Author Topic: 8Ball Problem  (Read 633 times)

aaronarmi

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8Ball Problem
« on: September 07, 2016, 10:46:38 AM »
Just finished this 8Ball build and I'm barley hear the effect way below the noise floor. I've rocked boxed and unboxed. So I don't believe it to be a grounding issue.

Voltages Average

1: 4.57
2: 4.57
3: 2.27
4: 0
5: 4:46
6: 6.62
7: 4.6
8: 9.14

madbean

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Re: 8Ball Problem
« Reply #1 on: September 07, 2016, 11:05:00 AM »
Voltages are a bit off. Pin3 is a bit low and pin6 is high.

Three things I would first do to debug this -
1 - Try a different IC (any dual op amp) and recheck the output and voltages.
2 - Check pin5 and pin3 with the IC pulled and see if you are still getting about 4.5v.
3 - Audio probe pins 3, 1 and 7 of the IC in that order then lug3 of the Tone pot to see where the signal is dropping out.
I own madbeanpedals (duh). I am part owner of Function F(X).

aaronarmi

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Re: 8Ball Problem
« Reply #2 on: September 08, 2016, 07:44:24 AM »
Thank you so much for the quick reply Brian. So, I had tried switching out the IC with other JRC's and TL0's. Should have mentioned that (my bad). I tried your step two and got roughly the same voltages. I don't have a probe. I know shame shame   :-\ I'll have to grab one as soon as i get the extra scratch. Another thing I should have mentioned is during the build I did carelessly solder the DPDT to the wrong side of the board like a dumb dumb. Needless to say, I played Hell desoldering it off. And there may have also been some prying involved. That being the case, I noticed from the the layout in the build doc there's power running to the DPDT. Could my issue be a burned out DPDT or fried circuit board?

midwayfair

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Re: 8Ball Problem
« Reply #3 on: September 08, 2016, 10:17:49 AM »
No one buys an audio probe. :P

You can make one with a single transistor and a couple alligator clips. Clip the sleeve to ground and the tip to one lead of a capacitor. Plug the other end into your amp. Poke around your circuit with the free lead of the capacitor.

If you want something more durable, take the end off a cable and solder the capacitor where the tip would connect.
Myself's music & things I make: http://jonpattonmusic.com. My band: http://midwayfair.org. PCBs of my designs from: http://www.1776Effects.com (Bearhug Comp & Cardinal Harmonic Trem); http://www.jmkpcbs.com (Hamlet+ delay & Blue Warbler envelope vibe); Snow Day OD/Flabulanche: www.madbeanpedals.com

aaronarmi

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Re: 8Ball Problem
« Reply #4 on: September 08, 2016, 11:22:39 AM »
HaHa thanks Jon! I'm still green with this pedal building craziness.

P.S. I've got my eye on your Rub-A-Dub and Echo PCB's. Probably gonna grab em in the next month or so after my next few builds!

kc chin

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Re: 8Ball Problem
« Reply #5 on: February 27, 2018, 04:05:53 AM »
Hi, I am new in this forum and in pedal building world. Just completed building the 8ball and tested it. The "soft" clipping side worked fine however there was this weird "sputtering" and "spitting" at the dying end of each note played on "hard" clipping side with the 2 red LEDs. This didn't happen on the "soft" side at all.

I also realised that i mistakenly used a DPDT on-on-on instead of the recommended just on-on. Was the switch the culprit in giving the "sputtering" thingy (switch at mid and down position)? Or was it defective LEDs?

Please help and thank you in advance.