Author Topic: Digital Multi Metre  (Read 3889 times)

9V

Digital Multi Metre
« on: December 27, 2004, 03:54:20 AM »
hello, i was wondering how to use the DMM, i recently got a EQUUS one, and they did not include the instruction manual, no online search luck either..

also to debugg a pedal, or to know what is wrong, will i just need a DMM for the job, or an audio probe? something like that?

please help this beginner.

thank you and happy holidays.
i haven't given up just yet!

guitarmonky55

Digital Multi Metre
« Reply #1 on: December 28, 2004, 11:27:19 PM »
does your dmm have beep mode? if so, thats probably the most useful tool for checking your solder joints and ground and such.  

an audio probe is very useful for checking the circuit itself, as you can tell exactly what happens where and where you lose your guitars signal.  a dmm will tell you voltages and such but really to effectively debug you need both(at least in my opinion)

the_badcliff

Digital Multi Metre
« Reply #2 on: December 29, 2004, 02:29:54 PM »
you will use the multi meter for several usesl

Frequently you will be measuring transistor voltages when testing a faulty circuit or adjusting bias.  This refers to the voltage from one of the legs of a transistor to ground.  For this, you would turn the dial to the 20V setting (or whatever the closest setting is that is higher than 9V), touch or clip the black probe to ground, and touch the red probe to the part you are testing.  You must have a battery or power supply plugged into the circuit for this test.

When I check for continuity, I don't have a beep mode so I just measure resistence.  If two component leads are connected then the resistence will measure close to zero (although never actually zero, usually 2-10 ohms).  When I check my ground connections by clipping a probe to the ring of a jack, and testing with the other probe.

An audio probe would be useful.  Heres one you can build http://www.diyguitarist.com/PDF_Files/DIY-AudioTester.pdf.

9V

Digital Multi Metre
« Reply #3 on: March 01, 2005, 02:46:22 AM »
thx guys,

but is the method of measuring different from one pedal from another?
like measurements and ie.. which i've seen before on the debugging page here..

don't know where to begin, i've followed the equus instruction manual found it), for a countiuity test where red is plugged "((o" and black to the right side hole, (under 70 , it would beep, but it's pretty weird since when the screen number is over 1000)??

they said it would damage the product if i do not be careful, i fear i'll brake it.
i haven't given up just yet!