PC/IC/amp/source interactions

Posted by jneutron (A) on April 28, 2004 at 09:22:51

Here's a drawing: it details the geometric loops that are made whenever you're audio components are connected..some can be addressed by the user...some cannot.

The green loop is the grounding loop formed by the wires. I drew one of the PC wires with a loop, to clearly show how the current that the amp draws can generate a voltage in that green loop. By modifying the coupling here, either by PC geometry changes, or even the inclusion of a ferrite assembly sliding over the PC, you can either lower or raise the coupling.

The green ground loop current will depend on the coupling of the amp draw, and the loop resistance of the green.

The blue shaded regions are the goemetric coupling loop areas within the amp and source, where green loop currents will generate error voltages. Both the source and amp error voltages will show up as errors in the amplifier inputs.

What was not included in this drawing is the output currents, and how they will couple. They can make it into the line cord via the power supply loops, or they can corrupt the ground mechanism within the power amp.

Output current/input coupling to a level required for accurate imaging to 1 foot, ten feet away, requires 5 to 20 uSec stability. Measurement of that stability is outside the bounds of normal FFT analysis, as well as most analog designers to measure..measurement of high frequency high current low impedance circuits is even more a PITA than most are aware..

Lets talk...

Cheers, John

PS..my apologies to those who frequent AR...that's where the image is from.

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Topic - PC/IC/amp/source interactions - jneutron 09:22:51 04/28/04 (23)

Are we missing the interesting point about this post? - Commuteman 09:19:08 05/03/04 (3)

makes sense - Mau'dib 19:08:20 05/05/04 (0)

Re: Are we missing the interesting point about this post? - Jon Risch 10:39:29 05/03/04 (1)

Re: Are we missing the interesting point about this post? - jneutron 08:09:04 05/04/04 (0)

Re: PC/IC/amp/source interactions - Jon Risch 17:54:35 05/02/04 (14)

You gotta read the posts accurately, and review my diagram. - jneutron 07:24:17 05/03/04 (12)

Re: You gotta read the posts accurately, and review my diagram. - Jon Risch 10:35:14 05/03/04 (11)

Re: You gotta read the posts accurately, and review my diagram. - john curl 20:47:50 05/04/04 (7)

Re: You gotta read the posts accurately, and review my diagram. - Steve Eddy 21:40:52 05/04/04 (6)

Re: You gotta read the posts accurately, and review my diagram. - john curl 21:48:35 05/04/04 (0)

Re: You gotta read the posts accurately, and review my diagram. - john curl 21:47:33 05/04/04 (4)

In addition to the "allegations" from cables... - jneutron 06:14:38 05/05/04 (0)

Re: You gotta read the posts accurately, and review my diagram. - Steve Eddy 22:41:12 05/04/04 (2)

Re: You gotta read the posts accurately, and review my diagram. - john curl 23:50:16 05/04/04 (1)

Re: You gotta read the posts accurately, and review my diagram. - Steve Eddy 11:44:21 05/05/04 (0)

Holy mackeral Jon, READ THE DAMN POSTS ENTIRELY - jneutron 07:55:25 05/04/04 (2)

Re: Holy mackeral Jon, READ THE DAMN POSTS ENTIRELY - Phil Tower 08:30:18 05/04/04 (1)

Thanks Phil. - jneutron 08:52:16 05/04/04 (0)

Re: PC/IC/amp/source interactions - Dan Banquer 06:28:50 05/03/04 (0)

So..... - Commuteman 10:35:39 04/30/04 (3)

Re: So..... - jneutron 11:48:19 04/30/04 (2)

It's like this.... - Commuteman 09:06:19 05/03/04 (1)

Re: It's like this.... - jneutron 08:20:16 05/04/04 (0)

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