I get signal just no effect. Pot don't seem to change anything either. Here's my readings:
TL072:
1. 4.54
2. 4.54
3. 4.54
4. 0
5. 4.54
6. 4.54
7. 4.54
8. 9.0
PT2399:
1. 4.49
2. 2.22
3. 0
4. 1.05
5. 4.31
6. 0
7. .05
8. 4.14
9. 4.24
10. .66
11. 2.22
12. 2.22
13. Same
14 same
15 same
16 same
Regulator:
VI: 9.09
G: 0
VO: 4.48
Also my regulator is pretty hot like could burn yourself if you held your finger there too long.
Any thoughts?
Thanks,
Aryk
IMO pin 4 must be 0v as pin 3, its grounded internally via 10 ohm resistor check value near pin 4
Yep pin 4 is at 1.05 not sure what might cause this
Quote from: Aryk on December 11, 2014, 02:21:34 AM
Yep pin 4 is at 1.05 not sure what might cause this
Hace ypu tried another pt2399???
I have yes. What other parts are connected to pin 4 that would allow voltage to get to it?
you could check r18 and delay pot
Pins 4 - 10 are all off. Here's what you should be getting:
1. ~5v
2. 2.5
3. 0
4. ~0
5. >=2.5
6. 2.5
7. <1
8. <1
9.-16. 2.5
The fact that your regulator is hot means something is wrong. Are you using an LM78L05?
sounds like a bad reg or bad IC to me, pins 5 to 8 have voltage surge direct to the reg, if not supplied ok, could be reg or a jumpered pad somewhere
I'm using an LM78L05ACZ and have swapped out the regulator and IC with no change
Quote from: Aryk on December 11, 2014, 07:46:59 PM
I'm using an LM78L05ACZ and have swapped out the regulator and IC with no change
can you post photos of the board??
(http://tapatalk.imageshack.com/v2/14/12/11/5f34ee1ab49ee8fa872aa736e4d194d1.jpg)(http://tapatalk.imageshack.com/v2/14/12/11/40578885f78a51af2b7ee3affe844680.jpg)
Here you go
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first i see you are wiring cables of pots upside down... why??
It's to fit it into the enclosure they aren't upside down
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Or at least are wired correctly.
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i saw it now its right wiring on the pots, have you tried to move de delay pot??. also the best its to make a probe and on the IC(pt2399) input give a shot. also once happened that the input was grounded and the output too, if that its so, the you get only bypass output
Hm, I wonder if it might be worth touching up those solder joints on the pots again, just to make sure they're making good contact... I'm also curious about the offboard wiring, that always seems to be the thing I mess up consistently. Are the ins and outs going to a switch, or did you just hook up the jacks so far?
Of course, none of this has to do with the regulator being hot, which might be the first thing to solve.
I don't see anything obviously wrong with your build or the PCB itself. Have you tried remelting the solder joints on and around the PT2399? Possibly there could be a small solder bridge somewhere.
Also, I am curious to find this out: if after you remelt the joints and are still experiencing a problem, try pulling the PT2399 from its socket then take voltage measurements on pins 1 - 8.
K I replaced it and now pin 4 has a 0.0v rating but the others remain the same. Which makes me believe it's not the IC anymore. I'll check the solder joints which have been reflowed already just to be sure. My guess is a wrong value cap or resistor any clues as to where I might look?
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So with the PT2399 out voltages are ~9v at pin 1 and 0 everywhere else
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Are you sure? You should be getting 5v at pin1 regardless of whether or not the PT2399 is in or not.
Sorry 5v
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Where does the audio path run? Gonna go through with a probe and see where I'm not getting sound.
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Did you figure this out?. Oddly I am having the same issue. But regulator is not hot to touch. I did have feedback the first time I turned it on but we-worked a few solder points and that stopped but then no sound at all. Was thinking I fried something.
Not yet don't know the audio path to test it out
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If I figure out my issue I will post it and maybe it will help out yours.
Much obliged
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The build doc has a schematic; it takes some practice to read those, but if you print out the schematic and the board layout, you can follow the audio path with your audio probe on your board. Start at the spot marked input on the schematic, try to find that on your board, and using your audio probe, work your way through the components that lead to the next stage, making sure the signal stays present. You won't get sound on the side of a component that leads to ground, and you can also skip any connections that are leading to voltage.
I just did this moments ago on my Azabache vero, I had a tiny bridge just before the output, ie, last thing in the path.
Oh, one thing to add, which you may already know, but on the schematic, the IC1 connections are shown as separate components, but they are just different pins off of the same IC. The TL072 is a dual op-amp, so, yeah, two op-amps in the same package.
Thank you morgan, I am firing up my DMM and will see if I can find a mix up, solder bridge or something. I have this feeling it is something obvious I am missing like a wire connected backwards.
Well it works now but I have to crank my amp to get volume from it. It sounds amazing when I can hear it. A little "buzzy" and "crackly" when I am adjusting the pots but it is not fully enclosed in the box at the moment and wires are being wriggled as I adjust the effect levels so maybe that is the issue there. Any suggestions on the low volume when effect is engaged?. Jumps way up when I turn off the effect. Happy it works (sort of) and have to say it is one awesome sounding delay.
I get that sometimes if the signal is shorting to ground somewhere, or sometimes if you have the ground and lead reversed on your jacks. You crank the amp up, and you can hear the effect a little, because some of that is bleeding through your ground.
You might use your multimeter to check for continuity to ground where you should have none. But I've found the audio probe to be even more useful for diagnosing. If you follow that path on the schematic, and find the spot where the signal dies, you'll find the culprit.
As a side note, I always feel like I learn much more when troubleshooting than when I'm just stuffing parts in a board.
Quote from: pogart on December 15, 2014, 06:53:11 PM
Well it works now but I have to crank my amp to get volume from it. It sounds amazing when I can hear it. A little "buzzy" and "crackly" when I am adjusting the pots but it is not fully enclosed in the box at the moment and wires are being wriggled as I adjust the effect levels so maybe that is the issue there. Any suggestions on the low volume when effect is engaged?. Jumps way up when I turn off the effect. Happy it works (sort of) and have to say it is one awesome sounding delay.
Sorry to ask this, but can you give us one more pic of the top? One with all the resistors in view. I can read off the resistors for you to see if you have a wrong value somewhere. That would be a likely cause of low output.
Hers is the front of my board. Hope this is ok since I was not the original poster here. We did seem to have similar problems with the build. I'm learning but a little frustrated. Thanks to everyone that has posted tips and help.
POGART
Brian, i have a very small question im building the ZPMII but im forgot to get a 10pf cap, only have 100pf caps, C2 seems tobe feedback on IC1 on the first OPamp, would the change to 100pf make a big problem?? IMO no... but maybe it will alter the amp stage a bit... so im no so sure... btw man love that layout and the muddbuny amazing look
Pogart - Don't know if you noticed yet but thought I'd mention it. It looks like the TL072 IC is backwards.
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totally right, that IC its backwards, that why you are not getting it right
Holy crap it's been staring me in the face for ages lol. Thank you so much for the extra eyes and speedy input guys. I rewired, reflowed and reworked this thing a whack of times. I will flip that around and let you know how it go's. Again thank you so much.
POGART
Let's just hope that's the fix if so awesome!
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I flipped it around and plugged it in and all I get now is a high pitched feed back and the IC and the pt2399 heats up fast. I didn't leave it on for more than 30 seconds and it was hot to the touch. I had some effect sound before but now it's just feedback type squeal and heat. Any suggestions would be cool.
POGART
can you get voltages again?? on the PT and on the TLC072
TL072s get really hot when you install them backwards.
Try a new one in the orientation you had previously.
I had a similar issue with a deep blue delay build. First it got hot, then I switched it and low output. New part did the trick.
good luck!
OK cool, so I guess the first way I had it was correct?, since it is now hot to touch?. As for readings I can't seem to get anything close to recommended. All are negative?. Maybe I am testing wrong but at least I am keeping my patience...sort of lol
just keep you black testing end on a ground place and the positive REd on the points to meassure
Thanks man, I flip the ic and then take the readings again. I'll post them regardless of how odd they look and maybe that will point me in the right direction. I had it working but just low volume then I tinkered around with it and lost it.
hey buddies i just finish my ZPMII and had a bunch of PT2399 to try most of them taydas and some are noise buy i got one that does the same no delay no pots about the same of yours readings so im guessing that you problems its the IC, what i do its i have a cave dweller just to try any Pt2399 before soldering right without any sockets just to know the IC was good before soldering and always take my time on soldering the ICleg by leg and letting cool before going to another leg
Quote from: pogart on December 17, 2014, 11:44:43 PM
Thanks man, I flip the ic and then take the readings again. I'll post them regardless of how odd they look and maybe that will point me in the right direction. I had it working but just low volume then I tinkered around with it and lost it.
could be other things but sounds like a problem with the op amp or something between it and output.
Thanks for the info. I tried a new ic with same results, no sound. I will post the readings when I'm back from vacation. They were still very odd, mainly negative. Again I'm very thankful for all the help and input and time you take to help me figure this out.
POGART
Ok I have sound on this pedal but kind of noisy,hissy and not very loud. I have some readings and they seem close to what is required but a few are not exact. Any suggestions? And thank you for pointing out the backwards ic (sockets are now my best ever friend). I hope this is enough info to get an idea on my problem. Thanks again for all the help and treating my newb questions with kid gloves.
pt2399
1=5
2=2.5
3=0
4=0.84
5=2.9
6=2.5
7=0.71
8=0.72
9 through 16= 2.5 (pin 14 was 2.49 but I figured that was close enough)
ic 1 lm78l05
1=0.56
2=0.56
3=4.46
4=0
5=4.43
6=0.55
7=0.52
8=8.90
regulator= 8.96/0/5.0
I think you mislabeled the voltages for the op amp as lm78l05 (that's the regulator).
if so, those voltages look off to me. probably a wrong resistor value nearby.
Thanks for the information and the help. I got it all boxed up and working finally. Turns out a few bad ic's make for an unhappy pedal ( and one frustrated newb builder). Sockets are now my best ever friend : )
Onto the next build project.
Quote from: pogart on January 17, 2015, 04:10:12 AM
Thanks for the information and the help. I got it all boxed up and working finally. Turns out a few bad ic's make for an unhappy pedal ( and one frustrated newb builder). Sockets are now my best ever friend : )
Onto the next build project.
was the pt bad?? or the op amps?? that should help many others if you can tell
It was the op amp. I switched the pt2399 as well after to see if the spare I had was less "noisy" as they say. No difference . I rewired everything as well to be on the safe side before I stuffed it into the box. I have to say it is one cool sounding delay pedal. Really like the swashy kind of tails as they diminish.