madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: pickdropper on April 06, 2012, 03:41:23 AM

Title: Cosmopolitan Voltages
Post by: pickdropper on April 06, 2012, 03:41:23 AM
Would somebody mind posting their Cosmpolitan voltages for me?  For what it's worth, this is what mine are with the pots at max settings:

BS170   Volts
S   3.06
G   5.36
D   5.38

BC109   Volts
E   0
B   0.55
C   0.59

2N1306   Volts
E   0.49
B   0.59
C   2.8

So far, this is what I've done:

- I've double checked the components, which appear to be correct.

- Checked continuity on all of the pot solder joints.

- Visually inspected the solder joints under a microscope.  I reflowed one of the joints.  It was probably OK, but it wasn't as shiny as I like, so I reflowed it.

- Audio probed and the output of the BS170 is VERY weak.  Changing the fuzz pot doesn't change the voltages either.  I suspect there could be an issue with BS170, but I don't have a spare here.  Unfortunately, I don't even have a 2N7000 to try out.  Time to add some stock, I guess.

Additional notes:

- I did beat up the board a bit.  In a fit of mindlessness, I soldered the pots on backwards first, so I had to take a heat gun to them.  I have verified with a multimeter that the pots all still function.


Title: Re: Cosmopolitan Voltages
Post by: pickdropper on April 15, 2012, 04:16:04 PM
We can close the book on this one.  As suspected, it was a bad BS170.