I think I killed it... PLZ HALP

Started by PubliusValerius, July 01, 2016, 11:04:15 AM

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PubliusValerius

So... I did like my second pedal mod project, which was converting my Ibanez TS-5 into an 808 by virtue of swapping the two resistors and Opamp (JRC4558D with socket) - I also went for asymmetrical clipping by installing a 1N4002 diode and a red LED (initially had polarity wrong on the diode, but desoldered and fixed it before I added any power to the pedal - I'm still learning), and I read about swapping out the .001mf cap coming off of the flip-flop switch to a .01mf which is supposed to make switching more reliable, so I swapped that as well. Plugged it all in and...... nothing.

I know it's probably hard to help much without seeing it, but can you guys share any wisdom or place to start first as I test? Could I have overheated the board itself when I was desoldering? Any help or guidance would be appreciated.

PubliusValerius

I had the wrong Opamp in it... I was running a RC4558P when I should have had a JRC4558D - I swapped them out, and now it's working! But it won't switch off... it stays on no matter how many times i hit the switch.

R.G.

 You're  learning a valuable lesson: until you fully, fully understand what a change does, never change more than one thing at a time, so you can go back from "Uh-oh. That didnn't work."

Where to start first is contained in that "Debugging thread: what to do when it doesn't work" sticky that you have to ignore to get to the rest of the forum  posts.  Highly suggest that you read that thread, as it's specifically intended to help people in your situation.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Tony Forestiere

Quote from: PubliusValerius on July 01, 2016, 11:04:15 AM
...and I read about swapping out the .001mf cap coming off of the flip-flop switch to a .01mf which is supposed to make switching more reliable, so I swapped that as well. But it won't switch off... it stays on no matter how many times i hit the switch.

Not meaning to be an ass, but how is that working out for you?
Welcome, and heed RG.
"Duct tape is like the Force. It has a light side and a dark side, and it holds the universe together." Carl Zwanzig
"Whoso neglects learning in his youth, loses the past and is dead for the future." Euripides
"Friends don't let friends use Windows." Me

PubliusValerius

Quote from: Tony Forestiere on July 01, 2016, 02:43:51 PM
Not meaning to be an ass, but how is that working out for you?
Welcome, and heed RG.

Well, it was one of our fellow forum members here on this site that strongly suggested the cap switch, and stated he had done it successfully multiple times - so I took his advice.

bluebunny

Quote from: PubliusValerius on July 01, 2016, 12:29:03 PM
I had the wrong Opamp in it...

A 4558 is a 4558.  Kinda.  It's a "YMMV" thing, but none is "wrong".  It's just a dual opamp.  A TL072 or OPA2134 would do just as well (for undocumented values of "well"...).
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Ohm's Law - much like Coles Law, but with less cabbage...

GibsonGM

^   Yup.   Maybe the 1st opamp was loose in its socket, or bad?     As long as the pinouts match, you are golden, and in this case they sure do.

Sounds like there might be a few other things need checking there, Debugging page....
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

PubliusValerius

UPDATE: Fixed it. And it sounds like the classic 808 like I wanted! All it was was a tiny little solder bridge I had on that new cap I put in. And I can attest that the bigger cap swap is beautiful. Clean switching every time.

GibsonGM

  • SUPPORTER
MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

Tony Forestiere

Quote from: PubliusValerius on July 01, 2016, 03:14:27 PM
Quote from: Tony Forestiere on July 01, 2016, 02:43:51 PM
Not meaning to be an ass, but how is that working out for you?
Welcome, and heed RG.
Well, it was one of our fellow forum members here on this site that strongly suggested the cap switch, and stated he had done it successfully multiple times - so I took his advice.

Quote from: PubliusValerius on July 01, 2016, 05:46:52 PM
UPDATE: Fixed it. ...All it was was a tiny little solder bridge I had on that new cap I put in.

Glad my hint helped. Again, welcome to the forum.  8)
"Duct tape is like the Force. It has a light side and a dark side, and it holds the universe together." Carl Zwanzig
"Whoso neglects learning in his youth, loses the past and is dead for the future." Euripides
"Friends don't let friends use Windows." Me