SOLVED Sunflower Fuzz - power but no sound

[benevolent-fur]

Hi all,

Looking for some advice on what I've mucked up here on my first pedal attempt. I'm able to get power (i.e. the LED turns on). However, when I engage the footswitch the guitar signal completely cuts out.

Hoping someone can see a simple mistake I've made. The assembly wasn't without it's hiccups. I soldered the germanium transistors to the sockets without any heatsink before I read that they are sensitive to heat. I also installed one of the capacitors backwards before I realised that polarity matters (and desoldering was required)! Apart from that there weren't any glaring mistakes that I noticed. I appreciate it's not pro level soldering, but I don't think any of the solder joints are touching.

Cheers.

 

[jwin615]

Charge pump is inverted for one

 

[benevolent-fur]

Thanks I spun that around, but no change unfortunately.

 

[Nostradoomus]

Where did you get your transistors? How did you bias them?

 

[benevolent-fur]

The transistors came with the kit I bought from musikding. Haven't tried biasing them as there is no signal at all once the pedal is engaged.

 

[Nostradoomus]

okay, the bias can completely cut off all the signal if it isn't set properly. Hook up your guitar and amp as usual with the volume knob on 10, adjust the bias trimmer, you will hear something eventually if you have the transistors oriented correctly.

 

[benevolent-fur]

Thanks for the suggestion, but no luck there I'm afraid. Still no signal when the footswitch it turned on, but the signal is fine when the pedal is off. Makes me wonder if it's some type of grounding issue...I've taken the entire thing out of the pedal enclosure in case it was touching the walls, but the issues persists.

 

[Nostradoomus]

your 1n5817 is backwards, upon a bit of inspection

 

[benevolent-fur]

Okay, I guess I know what I'm trying to take apart tonight (it just had to have the pot covering it didn't it?!). Thanks for the help. All very new to me. I've wired up a few guitars before but never had to worry so much about polarity. Looks like I'll be learning the hard way!

 

[jwin615]

That's actually kinda good news because it means you may not have fried your inverter. Unless your DC jack is backwards too. The trifecta!
Once you flip your D100, check the output voltage of the charge pump.
Negative DMM lead to ground, red lead to
Pin 8: 9v ish
Pin 5: -9v ish


If you are struggling with desoldering, you can snip the diode in half and do one leg at a time. You'll obviously need a new 5817 but you can replace it with a jumper temporarily as long as you are certain your DC jack is wired properly and you are using a center negative adapter.
Actually. I would go ahead and test the diode as it may be shot already.
The fact that your LED turned on tells me your DC jack is probably correct.

okay, the bias can completely cut off all the signal if it isn't set properly. Hook up your guitar and amp as usual with the volume knob on 10, adjust the bias trimmer, you will hear something eventually if you have the transistors oriented correctly.

I read this as "amp on 10" and it gave me a good chuckle.

 

[Nostradoomus]

I read this as "amp on 10" and it gave me a good chuckle.
View attachment 95007

sometimes i drink a little

 

[benevolent-fur]

Thanks everyone! After a few solder iron burns and a couple of choice words I was able to get the diode out (ended up having to snip it as suggested) and replace it with a new one and hey presto we have a fuzz face!! Embarrassed to admit that I didn't notice the idiot-proof diagram on the PCB showing the way the diode was supposed to be oriented when I first installed it...this is how we learn.

Definitely keen to jump into the next pedal, but I might put that Low Tide I ordered to the back of the queue until I've completed a few easier models.