Ive got three chokes (Hammond 193M) in my system now and love the effect, However you have to try them in different positions or you can make the sound worse.
The hypothesis of these devices, which are usually used in series for DC, being used in parallel across AC, is that they are a broad spectrum high frequency dampener, similar to the effect of an RC filter network. If you think of your AC power wiring as a network where RF resonates in every node, then putting a choke in at the node ends (power points, component IECs) dampens RF at that point. Usually this is good, but sometimes it can change the RF resonant frequencies elsewhere in the system which may be more audible depending on the equipment.
So once they are burned in (about 10 days for the 193L, and about 20 days for the 193M) move them around to different components / power points to tune the effect. The system will sound overly warm before they are burned in.
Use 193L on individual components and 193M on power boards or 240V.
I add a power cord to my 193Ms so I can swap them from one receptacle to the next to get the most pleasant configuration.
