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 8) 9.49
Q1 Q2
C) 3.29 C) 3.27
B) 3.77 B) 3.68
E) 9.49 E) 9.49
Care to fill us in on what the problem is? What stomp wiring did you use? Didst thou rockit before boxit?
;D
Quote from: jimilee on March 12, 2014, 02:40:56 AM
Care to fill us in on what the problem is? What stomp wiring did you use? Didst thou rockit before boxit?
;D
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.
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?
Just double checked that, and nope, they sure aren't.
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
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
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
Quote from: jkokura on March 12, 2014, 03:29:10 AM
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.
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
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 :D
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.
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 ;)
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 :D rotate the output jack away from the LED bezel and see if you get anything on the output.
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
Are pins 5 and 6 connected on the footswitch?
Man, you are in the right direction. Lots of experienced people here....and smart asses like me trying to help :P
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
Quote from: davent on March 12, 2014, 04:20:55 AM
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!
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.
Am I correct in assuming that a non switching Jack is the same as cutting the third lug off?
Quote from: tunatuk on March 12, 2014, 02:03:54 PM
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".
I've just seen them. I have about 30 normal jacks that I'm gonna use. I was just curious.
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.
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.
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.
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.
Quote from: chromesphere on March 13, 2014, 01:45:56 AM
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.
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.
I scratched through everything, reflowed, then rescratched. Same results.
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.
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!
Right on bro! Feels good, no?
Feels better, that's for sure. Just need to figure out the tone pot. It should have an audible change with the sound, right?
Good one tuna! Well the Tone pot will have a very obvious effect when its working so theres probably, you guessed it, a short or component value error :D Make sure there are no shorts between the wires of the tone pot as well
Quote from: tunatuk on March 13, 2014, 02:31:49 AM
Feels better, that's for sure. Just need to figure out the tone pot. It should have an audible change with the sound, right?
Yeah, it should work but you're past the worst of it. I would start by tracing your tone pot wires. Make sure they're the right way around. If the pot shaft is facing down/away from you, the lug order is 3,2,1. Make sure none of your wires extend through the lugs and contact the pot body too. It should be a w20k pot it think. I haven't built a TS for a while.
Tone will work even if it is wired the wrong way around (backwards, 123 -> 321) but still take note what Lee says because you will need to learn how to wire them up (if you want your pot dial turns to be the right way around). The wrong pot value could be a problem though. Either that or its a short / component value error / etc etc
The tone pot is wired up correctly, and I cut the wires, and resoldered them on. I was unable to find any short in it. I double checked tonepad's website, and it is a B20k pot, which is what I have wired up.
ok, there are other components in the tone control section of the circuit that make the tone pot work the way that it should. So you must have a wrong value, solder bridge, etc somewhere else.
Is the resistor for the led on the neg term looks like your shorting it that way from puc looks like its touching metal box
I'm trying to trace backwards from the tone pot...
http://www.tonepad.com/getFile.asp?id=81
I see several traces coming from the tone pot, and since I don't know exactly which ones are in the path, I checked them all. The entire board is correct with values. I use a ring light with a 5x magnifier on it to examine boards and solders, and I don't see any bridges. I'm still using my rig tester to troubleshoot, so I don't know where it could be shorting out.
I know the odds are low, but I'm going to try a new pot, just to ensure that it isn't faulty.
I should do a tutorial on using an audio probe to find faults...
But in the meantime, the best thing to do is to take a copy of the schematic, and then trace through the circuit with a highlighter or pen or something. Start at the input, and then follow the path. Everytime a part diverges with the main circuit, follow it and it will usually lead to either Power or Ground. You should get no sound at either spot.
Return back to the main circuit where you left off each time, and keep tracing forward with the audio probe. Sooner or later you will hear or find where something goes wrong. The trick is learning to recognize something that isn't right.
In this case, you feel that your tone pot isn't working correctly, so in that case you could in theory jump straight to that section of the schematic, which might really help you narrow in on the issue.
Jacob
Quote from: jkokura on March 13, 2014, 08:08:17 PM
I should do a tutorial on using an audio probe to find faults...
But in the meantime, the best thing to do is to take a copy of the schematic, and then trace through the circuit with a highlighter or pen or something. Start at the input, and then follow the path. Everytime a part diverges with the main circuit, follow it and it will usually lead to either Power or Ground. You should get no sound at either spot.
Return back to the main circuit where you left off each time, and keep tracing forward with the audio probe. Sooner or later you will hear or find where something goes wrong. The trick is learning to recognize something that isn't right.
In this case, you feel that your tone pot isn't working correctly, so in that case you could in theory jump straight to that section of the schematic, which might really help you narrow in on the issue.
Jacob
Jacob, a tutorial would be pretty much appreciated!
The Tonepad doc does say B20K for the tone pot but the correct pot is actually a W20K pot. The taper of this pot will make the tone function better if nothing is actually wrong. IIRC I build a tonepad tubescreamer and the tone pot was not very useful with a B20K. In fact, I've had this problem with all tube screamers that I've build using a B20K. My suggestion is to order a W20K next time you place and order and switch it out. You can get the solder lug style at small bear or Mammoth and tayda carries a straight PCB pin style that could be used in a pinch. If you have a B10K you could give that a try as well. I know that BYOC uses a B10K for their tube screamer clone and it definitely works better than a B20K...
Last time I ordered pots from SB they had w20k in 16mm pcb pin
Quote from: Leevibe on March 15, 2014, 08:35:18 PM
Last time I ordered pots from SB they had w20k in 16mm pcb pin
yeah right angle pcb pin should be available at SB but the tonepad pcb doesn't use pcb mount pots. The tayda pcb mount are not right angle so those would work better and obviously the solder lug would be best...
Tunatuk mentioned the tone pot doing practically nothing at all. My Tonepad tubescreamer tone pot is bunched up one end, but it definitely makes a big difference from 0 to 9.