Boneyard Boost Issue

[k.rock!]

Hey guys!

I have a very peculiar problem that has baffled me. My boneyard works perfectly with the boost ON, but once I turn it off, it sounds extremely low, distorted, controls are really not too responsive. I turn the boost on, works perfect.

I have:

1) Checked the entire board for solder bridges, cold joints, etc. None found. Everything is super clean.

2) Triple checked all resistor values. I should note, the ONLY two different values I have are 2.2K on R4 because I didn't have a 2k and 47R for R5 because it seems like this value sounds way better than the 470R called.

3) I removed the switch. Tested the switch for functionality and it works fine.

4) I have soldered wires 2 and 3 of the SW2 to test with the Boost ON and works great. Did the same with wires 1 and 2 to test with Boost OFF and it WORKS!  ...

so you're probably thinking the same thing as I did, if the circuit works when soldered directly to the OFF and ON positions of the switch, then it must a switch wiring issue.

Well, I have wired the switch (2PDT) twice. I mentioned I tested the switch and works great as it should. I do notice a peculiar characteristic that makes sense to me looking at the circuit, which makes me wonder how can the switch really work.

If the Boost pot is all the way up (max resistance), and the boost is ON, I have continuity only on B2 and B3

FOR REFERENCE:

    A     B
    1     1
    2     2
    3     3

If i turn the pot all the way down, then I have continuity on 1 to 2, 2 to 3 and 3 to 1, which means that the pot is acting as a short and therefore connecting all terminals together (pedal still works though, remember the boost is ON)

Now, if the boost is OFF, I get continuity on all (1 to 2, 2 to 3 and 1 to 3) regardless of the pot value 


And this is where I go...WHAT?!?


Can somebody check if this behavior is normal when the boost is OFF? I honestly do not think so, since it doesn't make any sense to me, but if it is it means i should looks at some faulty component? Which again doesn't make sense because the pedal works fine with the boost ON :S


I'm just rambling now....please any help with this would be VERY APPRECIATED! I'm really losing it with this one...


-Kaleb

[k.rock!]

I'm using mammoth wiring boards:




using the lug reference on the first post, this is the pinout:

1 = A2
2 = A1 which is jumpered to B3
3 = A3
4 = B1
5 = B2
6 = Jumper to number 3

The way I have the switch wired is:

(From left to right looking at the board component side up, switch wires named 1-2-3)

SW2 (1) -  4
SW2 (2) -  5
SW2 (3) -  2
Grounds (from board and daisy chained to other switches) - 1
LED negative -  3


Here are the pictures:









-Kaleb

[k.rock!]

Any ideas guys?

[oldhousescott]

If the Boost pot is all the way up (max resistance), and the boost is ON, I have continuity only on B2 and B3

That should be between B1 and B2.

If i turn the pot all the way down, then I have continuity on 1 to 2, 2 to 3 and 3 to 1, which means that the pot is acting as a short and therefore connecting all terminals together (pedal still works though, remember the boost is ON)

Now, if the boost is OFF, I get continuity on all (1 to 2, 2 to 3 and 1 to 3) regardless of the pot value

This is all correct operation.

SW2 (3) -  2

Remove this wire. Brian has already made the connection on the PCB.

[k.rock!]

Remove this wire. Brian has already made the connection on the PCB.

Hmm...I think this would actually solve my problem. I'll give it a shot tonight when I get home.

Thanks for taking the time to read this entire post! haha (I know it's really long, sorry about that)


-Kaleb

[k.rock!]

That did it! Removed the wire and worked perfectly.

Thanks very much man!! Here's the finished pedal: http://www.madbeanpedals.com/forum/index.php?topic=2273.0


Thanks again!

-Kaleb