Ferrite Chokes on ALL pwer cables-bad?

Great way to kill dynamics and stage.

Just found this discussion while searching out a problem I'm having with some old MIT Z-Cord IIs...with two very different pieces of gear!

With both a PreSonus 16.4.2 digital mixer and an Onkyo Integra Research RDC-7 surround preamp, simply using the MIT power cord introduces a distinct digital glare to the high frequencies.

Anyone else notice a glare from ferrite-choked AC cords?!

I can make the noise come back simply swapping out the PS Audio power cords for these older MIT ones...

Cheers,
John
Detroit

RPG -- In my previous comment I should have referred more broadly to the return conductor of unbalanced interconnects, not specifically to the shield. My comment and the contents of the paper I linked to apply to all unbalanced interconnects, regardless of whether the return conductor is a shield, a conductor in a twisted pair or braided configuration, or any other configuration.

The quantitative parameters that are involved, though, and therefore the degree of noise coupling that will occur, will of course vary depending on the specific cable design.

Best regards,
-- Al

MY IC's, with the exception of my Digital IC are all unshielded; Kimber KS1021 and Silver streak.

I removed all of the chokes and the sound improved a great deal, I'm not sure why I installed them in the first place.

Thank you to everyone :)
Rpg

Keep in mind that if your equipment is connected via single-ended (rca) interconnects, the most significant contributor to system noise (assuming your individual components have good noise performance) may not be the incoming power at all.

See the following paper, which explains that since the shields of unbalanced interconnects carry both signal return currents and extraneous ac-related interchassis noise currents, those shields are commonly where noise is introduced. Which can be improved by shortening the interconnects, using interconnects with lower shield resistance, using audio (not power) isolation transformers, sometimes by re-routing cables, and sometimes by the arguably unsafe practice of lifting ac safety grounds.

http://www.jensen-transformers.com/an/an004.pdf

Regards,
-- Al

I have a dedicated line for my system, high quality Hospital grade isolated ground outlet. I'm thinking, as I have a power conditioner that all my gear plugs into, to start over and observe one at a time as I add chokes which ones help vs which ones don't. Thanks!
Rpg

Rpg, do you have dedicated lines for your audio gear? If not, this is highly recommended, with dedicated lines and quality outlets you should not need ferrite chokes and the noise floor should not be an issue.

Cheers,
John