47 Labs OTA, a cheap alternative?

[homer09]

i already have a spool of belden's best teflon cat5 cable, cyro treated.

i guess i will use this, although your aproach, paulo, seems better...

 

[PauSim]

That´s 1585a isn´t it? Are you going to use it for interconnection?

 

[karma]

nice

 

[PauSim]

Here´s a better pic of the speaker cables: easy fit in the binding posts.

 

[pjpoes]

I am curious to know how these interconnects reject noise such as EMI and RFI, or if they dont. If they are supposed to be evenly spaced, how do they do that, just placement? Interconnects made in the Mapleshade way are kept spaced apart by the film they are suspended in. The Long run speaker wires he offers are to be manually spaced apart over the ling run, and he uses a double helix, so he says, for those speaker wires.

I have designed one interconnect, not using wire like this, I will have to try some as it sounds cheap, using FIM's new cable, in 20 guage. I spaced them apart using wooden blocks of equal size. This I figure should keep them a somewhat equal length apart. Problem I have is that they are now kinda heavy, the blocks are not big, but with this many, they got kinda heavy. Second problem is that I dont think they sound all that good thus far. They may need some run in, I litterally finished them last night at midnight, so we shall see. I may switch to something like Balsa wood for the seperators.

 

[carlosfm]

Homer, this is just ordinary RG59. My guess the insulation is polythilene, as it melts pretty quickly. Except for dampening properties, I´m not sure if Teflon would sound better as the wires are meant to be widely spread apart and so, capacitance is not an issue. If some Belden 1695a is used, any improvement in sonics must be due to better wire quality, if there´s any.

50 ohm 10Base-T coax network cable (RG58, if I remember) may be a better choice.
The insulation is very strong and holds some heat, because you could crimp or solder a BNC plug.
On some cables it may be teflon.

 

[PauSim]

Thanks for your reply

I am curious to know how these interconnects reject noise such as EMI and RFI, or if they dont.

They don´t.

If they are supposed to be evenly spaced, how do they do that, just placement? Interconnects made in the Mapleshade way are kept spaced apart by the film they are suspended in. The Long run speaker wires he offers are to be manually spaced apart over the ling run, and he uses a double helix, so he says, for those speaker wires.

Yes, it´s just placement. Capacitance is so negligible I just plug the cables and leave them as they are without worrying. The Mapleshade method allows the conductors to be evenly spaced apart, which will provide some consistency, but at those distances, with so much air in the midlle,I wouldn´t worry much. Their double helix are a different type of cables. It´s four twisted conductors arranjed in star-quad and so it should sound good.

I have designed one interconnect, not using wire like this, I will have to try some as it sounds cheap, using FIM's new cable, in 20 guage. I spaced them apart using wooden blocks of equal size. This I figure should keep them a somewhat equal length apart. Problem I have is that they are now kinda heavy, the blocks are not big, but with this many, they got kinda heavy. Second problem is that I dont think they sound all that good thus far. They may need some run in, I litterally finished them last night at midnight, so we shall see. I may switch to something like Balsa wood for the seperators.

This wire may be cheap but sounds like a million dollars and I bet the 47 Labs OTA real price must not be that far. Anyway, any RG59 costs very litlle unless it´s made of special materials like Teflon insulators, which I don´t think are essential to the OTA design. What counts here is the single strand inside a thick jacket.

Isn´t 20 gauge too much for a single IC conductor? That may be the reason why they don´t sound all that good. I would try a smaller gauge, from 24 upwards, before replacing the wood...

 

[PauSim]

50 ohm 10Base-T coax network cable (RG58, if I remember) may be a better choice.
The insulation is very strong and holds some heat, because you could crimp or solder a BNC plug.
On some cables it may be teflon.

Yes, the 50 Ohm coax is the RG58. I chose the 75 Ohm RG59 because it´s what I know after making some digital cables for my DAC. RG59 is also meant for BNC plugs, either crimped or soldered, but the 50 Ohm coax may have a thicker insulation...

 

[carlosfm]

RG59 is also meant for BNC plugs, either crimped or soldered, but the 50 Ohm coax may have a thicker insulation...

No, the insulation is thinner.
The central wire is thicker.

 

[pjpoes]

Thanks for the comments on my own experience. The 20guage I used because it is the smallest of this new FIM wire, and what they seem to feel is good for an IC connection. It looks like very high quality wire, and I have been wanting to use some monocrystal wire, but was unable to find any hookup wire like that at a reasonable price, other than Vampire, which I am yet to try.

What is it about the thick unsulation that you think makes this a good IC and Speaker wire. The dampening? If so, would further dampening, such as from a block of graphite, carbfiber, or wood be beneficial? That was sorta my idea with the wood blocks, I made the holes smooth and tight fitting, so they might dampen the wire, if it could make a difference. OH, and before I get any comments about how there is no way that a conductive cuircit or wire or whatever could possibly be affected by vibrations, Phonostages, which commonly amplify a signal 100's of times its unput level are natorious for being suseptable to vibrations being heard through the board. I have one that when tapped can be heard through its ouput, and can be even shown on an oscilliscope. Though I have not yet tried the same test with wire, I would not be suprised that, if carrying a low level signal, they too could be affected by a vibration, if only slightly.

 

[Hugh M]

PauSim

Have you thought of trying a pair of ics made from the centers of RG 58 stranded core. I would be curios to see if you hear much differance.
I'd try it myself but we moved awhile ago and I haven't got the work shop set up yet as I'm still doing some reno's and such.
Good to see people experimenting. The system here sounds real good in the new basement.

Regards
Hugh

 

[PauSim]

No, the insulation is thinner.
The central wire is thicker.

Oops, now I know. Looks like the 75 Ohm is the better choice for interconnects and the 50 Ohm for speaker cables...

 

[PauSim]

What is it about the thick unsulation that you think makes this a good IC and Speaker wire. The dampening?

Yes, I think good dampening is the reason why such a thick insulation was chosen by Kimura-san.
But judging from the wires inside the Gaincard, also maybe because he liked the colour

What you describe exists and is known as microphony.

Cheers

 

[PauSim]

Hugh,

The OTA clones are still under "listening tests" (how pompous these words sound).
AFAIK one of the primary aspects of Junji´s design was that with such a minimal geommetry, the wires should be single-stranded and thin enough to avoid negative skin-effects. At the shop I was offered some multi-stranded RG59 that I quickly ditched in favour of single-stranded. Not to say that multi-strands sound terrible, I got a few DIY here that sound very good...

Congrats on your new listening room.
My ladyfriend was here for the vacations and she convinced me to move all the furniture. Now the living room sounds like a chapel...

 

[homer09]

That´s 1585a isn´t it? Are you going to use it for interconnection?

yes thats the one i have (link ) i initally bought it to make speaker wire (a single twisted pair per channel) but will consider making ICs with it also.

 

[carlosfm]

My ladyfriend was here for the vacations and she convinced me to move all the furniture. Now the living room sounds like a chapel...

 

[Bgt]

Right.



Yes, that's it.
Hold the two ground wires on one hand and the two signal wires on the other hand and cross them tight.
It's not exactly "a la Kimber" like you saw on that pic, but the results are good and the cable looks better. The wires are too thin to be used "a la Kimber".

Beware, this is a good sounding cable, although of course there is better and you can diy better (at a price).
But as it is, even with the PVC insulation and made this way, it beats most 150~200 Euros commercial interconnect cables.
So now you see how most audiophiles are assaulted.

An UTP kabel has 4 pairs of wires so you use 2 pairs for ground and the other 2 for the hot line. I have no id how a kimber cable looks like? Any pic? The UTP is not shielded, it is very transparant for EMI then?

 

[pjpoes]

I have made "a la Kimber" cables with 28 guage wire before, its just a lose braid really, I dont thickness has anything to do with what makes the kimber or IXOS cables design, other than they tend to use fairly thick wire.

This design I would suspect would be very suseptable to EMI and RFI interference compared with some sort of sheilded design. The Idea behind a tristed pair or Braid is that the conductors will cross each other and that crossing allows them to cancel out interference. I dont know that the design was ever as effective as an actual shield, but people tend to feel it sounds more transparent. If I have gotten any of the facts here mixed up, I appolagize, I am a psychologist not an engineer, this is just what I believe I have read before.

 

[carlosfm]

This design I would suspect would be very suseptable to EMI and RFI interference compared with some sort of sheilded design.

It provides some small rejection, but nothing to compare with a shielded cable.
Even so, for line-level applications most of the times that's not a problem.
I just can't use these cables between my turntable and the phono pre. As expected.
But for every other sources, and for 'normal' lengths (0.5~1m) it's fine.

Btw, DNM Reson is solid core, not shielded, flat parallel cable.
It's even worse at rejecting noise, but it's a good cable.
As long as you don't live next to a radar.

 

[PauSim]

Well, the OTA clone as speaker cable has been superseeded by another extremely cheap design: the HD10! A certain reviewer from TAS raved about some orange 14 awg power cable from Home Depot that "killed" a number of expensive high-enders in a group test and subsequently made some "noise" in the magazine´s reader´s section, the CableAsylum and AudiogoN. Some say wonders about the cable, some say it´s pure joke.
So, while searching for some rubber O-rings at a hardware store I saw some orange power cable sold by the meter (for about € 1). It was 1,5 mm2 diameter, which corresponds roughly to 14 awg. However, I wasn´t sure about it and the 2,5 mm2 white version ( at € 1,99 per meter) seemed a better choice. When I got home I discovered I chose the HD10! And what a fine-sounding speaker cable it turned out to be.

So, what´s it all about? It consists of three multi-stranded copper conductors, in PVC insulation, barely twisted inside a PVC jacket. Yes, no OFC AFAIK, no Teflon, no cotton filler and no shielding. You can´t get more cheaper than this and nevertheless it´s amazingly good for audio. Just try it!

The TAS team used only one conductor per pole, and left say the earth wire, and it looks like this third floating wire is the cause for such a great sound.
I believe the reviewers didn´t have a clue about it. They just went to the nearest hardware store and took a good sized "lampcord" to make a supposedly unfair comparision that allowed the boutique cables to show-off and justify the high-price, in "see? I told you so" kind of manner...

Now, when the third wire is left unconnected it is in fact separating the other two, making for a very low capacitance. More or less like what Ixos do with their Gamma Geommetry design only this time instead of pure dielectric we have insulated metal...
Jon Risch says this creates an artificial ambience to the sound thus it is not transmitting a true signal from the amp and if we ground the third wire we should be hearing the nefast effects of PVC insulation (which I know sounds ).
So, I tried all possible connections: earth wire to the amp side or to the speaker side either to ground or to signal makes it sound brighter. Connecting to both sides (a la Kimber PBJ) either the ground or the signal binding posts sounded fine, but no thanks...
So I left it unconnected. Sounds better balanced.

The result: 222 pF capacitance for two meters! This is average 1m interconnect territory.

You may be thinking I´m reinventing the wheel, rediscovering the fact that what counts in speaker cable is gauge and nothing but gauge, but let me tell you this one sounds much better than plain shot-gun cable. Since it costs next to nothing I urge you to try it. Ten minutes of work and a wire cutter is all you need.
That is, if you´re not like me. I like my cables to look good and took more time to finish them as you´ll see...