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derekbMemberQuote:anyone performmed the Emitter or Resistor mods on an EC3003-C as well?
bumping out of interest
derekbMemberQuote:This is exactly what is happening with my muff and the tone knob! any updates on your fix?????a
actually yes, the pot would lose contact if not holding the knob slightly vertically up, so as a ghetto solution I inserted a small rubber o-ring into the gap created when pulling the pot stem. This keeps the knob held up and in contact, it adds some resistance to turning, but hey, it works!
derekbMemberanyone performmed the Emitter or Resistor mods on an EC3003-C as well?
derekbMembermight wanna trace the voltage out first to make sure components are actually getting juice
derekbMemberQuote:it might be the pot, i would use a multimeter on it and check the resistance at various points in its rotation. that may give you a clue if its bad.it certainly seems to just be the pot, once the knob is lifted about a millimeter out of the socket it rests in it clicks back in, and theres no physical movement on any other component since its secured in place. will replace and see what happens
derekbMember^ that video is not a correct method for tone bypass
my question is – is this diagram accurate for using a DPDT to perform the emitter mod, I hadn’t really seen one drawn up and threw it together rather quickly, from my understanding of DPDT switches I believe this to be correct, one position will pass the cut trace to the resistor, the other will jump over the resistor, but just wanted some verification.
edit: in addition are R12 and R16 the correct resistors on a V9 big muff pi
derekbMemberthanks for the link
On some additional fiddling I found what seems to be the problem, the tone knob is cutting out completely once turned past 12 o clock.
On further inspection, it seems the Tone knob cuts out the output unless I pull the knob physically upwards away from the unit. Should I just replace the potentiometer?
derekbMemberQuote:Its the same components to pull from ground (R5 & C8), i did it on this newer version of the circuit board and it worked fine.
I followed the circuit trace and lifted one leg of each component (the leg to ground) from the board. That is when looking at the component side up with the pots at the top the leg on the right hand side for both the resistor and capacitor is the one i pulled out (i’m pretty sure of this as i just did this about a week ago). I actually replaced the crappy ceramic .01uF cap with a poly film .01uF.I referred to this: http://www.muzique.com/lab/tbypass.htm
and
I used this as a guide: http://roadsideguitars.blogspot.com/2009/04/adding-tone-bypass-to-ny-big-muff.htmlI’ve seen another method of “tone bypass” on youtube that i’m pretty sure is wrong and does nothing but mimic the tone of just turning the tone pot full CCW, but never really tried that other method as this one is more logical.
my mistake I completely missed the R5 component since it was hiding right next to C8 on the 3003C!
derekbMemberQuote:It could be a number of issues, an audio trace is I believe like an “audio probe” there is a step by step guide on DIY stompboxes dot com on how to do this, basically its using a cable with a signal source plugged into it on one end (something that gives a constant sound, plucking a guitar is too cumbersome, so maybe a portable cd player or ipod) and capacitor on one lead of the opposite end and the other lead grounded. use the open lead of the capacitor as “the probe” contacting various places on the circuit board, not randomly as you should “trace” through the circuit from start to end, the output of the circuit is plugged into an amp to listen for the input signal, what this will find is if there is:bad solder point or trace on the circuit bad
or
bad component (capacitor, transistor, diode… resistors are tougher to destroy but…)
sounds interesting, any chance you ahve a link to the guide?
derekbMemberactually having the same issue on a spare big muff pi I have lying around, has anyone ever figured out the likely culprit for this? effects appear to work but unless you crank volume to max on the pedal, you cant even hear anything, and even then what you can hear is muffled by pedal hum. Any solutions?
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