Switch Pops !

[Easywider]

Heres the layout i used , : http://www.generalguitargadgets.com/index.php?option=content&task=view&id=49&Itemid=88 General guitar gadgets board right from Them . used this layout to wire in a 3pdt switch , : //http://www.generalguitargadgets.com/index.php?option=content&task=view&id=90&Itemid=118 . getting a switch pop , when I 1st turn the effect on , was suggested that I can run a 1Meg resistor to ground from the input , to help with the popping . theres already a 4.7M on the board itself 's R1 input , more than enough for switch pops , don't understand , any help greatly appreciated as always , Thanks ! !   

[GibsonGM]

Hi EZ...you can go back to your original post, and reply to it with more ?'s...keeps things tidier than starting a new one!

What I was interested in, was if you have an LED in your switching circuit...that makes a fix different than the one for your input resistor to ground.  Yup, the 4.7M should be keeping your potentials equalized, so I'm guessing the LED is the problem IF you've got one on your switch - if you're only using the DPDT and no LED, I dunno!  I'd make sure C5 and C6, and the diodes, are oriented correctly (actually, all those big caps)...a transformer develops a field around itself when put into operation, which involves inrush current - could be where the pop comes from.  Might be as simple as a buggy or miswired switch, or as complex as a short somewhere in the circuit you didn't notice.   Maybe someone will come along that's had these symptoms and offer a fix for ya, but til then you have to do the old 'going over it 100 times' thing, to be sure it's wired right...be patient, you'll get it!

[Easywider]

Mike , Thanks !..sorry about posting another thread ,wont ever do that again ! Have a LED in the switching circuit , with a 8.2k resistor to tame down brightness , going to the switch , switch is wired just like the tube screamer layout above , maybe i'll try disconnecting the LED , see if that corrects the problem , least then i know its the LED thats the culprit , right ?

Thanks again , any help greatly appreciated !

Chris

[GibsonGM]

LOL, it's not a hanging offense, Chris - just easier for someone trying to help to know the 1st thing didn't work
  No real rulez or anything!

Sure, dropping the LED temporarily will isolate that as the (a) culprit.  If that's the case, find the link I put in the other thread to AMZ, where you'll find the cure.  The cap gives a little 'reservoir' so the current surge when the LED comes on doesn't pull on the circuit, which causes the POP.  Sometimes you can live with the pop, sometimes it just gots to go...hope that helps out!

[Easywider]

Mike , So From What i Understand From the AMZ thread , The capacitor in the C1 position on the board can be changed to 10uf , 22uf , or 47uf as needed , if the LED is the problem is this correct ?

Thanks Again ,

Chris

[GibsonGM]

Nope! C1 on the octave schem is your input cap...it's in the signal path to shape the signal by only allowing thru frequencies above a certain threshold (it's filtering out low freqs), and to  block any DC that might be coming in on your line from another effect.  Increasing C1 would make your signal bassier.  C7 does the same thing on the way out of the circuit.   In the AMZ article, it's a "new C1" and R2, etc...

You have to go into your enclosure, and where the 1K resistor connects to the + end of the LED, disconnect the wire. Then, as shown in the AMZ article 
http://www.muzique.com/lab/led.htm,
you add another resistor in series with the one you already have there. 390 ohm or something close should work fine.  Where they meet, you run a capacitor to ground (it can run to the enclosure, the grounded input jack, or back to the board to the ground plane - my preference - on the back of the PCB).  + side of cap is toward the resistors/LED.  Try a 22 uF cap if you have one laying around.  The cap charges up and buffers the demand of the LED for current when it is swiched on. 

Hope this picture will help, sorry it's not very artistic, LOL!

[Barcode80]

one thing to check before you do that. i had a switch pop on my bluesbreaker build that nothing fixed, not the AMZ trick, not anything. then... well, here is what i posted in the build thread:

SUCCESS!!! What a dummy! I had the ground from the board connected to the led - which was also connected to ground. problem with that was that the voltage drain from the LED when it shut off got dumped onto the board! pop is gone now... Thanks for all your help!

if you star grounded the board at the same point as you did the LED, this may be the problem.