Tube Screamer Help

[Gledison]

Man, you are in the right direction. Lots of experienced people here....and smart asses like me trying to help
Look, from one of the pics it seems that your red and green wires are touching each other on the DC input.
Could u check this?
You will see that sometimes is just a little thing like that and Voila, start to work!
In my opinion, this is how you learn the most, and quick. I had lots of troubles in my first 2 pedals. The guys here helped me a lot!
Cheers

[peAk]

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

Hey, I'll take that tip....that is a good one!

[flanagan0718]

Just to add to the DC jack topic...If you are not planning on using a battery then I wouldn't even wire one up. I never use batteries so I just end up cutting the lug off the dc jack after I test for +9v. Here is a pic that might help. Also (because this happened to me) make sure nothing is touching the lead of the LED or CLR. Like Chromesphere said it will call unwanted grounds. I pounded my head against a wall for 2 months because a pedal was getting no signal. it turns out the lead from the LED was touching the metal bezel i was using.

[tunatuk]

Am I correct in assuming that a non switching Jack is the same as cutting the third lug off?

[flanagan0718]

Am I correct in assuming that a non switching Jack is the same as cutting the third lug off?

I guess, I usually cut it off for my own benefit. I have a process and wiring the dc to the pedal is last after boxing. So, to avoid confusing the lugs I test them when I get my order and cut the battery lug off. I don't think I have ever ordered a "non-switching jack".

[tunatuk]

I've just seen them. I have about 30 normal jacks that I'm gonna use. I was just curious.

[rullywowr]

As previously mentioned, you should get some sort of testing rig which allows you to connect 4 wires (IN/OUT/9V/GND) to your board before boxing it.  This takes all the offboard wiring out of the equation.

If you could post pictures, that would be a huge help as well.

Lastly, when wiring up your 3PDT stomp switch...you need to ensure the holes in the lugs are facing north to south...  The voltages look pretty good so it has to be an offboard wiring issue.

[Leevibe]

You need to connect the sleeve lug of your output jack to ground. Try running a wire from the ground lug of your output jack to the ground lug of your input jack or to the ground lug of your power jack. That should at least get your signal through in bypass and may get your whole pedal working! If it still doesn't pass a signal, go through and verify that every point that should be grounded is indeed grounded. If you have a DMM (digital multimeter) you can check your ground connections by using its continuity setting. Hold one probe in contact with a known ground point like the negative lug of your power jack or the sleeve lug of one of the jacks, and take the other probe and touch everywhere else that should be grounded. You should hear a beep at each connection. If not, tie it to ground. With the style of jack you are using, you would theoretically be grounded through the case anyway, but sometimes the paint can insulate enough to keep that connection from being reliable. 

Keep at it, tunatuk! Victory will taste sweet when you get it. I remember going nearly insane the first time I built an LPB-1. I even built up an entirely new board before I finally figured out that the third lug of the pot wasn't connected to ground. I was only missing one ground connection, but it only takes one.

[tunatuk]

OK, tested something and got progress.  I added a washer to the inside of the 1/4" jacks, and can get SOME sound in bypass, but its extremely low in volume.

When I engage the effect, I get a high pitched WHINE, and the LEVEL pot and the VOLUME pot can adjust the pitch of this.  Tone does nothing.  I also ensured that nothing is touching ground that does not need to be, such as the 1/4" jack tip, and nothing is touching the LED bezel, or either leg of the LED.

[chromesphere]

The input and output jacks must make a solid contact with the enclosure, ground runs from the input jack to the output jack.  Ensure that paint / primer is not stopping contact between either of the jacks and the enclosure and that their nuts are done up tightly.

As far as the whining goes, this is exactly the reason for 'rock before you box'.  You see how your fault diagnosing 2 problems at the same time?  It can get very complicated.  Anyway, if it was me I would cut that sucker out of the enclosure (cut the wires +9v, ground, in and out) and test it separately from the enclosure.  Get it working externally first then solder those 4 wires back in place when your confident the effect is working as it should.  If you STILL have issue then you know that its now offboard wiring that you need to turn your attention too.  Its a 'modular' way of thinking when constructing a guitar pedal and I highly encourage you to do this for your next build.

[tunatuk]

The input and output jacks must make a solid contact with the enclosure, ground runs from the input jack to the output jack.  Ensure that paint / primer is not stopping contact between either of the jacks and the enclosure and that their nuts are done up tightly.

As far as the whining goes, this is exactly the reason for 'rock before you box'.  You see how your fault diagnosing 2 problems at the same time?  It can get very complicated.  Anyway, if it was me I would cut that sucker out of the enclosure (cut the wires +9v, ground, in and out) and test it separately from the enclosure.  Get it working externally first then solder those 4 wires back in place when your confident the effect is working as it should.  If you STILL have issue then you know that its now offboard wiring that you need to turn your attention too.  Its a 'modular' way of thinking when constructing a guitar pedal and I highly encourage you to do this for your next build.

I cut it out the enclosure, like you suggested.  I get nothing outside of the box.  The only thing that was odd to me was that pin 4 of the IC was reading 3mV.  Other than that, I was getting normal voltages.  I checked to make sure I was getting the same voltage from the source, and I was getting 9.49v like I expected from the jack.  I'm thinking the whine that I heard earlier was a short somewhere in the offboard wiring, because I was able to replicate it, but only by touching the in and out connections together while the effect was in my test rig.

I don't see any solder bridges, but I'm about to go reflow it all just to be on the safe side.  Other than that, I don't know what to do.

[chromesphere]

Don't worry about the actual boxing up part now, just confirm that the effect is working on its own correctly, that will be one (large) part of the process you can check off then move onto boxing it up again.  Wire it with the test rig, if its not outputting overdrive then there is a problem with the effect somewhere.  Reflowing is good, before doing that though I would use a sharp knife and lightly scratch between pads to make sure there are no micro-solder bridges, ones you cant see.  Happens to us all and can be pretty frustrating to find.  Scratch the flux off and test it again.

[tunatuk]

I scratched through everything, reflowed, then rescratched. Same results.

[chromesphere]

Many people have built the tonepad tubescreamer so if its any consolation, the effect will work when everything is set up properly.  There must be a mistake, wiring, solder bridge, wrong component value, a strand of wire on one your pots shorting out with something else, etc.  Is your test rig wired up properly?  Check it over twice.

[tunatuk]

Got it sorted out...pretty stupid mistake I'm embarrassed to admit.  I had my alligator clips labelled wrong from the other night.  I'm getting a nice overdriven sound now, but the tone pot doesn't seem to change much, if anything.  Even if I bump the drive up to max, or pull it back to about halfway.

So I'm 3/4's of the way to a working Tube Screamer!