Populaed a Nucleon Super Fuzz and I get no signal. I probed it and found the signal loss is between lugs 2 and 3 of the 50kb Expander Pot. Bad Pot? Nope, switched it out and same results. Re-Flowed solder joints, same result. Here are my voltages
Q1: C 144.2mv / B 0.684v / E 5.33v
Q2: C 4.79v / B 5.37v / E 9.15v
Q3: C .3mv / B .1mv / E 9.08v
Q4: C .1mv / B .629v / E 15.8mv
Q5: Unstable
:o
The Schematic is here
http://rutgerockhorst.com/nucleon01.zip
I'd pull out the pot and make sure that lug 2 isn't connected to ground (lug 1) with a trace on the PCB (a manufacturing error), just use your continuity setting on your DMM and find where the signal is being shunted to ground in that area.
Hey Murdog, do Timbo's check and let me know. It sounds like a weird point for the signal to cut out. Just shows how valuable an audioprobe can be. I'll be happy to help of course, so please update :)
What happens if you short the pot out, so directly connect pins 2 and 3 or bypass it all together by going from electrolytic to electrolytic cap? Another thing to watch out for is a possible solder bridge between the Expander pot and D2, the pads are quite close together.
This should help with the debugging:
(http://i35.photobucket.com/albums/d154/rockhorst/SFuzz_schem_zps3826bd58.png)
(http://i35.photobucket.com/albums/d154/rockhorst/SFuzz_zps1e870f78.png)
Hmmm....so C5 negative to C6 positive did not work. I checked and the pad for lug 2 is grounded. I attempted to bypass this by connecting the positive pad of C6 to Lug 2 of the pot and pulling the lug 2 leg completely from the pcb. Still no luck. It appears that the positive pad for C6 is also connected to ground somehow. Sounds like a similar problem as the other guy who posted in a separate thread has. Checked all of my solder points and no bridges. With it fully populated this is going to be a bear to find where ground is tied in. Rutger, any chance you can probe around an unpopulated board to check for this? Thanks!
I fired my super fuzz up a couple weeks back with no problems. This is sounding more and more like a fabrication error on some of the PCBs. It doesn't happen often but this wouldn't be the first time I've seen it.
Though the design files used where all the same, I did order them in separate batches. I'll probe around a few different boards. Thanks for the detailed description, I'll get back to you in a few hours!
Murdog, could you try one more thing for me? Bypass both the pot and C6. So connect negative of C5 to the node that's connected to negative C6. If that doesn't work, go from the last transistor that outputs sound and connect it to a node further upstream until you get sound coming through again (for instance, connect the output of C5 to the input of Q6 and work back). That would make it easier to isolate which sections are malfunctioning.
I just probed around the five remaining board and I can't find a problem with those. Let's do a few more tests and if we can't resplve the issue, I'll send you a fresh board to compare and rebuild.
So I had a minute to play around and found that c5 output to the balance pot I get signal at lugs 1 and 2, not 3. From the schematic it looks like lug 1 should be going to ground and not lug 3. Right?
i'm following this thread. did you guys find a solution?
@Murdog: yes, lug 1 should be ground, lugs 2 and 3 should carry a signal. Notice the '1' printed on the pcb silkscreen and the orientation of the pot on the other side. It sounds like you might've put in the pot the wrong way round? (Just to be sure: the pots should not stick out but be entirely covered by the PCB. Lug 1 is the square pad. Remember Brian's mnemonic: 3, 2, 1 pot shaft faces down)
@Pietro: working on it
Yes I have it in correct :)
Ok, I just needed to check...weird, cuz like I said: the 5 boards I have left don't have this issue. I don't want to post the entire trace layout, but if I send a picture of it to you, could you compare the top and bottom traces of your board against that? Check your PM in a few minites.
As far as I can tell, it looks correct. That being said, it's difficult to say for sure with it fully populated. Here's something else that's strange, if I turn the expander pot fully counterclockwise it turns the LED off.
I just noticed that this layout is different from mine. Has anyone verified this particular layout yet?
Yes, I did. The pictures I posted of the board are a match with the very first proto I build, I just checked. This is sounding so weird to me. It's been about 10 months since I designed and build these, I'm trying to fill in the details. I have to .brd files on my computer: one is complete, the other shows no traces at all. As far as I can tell, all the boards have been manufactured from the correct .brd file, but there may have been a mistake. I can't check that by words alone. Could someone please post a picture of their board (Stomptown, Murdog or Pietro).
Here is the PCB that I got working without issues.
(http://music.codydeschenes.com/wp-content/uploads/2014/01/20140123-190542.jpg)
Looks like the picture of the one you posted on the first page.
Cody
Thanks for posting Cody, that's a great help.
I've traced the chronology of my Super Fuzz boards:
October 2013: uploaded prototype board to OSH Park, build working prototype
December 2013: placed medium run order with OSH, uploaded a new design file. This doesn't explain Murdog's and Pietro's problems though, since this is the board Cody used and is pictured above
January 2013: due to popular demand, reordered the original proto board, same file as on the OSH Park server in October 2013
To identify which board you have, look at the 9V and ground pads in the lower left corner. The October-January version indicates GND (once) and +9V. The December production run has GND, G-J and +9V printed on it (as in SelfDestroyer's photo).
Pietro and Murdog where the last ones to get a Super Fuzz, so my guess is they have a board from the third batch, which should be identical to the first.
So to recap: contrary to my previous statement, there are two different Super Fuzz designs around. I apologize for that mistake. However, this doesn't explain the problems Murdog and Pietro are having because both designs have produced working Super Fuzzes by different people. So I'd still like to see a photo of Pietro and Murdog's boards.
@Murdog: from your last statement it makes sense to remove the CLR resistor at the top of the board, thus disconnecting the LED part of the design. See what that does.
Also, what value did you use for CLR and how did you connect the L1 and L2 pads? Could you check with your DMM if there's a connection between L1 or L2 and lug 1 of the pot?
Quote from: Rockhorst on August 03, 2014, 09:34:37 AM
Also, what value did you use for CLR and how did you connect the L1 and L2 pads? Could you check with your DMM if there's a connection between L1 or L2 and lug 1 of the pot?
FYI, On my build I used a 4k7 CLR but I ended up using my LED on my 3PDT board and not on your PCB. I did not soldier on a LED at all onboard of the Superfuzz PCB.
Cody
Here's a gutshot of my SuperFuzz proto
(http://i35.photobucket.com/albums/d154/rockhorst/IMG_2386_zps396558f8.jpg)
I got one of the boards from the same batch as Cody. Mine works find although like Cody I left off the onboard LED...
hi. i checked the traces on my pcb. the bottom looks the same as the files, for the top i cannot be sure but it seems right. it is fully populated and it is in a poor condition now because of the desoldering work that i did a few times. the files with the traces help a lot to visualize. i didn't use the led.
btw, my pcb looks like your proto
Hi Pietro, PM me your address, I'll send you a fresh board. Sometimes it's best to start over if you can :) I'll populate a board somewhere in the next few days as a double check. Still hope to fix Murdog's.
ok, but i wanna pay for it. a fresh start is a good idea. you know, more that i look at the board more that i don't see anything wrong with it, i don't know. sometimes they just go bad.
I don't have mine available right now to look at but I'm sure it is a different layout than Cody's.
Quote from: Rockhorst on August 03, 2014, 10:04:48 AM
Here's a gutshot of my SuperFuzz proto
(http://i35.photobucket.com/albums/d154/rockhorst/IMG_2386_zps396558f8.jpg)
This is the layout that I have.
Pulled the CLR and the LED just for grins and no change.
I'm losing signal somewhere between C5's negative and Q6's base. I just can't figure out what our why :o
i'm gonna butch mine tonight, to see if i find something with the traces.
the boards may really have manufacturing difects
Pietro, let's just keep it shipping cost then. Really, more than that is not necessary.
ok. btw, my pcb now is empty and it looks like the files you sent me. i understand that the bottom plane is ground and the top plane is power. everything seems good to me.. i don't understand.
I pulled all of the components between C5 and Q6. Checked them all and they are all functional. Just for the hell of it I replaced them all. Still same issue. Not sure where to go at this point.
I'm out of suggestions too. Give me a few days to build and verify one of the boards I have in stock and if it passes I'll send you and Pietro a new board. If I run into problems I'll order fresh ones from OSH Park.
Quote from: Rockhorst on August 05, 2014, 11:23:03 AM
I'm out of suggestions too. Give me a few days to build and verify one of the boards I have in stock and if it passes I'll send you and Pietro a new board. If I run into problems I'll order fresh ones from OSH Park.
That's mighty kind of you. Let me know how it goes :)
Update: I just populated and verified a board. No problems found, fired up straight away. Murdog and Pietro: check your PM. I can either send you a new pcb or the populated board if you want the short cut :)
the new pcb arrived today. i built it and it worked at the first fire. very cool. i don't like the tone stack, but that has nothing to do with the pcb. i would like to say i'm sorry for my behavior to rockhorst, you are a good guy.
thanks to everyone guys
It's all cool. I'd be curious to see a picture of the box, so maybe post that in the build report section?
@murdog: how's yours coming along?