Post by Owen Y on Nov 26, 2018 9:04:50 GMT 12
Very interesting Owen. I remember those Essex Eco articles in Hi Fi News. I'd like to try experimenting, how many wires do you think I would need for a 40 watt tube amp to speakers with 85dB sensitivity? Jaycar stock enamel copper wire in 1.25, 0.315, 0.4 and 0.8mm sizes, are any of these suitable? (the 0.8mm is closest to yours) Is there any advantage in using multiple sizes when using more than one conductor per +/ - ? Thanks. Hi mijoh - when I was using Spendor SP1 loudspeakers (87dB/W sensitivity), I was using 3 strands per polarity (3 for +ve, 3 for -ve) & a spkr cable run of around 3.5m per side. 85dB/W is a little less sensitive, but should be fine, esp if runs are not real long. What are you spkr cable lengths, loudspeaker model, general placement in proximity to walls & listening distance? (What's nice about the 'solid core' approach, is the 'coherence' of the tonal range & harmonics. Also, with the 'air-dielectric' philosophy, you get v little harshness & 'hash' typical of bunched wire geometries.)
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Post by mijoh on Nov 27, 2018 1:57:10 GMT 12
Hi Owen, my room setup is similar to yours with equipment on the left. The loudspeakers are Kef LS50's (wired) with a pair of subs that are all about a metre out from the back wall and 2 metres from the side walls. It's about 3 metres to the listening position and the speaker cables are about 4.5 metres long.
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Post by Owen Y on Nov 28, 2018 9:35:44 GMT 12
mijoh - although the l'spkrs are low sensitivity, listening distance is not large at 3m & with powered subs, the 40wpw amp should be powerful enough. After some subjective experimentation with various solid core 'cable' configs, I concluded that: - 0.7mm diam (22swg) copper sounded best to me (compared with 0.65mm or 0.9mm) - bare copper was hard to source & 'enamel' coated winding wire sounded fine. - The 'air dielectric' approach was cleanest sounding, ie. use air-separation/spacing between conductors. - The conductors need to be 'held' somehow, ie. letting them float in space on the floor, did not sound good (un-dynamic). That's why I came up with the idea of spiralling wires around a plastic tube (with bands of 'ceelon' plumber's tape every now & then, holding them in place). - Arrange the +/- conductors as pictured below & spaced apart. This seemed to sound best (most dynamic) to me, perhaps something to do with the non-opposing concentric electrical fields surrounding each AC signal conductor when +/- conductors are in close proximity. With just 2 strands, the cable geometry is not a problem, but with 6 strands, the geometry/interaction becomes an issue. - Terminations - bare wire is good where practical (where speaker & amp connections suit, scrape off the enamel coating as smoothly as possible with a knife) or solder into simple copper 'spades' if necessary (I use Electrician's spade/fork connectors with tin plating filed off the spade end). I use Caig Deoxit contact cleaner/treatment to minimise oxidation of the bare copper - also on bare wire ends.  
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Post by Owen Y on Nov 28, 2018 9:43:39 GMT 12
Jaycar stock enamel copper wire in 1.25, 0.315, 0.4 and 0.8mm sizes, are any of these suitable? (the 0.8mm is closest to yours) Is there any advantage in using multiple sizes when using more than one conductor per +/ - ? Thanks. I would go with 0.8mm. (You may be able to get some 0.7mm/22swg or even 0.65mm, from a motor winder.) I have tried a 'Cardas golden ratio' config using different gauge wires, but did not manage a better sounding cable using the sizes that were available. However, this was not ugly sounding & is an option if the single gauge does not suit your ear or system.
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Post by mijoh on Nov 28, 2018 16:09:04 GMT 12
Owen, thanks for the info and your help in answering my questions. I've found that RS have a better choice of wire sizes. They include 0.63 mm and 0.78 mm, which do you prefer?  Bunnings have the plastic tube and I am going to go with the 5mm diameter for interconnects and 10mm for speaker cables. I will use spades for the speaker cable as you suggest.  I notice in the pic above that you have used what looks like plastic bodied IC connectors, was there a particular reason for this, or just what you had on hand? I suppose there's a (small) possibility of the enamel wearing off the copper wire rubbing against a metal body and shorting. Plastic would avoid that. Mind you, in my experience it takes a lot of scraping to remove! The late Allen Wright is quoted as having stated that cheaper lightweight RCA plugs are better sounding than the extra heavy metal variety. That's from a review of his SuperCables Cookbook. Do you have any tips on constructing these cables, for example do you stretch the plastic tubing taut between two points and wind on each conductor individually?
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Post by Owen Y on Nov 29, 2018 8:01:50 GMT 12
Hi mijoh.... - 0.75mm diam is listed as 21AWG, which is 0.72mm OD, so that looks similar to what I have been using. On the other hand, if most of your bass freqs are handled by a sub, then 0.63mm could work OK too. (I have occasionally used 0.63mm, with its 'leaner' tone, but usually prefer the fuller range of 0.71mm.) - Plastic tube (aquarium-type air tube) - I use 8-10mm OD for ICs & 10-17mm for spkr cables. Gentle spiralling, enough to hold the wires in place & use a bit of Ceelon plumber's tape every now & then, to hold the spkr wires esp on the tubing. - RCA plugs - those are Eichhman Bullet copper RCAs, best sounding to my ear, because of their design that (i) does not have excessive metal where not needed for signal carrying (ii) has a nice simple signal path design without metal threads etc in the signal path (iii) the contact design is clean & firm. You'll find that the 'enamel' or other heat-proof wire coating is tough & you only need to scrape off a cm or so at the ends. (Knife scraping is better than filing IMO because you want to maintain the smoothness of the copper surface as much as poss, because the signal travels at/near the conductor surface.) - No special construction techniques, it is fairly easy. Lspkr cables are a bit more of a handful with say 6 wires, but (i) it's helpful to mark/label the +/- wires if you don't have a multimeter & (ii) use the Ceelon tape (adhesive free) or other tape, as mentioned. Try to keep multiple strands equal in (signal path) length. These electrical spade connectors work well with solid strand cables - just check the 'stud size' to fit your lspkr post & rub off the tinning on the spade end on a metal file. Solder the wires into the cable end, with minimum of solder. 
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Post by Owen Y on Nov 29, 2018 8:57:00 GMT 12
Comparison of Eichmann Bullet with typical 'audiophile' RCA plug. -ve contact pin is small but v tight contact design & has proven to not lack LF power delivery.  
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Post by mijoh on Nov 29, 2018 21:44:33 GMT 12
Excellent information there, thanks Owen. The comparison photo illustrates the excessive area of metal in the regular RCA plug very well. In many ways the old DIN connector was far superior to the RCA in this respect. Thanks for introducing me to Keith Lewis Eichmann. On Googling his Bullet RCA connector I see that he has a new range called the KLE Harmony which is said to offer some improvements on the Bullet, so I probably will get a set or two for this project. If anyone's interested in buying some, Parts Connexion are selling a set of 4 Copper Harmony for US$36.82 while several places in the UK are charging about £54.00 which seems rather high by comparison. 
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Post by Owen Y on Nov 30, 2018 8:03:57 GMT 12
Yes, the ol' DIN audio connectors were good IMO, but the plastic in those days was not so good & folks began to use bigger cables. Keith Eichmann I think sold Eichmann (ETI) & re-started as KLEI with a new range. I have never tried the KLEI products, as they seemed more costly. I have picked up (copper & occasionally silver) Bullet Plugs s/h or economically whenever I can. Yes, Parts Connexion, Hifi Collective UK, or Totally Wired in Dunedin.
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Pundit
Post by Gryffles on Dec 1, 2018 10:35:47 GMT 12
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Post by michaelw on Dec 1, 2018 19:05:44 GMT 12
and in using metal they have negated the primary design feature of the eti - minimal use of metal in the plug.
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Pundit
Post by Gryffles on Dec 2, 2018 10:59:20 GMT 12
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Post by Owen Y on Dec 3, 2018 19:02:12 GMT 12
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Post by mijoh on Dec 4, 2018 0:19:01 GMT 12
Thanks for the link Gryffles, if I hadn't ordered the others on Friday I would have considered these.
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Post by mijoh on Dec 4, 2018 0:36:02 GMT 12
Thanks Owen, I ordered the 0.71mm 500g (120 metres) roll from RS as it is the most economical size for my speaker cables, 4.5 metres x 12 runs (6 runs per cable) But after seeing your link I think will get a 100g roll of 0.63mm from Surplustronics for the IC's to experiment with.
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Post by Owen Y on Dec 4, 2018 8:44:30 GMT 12
To my ear, the 0.63mm sounded obviously less full, possibly more extension at HF end. I have used it for tweeter runs, or mixed 0.71mm / 0.63mm for +/- legs of a 'cable'. But YMMV of course. Interested in what your ears tell you 
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Post by mijoh on Dec 4, 2018 22:49:50 GMT 12
Very interesting Owen, I will make up one pair of IC's to each size and hope to hear for myself what a difference 0.08 mm of copper wire makes! 
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Post by Owen Y on Dec 5, 2018 9:06:40 GMT 12
Haha, yes, the diameter difference is not large (~11%). In theory, Hawksford argued that an ideal conductor at audio frequencies should neither be too large or too small diameter. But let your ears be the judge.
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Post by mijoh on Dec 11, 2018 1:05:36 GMT 12
Earlier in this thread I mentioned that I ordered some KLEI silver plated copper Harmony plugs. All my equipment has gold RCA sockets and somewhat belatedly the thought that I have known about for years, popped into my head about using dissimilar metal connectors together is not a good idea! What do you think?
Eichmann has dropped gold from the Harmony range and there are only silver variations now, but gold is available in the cheaper eBay Star Line range.
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Post by Owen Y on Dec 11, 2018 9:47:44 GMT 12
Hi mijoh - all my RCA sockets are gold-plated (over brass). I use copper Eichmann bullets mostly, but the sockets are brass, a harder material. I have some Furutech RCA sockets, which I have yet to try - also gold-plated copper I believe & a thin conductor + plastic design, similar in principle to the Eichmanns (& KLEI, WBT NextGen). I don't think it matters much, all these metals are high conductivity, but plating does affect sound, because as we've mentioned HF signals esp, travel on or near the surface of conductors. I use silver wire (mostly internal hook-up wire, because I have some silver wire on hand), I'm not concerned either way to mix copper & silver. My feeling is that I'm happy with the tone of copper. Gold is used primarily of course, to avoid tarnishing of copper or brass. Rhodium does the same job, but I went away from the rhodium Cardas plugs/sockets that I once used - both the rhodium plating & the chunky plug design didn't appeal. However, I remember that Mark Jenkins liked the sound of some gold content in his popular Antipodes cables. For many years, I used these cheap nickel-plated (brass?) RCA plugs - because they were easy to experiment with & sounded fine.... (Note how a wire can be inserted right down the centre pin to the tip & you can solder also directly to the thin outer shell.) 
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Post by mijoh on Dec 11, 2018 22:27:37 GMT 12
Owen, those little nickel-plated plugs were quite common in the 1960's and can be used to make good compact shorting plugs in unused input sockets. I have a few in my spares box. Do you find that you have to clean the Eichmann 'naked' copper plugs more often than plated plugs? Before I wrote my last post about dissimilar metals, I came across this blog about dissimilar metals and galvanic corrosion in mating connectors, but have since realised that the process needs an electrolyte such as water, so since my listening room isn't normally under water I won't worry anymore about that!!  blog.samtec.com/post/dissimilar-metals-in-mating-connectors/
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Post by colinf on Dec 11, 2018 23:47:49 GMT 12
I would have thought that a little humidity in the air would be enough to tarnish copper and silver, and act as a weak electrolyte to dissimilar metal connections?
AMR-iFi R&D
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Post by Owen Y on Dec 12, 2018 9:49:19 GMT 12
colinf is of course correct, that moisture in the air is enough to facilitate (galvanic) corrosion. I almost always clean connectors with (& leave a residual coating of) Caig Deoxit, esp on those metals down the 'galvanic scale' & most subject to corrosion, ie copper, brass, silver. That, together with the wiping action of the Eichmann Bullet design, seems to keep contacts minimal maintenance As others have found too, even Gold plated sockets etc benefit from occasional cleaning - regular 'dirt'. (I Deoxit my valve pins & sockets too )
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Post by mijoh on Dec 12, 2018 23:08:12 GMT 12
Good points, I'm armed and ready with the Deoxit! 
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Post by Owen Y on Sept 18, 2020 15:55:03 GMT 12
A wee update for the cable DIYers... Recently, I have made a small mod., to first the interconnects & just recently, the speaker cables. The solid core conductors, because they are unsheathed on the outside, are not 'held' very firmly (& can 'vibrate' with the AC signal field). Not wishing to use any synthetic materials & trying to maintain the 'air dielectric' approach (I know the winding wire is coated copper, but it sound fine to me), I spiralled some natural cotton 'string' over the conductor wire strands, in a 'counter-direction' to the wire spiralling. Still evaluating, but I think I have a slightly 'tauter', more precise, cleaner-edged sound, with a enhanced sense of 'decay' (quietness?).   (The speaker cables, re-purposed from my previous spkrs, have 6 strands (3+3 ea polarity) but, with these high sensitivity speakers, I connect only 2+2 at ea end.)
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