Shielded twisted pair, ie balanced cable with the pair carrying flow and return and the shield connected to the return at the send end.
@Douglas, I wrote my "commandment" in the context of the "efficacy" of doing so. 30 year ago I participated in the Audio notes at Digital Equipment. A guy claimed he could hear the difference when he introduced a pair of RS right angle RCA adapters into his signal chain. My gosh the flames over that one - and it was just a 100K employee company, not world-wide like here.
These guys were doing stuff like shunt regulators on their op-amp +/-15V supplys, exotic caps in servo amps and of course, cables. I was even prompted to sink a 3.5" CD into a styrofoam bowl (obtained from the cafe) of liquid nitrogen (obtained from the thermal lab) to see if, well, what it did. Green lines on CD edges, modeling clay damping within the player and op-amp swapouts galore. One engineer told me he deliberately injected electrical transients into an op-amp's +/- power supply and heard nothing - until they reached a ridiculous multi-volt amplitude.
I guess people will naturally become defensive over that money / time spent for "what they can hear" so I've learned to let that sleeping dog lie, regarding challenging it. Now if you can talk some sense before the investment is made, maybe then you could save someone 7.5K$. The assertive salesman isnt going to let go so easily. I sold at "Olson's" when I was in college, there you were expected to sell junk and then offer a costly repair service when they brought it back being defective! It's all Capitalism at its best - I couldnt do that to people, but for some reason they kept me and fired the manager! I liked him; he told me to get a Grado phono cartridge for better sound...
These guys were doing stuff like shunt regulators on their op-amp +/-15V supplys, exotic caps in servo amps and of course, cables. I was even prompted to sink a 3.5" CD into a styrofoam bowl (obtained from the cafe) of liquid nitrogen (obtained from the thermal lab) to see if, well, what it did. Green lines on CD edges, modeling clay damping within the player and op-amp swapouts galore. One engineer told me he deliberately injected electrical transients into an op-amp's +/- power supply and heard nothing - until they reached a ridiculous multi-volt amplitude.
I guess people will naturally become defensive over that money / time spent for "what they can hear" so I've learned to let that sleeping dog lie, regarding challenging it. Now if you can talk some sense before the investment is made, maybe then you could save someone 7.5K$. The assertive salesman isnt going to let go so easily. I sold at "Olson's" when I was in college, there you were expected to sell junk and then offer a costly repair service when they brought it back being defective! It's all Capitalism at its best - I couldnt do that to people, but for some reason they kept me and fired the manager! I liked him; he told me to get a Grado phono cartridge for better sound...
Don't know. The terminations were standard RCA, but no continuity from shield to shield. I don't think we much cared about the internal wire construction. The problem was fixed with good old "Amazon Basics" cables which, far as I know, he's still using.
Last edited:
I spent most of my time in service... fixing stuff and installing stuff, mostly office automation but also PA and Intercom systems. The audio tangent was mostly part time, for my friends, kind of work but I always enjoyed it the most.
Now, if only I had a ten spot for every time I've been around the cycle of ... Don't do that ... Can you fix it... and I told you so. So much wasted money and effort. I really do feel sorry for these guys who get ripped off this way. Makes it a bit hard to keep quiet about it.
Of course this is only going to get worse as younger generations become less and less tech-savvy and start inventing ways to explain things through super-powers and magic.
Center pin only. The shield was connected at one end only and the cable was marked with an arrow to indicate the signal direction so that the shield connected at the output end. Of course this creates a floating input which is going to be very susceptible to hum and interference... Moreover, this wasn't a fluke. They were all like that.
I've also seen RF Coax, unshielded wire, silly little battery boxes, mystery bulges, wires so heavy they break the females on the back of the gear and so on.
At best they are no better ... more likely they will cause problems.
Common ground? Apparently not because it was humming.
Even if it did, relying on the 3rd pin in a power cord is a really bad choice.
The single ended shield stands a very good chance of becoming an antenna.
Even if it did, relying on the 3rd pin in a power cord is a really bad choice.
The single ended shield stands a very good chance of becoming an antenna.
Yes we heard music but with the hum mixed in.
The minute I connected a proper cable the hum stopped.
Please get to your point...
The minute I connected a proper cable the hum stopped.
Please get to your point...
Last edited:
To be honest, I didn't bother figuring that out. I assume it was finding a path with some substantial resistance someplace outside of the cable.
This might help ... AudioQuest Page
"the metal shield is attached to ground at only one end, thus defining the cable’s directionality."
So even with an internal conductor, it still works as an unshielded cable. The hum could have been coming from anyplace... lights, transformers, wiring in the walls...
This is their Canadian Price List...
Now given that cables costing Upwards of $250 caused a problem that was fixed with a $10.00 cable from Amazon, I'd have to say that AudioQuest is quite the rip off.
This might help ... AudioQuest Page
"the metal shield is attached to ground at only one end, thus defining the cable’s directionality."
So even with an internal conductor, it still works as an unshielded cable. The hum could have been coming from anyplace... lights, transformers, wiring in the walls...
This is their Canadian Price List...
Now given that cables costing Upwards of $250 caused a problem that was fixed with a $10.00 cable from Amazon, I'd have to say that AudioQuest is quite the rip off.
Last edited:
You edited out the most important part in your quote: "negative has its own internal conductor and the metal shield is attached to ground at only one end".
It's an STP cable. If you couldn't measure continuity between the connectors' outer rings, it was broken.
It's an STP cable. If you couldn't measure continuity between the connectors' outer rings, it was broken.
If you had read my next sentence: "So even with an internal conductor... "
Now who's editing for advantage?
Shielded Twisted Pair only works with differential signalling. When used single ended you run the risk of the floating end of the shield conducting common mode noise into the cable, that can't be removed at the next stage's input.
Really that doesn't matter. The bottom line from this example and several other situations like it is that the high priced cables caused problems, rather than solving them. Whatever might have been claimed is totally undone by overpriced bad engineering. When I can pull out a $200 or more cable and replace it with a $10.00 cable and get a better result, you have got to start thinking the higher priced cables aren't much of a bargain at all.
This is the whole issue... people are spending ludicrous amounts of money on the word of smarmy salesmen and getting worse results than they would get by grabbing the cheapie cable off the display at Best Buy. They are being ripped off.
Now who's editing for advantage?
Shielded Twisted Pair only works with differential signalling. When used single ended you run the risk of the floating end of the shield conducting common mode noise into the cable, that can't be removed at the next stage's input.
Really that doesn't matter. The bottom line from this example and several other situations like it is that the high priced cables caused problems, rather than solving them. Whatever might have been claimed is totally undone by overpriced bad engineering. When I can pull out a $200 or more cable and replace it with a $10.00 cable and get a better result, you have got to start thinking the higher priced cables aren't much of a bargain at all.
This is the whole issue... people are spending ludicrous amounts of money on the word of smarmy salesmen and getting worse results than they would get by grabbing the cheapie cable off the display at Best Buy. They are being ripped off.
Last edited:
You said the $250 one was broken. I didn't. I don't actually know if it was broken or made that way and I don't care.
Even if the whole thing worked perfectly that kind of money for something that can be replaced with a much cheaper item for the same result is still a rip off.
Are you in the habit of spending more money than you need to?
You may want to give that some more thought.
Even if the whole thing worked perfectly that kind of money for something that can be replaced with a much cheaper item for the same result is still a rip off.
Are you in the habit of spending more money than you need to?
You may want to give that some more thought.