need help, mxr envelope filter (tonepad) not working :\

[someone927]

hi guys,

ive wanted to build a guitar effect so badly for so much time, so now, ive made it (almost..), ive choosed the envelope filter since i like wah effects.
also, this was the first elect' circuit i have ever done, and, my knowledge in electronics equals to my knowledge in nuclear physics.. :\

so, ive made the pcb, ethced it (came up..pretty..OK.. ), drilled it, soldered all the parts, right directions..

connected the power.. and.. nothing..just a little hum on the speakers.

tried to debug according to what i can think of, and yet, after a few more changes, nothing..

tried to mannually make shorts on the circuit to see if the hum changes, or even just to hear a 'crunch', nothing !

im lost.. im sure about the parts, being the right ones and in their right places,

im confused with that project..

i would much appreciate any help,

thanks ahead,
Elad.

[Bernardduur]

You've got everything connected? Input, output, ground, power? Which chips did you use? Did you imply the mods as suggested on the Tonepad site?

[Mark Hammer]

Although they are reasonably robust and immune to most reasonable handling, the CMOS chips used in this circuit are static sensitive.  The static voltages that can damage them can come from ungrounded soldering irons, or even from finger tips of someone who dragged their feet across a shag rug.  There is every reason to want to solder them to the board so as to assure good contact and provide a lower profile, but unless you have some reasonable experience with CMOS chips it might be advisable to use sockets instead so that chips can be pulled and replaced easily for troubleshooting purposes.

[someone927]

hi again 

yes, everything is connected, input and output, i havent connected the ground since im using mono jacks which hasent got 3 legs (got pretty confused with input\output connecting.. ), for power ive connected an ac/dc adaptor on 9v (600ma).
the chips are :
2X CD4069UBE by "Ti"
1X MC14066BCP by motorola
none mod's have been made.

indeed i have placed the chips into sockets, if they are demaged, that i cant tell..
is there anyway to check the chips ? maybe with a multimeter..?
also, if a chip is dead, is it like a cut in the circuit or the signal comes thru but without any electric effect from the chip..?

thanks,
elad.

[Bernardduur]

I guess you need to ground the unit; you don't need three lugs. Just connect it to the lug that is connected to the middle ring

[someone927]

those jacks havent got any 3rd leg, or a middle ring :\
         ___________
        |0|              /
   ---||0||         {/
   ---||0||____1sleeve
        |_|_________2tip


0 = ring
1+2 are soldering legs, the middle ring is the tip connector.

[someone927]

ok, heres a new one..

a friend has told me that, it is possible that the circuit wont run because im using an ac/dc adapter instead of a battery, so, now ive wanted to test it with a 9v battery.. but, the only unit in my house that holds that kind of battery is the multimeter, so, my brilliant idea was to take the battery out, use it with the circuit, and use the adapter with the multimeter to test the circuit, resault = dead multimeter.. my guess = experiment shows well about what my friend told me of the ac/dc adaptor, i might have killed the circuit on the first try...
im feeling stupid :\
on the adaptor, it says clearly "input AC 220V output 3/4.5/6/7.5/9/12 V DC", i thought it would be the same...

i dont realy mind about the multimeter.. its the cheapest one, i just think, if any part in the circuit is also dead because of the wrong power source, what is the part... i guess i should take all the parts out, save the live res's and throw all the others since i cant be sure which are still good.., and then, start all over again.... 

[QSQCaito]

I'd suggest you to buy a battery, a multimeter, read the post at the top on how to debug, post all your results. And you could also build a signal tracer, to find where your problem is (http://www.aronnelson.com/gallery/, searh for signal tracer)

Ok, hope it helps

bye

DAC

[funkbass187]

those jacks havent got any 3rd leg, or a middle ring :\
         ___________
        |0|              /
   ---||0||         {/
   ---||0||____1sleeve
        |_|_________2tip


0 = ring
1+2 are soldering legs, the middle ring is the tip connector.

don't you need a stereo jack to complete the circuit?

[someone927]

thanks, i will buy those two and read the article about debuging, shouldnt i buy the whole set of components again..? i only know how to test res's with the mutlimeter.. is there a way to check on cap's and IC's in order to find out which are good and which are dead ?.

ive tried to figure out what does this signal tracer, is it like the I/O on the multimeter ? (closed circuit beep/open circuit)


for the jacks,i have 2 like this one :

i wasnt sure which jacks to buy, since the guitar's cable is mono :



also, maybe im mistaking about the middle ring, is it like that ? :


so, what jacks do i need, ? (every step, i find that electronics is more and more confusing  )

[christian]

The ac/dc adapter you had should work, as long as you have set the correct polarity on it! But it might be safer with the battery

for the jacks,i have 2 like this one :

The long sproingie thingie that connects to the end of the plug coming from the guitar is the tip and this is your input/output, so with your new multimeter check which soldering lug connects to it and the other has to be connected to ground on both in- and outputs!!!

You only require 3 lugs (stereo) if you want to use battery-switch system for the input. Then you'd connect the - end of the battery to the ring of the stereo-jack, but without this hack you connect the battery directly to ground.

ch.