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No worries, thanks for your thoughts anyway.

I'm happy to report that it is  fixed.

I have a friend who has a TU-3, and he was kind enough to let me borrow it to compare with mine.

The way Boss laid out the circuit board in this pedal is interesting. When you lift off the bottom cover, you'll see the back of the circuit board. To get to the side where most of the components are  you have to lift the board up.

But, there are a number of spots that have connection through the board (to the side you can see when you remove the cover) and are labeled as "TP". (Test point, maybe?) After a bit more poking around, I found a drop of solder bridging one of the test points, which connects to a transistor (that, from it's position, I believe is the output buffer) to ground. And after I popped it off, the pedal has worked perfectly

I don't think it looks like anyone has been soldering anything in it before, so it's possible that it's been there since it was new. But how that would have passed QC, I'll never understand.

Thanks again for taking the time to read and offer your thoughts.

Thanks!

Actually, though the footswitch works, because the pedal turns on and off.  It just never puts any signal to the output jack.

The TU-3 is definitely not true bypass. I'm assuming that it's a fairly standard Boss buffer and flip-flop (?) swiching system. I just don't understand well enough exactly how the buffer/switching works to be able to troubleshoot it, especially without a schematic.

Hi everyone, and thanks in advance for taking the time to read this.

I have a problem with my Boss TU-3 Tuner. The tuner works, but it doesn't pass any signal through the output jack in the bypass mode. It does, however pass signal through the bypass jack.

Does anyone have a schematic for it?

I've partly traced the circuit with an audio probe. I'm sort of assuming that, since the tuner turns on and off and the tuner part does work, that it's something related to the switching section, but I don't understand how it works well enough to troubleshoot it, and I don't have a schematic for it, either...

Has anyone else run into something like this? Does anyone have any suggestions for troubleshooting it?

Again, thanks in advance for any help you can offer.

I'm happy to report that this one is fixed.

The problem was a cut trace on the pcb between C10 and pin 8 of the PT2399. Most of the components on this build were cut off dead flush with the board, and it looks like the person who did it snagged the edge of the solder pad where the trace meets up to it and cut the trace.

So, with the trace repaired, everything works as it should. Hopefully this will help someone else out. It certainly had me stumped for awhile!

Hi everyone, and thanks in advance for your help.

I have an Aion Vector delay (the original, not the newer 125b version) build that someone else did that I'm trying to troubleshoot. The build document is available here- https://aionelectronics.com/project/vector-deep-blue-delay-clone/  It's built as the Deep Blue Delay, not the Rebote 2.5.

The problem it has is that while the dry signal comes through fine, the echo is static. Not a little fuzzy, but completely static. (completely distorted, maybe?)

I've been through the circuit and found a couple of incorrect resistors, which I changed, and the current-limiting led (D2) was reversed, which I also corrected. But, neither of those made any difference. With my audio probe, I get a good, clean signal to the C5 side of R7, but on the other side of R7, the echo turns to static. Measuring C6 in the circuit with my capacitance meter gave me a really weird reading, so I replaced it, but the new capacitor doesn't make any difference, and the old one reads correctly out of the circuit.

I also tried a couple more PT2399 chips, one out of a working delay that I built, and tried this one in the other delay. This one works in the other pedal, and none of the others make any difference in this pedal. I've also looked for solder bridges and damaged traces, but I haven't found any yet.

The voltages on the ICs are (using a Boss PSA power supply)-
PT2399-
Pin 1- 5.05
2- 2.52
3- 0
4- 0
5- 2.88
6- 2.52
7- 1.77
8- 1.97
9-16- 2.52

TL072-
Pin 1- 4.45
2- 4.45
3- 4.42
4- 0
5- 4.42
6- 4.45
7- 4.45
8- 8.90

I've attached a gut shot, too.

This is the first time I've done any troubleshooting on a PT2399 circuit, so I'm a little out of my depth. Again, thanks very much for taking the time to read this and offer your input.

Well, it was the transistors. I got a couple of matched 2N5952 quads, thanks to Haberdasher (Lectric-fx.com), and they work in both.

It sounds like Jimilee, at least, is familiar with Haberdasher, but for anyone reading this who isn't, let me put in a plug for him. He was very helpful, and has some very interesting-looking pcb's for sale in his store. I'll definitely be ordering some from him in the future.

And thanks to all of you who took the time to offer advice. I've built and/or repaired several dozen pedals at this point, though I don't understand nearly as much as I'd like about how all this stuff works, and people on this forum have saved me quite a bit of time and headache several times when I had some issues. You guys are great! Hopefully I'll be able at some point to help some of you out, too.

Awesome, thanks! I'll give that a shot.

And this might be a dumb question, but what about J201s? I do have a decent amount of them, though they may be from Ebay, too.

Yes, I installed R99, since I was planning to at least see what the flashing led looked like, but I haven't hooked it up yet. I didn't drill the hole for it, since I wanted to see what it was like first, and holes are kinda permanent.

The build document says that the pcb label for the JFETs is oriented for 2N5457s, which is what I used. The 5952s are supposed to be reversed, like you have them, Bio77.

Jimilee, I've bought most of my parts from Tayda, but looking back through my order emails, I don't see any 2N5457s, so I probably got all mine on Ebay. I do have more, and probable a couple more matched sets, but they likely all came from the same place. I've been using them in other pedals, mostly drives of one sort or another, and they've worked fine in everything else I've used them in, but these are the first phasers I've tried.

Where is the best place to get 2N5457s or 2N5952s? GuitarPCB is sold out of the matched sets. Is there a particular spec that I need to make it work correctly? Obviously, as the build document says, JFETs can vary quite a bit.

Are there any other, more readily available JFETs that will work? I do have some other, different ones, too, but I'd have to check my parts box to see exactly what. And I'd obviously have to see what I have that I can sort into matched sets.

Yes, it does it at any speed. I picked a speed for the video where it was fairly obvious. But the speed doesn't matter.

I haven't had a chance to go back over and double check the NomNom. I was building both at the same time, but I finished the NomNom first. After it sounded odd, I went ahead and finished the Smoothie, thinking I could use it for reference to troubleshoot the NomNom.  But then it did the same thing, too.

I try to be very careful with the assembly- measure each resistor before installing it, that sort of thing, and I was extra careful with the Smoothie after the problem with the NomNom. Which certainly doesn't mean that it's impossible that I made a mistake, but the odds that I made the same mistake on both seems fairly slim. Which is why I went ahead and posted this before I had a chance to go back over it.

Which resistors would affect the LFO? I've built a couple dozen pedals at this point, and repaired a number for other people,  but I have to admit that I don't know nearly as much as I'd like to about how these things work. I'm an automotive technician by trade, and I'm used to using a lab scope to troubleshoot components, communication networks, and such, but you do have to know what you're looking for to be able to find the problem...

Here's a link to a short video clip showing the problem, with an MXR Phase 95 on the Phase 90 setting for comparison. I know they're not set at exactly the same speed, but hopefully you can hear what I mean. Pardon the poor quality, and the weird noise at the beginning. Some sort of electrical interference that came through the amp?

https://youtu.be/foH0_EvydMA

And the NomNom.

Here's a picture of the Smoothie.

Thanks!

Do you mean the feedback trimmer, or the other one? The other one does have a very small sweet spot, but that's where I have it set at the moment, at least as best I can determine. I still get the fast sweep that seems like the LFO is putting out a square wave rather than a sine wave.

What pin(s) can I monitor the LFO output at? I do have a lab scope that I can look at it with, if a visual might be better than my ears.

Thanks!

I've played with the feedback trimmer some, and it doesn't seem to make much, if any difference. To be honest, I'm not completely sure what effect the Nom/feedback switch is supposed to have, and I'm not too concerned about it at this point. I just mentioned it in case it was relevant.

I've adjusted the other trimmer on both, and it seems to balance between the ends of the sweep. In other words, if you turn it one way, it seems to stay at one end of the sweep longer, and if you turn it the other way, it stays at the other end longer. And if you turn it far enough at least one direction, you get no phasing at all.

But the trimmer doesn't seem to change the fact that it seems to sweep quickly and stay at either end of the sweep instead of of having a slower, smooth sweep.

If all that makes sense?

Hi, and thanks in advance for your help.

I just finished both a NomNom and a Smoothie. They both seem to work, at least mostly, as in, they both seem to do the phaser thing.

However, they both seem to sweep quickly from one extreme to the other, stay there for a  second, and then sweep quickly back to the other extreme. (Obviously how fast it does it depends on where the speed knob is set.) Almost as if the sweep is using a square wave instead of a sine wave, if that makes any sense.

Both builds went fine, and I used the breadboard layout in the NomNom build document to match the transistors. The Smoothie has exactly matched transistors, and the NomNom has transistors that are within 1% of each other. I used the recommended 2N5457 transistors in both.

I'm also not sure that the Nom switch on the NomNom is really doing much of anything, but I haven't really looked into that yet.

Does this suggest anything in particular that I might have done wrong?

Again, thanks for taking the time to read this, especially if you can offer some helpful advice.