Built my big muff..... no true bypass, and led always on :-S

[loki]

Hi guys, I just finished (after many tribulations) building my second stomp box, a big muff Pi tweaked a bit to use it with my bass...
The pedal works, I mean the effect's great and I love the sound of it, but i seem to have problems with switching....
When the effect's switched off I don't have true bypass, and the sound is cut on its high frequencies.... and the led is always on, both when the effect's engaged and when it's not.... it just switches off briefly if i keep the switch pressed and don't release it.....
can somebody tell me what can it be? I'm sure i connected all the components and the wires well... I followed GeneralGuitarGadget's schematic except for the 4M7 pulldown resistor and the 100uF cap for wall wart power which i didnt mount on the board... and some cap values i changed.... and i used a 3PDT switch
thanks!
bye

[u1061810]

It sounds like the problem may be the switch. Check it with your meter to see if it's working right.

[loki]

could you explain me how to do it exactly? I have an analogue multimeter
thanks

[u1061810]

Set your meter to Ohms and check that the correct lugs are engaged, disengaged when you hit the switch.
That would mean the top lugs connect with the center lugs just beneath them-hit the switch-the bottom lugs connect to the center lugs just above them.

[Rain Dog]

Cool! I'm building my first pedal and it is a GGG's Muff modded for BASS also. I finished the circuit today but I made some wiring mistakes because it doesn't work. I think I got some wires crossed in the clipping circuits. I'll go through it carefully tomorrow.

When I get mine working it would be interesting to compare circuits and how they sound. I have never posted an MP3 on the net but I think I can.

Good luck!
-RD-

[u1061810]

http://www.diystompboxes.com/sboxforum/viewtopic.php?t=970

Look here.

[loki]

thank you u1061910... you were right
i checked with a multimeter and on one of the outer column the top middle and bottom lugs are always connected between them no matter the position of the switch....
i had another switch lying around I tested it and had the same results.....
so i guess i can use it as a DPDT and add millenium switching for the LED..
thanks again.

for Rain Dog:
Sure we can compare the circuits, i don't know if i'll be able to post some sound clips, but i can list you all the mods i've done...
bye!

[u1061810]

I'm not following you.You tried another switch and it acted the same.

Are you disconnecting the jumper that goes from the middle lug on one side of the switch to the corner lug on the other side when you're testing the lug connections? If you dont you'll get a reading on that side.
 Sorry if I'm misunderstanding you.

[loki]

yes it's exactly what i said, i disconnected the switch and tested it with no wires connected.... i got a constant connection on one column of lugs.
I had another switch, which i tested, with no wires connected, and has the same exact problem....
i just guess i have two bad switches that's all
thanks anyway