You know, I’ll try everything for you, dear reader, especially if it’s cheap. I’ve heard that some audiophiles’ use EMI RFI (Electro-Magnetic Interference and Radio-Frequencies Interference) clamps that attach to power cords to upgrade their system, so what can I do but try them? I brought mine on Ebay at $20 for 10 clamps including transport. Here’s their claim:
‘Cut down on RFI, “radio frequency interference” with this effective and easy to use clamp-type split generalpurpose ferrite choke core. Made by Kitagawa. Simply snap it over any coax cable, AC or audio cord. This is a ferrite RFI reducer for round cables. Great for Ham-Radio interference issues, fluorescent lights, motors, anything electrical that’s generating RFI. Please check the graph for the bandwidth and impedance that these were intended. 100’s are sold at hamfests with many repeat customers.’
- Max cable diameter mm: 11MM
- Impedance at 25 MHz: 95Ω
- Impedance at 100 MHz: 236Ω
- 26.6MM Width (1.047)
- 34MM Long (1.338)
- 25.4MM in Height
- Clamp-type fitting
- Uses high-performance ferrites (Nickel-Zinc) that reduce high frequency noise
- Split ferrite assembly are fully enclosed in a ROHS Compliant Nylon snap-case
- Can be installed before or after product setup and assembly
The best way to use them is to use them on all other electric/electronic device in your home. Why? It’s a fairly simple answer: these devices (especially fridges, computes, DVDs etc…) emit electric garbage back to the grid, which can affect the quality of the current feed to your sound system. Why shouldn’t I use them directly in my system? This is a touchy answer because it mostly depends on your system. First is to consider that they are not conceived to audiophile specs and can affect or even restraint the power coming to the component. But it can also help to lower the background noise by reducing trash coming in and out of your CD player for example but it normally affect the dynamics by affecting it’s range. So please don’t email me on that, its system specific and it’s a choice.
So I’ve put all the clamps on home devices: fridge, microwave oven, 2 on the AC cables of the home theater set-up, one on the AC cable for the bedroom stereo and 4 on lamps (supposed to work especially on dimmers since they reject a lot back in the electric circuits). They can go on all but the thickets cables (11mm, about 3/8’’ in diameter) as I’ve put them with ease. What happened? The stereo system in the bedroom, consisting on a Technics CD player, Yamaha integrated amplifier and Sony speakers got ok results. It was really easy; this system has noticeable noise and hum. The sound is only (barely) adequate for background music; it would be a long stretch to think the clamps could change to something great. The high are a bit sweeter and details easier to make out as the noise diminished by half but it still there, for the other aspects of the sound are about the same.
On the reference system which already has a Monster Cable HTS1000 power conditioner and a Blue Circle BC86 MKIII power filter, the clamps didn’t change the sound in a way I could easily spot. I can tell you that the background may be a little blacker, the soundstage height may have gain a bit and the dynamics gain a shade more scale. But I wouldn’t bet anything on this.
These clamps tend to break if you try to detach them from their cord so it’s difficult for me to assess their performance if no power conditioning is used (having a reference before and after). But I’ll be inclined to think it’s a very inexpensive first step in the good direction for unfiltered systems. Does it really work? Your mileage may vary but I didn’t really have a serious improvement in my system.
from aﬀordableaudio, By Charles Painchaud