|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: Scroll down to 1957 on this link. posted by gusser on September 18, 2006 at 10:47:50:
How do we know for sure those "steel can(s)" were merely STEEL cans and not Mu-metal? Don't you think a company like McIntosh would have gone all out and used the stuff if it was available?Mu-metal - From Wikipedia, the free encyclopedia:
Mu-metal is a nickel-iron alloy (75% nickel, 15% iron, plus copper and molybdenum) that has a very high magnetic permeability. Permeability is represented by μ, the Greek letter mu.
The high permeability makes mu-metal very effective at screening static or low-frequency magnetic fields, which cannot be attenuated by other methods.[1]
Mu metal requires special heat treatment — annealing in hydrogen atmosphere, which reportedly increases the magnetic permeability about 40 times. The annealing alters the material's crystal structure, aligning the grains and removing some impurities, especially carbon. Mechanical treatment may disrupt the material's grain alignment, leading to drop of permeability in the affected areas, which can be restored by repeating of the hydrogen annealing step.
Consider this "ad" I found on McIntosh's website for the latest McIntosh tubed preamp:
The McIntosh C220 is an amalgamation of McIntosh’ 56 year expertise in tube design and newly developed control circuits. It has all the flexibility modern systems require while maintaining the highest quality two channel performance.
As an example, all signal switching is done inside glass cylinders filled with inert gas. These switches are located adjacent to the input/output jacks, virtually eliminating crosstalk. Switch cleaning is a thing of the past.
"...glass cylinders filled with inert gas"
And you're SURE they didn't (or don't) use this Mu-metal stuff? ? ?
- Brian
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Nice link, but. . . - BrianM23@msn.com 20:39:05 09/18/06 (3)
- I don't know for sure but.... - grhughes 06:49:53 09/19/06 (1)
- Thanks! (nt) - BrianM23@msn.com 09:40:38 09/19/06 (0)
- I don't see the relationship - mikeyb 05:56:35 09/19/06 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
