DC offset voltage

I am trying to learn or understand the most accurate way of measuring dc offset voltage at the input of my output transformer.

In other words,measure the offset coming out of the buffer/servo to see if it is low enough to drive the output transformer without the need for coupling caps.
Under 1mv is rule of thumb to keep distortion at bay.
My ears tell me it is good but I would still like to measure it accurately with a multimter.Or at least very close.

O.K. this guy says do it like this for his headphone amp:
http://tangentsoft.net/audio/input-cap.html
Is it that simple?

Or do you have to proceed in this manner?

http://www.ele.uri.edu/Courses/ele343/lab/lab4/lab4.html

If you ground an input on any opamp in your circuit to measure the offset you would have to take it out of the circuit to do this.Right?
Would like to measure dc offset voltage with entire circuit complete.
Possible?

> Is it that simple?

Yes.

Measures 1.5mv using that method. :grin:
More/Less offset in this case may be a good or bad thing.

Using this method raises some serious questions about my SPL pre though!
18VDC on channel 2 and 11VDC on 1 read on the output of this unit.
Way too much DC!I have to dig in to see whats flying around this circuit.
Thanks PRR.

You might be measuring a charged cap... always measure across a couple of 1kΩ-to-ground resistors, see if it drops, and then remove the resistors to see if it rises again.

Keith

Using this method raises some serious questions about my SPL pre though!
18VDC on channel 2 and 11VDC on 1 read on the output of this unit.

Click to expand...

:shock:
Correction.I was trippin.Reading the wrong section of the circuit.All's well. :grin: