|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
|
|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
In Reply to: Re: Your proposal should work. posted by Charles Peterson on December 31, 2005 at 15:51:50:
John Curl observed that noise measurements should be made with the input shorted. This is standard practice and is done to remove the variable of environmental RFI/EMI entering through the input jack. I believe you would get similar results if you used a resistor/capacitor combination to emulate a typical source component driver stage, instead of a simple short. This is because the effective source impedance of remote RFI sources is very high, so that a 1K resistor looks like a short in that context.Moving your equipment to the quietest part of the house and turning out the lights helps, but does not eliminate external RFI/EMI. You would need a very expensive screen room to do that.
Shielded cables may or may not help. The shields themselves can act as RF resonators if the cables are made with low-loss materials. Connecting the shields to audio ground, even if only through the stray capacitance of chassis-to-audio ground, can dump the resonant peaks into the audio chain where they can mix with the audio signal and produce spurious tones. You will not measure these in your test setup, but they will affect your audio enjoyment.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Shorted versus open input. - Al Sekela 08:30:03 01/01/06 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
