) I'm a complete noob at this, have tried several times (unsuccessfully) to build pedals, and have only gotten a couple half-ass working so far.
2) I'm not getting anything at all.  Even in bypass, which is weird because in all of my failed attempts, I can get bypass.
3) I am currently wired up using the tonepad 3pdt layout.  I tried the madbean layout, which I prefer, but it didn't work either, so I figured to try the tonepad.
4) I hooked up the circuit to my testing rig, and got nothing either, but set the test rig in bypass and I got sound, so I know it isn't the hookups on that.

[lincolnic]

It's a little hard to tell in the picture, but are your power and ground connections shorting against each other on your DC jack?

[tunatuk]

Just double checked that, and nope, they sure aren't.

[chromesphere]

Hey Tunatuk.  I would like to offer you some general beginner advice. 

Firstly, the offboard wiring (madbeans vs tonepads).  Just so you know, they both work, we all here on the forums use both of them on a daily basis.  If the madbean wiring didn't work its because...well...sorry to be blunt, but you didn't wire it up properly.  That's the cold truth of it.

You mentioned that bypass didn't work with the tubescreamer?  That indicates that there is a DEFINITE issue with your offboard wiring.  If it was the effect that was malfunctioning then you would get nothing when the effect is engaged but you would still get your clean signal when the effect is disengaged (bypass).  So you have definitely made a mistake with this offboard wiring on your tubescreamer.

Lastly and absolutely MOST IMPORTANT THING YOUR EVER GUNNA READ ABOUT BUILDING GUITAR PEDALS.  (sorry caps are required before this statement.):   Rock it before you box it, as they say.  What that means is test the effect before you box it up inside your enclosure.  Absolutely critical step.  boxing up an untested effect significantly increases your chances of an non-functionally pedal and is probably the reason why you have struck out with your builds.  Even pro's on this forum that have built 1000+ pedals test their pedals before boxing it up.   How do you test it?  well its pretty simple, just get some alligator clips and a battery snap and wire it up like on page 3 of this build doc for my 7 min fuzz:

http://www.diyguitarpedals.com.au/shop/boms/7_Min_Fuzz.pdf

I hope I have assisted you and good luck
Paul

[jkokura]

The voltages don't seem terribly off. They look right, except your bias at 5.18 seems a bit odd to me.

Anyway, the next step is to use an audio probe. Have you seen anything about that? I'd jury rig one up if you can..

Jacob

[tunatuk]

Thanks Paul. I've double, triple and then checked again on my offboard wiring and I can't seem to find the fault. I know it's in there, and I take no offense. I'm a cop out here, so saying I messed something up is nice compared to some other things I get called lol

[tunatuk]

The voltages don't seem terribly off. They look right, except your bias at 5.18 seems a bit odd to me.

Anyway, the next step is to use an audio probe. Have you seen anything about that? I'd jury rig one up if you can..

Jacob

No audio probe yet.  Didn't have a chance to run and get another probe today from the hardware store.  Might be able to rig something else up though in the meantime.

[jkokura]

You have a testing rig, correct? Just connect a medium value cap (10-100nF) to the 'out' connection on the testing rig. Use one leg to poke at the circuit. Start at the input, and look for where the signal disappears.

Paul's right though bud. Make sure the circuit works BEFORE you wire it up. If your wiring isn't working, just remove it from the issue.

Jacob

[chromesphere]

Don't take failure in beginner building pedals to heart tunatuk.  We ALL start here.  But we all get better as well.  Stick with it, you will learn a lot and you will be building some awesome sh!@# before you know it

There absolutely HAS to be a fault in your offboard wiring if you are not getting a bypass signal.  Double check closely every single solder joint for a short.  Move the pedal around, look at different angles.  Inspect each joint.  Make sure there are no fine connections between them.

[hoodoo]

Make sure your positive leads , from pcb and battery, are on the correct tabs of your dc jack,  and i'd look at that output jack socket. With a jack inseted that looks like it would make contact with the LED, maybe 

[chromesphere]

Just noticed that too matt.  your output jack tip is incredibly close to the led bezel.   Remember the enclosure is ground (negative).  Anything metal touching the enclosure is also ground.  So if the tip of your output jack is touching ground, your guitar signal gets sent to ground and you get silence through your amp   rotate the output jack away from the LED bezel and see if you get anything on the output.

[davent]

Fried switch? Can you check the switch with your meter to see that the switch is doing what it's suppose to?

A tip for assembling, with the symmetrical control layout you could mount the pots and switches on the outside of the enclosure and do your wiring there, helps in keeping wire neat and not overly long. Once it's wired and working you take the pots and switches off and re-assemble inside the enclosure. Protect your paint job if assembling on the outside of the box.

dave

[Matt]

Are pins 5 and 6 connected on the footswitch?