It is actually easier to just make the box out of aluminum. Pots, switches, and connectors have to be connected to or in close proximity to the box, so steel is a lousy second best. Stainless steel would be OK, but then the shielding quality would be impaired by the resistivity of the steel. Aluminum is not too bad, copper or silver would be better.
Taiwan's Neotech company makes a very good all siver cable, I use it on a regular basis, the price was (locally) US$ 14 per metre (app. 3 ft). For a US$10k bundle, you can have it marked as John Curl's Wire or whatever.
FYI, they are the OEM for several European High and Ultra High End vendors, such as for example Ecosse. I measured their Big Red cable against Neothech's original cable all values came in with a +/- 1% toleance, but their Big Red costs 8 times (!!!) more.
Also, Neotech's interconnect wire is silver plated OFC hybrid, and in my view, it sounds better than the all silver variant at 1/2 the cost (different from the above internal all silver).
Any thoughts and/or hands-on experience with SK 389 FETs? Can they be replaced with the classic SK 170 FETs? Anyone?
Wire is chosen for its current carrying capacity, the dielectrics chosen to handle the extremes of temperature, silver plated copper etc is chosen for temp range or in some cases for skin effect with high frequency rf, nothing special.
How can one cable sound better than another? if they are specified correctly.
Doing near space stuff at the moment down at Cobham, cable is chosen with the above parameters, funnily they don't seem to believe in cable magic, just correctly specified cable... To various MIL specs etc. but nothing super exotic, just cable.
Housings are aluminium, like all screening its down to seams and slots and ensuring no holes, slots etc for the rf to escape.
How can one cable sound better than another? if they are specified correctly.
Doing near space stuff at the moment down at Cobham, cable is chosen with the above parameters, funnily they don't seem to believe in cable magic, just correctly specified cable... To various MIL specs etc. but nothing super exotic, just cable.
Housings are aluminium, like all screening its down to seams and slots and ensuring no holes, slots etc for the rf to escape.
Well outgassing specs will be high on the list along with radiation resistance. Satellites also used to use a lot of DB9 connectors. With the most beautiful soldering. The loom is the first thing to be built on a spacecraft. sometimes two years before payload integration!
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19710022895.pdf
I posted the ESA spec on wires and cables a couple of years ago, away from the office so cant get to the NASA specs, but they will be out there somewhere. Have a look at Axon cables they do radiation resistant cables... tend to be PTFE and other more exotic insulation, the wire its-self is wire, copper plated with tin or silver... With all electronics if the cable changes the signal passing through it to the point where something changes then there is a serious problem with the design...
I posted the ESA spec on wires and cables a couple of years ago, away from the office so cant get to the NASA specs, but they will be out there somewhere. Have a look at Axon cables they do radiation resistant cables... tend to be PTFE and other more exotic insulation, the wire its-self is wire, copper plated with tin or silver... With all electronics if the cable changes the signal passing through it to the point where something changes then there is a serious problem with the design...
Some more NASA stuff, of course they use the Devils connectors quite often, D38999 and similar, horrible things to put on a PCB, great for harnesses...
https://workmanship.nasa.gov/lib/insp/2 books/links/sections/401 General Requirements.html
https://workmanship.nasa.gov/lib/insp/2 books/links/sections/401 General Requirements.html
Marc,
Nice to see your back working down in Cobham, probably hating the drive again. Hope all is well with you.
Nice to see your back working down in Cobham, probably hating the drive again. Hope all is well with you.
Hi Steve,
not really, but down here I'm away from it all for a few days each week. Still sorting my Dads estate (travel down each weekend to sort the house out, doing over a 900 miles a week at the moment), now the taxman's involved its become a pain as they want exact figures! Hopefully by June/July I may get my life back and be able to sit back and chill. Due to certain hormones being reduced etc. I have been going through what the doctor called the male menopause, they have been discussing hormone therapy for a while now! Might become a man again...🙂
not really, but down here I'm away from it all for a few days each week. Still sorting my Dads estate (travel down each weekend to sort the house out, doing over a 900 miles a week at the moment), now the taxman's involved its become a pain as they want exact figures! Hopefully by June/July I may get my life back and be able to sit back and chill. Due to certain hormones being reduced etc. I have been going through what the doctor called the male menopause, they have been discussing hormone therapy for a while now! Might become a man again...🙂
Lots of metal bashing going on here . . .
If you put your electronics in a steel chassis and you measure it with an AP and it shows no measurable difference, then use it. If your distortion goes up, and its perceptible, then don't.
If you put your electronics in a steel chassis and you measure it with an AP and it shows no measurable difference, then use it. If your distortion goes up, and its perceptible, then don't.
Oddly enough, I purchased some titanium rods, 1/8th and 3/16th dia for a wooden gear clock I'm making. Also, some hardened drill rod as well. I was very shocked that the titanium was easily flexed, not what I needed. The drill rods, major strength..
But man, that titanium is light. Oh, it also came with about 15 pages of cert, it was apparently Airbus overrun stock.
I believe it's in the tail assembly of the 747 as a counterweight.
Just wrap some aluminum foil around it..
John
I have plenty of mid-fi audio equipment that has steel as the basic building block for the case. It is cost effective, shields well, and once you paint it, looks OK. However, my best designs like the CTC Blowtorch are made with aluminum or silver. Copper is always there, but not preferred.
The CTC Blowtorch was designed to compete with the world's best audio equipment, not to compete in the mid-fi marketplace. We used every approach that we had found from experience, or even rumor, to make a subjectively successful product. Did we go too far? I don't think so, and for the rest of my life, I am happy with the result. Now, I have power amps and discrete phono stages to design and evaluate. I will still use aluminum for the cases where I can, but I have to live with steel for the lower cost products.
Wire is another problem. We still do not completely understand why different wires sound different. Ed Simon has done some interesting measurements in this area, and Vandenhul did some important work decades ago. Still, we hear the differences and accept what we hear as the most important, especially with regards to internal hookup wire. The Blowtorch was made with wire connecting individual modules, and used a lot of hookup wire, more than usual. Most of our designs try to remove the need for hookup wire for the most part. This is especially good when we are forced to use typical hookup wire. However, when we could get this special silver wire, we found that once it was broken-in, and directionalized, it was exceptionally clear sounding. BUT that took skill and patience, that even I don't have, so has become impractical to push for it. Without extreme break-in, all silver wire that I have ever tried sounds too bright. Why, I don't know.
The CTC Blowtorch was designed to compete with the world's best audio equipment, not to compete in the mid-fi marketplace. We used every approach that we had found from experience, or even rumor, to make a subjectively successful product. Did we go too far? I don't think so, and for the rest of my life, I am happy with the result. Now, I have power amps and discrete phono stages to design and evaluate. I will still use aluminum for the cases where I can, but I have to live with steel for the lower cost products.
Wire is another problem. We still do not completely understand why different wires sound different. Ed Simon has done some interesting measurements in this area, and Vandenhul did some important work decades ago. Still, we hear the differences and accept what we hear as the most important, especially with regards to internal hookup wire. The Blowtorch was made with wire connecting individual modules, and used a lot of hookup wire, more than usual. Most of our designs try to remove the need for hookup wire for the most part. This is especially good when we are forced to use typical hookup wire. However, when we could get this special silver wire, we found that once it was broken-in, and directionalized, it was exceptionally clear sounding. BUT that took skill and patience, that even I don't have, so has become impractical to push for it. Without extreme break-in, all silver wire that I have ever tried sounds too bright. Why, I don't know.
So you prefer aluminum, for the cases, over copper? How about thin copper layer on the surface.
- Status
- Not open for further replies.