Hey folks,
Just put this one together and, after running initial tests and traces on the board, I immediately started noticing some oddities. I'm usually pretty good at debugging drives and fuzzes. It's the other stuff that I have a problem with. Did a full inspection, touched up a few spots with solder, but still can't figure it out.
I'm getting a signal off TP1, but it's a bit distorted. No signal off TP2 at all. Voltage readings off the first few IC's check out fine. However, once I got to IC3 (MN2007), I started getting some wildly different voltages than what's expected. Same with IC7 (CD4013BE) and IC8 (CD4049UBE).
Attached are pics of my board as well as the voltage measurements. Any help in debugging this sucker would be most appreciated. Just need to be pointed in the right direction. :D
Thx in advance!
Quick update. So my audio probe is totally hosed. Seems that it just causes a constant hum when in use so...ordered a pre-made audio probe from Rattlesnake Cables. Once I get it, I'll resume debugging and, hopefully, will find where in the signal path everything is breaking down.
No clock (1/2 supply on pin 2 & 6 of 3007 when working) = no BBD signal.
4013 and Q3-5 are where you have to dig.
Quote from: jeffwhitfield on July 06, 2022, 03:41:46 AM
Quick update. So my audio probe is totally hosed. Seems that it just causes a constant hum when in use so...ordered a pre-made audio probe from Rattlesnake Cables. Once I get it, I'll resume debugging and, hopefully, will find where in the signal path everything is breaking down.
Is this your first audio probe or probe usage? Generally you get nothing but hum/noise until you hit an audio signal. I'm not sure how your probe would break unless a wire broke or a solder joint was bad since there are no active parts in a probe. At the very least there should have been signal at the input.
Sent from my Pixel 5 using Tapatalk
Quote from: Thewintersoldier on July 06, 2022, 11:37:59 AM
Is this your first audio probe or probe usage? Generally you get nothing but hum/noise until you hit an audio signal. I'm not sure how your probe would break unless a wire broke or a solder joint was bad since there are no active parts in a probe. At the very least there should have been signal at the input.
Sent from my Pixel 5 using Tapatalk
It's not my first probe. The current one is an sProbe I put together. And, yeah, even with the ground attached and probe hitting an active part it still results in hum/noise. Switched out the capacitor but, nope, still not having it. I'll likely play with it later, debug it, and get it working as a backup. But, for now, I just need a working probe. :P
If you don't wanna wait
http://diy-fever.com/misc/audio-probe/
True, true. Built one of those prior to building an sProbe. New one will be here by Friday anyways so I can wait. :P
Try wiggling Q3-Q5, one might be loose in the socket.
Quote from: Bio77 on July 06, 2022, 08:56:57 PM
Try wiggling Q3-Q5, one might be loose in the socket.
Will do! Probably need to test those transistors to make sure they're good. They were from a know good batch but...hell, could be a bad one in there. :P
Ok, got a working probe. TP1 works. TP2 doesn't. Going off IC3 (MN3007), pin 3 is getting a clear signal in. I would assume that I would get a signal off pin 7 and 8. Nope.
I tried switching out the Xvive chip I got for a MN3207 which technically should still work, albeit not well. Nope. Might go ahead and order another MN3007 to see if maybe I just got a bad chip.
Other things I did: reflowed all the solder joints; removed, tested, and reseated all transistors
BBD is probably fine. You don't have a clock. You should follow Scruffie's advice. He's the Yoda of BBDs ;D
Quote from: Bio77 on July 08, 2022, 01:38:21 AM
BBD is probably fine. You don't have a clock. You should follow Scruffie's advice. He's the Yoda of BBDs ;D
Good advice!
Ha! Yoda of BBDs! That's awesome! :P
Quote from: jeffwhitfield on July 08, 2022, 12:18:10 AM
I tried switching out the Xvive chip I got for a MN3207 which technically should still work, albeit not well.
Sorry to have to tell you, but you've killed or at the very least damaged that 3207 now.
A 3207 has inverse power and ground requirements and a maximum supply voltage of 12V (or is it 11?)... you have to account for that when swapping them.
Quote from: Scruffie on July 08, 2022, 04:06:24 PM
Quote from: jeffwhitfield on July 08, 2022, 12:18:10 AM
I tried switching out the Xvive chip I got for a MN3207 which technically should still work, albeit not well.
Sorry to have to tell you, but you've killed or at the very least damaged that 3207 now.
A 3207 has inverse power and ground requirements and a maximum supply voltage of 12V (or is it 11?)... you have to account for that when swapping them.
Fortunately, that's not the case. Popped the same chip into a know working chorus pedal. Works fine. Guess I got lucky. :P
One thing is for sure, this whole thing is making me feel stupid. Definitely don't know shit about flanger circuits. Durp!
Quote from: Scruffie on July 06, 2022, 10:39:37 AM
No clock (1/2 supply on pin 2 & 6 of 3007 when working) = no BBD signal.
4013 and Q3-5 are where you have to dig.
Thanks for the tip here. Unfortunately, I'm still bust. I did switch out all the transistors as well as the 4013 (and the 4049 while I was at it). Checked the continuity around that area. Also switched out the two 120pF's I had in place for C23 for a 68pF that measures around 65pF (just for testing). Still no change.
I'll admit, I'm dumb as a stump when it comes to a circuit like this. Can measure voltages, continuity checks, and traces...but no idea on properly troubleshooting a circuit like this. Good with drives, fuzzes, and such. But, man, this is a challenge! :P
So...what's the next logical step?
Alright, fixed the problem! Thanks to Scruffie for pointing me in the right direction.
Turned out to be something pretty damn simple. The problem was the 3K resistor that runs off of Q5. The bag of resistors was mislabeled. What was installed was a 620R resistor. Seems that Tayda screwed up and put the wrong resistors in the bag. Switched out the resistor for the correct value and all is good.
So, lesson learned: Don't trust the label on the bag! Check that the values match before use! I will say that this kind of crap happens way, way more often with Tayda than anyone else. Rarely ever have issues like this with other vendors. But, considering where Tayda ships from and how cheap their components are it honestly doesn't surprise me. :P
Pedal is a bit on the noisy side so I'll need to tweak the internal pots a bit more and see if I can knock the noise down a bit. Otherwise, appears to be working just fine. :D
Congrats! I like how Tayda supplies their resistors because I can check the whole bag quickly. I find most of their stuff is in spec, but occasionally I have to pull a few out of a bag and pitch them. Happens more for low values like 10R. I've never had a mislabeled bag before, that's concerning.
I did a look over your picture to see if I noticed any other alternate values. Maybe double check the values on R38 and R32.
If you still have noise after setting the trims, suggest the audio probe. I just built this and it's crazy quiet for a flanger.
I have never had tayda put the wrong resistors in the bags, never once in like 7 years. In fact the only time I ever got the wrong thing from them was because I clicked on the wrong thing. I also don't think where they ship from has anything to do with not checking values before a part is inserted. Doesn't seem fair to blame a company for an error of the builder.
+1 with Bio77, this thing is crazy quiet with a decent power supply.
Quote from: Bio77 on July 15, 2022, 12:30:17 AM
Congrats! I like how Tayda supplies their resistors because I can check the whole bag quickly. I find most of their stuff is in spec, but occasionally I have to pull a few out of a bag and pitch them. Happens more for low values like 10R. I've never had a mislabeled bag before, that's concerning.
I did a look over your picture to see if I noticed any other alternate values. Maybe double check the values on R38 and R32.
If you still have noise after setting the trims, suggest the audio probe. I just built this and it's crazy quiet for a flanger.
I did a full audit of all the resistors but can't hurt to double check those particular ones. :D
Quote from: gordo on July 15, 2022, 01:39:46 AM
+1 with Bio77, this thing is crazy quiet with a decent power supply.
I might try a different power supply. The one I got is a pretty cheap one so...yeah...
Quote from: Thewintersoldier on July 15, 2022, 12:38:15 AM
I have never had tayda put the wrong resistors in the bags, never once in like 7 years. In fact the only time I ever got the wrong thing from them was because I clicked on the wrong thing. I also don't think where they ship from has anything to do with not checking values before a part is inserted. Doesn't seem fair to blame a company for an error of the builder.
I've had a few errors here and there from Tayda, usually a missing part...but that's been rare. Nothing like this though. Just in the past two orders I had parts that were wrong. In one order, what should have been MLCC capacitors ended up being a set of flat washers for toggle switches. Label was correct but the bag contained washers instead of caps. And then there's this one...bag says 3k resistors but what's in it is actually 620 ohm resistors.
Only conclusion that I can make is that they changed something about their business. With all the updates to how shipping is handled, something seems a bit askew. Used to be that U.S. orders were shipped out of a warehouse here domestically with some orders being delayed due to parts being shipped from overseas. But many of those orders were processed and shipped really fast. Not the case anymore. Seems virtually everything is now processed and shipped from Thailand...which isn't a problem really if orders are processed accurately.
Don't know what to say really other than that's been my experience lately. Doesn't exactly leave me with a fuzzy feeling. It's one thing if I'm ordering parts for a personal build. I can deal with that. It's another if the parts order is for a batch of pedals I'm building to be sold on Reverb or the like. Not exactly a great scenario. Mistakes happen...I get it. But this just seems to be a bit of a trend.
Quote from: jeffwhitfield on July 15, 2022, 02:02:58 AM
Quote from: Thewintersoldier on July 15, 2022, 12:38:15 AM
I have never had tayda put the wrong resistors in the bags, never once in like 7 years. In fact the only time I ever got the wrong thing from them was because I clicked on the wrong thing. I also don't think where they ship from has anything to do with not checking values before a part is inserted. Doesn't seem fair to blame a company for an error of the builder.
I've had a few errors here and there from Tayda, usually a missing part...but that's been rare. Nothing like this though. Just in the past two orders I had parts that were wrong. In one order, what should have been MLCC capacitors ended up being a set of flat washers for toggle switches. Label was correct but the bag contained washers instead of caps. And then there's this one...bag says 3k resistors but what's in it is actually 620 ohm resistors.
Only conclusion that I can make is that they changed something about their business. With all the updates to how shipping is handled, something seems a bit askew. Used to be that U.S. orders were shipped out of a warehouse here domestically with some orders being delayed due to parts being shipped from overseas. But many of those orders were processed and shipped really fast. Not the case anymore. Seems virtually everything is now processed and shipped from Thailand...which isn't a problem really if orders are processed accurately.
Don't know what to say really other than that's been my experience lately. Doesn't exactly leave me with a fuzzy feeling. It's one thing if I'm ordering parts for a personal build. I can deal with that. It's another if the parts order is for a batch of pedals I'm building to be sold on Reverb or the like. Not exactly a great scenario. Mistakes happen...I get it. But this just seems to be a bit of a trend.
You are the first person I've heard of having these issues. The real question is why aren't you checking values before you populate and did you learn your lesson🤪
Quote from: Thewintersoldier on July 15, 2022, 02:26:04 AM
You are the first person I've heard of having these issues. The real question is why aren't you checking values before you populate and did you learn your lesson🤪
Oh, man, I seem to attract stuff like this. If it's not errors with orders it's defects with stuff I buy. I've had a few defective pedals that I had to exchange this past year. Before that, when I was building my two bikes, I had a bunch of parts with defects.
And, yeah, definitely learned my lesson. I've been testing capacitors and such prior to installing...but not so much the resistors. So, yeah, will be checking those to make sure that A) the actual value matches what's on the bag and B) that the value falls within an acceptable range. Almost never have problems with resistor measurements though.
Quote from: jeffwhitfield on July 15, 2022, 02:02:58 AM
Quote from: Thewintersoldier on July 15, 2022, 12:38:15 AM
I have never had tayda put the wrong resistors in the bags, never once in like 7 years. In fact the only time I ever got the wrong thing from them was because I clicked on the wrong thing. I also don't think where they ship from has anything to do with not checking values before a part is inserted. Doesn't seem fair to blame a company for an error of the builder.
I've had a few errors here and there from Tayda, usually a missing part...but that's been rare. Nothing like this though. Just in the past two orders I had parts that were wrong. In one order, what should have been MLCC capacitors ended up being a set of flat washers for toggle switches. Label was correct but the bag contained washers instead of caps. And then there's this one...bag says 3k resistors but what's in it is actually 620 ohm resistors.
Only conclusion that I can make is that they changed something about their business. With all the updates to how shipping is handled, something seems a bit askew. Used to be that U.S. orders were shipped out of a warehouse here domestically with some orders being delayed due to parts being shipped from overseas. But many of those orders were processed and shipped really fast. Not the case anymore. Seems virtually everything is now processed and shipped from Thailand...which isn't a problem really if orders are processed accurately.
Don't know what to say really other than that's been my experience lately. Doesn't exactly leave me with a fuzzy feeling. It's one thing if I'm ordering parts for a personal build. I can deal with that. It's another if the parts order is for a batch of pedals I'm building to be sold on Reverb or the like. Not exactly a great scenario. Mistakes happen...I get it. But this just seems to be a bit of a trend.
Have you tried emailing Tayda about your issues? From my own personal experience, Hugo is a pretty stand up dude and tries to make things right when something like what you're describing happens. On a different forum, someone had an issue with an enclosure and Hugo hooked them up with a free replacement. Just food for thought.
Quote from: blackhatboojum on July 15, 2022, 03:43:46 AM
Have you tried emailing Tayda about your issues? From my own personal experience, Hugo is a pretty stand up dude and tries to make things right when something like what you're describing happens. On a different forum, someone had an issue with an enclosure and Hugo hooked them up with a free replacement. Just food for thought.
I probably will here soon. He definitely needs to be made aware of these few issues. If it's happening to more customers then it's a trend he'll likely want to tamp down on.
They are good peeps to deal with. I've had a few minor errors but they've been pretty rare. I used to test every part before I put it in on one of those little multi tester thingies but have gotten lazy lately.
The supply I used is an old as dirt Radio Shack (!!!) bench power supply that is amazingly stable. I've had it for 40+ years. I've also used the 18v out of a Dunlop Brick.
Quote from: gordo on July 16, 2022, 01:07:20 AM
They are good peeps to deal with. I've had a few minor errors but they've been pretty rare. I used to test every part before I put it in on one of those little multi tester thingies but have gotten lazy lately.
Yep, definitely good people. Did report it and they gave me some credit on my account. :)
Quote from: gordo on July 16, 2022, 01:07:20 AM
The supply I used is an old as dirt Radio Shack (!!!) bench power supply that is amazingly stable. I've had it for 40+ years. I've also used the 18v out of a Dunlop Brick.
I got a different power supply and it made a world of difference. Quality power supply is super, super important for sure. Cheap ones suck and just cause noise. :P