need help interpreting DC readings

Hey all;

I'm trying to isolate sources of DC from my guitar effects pedalboard so
I've cracked open a few of the pedals themselves to check them out. on the
1st pedal, I measure 0.1 mV on the output (measuring from cap to ground). It
doesn't float around a bit 1st, it just measures 0.1 On the next pedal, the
readings are all over the place. They range from about -2mV to +3mV, and
constantly floats around, never settling. I figured the cap must be leaky,
so I replaced it with a new metal film, but I get the same readings. I
measured the next pedal, and I get the same type of reading where the DC
level is floating all over the place. I haven't replaced that cap, since
replacing the cap in the other pedal didn't seem to change things. in all 3
pedals, there is a 100K resistor at the output to ground. Given the new cap
and the resistor to ground, how can there be any DC at all there?

Also, the inputs of each of the pedals show a DC level that starts out at
around 350mV and settles down to 0.2mV over the period of about 15 seconds.
Is that normal, or should I consider these caps leaky also?

Thanks



.

Relevant Pages

  • Re: need help interpreting DC readings
    ... I'm trying to isolate sources of DC from my guitar effects pedalboard so ... I've cracked open a few of the pedals themselves to check them out. ... I haven't replaced that cap, ... and the resistor to ground, how can there be any DC at all there? ...
    (sci.electronics.basics)
  • My GAS Range (RangeMaster) pedal
    ... Pedals are a pain ... I used the suggested .10uf output cap, ... and it's wired PTP between the pot, and the DPDT Carling stomp switch. ... using cloth covered solid core wire because I like using it, ...
    (alt.guitar.amps)
  • Re: need help interpreting DC readings
    ... I've cracked open a few of the pedals themselves to check them out. ... I measure 0.1 mV on the output (measuring from cap to ground). ... so I replaced it with a new metal film, but I get the same readings. ... replacing the cap in the other pedal didn't seem to change things. ...
    (sci.electronics.basics)
  • Re: The Case for Working With Your Hands
    ... One time a friend of mine got to buy a Case 1450C dozer in which the previous owner dumped a whole bunch of money. ... That meant that the brake and the torque converter were working properly, but were coming on at the wrong time. ... For anyone that doesn't know how the steering pedals work on the 1450C, when you push them half way down it dis-engages the drive to the left or right track. ... Anyone can keep replacing parts until the thing runs, its replacing only the bad part to get the thing back on line. ...
    (rec.crafts.metalworking)
  • Re: Help - broke my crank / the big sprocket at the front
    ... What's the procedure for replacing this part? ... Instructions can either be found here: ... Some pedals have allan key holes in them, others require the use of a 15mm spanner, some have both. ...
    (uk.rec.cycling)