Nucleon Superfuzz

[dannoceti]

I built the nucleon superfuzz over the weekend, first build of 2015. It sounds great, and I learned a lot about silicone transistor matching. Right now q4 and q5 are at a hfe of 590 and 600, so I guess that's a bit high, but they are socketed so I can change them later.  I did get a switch pop when activating. I tried alligator clipping a pull down resistor, but it didn't help. I think it's the switch so I'm going to have to replace it, which sucks because this is my cleanest wiring job to date. And I know, rock it before you box it, but I never have (because I don't know how) and am impatient. This is my 18th build and have been able to get everything else to work, but should probably look into a testing rig.  I think I might add a optical click less to try and fix the pop. Also I had originally ordered cream fender cupcake knobs, but one didn't fit so I hit it with a rubber mallet and it cracked, haha oops



Sent from my iPhone using Tapatalk

[lars]

That is some very nice, clean wiring there!

I'm not surprised that a pulldown resistor didn't help with the "pop". I've never had a pedal that popped where a pulldown resistor fixed the problem. Usually making sure the input is properly grounded on bypass will and does help. But other than that, you have to look into buffered "clickless" bypasses and the like. Popping is usually an indication of a bigger problem than just the broken record "add-a-pulldown resistor" (waste of time IMHO).
You're most likely right about your switch having a mechanical problem, so that's a great place to start.

[Hogharry]

That's a really neat job, well done.

A test rig is the way to go. There's nothing worse than finishing a neat build in a beautiful box, then it doesn't work. It also means that you get to hear the ones that do work sooner, so it actually works well for impatient people (me included).

[davent]

Where does the ground from the input jack connect?

[Rockhorst]

Hey Dannoceti, that's super nice looking. Great to hear about the build

I have a suggestion to fix the switch pop: It's usually recommended to ground the input of the board when in bypass (which is what you're doing with that diagonal wire from top left to lower middle). It's my experience that this can actually cause a switch pop, esp. when using a pull down resistor on the board. I started omitting that connection last year and never had switch pops since. So I'd suggest clipping that piece of bare wire and see if it works. It might fix the problem and you don't have to mess with your clean looking wiring. If it doesn't work out, it's easy to put it back in.

@Davent: the ground from the input jack connects to a ground pad on the board (it's the second wire from the left going to the board, it seems to go under the first).

[davent]

The curse of monocolour wire culture, I'm still puzzled... i'm looking at the blue wire from the ground lug of the input jack, heads east then a 90º turn south at the end of the jack disappearing behind the switch.
dave

[Rockhorst]

The curse of monocolour wire culture, I'm still puzzled... i'm looking at the blue wire from the ground lug of the input jack, heads east then a 90º turn south at the end of the jack disappearing behind the switch.
dave

I'm not too sure now...indeed I prefer solid black for ground wires and different colors for power and signal wires. The ground pad on the lower left was intended for grounding the jack when I designed the PCB. No clue if it's used that way, but I think so.

[davent]

Yes, i'm all for colour coding too, the g. pad you mention is clear but can't tell what's connected there. I count eight blue wires heading to/from the switch but can only account for six connecting to the switch so hard to know what might be connected where.

[Rockhorst]

It follows my preferred scheme:
left vertical row: all input (top to bottom: board in, pedal in, bypass to output)
middle vertical row: from LED (which is board mounted), ground (middle lug) for LED and board input (lower connection)
right vertical row: all output (board out, pedal out, bypass from input)

[lars]

I have a suggestion to fix the switch pop: It's usually recommended to ground the input of the board when in bypass (which is what you're doing with that diagonal wire from top left to lower middle). It's my experience that this can actually cause a switch pop, esp. when using a pull down resistor on the board. I started omitting that connection last year and never had switch pops since. So I'd suggest clipping that piece of bare wire and see if it works. It might fix the problem and you don't have to mess with your clean looking wiring. If it doesn't work out, it's easy to put it back in.

I would second the above suggestion, given that pcb is almost guaranteed to already have a pulldown resistor in the layout. Dunno why most layouts assume you have to have a pulldown resistor on the input, but again, at some point years ago somebody got it to solve the "pop" problem on true bypass, and everybody ran with it as the end all solution to all popping. Now it's set in stone that you have to add pulldowns to your pcb layout. I always leave them off, especially when building "vintage" effects. I don't want to deal with the potential changes to my input impedance that pulldown resistors can and do create.

[dannoceti]

Hey guys so it's hard to see in the pic but I wired it exactly like this picture I will clip the wire in the lugs tonight to see if it helps. Great suggestion, thank you!


Sent from my iPhone using Tapatalk

[davent]

And i have to apologize, i was right out to lunch on the input jack lugs... can't see for looking, dazed and confused i'll crawl back into my igloo, 166 days until summer...
dave

[dannoceti]

Clipped the jumper on the lugs, but still a pop. I'm just going to add a optical clickless, if that doesn't work I'll rewire the LED off the board. My fault for not rocking before boxing, but I don't mind, trouble shooting is what has helped me learn the most about building pedals


Sent from my iPhone using Tapatalk