Members p00n Posted June 1, 2010 Members Share Posted June 1, 2010 Narrowed it down to one pedal that causes EVERYTHING in my true bypass looper to pop loudly. I had to individually swap out pedals in the loop till I found that my Magicstomp is the source of the pop. When it's in the chain, it causes all the true bypass switches to pop. Those in the loop itself, and the rest of the loops on the looper too. Any idea what's causing this? I heard DC leakage might be a problem, but the Magicstomp is 12V AC. Link to comment Share on other sites More sharing options...
Members p00n Posted June 2, 2010 Author Members Share Posted June 2, 2010 bzump Link to comment Share on other sites More sharing options...
Members Reauchambeau Posted June 2, 2010 Members Share Posted June 2, 2010 I've made my own TB boxes and I put a 1meg tie down resistor between the switch, and the ground lugs of the input and output jack (one resistor each). this eliminates pops, if yours doesn't have them it's worth a try, I've never had pops. Link to comment Share on other sites More sharing options...
Members Jack Deville Posted June 2, 2010 Members Share Posted June 2, 2010 DC leaking at the input/output coupling capacitors probably is the culprit.It may take AC in, but it will rectify and filter the AC into DC internally.This goes back to the Edison/Tesla debate; my guess is if measured, you will see a little bit of DC leaking at the input and output of the pedal. This would not present a problem if the unit is in the chain at all times. The TB looper removes it from the chain allowing the symptom to manifest itself. A pulldown resistor AT THE INPUT/OUTPUT COUPLING caps may offer a solution, verify the problem exists before wasting time, effort and parts. Keep in mind, incorrectly placed pulldown resistors will not only NOT PULL DOWN, but will lower the resistance to ground of the path potentially reducing signal strength causing "tone suck." Link to comment Share on other sites More sharing options...
Members Reauchambeau Posted June 2, 2010 Members Share Posted June 2, 2010 DC leaking at the input/output coupling capacitors probably is the culprit.It may take AC in, but it will rectify and filter the AC into DC internally.This goes back to the Edison/Tesla debate; my guess is if measured, you will see a little bit of DC leaking at the input and output of the pedal. This would not present a problem if the unit is in the chain at all times. The TB looper removes it from the chain allowing the symptom to manifest itself.A pulldown resistor AT THE INPUT/OUTPUT COUPLING caps may offer a solution, verify the problem exists before wasting time, effort and parts.Keep in mind, incorrectly placed pulldown resistors will not only NOT PULL DOWN, but will lower the resistance to ground of the path potentially reducing signal strength causing "tone suck." you sound like an expert, I admit that I'm not, is my suggestion misleading or incorrect? I'm curious to know because my boxes have never popped and I've never noticed any tone suck. Link to comment Share on other sites More sharing options...
Members Dr.Pain-MD Posted June 2, 2010 Members Share Posted June 2, 2010 you sound like an expert, I admit that I'm not, is my suggestion misleading or incorrect? I'm curious to know because my boxes have never popped and I've never noticed any tone suck. If you mess with the input/output impedance too much, it will cause tonesuck via filtering off the high end. Link to comment Share on other sites More sharing options...
Members p00n Posted June 2, 2010 Author Members Share Posted June 2, 2010 UPDATE The pop completely disappears with a simple Boss buffer after the Magicstomp! Is it a legit fix? I measured the DC leakage from the pedal output with a multimeter and it registers 10mA, so it's definitely the source. Is there any possible bad side effects of installing a buffer in the true bypass looper's return? So far everything worked as it should with the Boss buffer in place. Link to comment Share on other sites More sharing options...
Members Jack Deville Posted June 2, 2010 Members Share Posted June 2, 2010 You've isolated the source of the problem to leaking DC at the output of the Magic Stomp. Sounds like you found a nice tidy solution. Congrats! Link to comment Share on other sites More sharing options...
Members p00n Posted June 2, 2010 Author Members Share Posted June 2, 2010 Any buffers to recommend? I'd need a really high headroom one since my Magicstomp is in a feedback loop, so I'm thinking of putting the buffer in the return of the feedback loop. Gets really loud, so clipping wouldn't be nice. The Barber B-Buff looks sweet, but DIY is always welcome. Link to comment Share on other sites More sharing options...
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