Bugle DC Offset

Darterboy · « **on:** 24 Jun 2004, 03:46 am »

What is it? How do I measure it? what values are acceptable/unacceptable?

hagtech · « **Reply #1 on:** 24 Jun 2004, 05:18 am »

There can be a small dc offset at the Bugle outputs. I forget how much, maybe up to +/-20mV. I designed it that way on purpose to eliminate the critical output coupling cap.

You can measure by just using a DVM on the output. Read DC voltage. Don't apply any input.

jh

Darterboy · « **Reply #2 on:** 24 Jun 2004, 05:40 am »

With my meter set to DCV, and one probe touching the inner conductor and the other touching the outer conductor of the same RCA jack, I measure 5mV DC (.005 V) and 2mV DC (.002 V)on the left and right outputs repectively. Sounds like I'm cool. Thanks!

-Stott

slappomatt · « **Reply #3 on:** 11 Jul 2004, 09:19 pm »

wow! just checked this with nothing hooked up to it and powered up. i get 2.13v and 2.15v at the outputs. and .2 at both inputs. why is there voltage at the inputs? looks like i need to go back and have a look at my values and such.

hagtech · « **Reply #4 on:** 12 Jul 2004, 06:25 am »

Slappo,

Yeah, that's because you have no negative supply. With only a positive supply the opamps cannot drive a signal to zero. The bias and output circuitry headroom can best do about 2V from the rail.

jh