Most Effective Tweaks?

Big fan of mu metal around transformers. I’m also a big fan of double wrapping and implementing spacers between layers. One layer absorbs 75% of the mag field, two layers absorb 96%. I also like wrapping those flimsy little exposed ribbon connectors with mu metal, not to mention Mr. Fuse.  No goats, no glory.

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dweller
1,241 posts
02-24-2016 7:01pm
I don’t mean to step on the OPs intentions but does anyone remember the name of the panels to stick on the sides of large speakers?

Something like "Tek-Sonic" or "Sonic-Tek"?

These were/are from the 90s and are meant to absorb and convert

vibrations into heat. Are they still made?

tekna sonic was the company in CA that made those cool looking dampers with black fins for speakers and a larger one for subwoofers. Before that they were Micro Scan. I’m quite familiar with them since Tekna Sonic was an OEM for my iso stands for quite some time. I bought up the last of their stock a long time ago about the time they went belly up. Geez, that’s probably ten years ago.

geoff kait
machina dynamica
no goats no glory

 
dweller
1,243 posts
02-24-2016 9:48pm
geoff kait: Any idea where I can lay my mitts on some? thx

no, sorry, long gone.

I realize this will probably come across as argumentative or beating a dead donkey, nevertheless what I’m actually referring to is not EM or RF. I’m referring to the induced Magnetic field from the transformer or in some cases from adjacent AC cords. That’s why wrapping mu metal around a transformer improves the sound, because the mu metal absorbs the magnetic field. Mu metal has nada to do with shielding RF or any such thing. It’s also why it’s a good idea to avoid parallel runs of any cables or cords. In some cases the 60 Hz hum is due to the physical mechanical vibration of the transformer.

mapman,
Thanks for the details!
This has been an ongoing issue for me for years. It’s managable but creeps into audibility at higher volumes. I’ve chased it with ICs, power cords, rack placement, "cheater plugs", medium output cartridges, etc. I think the hum is associated with the placement of my rack in the room (in front of an ornamental fireplace with the furnace/boiler directly below in the basement) and I have no options to move the entire rig. I have the system on a dedicated line also. So seeing your post, I was wondering if the mu metal might be wrapped around my already shielded ICs or some other placement around the rack, or even in the basement.....
Might be worth the experiment.
Thanks again!
Dave
PS: I know there are many Audiogon forums on RF.


Mu mu metal does not address RF issues. It’s a high permeability magnetic alloy used primarily to absorb the low frequency magnetic field produced by transformers, the toxic magnetic field that would otherwise degrade the audio signal anywhere in proximity to the xformer. In some cases audible hum is produced by the 60 Hz transformer but it can also be produced by other causes such as low level signal wires being too close to AC cords which is not an RF issue either.

Mapman wrote,

"Tube dampers another effective and inexpensive tweak."

Yes, they are. As long as they’re Herbies tube dampers. I have tried all the others, including the very dear Swiss tube dampers from Ensemble and while it took me a long time for it to dawn on me, they all subtly hurt the sound. It's a case of it just seems like such a great idea, of course they couldn't HURT the sound. All of them save Herbies. It’s a lesson in how easy it is to over damp things. And for my prized ’52 Badboys and ’42 Tung Sol rectifier two Herbies were the cat’s pajamas, one on the glass at the location of the getter and one on the base, even though it should be pointed out the cost of the dampers can approach or exceed the cost of the tubes.