cat-5 question(s)
I'm building BIBs for 166Es which will be powered by an Trends Audio T-amp. Input will be a cheap turntable.
From searching these forums it looks like cat-5 is the way to go for speaker wires.
I planned on using two pairs per speaker (use all the wires in the cable).
GM advocates using two wires per speaker. At what length would I need four wires per speaker? Can I simply disconnect half of the wires from the amp for a A-B comparison? Will
How bad is it to leave cat-5 as is, i.e. still in the casing.
My speaker wire run will be about 7mts or 22ft.
It's amazing how many times I can reread posts here and increase my knowledge/confusion.
Thanks everybody.
I'm building BIBs for 166Es which will be powered by an Trends Audio T-amp. Input will be a cheap turntable.
From searching these forums it looks like cat-5 is the way to go for speaker wires.
I planned on using two pairs per speaker (use all the wires in the cable).
GM advocates using two wires per speaker. At what length would I need four wires per speaker? Can I simply disconnect half of the wires from the amp for a A-B comparison? Will
How bad is it to leave cat-5 as is, i.e. still in the casing.
My speaker wire run will be about 7mts or 22ft.
It's amazing how many times I can reread posts here and increase my knowledge/confusion.
Thanks everybody.
hermanv said:
In 2 of my 3 current systems, which are presently all Fostex Fullrangers* - CAT5 wire (also as internal speaker wire, and several of the DIY interconnects.) The remaining system (wife's living room) is some generic 20 gauge zip wire, because she couldn't tolerate the blue jacketed CAT5.
*the only loudspeaker XO's in the house are the 2 Logitech computer systems.
tilroh:
I think GM means 2 conductors per speaker : i.e. one of the 4 twisted pairs. Some folks (myself and DaveD included) untwist the conductors, and get pretty funky in separating them with packing tape. In my case, they're spiral wrapped around a length of 3/8" manila rope, and covered with Teflex sleeving (the latter just for cosmetics.
I had to look up what triboelectric meant... Generating electricity by rubbing certain materials together, Eg: amber and wool, glass and silk.
I work with RF coax cables nearly every day. None of the teflon and silver cables I've encountered are likely to rub, if you've ever tried to strip one you'll see what I mean. even the braid is very tightly laid with a very tight outer sheath. It takes a lot of practice to strip it without nicking the conductors. We use teflon and silver for a few reasons, one of which is the speed of electricity is much higher in teflon and silver cables. about 0.9c compared with about 0.7c (it's called velocity factor and is important with tuned lengths.) Teflon cable is usually double screened as well. Ordinary cheap coax is surprisingly leaky. Another biggie is nickel plated connectors, silver is best. even better than gold. Of course 90% of that has nothing to do with audio, I'm talking hundreds of megaHertz here.
On the other hand I've seen amps built with solid silver wire poked into small teflon tube which is quite loose on the cable. This might cause a problem, but only if it develops charge faster than it self-disharges in moist air. Highly unlikely but not impossible. Simply bending the wire a bit should be enough to hold the tube still.
Tiroh, use a one pair per three metres, If your speakers are three metres from your amp that is one wire for + and one for - and six wires left unused.
Solid core wire tends to fatigue easily. Don't bother with banana plugs, just stick it in the binding post and tighten it with moderate force. Check it is still tight after a week. It will probably break before it corrodes.
I work with RF coax cables nearly every day. None of the teflon and silver cables I've encountered are likely to rub, if you've ever tried to strip one you'll see what I mean. even the braid is very tightly laid with a very tight outer sheath. It takes a lot of practice to strip it without nicking the conductors. We use teflon and silver for a few reasons, one of which is the speed of electricity is much higher in teflon and silver cables. about 0.9c compared with about 0.7c (it's called velocity factor and is important with tuned lengths.) Teflon cable is usually double screened as well. Ordinary cheap coax is surprisingly leaky. Another biggie is nickel plated connectors, silver is best. even better than gold. Of course 90% of that has nothing to do with audio, I'm talking hundreds of megaHertz here.
On the other hand I've seen amps built with solid silver wire poked into small teflon tube which is quite loose on the cable. This might cause a problem, but only if it develops charge faster than it self-disharges in moist air. Highly unlikely but not impossible. Simply bending the wire a bit should be enough to hold the tube still.
Tiroh, use a one pair per three metres, If your speakers are three metres from your amp that is one wire for + and one for - and six wires left unused.
Solid core wire tends to fatigue easily. Don't bother with banana plugs, just stick it in the binding post and tighten it with moderate force. Check it is still tight after a week. It will probably break before it corrodes.
Mike, let me tell you a story...
Some years ago, I wanted to experiment with subtractive crossovers. I built up an op-amp based unit on perfboard using AD712s. The damn thing drove me crazy it was so microphonic. I couldn't seem to localize the components causing the issue. No matter what I tapped, the noise was the same. Mind you, this was a line-level circuit, so the weird subtle effects seen at microvolt levels weren't in play here.
I finally gave up, deciding that either the circuit wasn't stable or the microphonics were due to the perf construction. Either way, total rebuild was needed and I just didn't have the time. It sat in a box for about 20 years, until one day when I read about triboelectric effects. A light went on... The lead-in and lead-out signal cables for that crossover were an ultra-premium Teflon-silver coax, tight braid and all, salvaged out of some surplus RF equipment, where it had worked perfectly. Just for fun, I pulled the crossover board out of storage, hooked it up, and heard the same microphonics. I pulled out the Teflon/silver coax, replaced it with some cheap Radio Shack shielded wire and, yes, the crossover was now quiet. It had been the cable's fault. Nothing was loose at all in the cable's construction, but the triboelectric effect was triggered by the strain in the cable induced by small amounts of vibration or even rubbing against the workbench.
Will this be an issue at speaker level with cables terminated at both ends with a low impedance? Probably not, but I won't say impossible. And I learned about one more non-mysterious way that cables can indeed be audible!
Some years ago, I wanted to experiment with subtractive crossovers. I built up an op-amp based unit on perfboard using AD712s. The damn thing drove me crazy it was so microphonic. I couldn't seem to localize the components causing the issue. No matter what I tapped, the noise was the same. Mind you, this was a line-level circuit, so the weird subtle effects seen at microvolt levels weren't in play here.
I finally gave up, deciding that either the circuit wasn't stable or the microphonics were due to the perf construction. Either way, total rebuild was needed and I just didn't have the time. It sat in a box for about 20 years, until one day when I read about triboelectric effects. A light went on... The lead-in and lead-out signal cables for that crossover were an ultra-premium Teflon-silver coax, tight braid and all, salvaged out of some surplus RF equipment, where it had worked perfectly. Just for fun, I pulled the crossover board out of storage, hooked it up, and heard the same microphonics. I pulled out the Teflon/silver coax, replaced it with some cheap Radio Shack shielded wire and, yes, the crossover was now quiet. It had been the cable's fault. Nothing was loose at all in the cable's construction, but the triboelectric effect was triggered by the strain in the cable induced by small amounts of vibration or even rubbing against the workbench.
Will this be an issue at speaker level with cables terminated at both ends with a low impedance? Probably not, but I won't say impossible. And I learned about one more non-mysterious way that cables can indeed be audible!
chrisb said:
Oh I have Chris. It's just that I figure that it's a bit of a hiding to nothing as it's so system dependant.
Re the microphonic issues, I was primarily refering to conditions where the lead is subject to movement or vibration. Due to the relative stiffness of both materials, it's transmitted & you risk some ringing. Not a massive issue for audio as I've said before, but given that it doesn't provide any worthwhile benefits for our purposes, I can't really see the need.
This is most interesting; Teflon and silver foil capacitors are amongst the highest cost capacitors available. They are reported as being very good capacitors. Due to the nature of how capacitors are built there is far more surface area between the silver and the Teflon than in a cable. I suspect that the tension between the silver and the Teflon is also less in a capacitor due to the requirement of not tearing either film during winding.
I'm not disputing your story, I just wonder how the capacitor folks can make a part that is frequently used in crossovers (often a high vibration environment) and get it to work?
My previous RCA interconnect cables were also silver/Teflon, they were expensive and sounded quite good. Here again, the cables were located in a high vibration environment caused by the acoustic output of the nearby speakers.
A mystery.
Hmm. Looks like I'm not alone in having some reservations about silver / teflon: http://www.audioholics.com/education/cables/cable-distortion-and-dielectric-biasing-debunked
As always, YMMV though, and it's probably highly dependant upon application. I well remember the best amplifier, bar none, I've never heard. My friend Nick's 300b design, which was superb with the stock valves. We swap in Steve's 300a's and it vanished. Couldn't hear any signiture at all. Shocking. The speaker cable was solid core twin + earth mains, about £0.30 a foot. From that point, it never really occured to me to worry about wire. The speakers? Oh yes: open baffles, Lowther EX4s, supported by twin 12in vitage Goodmans per channel, so the quality of the drivers wasn't really an issue.
As always, YMMV though, and it's probably highly dependant upon application. I well remember the best amplifier, bar none, I've never heard. My friend Nick's 300b design, which was superb with the stock valves. We swap in Steve's 300a's and it vanished. Couldn't hear any signiture at all. Shocking. The speaker cable was solid core twin + earth mains, about £0.30 a foot. From that point, it never really occured to me to worry about wire. The speakers? Oh yes: open baffles, Lowther EX4s, supported by twin 12in vitage Goodmans per channel, so the quality of the drivers wasn't really an issue.
I still have some of that wire in case you want to come over and play with it.
Two observations. First, the only really microphonic caps I've run across were ultra-expensive audiophile ones. The source for them swore that they'd increase the "bloom" and "sounstage." Probably would, too, adding that subtle hint of reverb.
Second, the foil and film are wound in a cap (I think that's the source of the microphonics, the less-than-stellar winding tightness of fashion caps), wheras in cables, the Teflon is extruded onto the wire. I'd expect the interface to be quite different.
I am most curious about the wire and hoped someone had experience or an observation as to what is going on.SY said:
I agree fully about winding tension, specialty capacitors are often made by boutique shops in low volumes, quality control and repeatability are probably a problem. I have used film and foil (not the silver/Teflon. can't afford them) without difficulty in crossovers.
I live in Santa Rosa, not that far from Napa, only sheer laziness prevents me from taking advantage of your generous offer.
Most interesting Sy.
I have heard "speakerphonic" capacitors a quite few times. Audio that is quite intelligible coming from the capacitor. Usually in less than elegant AM transmitters. The caps are usually ceramic and sometimes metallized polypropylene.
I expect the oil in PIO caps would damp vibrations.
I use teflon coax (in Frequency Modulated applications) at levels at low as 0.2uV I wonder if the capacitance of the particular length of that particular cable had anything to do with your problems.. It can form tuned circuits at radio frequencies which will be invisible on the typical CRO.
A lot of our audio wire around equipment rooms is tinned copper teflon insulated 5 pair cable with a foil on plastic screen then more teflon over the top. those run about line level and some are unbalanced and 30 metres long. the whole place is filled with mechanical vibrations from turbines and pumps.
I don't doubt you, I've never had that problem myself but I might one day so I'd like to learn about it.
I have heard "speakerphonic" capacitors a quite few times. Audio that is quite intelligible coming from the capacitor. Usually in less than elegant AM transmitters. The caps are usually ceramic and sometimes metallized polypropylene.
I expect the oil in PIO caps would damp vibrations.
I use teflon coax (in Frequency Modulated applications) at levels at low as 0.2uV I wonder if the capacitance of the particular length of that particular cable had anything to do with your problems.. It can form tuned circuits at radio frequencies which will be invisible on the typical CRO.
A lot of our audio wire around equipment rooms is tinned copper teflon insulated 5 pair cable with a foil on plastic screen then more teflon over the top. those run about line level and some are unbalanced and 30 metres long. the whole place is filled with mechanical vibrations from turbines and pumps.
I don't doubt you, I've never had that problem myself but I might one day so I'd like to learn about it.
i just got my hands on some 13gauge magnet wire and would like to make a pair of 6-8 foot speaker cables (unterminated of course). any suggestions on whether to twist the cables or leave them separated? once twisted i don't think i'll be able to untwist them neatly as they are quite thick.
lastly any suggestions on material to sheathe them with?
thanks,
larry
lastly any suggestions on material to sheathe them with?
thanks,
larry
The twin & earth you mean? It was just generic solid core ring-mains wire in a stiff gray plastic jacket from down the local B&Q (our equivalent to Home Depot). Conductors would be about 16ga. Maybe 14ga. You could probably find offcuts in skips on a building site, as it's generally sold to builders / electricians. To be honest, I didn't pay a great deal of attention. My point is, if the cheapest, nastiest wire from off the rack at the local DIY superstore allows you to hear those differences, that says it all about most of the drivel espoused about cable. Smoke & mirrors. That's all it is. Assuming that you don't actually want your wire to do anything to the signal (which isn't always the case), then, if you haven't already read it, this is good for a laugh as Rod tears most of the nonsense surrounding wire to shreds: http://sound.westhost.com/cables.htm
A selection of good discussions adding onto the above. Note that there are two pages of links, so be sure not to miss the second if you're interested: http://www.audioholics.com/education/cables/allContents?b_start:int=0
'ear be a perfectly sensible DIY speaker cable in this mould, from 6moons (clearly, they were getting fed up with the insanity too). Incidentally, I believe the expensive commercial cables refered to that Stephaen junked in favour of this cheap mains lead were Audience Au24s. One 'audiophile approved' high-end wire there for very little outlay, with the correct image, if that side is important to you too. http://www.6moons.com/audioreviews/whitelightning/moonshine.html
Re the twisting, watch the capacitance. Shouldn't go up in this case sufficiently to cause much in the way of problems though.
A selection of good discussions adding onto the above. Note that there are two pages of links, so be sure not to miss the second if you're interested: http://www.audioholics.com/education/cables/allContents?b_start:int=0
'ear be a perfectly sensible DIY speaker cable in this mould, from 6moons (clearly, they were getting fed up with the insanity too). Incidentally, I believe the expensive commercial cables refered to that Stephaen junked in favour of this cheap mains lead were Audience Au24s. One 'audiophile approved' high-end wire there for very little outlay, with the correct image, if that side is important to you too. http://www.6moons.com/audioreviews/whitelightning/moonshine.html
Re the twisting, watch the capacitance. Shouldn't go up in this case sufficiently to cause much in the way of problems though.
Copper is pretty soft stuff. A lot of commercial copper wire is alloyed with steel to reduce "sag". To my ears the only awful wire I've heard was a twin lead with a high steel content.
Once the copper is pure enough further "magic" probably has little or no effect.
Low inductance results in a more constant group delay, sure seems like a good idea.
The diminishing returns rule clearly applies to speaker cables, the first step is worthwhile, after that, just how good is your system?
Once the copper is pure enough further "magic" probably has little or no effect.
Low inductance results in a more constant group delay, sure seems like a good idea.
The diminishing returns rule clearly applies to speaker cables, the first step is worthwhile, after that, just how good is your system?
I don't honestly think how good the system is makes much difference either, given the above anecdote. Lower inductance = good, providing you don't push capacitance through the roof in order to achieve it.
I'll have you know my teflon insulated mercury wires, once they have been used for a week as a g-string by blonde Chachapoyan virgins, and then custom braided by the aforementioned, have no magic whatsoever. None at all.
I'll have you know my teflon insulated mercury wires, once they have been used for a week as a g-string by blonde Chachapoyan virgins, and then custom braided by the aforementioned, have no magic whatsoever. None at all.
Scottmoose said:I don't honestly think how good the system is makes much difference either, given the above anecdote. Lower inductance = good, providing you don't push capacitance through the roof in order to achieve it.
I'll have you know my teflon insulated mercury wires, once they have been used for a week as a g-string by blonde Chachapoyan virgins, and then custom braided by the aforementioned, have no magic whatsoever. None at all.
liquid wires:
http://www.teoaudio.com/liquid_cable.php
blonde Chachapoyans would be pretty rare indeed
Yeah. Exactly what they're hoping to achieve sonically is anyone's guess (other than a substantial increase in the size of their bank-ballance ). I like the creativity though -I suspect people will pay whatever they're asking because they're different from the norm. Mercury's been mooted & even used in the past by some mad scientist types, but the toxicity issues killed any potential commercial viability (& probably the users as well when you accidentally run over the tube with the old hoover)
Oddly enough, the idea of blonde Chachapoyan's isn't actually as far fetched as it sounds: http://www.freerepublic.com/focus/f-news/1715581/posts
). I like the creativity though -I suspect people will pay whatever they're asking because they're different from the norm. Mercury's been mooted & even used in the past by some mad scientist types, but the toxicity issues killed any potential commercial viability (& probably the users as well when you accidentally run over the tube with the old hoover)Oddly enough, the idea of blonde Chachapoyan's isn't actually as far fetched as it sounds: http://www.freerepublic.com/focus/f-news/1715581/posts
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