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PostPosted: Mon Feb 19, 2018 2:15 pm 
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Hey guys got my bg fuzz finished and the LED works, bypass works fine, but has very minimal output. Almost not audible. The volume and tone pots are in the correct spots, and i've checked the resistors. Assumed it was a cold joint, so i went over the board top and bottom, and the jacks and footswitch twice now. Hasn't changed for better or worse.

One thing i noticed before assembly was some dried crud on the toshiba IC. I scraped a lot off before installing thinking it was some kind of old rust inhibitor.

I'm aware of the solder bridge between the two 10k resistors that connect to pin 3 of the IC. The schematic shows they connect at the same node so I assume it's ok.

Thanks for any help!ImageImageImageImageImage

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PostPosted: Tue Feb 20, 2018 4:18 pm 
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please take voltage readings of the the IC and transistors. Do you have a signal tester?

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PostPosted: Tue Feb 20, 2018 5:01 pm 
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Here's the voltages; unfortunately i don't have a signal tester.Image

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PostPosted: Fri Feb 23, 2018 12:32 pm 
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Your power supply is a bit low. That's not necessarily a bad thing if it's intentional, but if you aren't meaning to intentionally sag your voltage, then it means you have a problem. Perhaps not with the pedal, but with the supply itself. If you're using a battery, it's probably pretty close to being dead. For the most part, your voltages look good relative to the power supply voltage, i.e., your reference voltages are about half of what your supply voltage is. However, pin 6 is too low regardless of the low supply voltage. It should be closer to 3.75 like pins 2 and 3. R8, R9, and/or C4 may need to have their solder joints reflowed.

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PostPosted: Sat Feb 24, 2018 12:15 am 
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Ok i'll have to reflow the joints when i get a new iron tip. I checked with both a battery and good known isolated psu, but written results are with the battery. Thanks for the reply!

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PostPosted: Sun Feb 25, 2018 1:21 pm 
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I've reflowed those joints with a clean tip and new solder, and i'm getting the same result. Using the isolated psu i get 4.41v on pins 2 and 3, 0.02v on pin 1, 1.39v on pin 6, and 9.02v on pin 7. Just so i understand correctly, pin 6 looks like it gets it's voltage from pin 2. How could the voltage be relatively close if it goes through a 2m2 resistor first?

I've checked voltage at nodes in the area. The node of R9 and pin 2 is 4.41v, then the other side of R9 goes to 1.39v. That makes perfect sense to me (not being an electrical engineer). Where would pin 6 be getting the higher voltage from?

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PostPosted: Sun Feb 25, 2018 1:34 pm 
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robgar91 wrote:
...Just so i understand correctly, pin 6 looks like it gets it's voltage from pin 2. How could the voltage be relatively close if it goes through a 2m2 resistor first?

I've checked voltage at nodes in the area. The node of R9 and pin 2 is 4.41v, then the other side of R9 goes to 1.39v. That makes perfect sense to me (not being an electrical engineer). Where would pin 6 be getting the higher voltage from?

The op amp doesn't work as you describe. The voltage at pin 6 does NOT come from pin 2; it's generated internally within the op amp, ultimately coming from the V+ source on pin 7. If you check out THIS VIDEO, it'll help you understand how an op amp with a feedback loop (which is what that is between pins 2 and 6) works.

My suspicion is that, if everything else checks out (correct component values; good solder joints) and seems to be working, your op amp is faulty and needs to be replaced.

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PostPosted: Sun Feb 25, 2018 2:49 pm 
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Thank you for the video! I made it 5 minutes before i couldn't take the guy's voice anymore lol. And thank you for the explanation i knew i was missing something. I will be happy to provide additional pics or voltage readings, but i have the suspicion of a faulty part as well. Should i email support or can i provide anymore tests?

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PostPosted: Mon Feb 26, 2018 2:05 pm 
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contact sales@buildyourownclone.com

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PostPosted: Sun Mar 11, 2018 11:58 am 
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That was the issue! This is a very cool sounding fuzz that's actually usable and doesn't woof out the bottom end. Thanks for the help!

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