One consideration is how rich your radio environment is.
You don't want radio and TV and cel traffic and UHF (ultra-high frequency) in your audio signal. If you have a lot of that in your neighbourhood, then you need a high quality copper shield to keep the crap out, and a star quad cable configuration to neutralize what comes through the shield.
Premium microphone cables do this. Canare Starquad is very good. I've used that a lot, but the dielectric is teflon, and you should be careful when soldering near that. Think industrial grade fume hood. Mogami 2534 is a starquad configuration, and it too is very good, does not use teflon, and the shield is easier to terminate. I use Belden braided shield, and it too is very good, but I haven't used their cable in ages.
While any premium microphone cable will serve, I would stick with Mogami 2534. If you are terminating with RCA connectors, connect both the blue wires to the centre pins, both white wires to the outer rings (or vice versa). Connect the shield to the outer ring at the amplifier end only.
Conventional solder with silver content is the standard - this is not silver solder, which is a completely different thing, more of an industrial process. WBT makes a good one, available from Parts Connexion and probably Michael Percy Audio.
I make my own cables like this, and use them in a high end system. Good luck! |
Yep. Looks good - when I make cables out of this stuff, I use a better quality connector, usually Eichmann or WBT. But this stuff should get you 90% of the way for the price of parking.
Interesting, Canare are now using cross linked polyethylene dielectric instead of teflon; just like Mogami.
I would definitely buy this, and then trade up only after an in-home demo demonstrates a clear improvement; and then, only if you can't make a bigger improvement by upgrading something else.
Well spotted. |
Thing is, Craig, cables are just another electrical machine, and not a very complex one at that. Doesn't mean anyone can design them - but it ain't Nobel Prize territory neither.
Thankfully, Eichmann (ETI) and WBT and Canare and Mogami have done all the work. It's ours to enjoy. |
@tls49
The problem with connecting the shield to the source end is that if a source has no ground connection, you will end up with an ungrounded shield. Many turntables and tonearms are like that, especially vintage ones - think two-prong plugs.
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@cleeds
By 'robust' I mean a solid connector and heavy gauge ground line. Unlike some pieces from the old days.
Agree with everything you say, except using the preamp instead of the amp.
Oh, I get it - if one is using mono blocks. Yes, in that case, use the preamp, if it has a good ground connection. |
@tls49
The shield should be connected to the component with the most robust ground, which is often the amplifier. Some phono/pre are even battery powered, whereas amps are not. Hence the suggestion. |
Taww, teflon is bad stuff to get hot because it decomposes into seriously bad compounds starting about 470F. Think HF (hydrogen fluoride), the stuff used to etch glass. Some modern non-stick uses a high temperature variant, or so I understand.
But I may have been wrong about Canare and teflon - I don't remember how I came to that conclusion back in the dark ages.
As for my components deserving better, I am still spending on things which yield unambiguous improvements, like vacuum capacitors, or things to protect equipment, like isolation transformers and Variacs for soft-starting the power supplies. Until I have finished there, I just don't have money to spare for things that don't demonstrate conclusively in my system, and for which I see no theoretical advantage. YMMV
Thanks for the corrective note about Canare and teflon. |
Craig, I'm sure that you will be pleased with the result. My first suggestion was predicated on the possibility that you might be in a radio-rich environment. Since it seems that you are not, unshielded may be a better solution.
If these work out, that is, no obvious radio frequency interference, you should never need to upgrade. |
@cleeds
"Almost all components today have a separate ground. If not, you can always run a wire from the chassis to ground."
Agreed. But for those which do not ...
"If you always ground at the source end, it’s easy to maintain star grounding. That helps avoid noise and hum by keeping all grounds at the same potential."
A star ground is important if ground is used as a circuit element, such as a signal return. A shield attached at one end is not part of the circuit, and cannot form a ground loop, or hum. Also, the term 'source tend' seems ambiguous to me - is it the turntable or the preamp?
"The typical pickup arm/phono cartridge assembly has a separate ground wire - it’s a balanced circuit with a separate ground intended to be connected to the preamplifier. Again, that helps maintain star grounding."
As noted, star grounding is unimportant in this case. The rest, I agree with - but vintage gear may vary.
Nice discussing with you Cleeds, helps me to clarify my thinking.
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@cleeds @tls49
Although we do not seem to agree about ground loops, nevertheless, thank you for the discussion. |
@cleeds
"we can say a "ground loop" is formed whenever two or more grounds are at different potentials"
I don't think so. From Wiki, "A ground loop is caused by the interconnection of electrical equipment that results in there being multiple paths to ground, so a closed conductive loop is formed."
Closed.
Two components with ground pins connected to different grounds, whose grounds are electrically connected e.g. with a shield, forming a loop. Or, a line inside a balanced cable connecting the grounds of two pieces of equipment, plus a shield also connecting same, forming a closed conductive loop.
"What would be the purpose of running all the grounds through the pickup arm and cartridge?"
Exactly my point.
@tls49
I think that this addresses your concerns as well.
Now let's return control of this thread to the OP, don't you think? |
