Paragon Mini (No Sound)

[alan441]

Hey Guys!

Finished this Paragon mini build a few weeks ago, but I haven't been able to get it to function yet. It currently works in bypass so there probably isn't an issue with the wiring. When activated the LEDs function, but absolutely zero sounds passes. The same is true if only one side is on or if both are. not even a hum. Weird! I tried a few different kinds of chips but nothing changed.

If any of you guys have a chance to check out the pictures below that would be awesome! It's always good to have another pair of eyes.

Thanks again!
Frankie A.

(I offboard wired 5 of 6 pots to fit in a bigger enclosure)

 

[Nostradoomus]

Is there any tape on the pots under the circuit board to make sure they aren’t grounding out?

Also the angle of your output jack, the long tab is for sure not touching that pot when a cable is in it?

 

[ErickPulido]

I had similar problem, it was a bad solder joint that got cracked once i boxed the pcb, then I removed it and saw it was floating, this was a capacitor in the signal pat

 

[Barry]

Is there any tape on the pots under the circuit board to make sure they aren’t grounding out?

Also the angle of your output jack, the long tab is for sure not touching that pot when a cable is in it?

Yeah those pots definitely need something on them, and that jack is too close for comfort

 

[alan441]

Is there any tape on the pots under the circuit board to make sure they aren’t grounding out?

Also the angle of your output jack, the long tab is for sure not touching that pot when a cable is in it?

So the top middle Pot is actually a board mounted right angle keeping the whole board away from the other five pots. But Just in case I double checked by moving the board and there is zero sound response, not ever crackling. Makes me think its not the pots, but I'm going to pull it apart soon and i'll definitely put some pot condoms on there for good measure. Thanks for the tip!

 

[Pimpoftheyear70]

Your input jack looks suspiciously close to the back cover ( When in place )
When you insert the cable the jack pushes the tang back possible touching the rear cover ?
Does it pass audio with the rear cover off ?

What are you using to isolate the PCB from the pots ?

 

[Chuck D. Bones]

Check the voltages on the opamp pins. Pin 4 should be 0V, pin 8 should be 9V, everything else should be 4.5V.

 

[oldacid]

Hey did you ever solve this? Same issue with a Paragon mini I just built.

 

[Chuck D. Bones]

This might be helpful.

 

[oldacid]

Fair enough. Was genuinely curious if he solved it or gave up. My opamp voltages are identical on both channels, and I'm close enough to 9v on pin 8 but every other pin besides ground is wrong.
1-1.31
2-1.29
3-2.12
4-0
5-0.90
6-1
7-1.35
8-8.63

 

[Chuck D. Bones]

Vref is knackered. Visually inspect the board. Verify R12 & R13 are 47K. Look for bad solder joints. If the ICs are socketed, pull them out and remeasure the voltage on pin 5.

Photos. Must have photos.

 

[danfrank]

I had this problem with mine and all the voltages on the two op amp pins were around 8 volts except for pin 4 which was at ground (0v). Both sections behaved the same. As soon as I took it out of the enclosure, it worked.
One side of the PCB was touching the side of the enclosure and it looked like the top tone pot pins were VERY close to the bottom tone pot. I never did figure out which one it was, but I did put a piece of electrical tape in between the top and bottom pots and centered the PCB so it's sides weren't touching the case. It worked after that after it was in the enclosure.

 

[Chuck D. Bones]

Electrical tape is unreliable. Don't be surprised if the problem resurfaces. This thread describes how to align the pots and board prior to soldering so the board doesn't touch the enclosure.

 

[danfrank]

Well it was electrical tape and a THICK slab of velcro. I like using the fuzzy side... The "hook" side looks too itchy for comfort.

 

[oldacid]

Yep, R13 was 4.7k, not 47k. Trying to work too fast. Also C13 had a cold joint. I took out the board mount pots and replaced them with off-board as that was making me nervous as well and all is good now except: the first footswitch (left) activates the second (lower) row of pots, second switch activates the top row? Maybe this is normal operation as I've never seen this pedal in action, but that seems strange to me.

 

[danfrank]

Yes, looking at the face of the pedal like you would be using it, left footswitch activates bottom pots. The left footswitch is actually the second "bluesbreaker", the one that analogman sets as boost. The right footswitch is the first bluesbreaker that analogman sets as overdrive (soft clipping).

 

[oldacid]

Ah ok, now that I've thought about it I can see it both ways. Working left to right the first channel would be left then boost on the right (I have a few pedals like this), but signal flows right to left on a pedalboard so it makes sense that way too. Thanks for clearing that up.