[zbuddah]

I guess the question says it all. I have a multimeter with a DCA section, which I figure is an ammeter. right? How would I go about measuring the current out of my meta? I'm wondering where I should probe and I guess I have to have the amp on too? I'm pretty clueless so any help would be great.

 

[PeterR]

Current draw or current output?
Ok, assuming you want to know the current draw from e.g. the battery. First disconnect the battery at one end. Then connect one test lead of the meter to the battery, the other test lead goes to where the battery was connected to. Note that you often will have to plug the red test lead into another jack for current measurements. Now turn on the amp and the meter will show the current.

 

[rickcr42]

across the psu connections to the active stage

no signal/no load = idling current of the device

calibrated signal generator and load for draw under "operating" conditions

clean audio signal generator (sine wave) and a scope to monitor the signal , real or "fake " load (worst case R/C/L discrete resistor/cap/inductor) and measure across the output while monitoring the signal for signs of clipping

back off to just below the clip point (again , under the expected load) and measure the output across the load for the current output capability

 

[binary_digit]

just a pic of basic current draw setup for ya. I hope I'm right on this.

 

[Chipko]

I just short the leads on my powerswitch with the multimeter set to measure current. Switch in the off position.

Some meters are only really designed to measure AC applications at line frequency 50-60Hz, using a 1000Hz sine wave can produce misleading results, check your manual.

 

[zbuddah]

arlite i finally hooked up the probes to the multimeter correctly and I finally got a real reading instead of 0.00!

thanks guys.

no signal generator so I played music through it muhahah.
I'll post some numbers if some people wanna see out of curiuosity

spec goes as:
AD 8610 JFET Cascode
R10 = 500 ohms
two 9 volts in series

Only things I changed are the various buffers I had, just to see how much of a change in current draw there was between them. I can't really use the latter few with batteries at all until I buy/find/build myself a power supply.

|Ground Buffer: EL 2001 x2
|L & R channel buffer: El 2001 x2
Total Amp Draw: 16.55 mA

|Ground Buffer: EL 2002 x1
|L & R Channel Buffer: El 2001 x2
Total Amp Draw: 18.67 mA

|Ground Buffer: El 2002 X2
|L & R channel buffer: El 2001 x2
Total Amp Draw: 23.1 mA

|Ground Buffer: EL 2001 x 2
|L & R Channel Buffer: El 2002 x2
Total Amp Draw: 30.2 mA

|Ground Buffer: El 2001 x2
|L & R Channel Buffer: EL 2009 x1
Total Amp Draw: 120.2 mA

|Ground Buffer: EL 2002 x2
|L & R Channel Buffer: EL 2009 x1
Total Amp Draw: 126.6 mA

I have a single EL2002 buffer somewhere but I can't find it so I couldn't do the L and R Channel buffer with one stack of EL 2002.(don't want to unsolder the pairs

)

thanks guys for the help, i'm probing everywhere on my amp now muaha my led eats 1.45mA oooo. one more question is it possible to measure the opamp alone to see how much mA it is eating up? i don't want to do anything that might blow it up or short it out. thanks again