I have seen the other threads about "OTA cable kit" and have not seen anybody give a website for it. Can someone tell me where to find them. I am extremely curious after reading many threads on it. Does it have a particular sound? Is it better for bright gear or to bring some life into a system? |
Sean, read the "Sakura Systems OTA Cable Kit" thread. 160 feet of wire, enough RCAs to put together 3 sets of ICs for $600. |
What is this "OTA" and where can i read about it ?
As to "low powered", the only system that i have that somewhat falls into that category would be my "antique" Marantz 8 (30 wpc). That amp may be going out the door soon in a trade ( of some type ) though. A local Marantz collector wants it, so who am i to deny his collection : ) Besides, it is very clean and does deserve to be "preserved" in his "Marantz Museum". Not sitting in my cold, dark basement.
Boy, how i wish i had the money for a TDR ( Time Domain Reflectometer ). This device can tell you just about ANYTHING that you wanted to know about a cable in a matter of moments. Then again, i don't happen to have $35K - $50K just laying around at my disposal : ( If i did, you can bet that i would be building cables professionally with very detailed specs to back them up.
With that point in mind, i have to wonder how many cable "manufacturers" ( or should we call them "re-packagers" ??? ) actually have "real" test equipment and make use of it ? I know that Ray Kimber does but as to any others, who knows ???? Sean
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Dekay, the OTA worked great with the pass X350 if you like ss. No problem pumping out 350 watts. Sean, I would urge you to try the OTA. Not much to lose. With all your systems, I am sure you would find a home for it in one of them. |
Sean: It is a loose adaptation of a concept shared with me by Richard @ Vantage Audio. Their design (which I do not feel comfortable sharing) is of course much more refined than this "wing it" cable, but I really cannot thank Richard enough for his guidance on this project (I really enjoy his "out there" thinking). Oddly, I received an email which stated that other OTA user's had benefited by making the "Cold" lead a bit longer (just the opposite), but this did not pan out in my setup. Yes, I suspect that this is all system dependent and my intention was only to point out that one should not "limit" themselves when designing a cable. I don't feel that we really know enough about this "whole thing" to do so @ this stage in the game. Based on the EE comments that I have read @ AA the OTA cable should not function as it does, anyway, but it does in that it provides full frequency response from the LF's to the HF's (other 26 gage copper/Teflon cable that I have experimented with does not). Go figure. If three people were to "share" one of the kits @ $200 a pop, they would receive enough cable/RCA's to make up a single pair of 10' speaker cables and a set of 1.5 meter (or longer) analog IC's (each). I think that you would get a kick out of this product in one of your lower powered systems (don't know if I would want to pump 1000 watts through it though:-). |
Ditto Dekay,my best digital cable is not a 75 ohm one; it is a rca-rca audio cable. And IMO most quality audio cable sound better than real digital 75 ohm one. |
I'm pretty sure that i can picture what it looks like from your description. It sounds as if you've created some type of inductive load with non-symetrical loading between the polarities. Due to the "loops" or "knots", the hot side would see a greater percentage of this inductance. As to the rest of the cables, are they anchored together at any point or somewhat hanging loosely around each other ? The further that they are spread out from each other, the greater the inductance.
As such, it is possible that you've somehow created a "resonant trap" that is tuned close to the output frequency of the transport or a harmonic of it. Playing with the size and placement of the "loops" would alter the impedance, therefore changing the resonance or tuning of the circuit. The farther that you got away from the central beneficial frequency, the more the effect would "collapse". Keep in mind that this is strictly a guess at what's taking place.
One more question. Where in the world did you come up with this configuration ??? : ) Sean
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Sean: The long portion is looped around the short one in seven half knots which are approx. 3" in diameter. No metal RCA's either (this is the one made out of the 47 Labs OTA kit which is 26 gage solid core copper enclosed in extremely thick Teflon isulation along with plastic RCA's). The cable exibits less "smearing" (by a long shot) over any traditional cable that I have used in this application. It can also be tuned (to a certain extent) by the location/spacing and size of the loops (the larger the loops, within reason, the more open and realistic the sound, but too large and you loose imaging). It's an ugly sucker, but it sure sounds good. The Mapleshade cable (not as good, but still no sluff) is also not a 75 ohm design, but is quite unusual as well in its construction. |
Dekay, you have me REALLY confused. The way you described things, you have an interconnect that has a 60" center conductor with a 30" ground ??? If this is the case, either the center cable is coiled to equal the same distance as the other shorter cable or the cables do not run parallel to each other for their entire length. Either way, i would venture to say if either of those guesses is close, your cables are FAR from a nominal 75 ohm impedance.
The idea of different length conductors could help to "play games" with or "hide" standing wave based problems, but might also contribute to time smear.
Can you clarify what you were trying to describe to us ? Sean
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Hi Ken; I'm glad to hear that such a simple change has made such a big improvement in your system. I can identify with your findings re digital cables. I now use a Cardas AES/EBU digital cable between transport and DAC (both Levinson). The Cardas is very "musical". The only other one I've tried is a Levinson AES/EBU, that I expected to be a very good cable for their own components-- not so-- it was detailed to the point of being analytical and PRaT was really poor. It was a simple change (and both cost about the same), but with the Cardas, the improvement in quality/character of music was huge. Thanks for sharing. Cheers. Craig |
Ezmeralda - The cable I replaced was fairly generic RG-59 coax with relatively inexpensive audio RCA connectors -- likely not a 75 ohm connection. The new cable uses Belden 1506a coax with 75 ohm Canare RCA and BNC connectors. Its hard to say specifically where the differences lie, but in every area the new cable is certainly higher quality than the previous one. And, aside from an hour of my time, the total cost was about $20. Not a bad value.
Sean - You're right in pointing out that the improvements I'm hearing may well be manufactured by my overly swelled pride. As yet, I'm the only one who's listen to the system since yesterday so its tough to know for sure. However, the changes I'm hearing are not subtle, and the problems I've had in the past were very specific and easily recognizable. After a night and most of a morning's listening, I'm happy to say that many of the issues I've had have either been eliminated or significantly reduced, and the system is now overall much more enjoyable to listen to. To be certain, I have a few friends with reasonable ears coming by tonight, so I'll reserve final judgment until then.
To be specific, these are the changes I'm experiencing:
1) I've always had a problem with "unstable" deep bass - that is, sustained bass notes that would waver continuously in volume, and sounded "impure" - almost as if the tones coming out of each speaker were slightly different. My example for this is Arvo Part's I am the True Vine where the vocals are accompanied by steady organ pedal tones. With the new cable, these notes are both entirely stable and beautifully pure. This is a major improvement.
2) Complex musical passages, such as the last movement of Pictures at an Exhibition or Jupiter from The Planets have always been muddied to the point of being distorted. I had attributed this to deficiencies in the DAC, but having heard both of these pieces sound very nice with this DAC in other systems, I was a bit skeptical. Both of these pieces are now very clear, with the individual instruments being well defined and easily recognizable (including the giant bell at the end of Pictures, which is now actually a bell).
3) The placement of instruments and voices within the soundstage were often difficult to pinpoint, and when found would move about quite a bit. Now, not only are the positions of the musicians solid, but there is a well defined difference between being in the correct listening position, and being outside of it. Previously, changes in listening position made very little difference in the overall sound.
I'm willing to believe that what I'm hearing is all psychological and that objectively, things really aren't any different. If all it takes is an afternoon project and an over inflated sense of pride to improve my listening experience, well, I'll be happy to keep it up ;-). However, I'm inclined to believe my ears in this case and appreciate the difference that a better digital cable can make.
Thanks for all of your comments about my epiphany. And now that I have my soldering iron out (and another successful diy project under my belt), perhaps its time to take Brulee's suggestion and try building some better quality power cords. At the very worst, it'll keep me out of trouble for a while :-).
Thanks all,
Ken |
Ezmerelda: A 75 ohm cable (true or otherwise:-) is not always needed for quality digital. My two best sounding digital IC's are neither. I am not quite certain as to how to measure the length of one of them as the Hot lead is 60" long and the Cold 30" (figure 90" or approx. 2.0 meters in the signal path). One IC is a Mapleshade Double Helix (this one is 1.0 meter) and the other is fabricated out of the 47 Labs OTA cable. Both are superior, IMO, to 75 ohm cables that I have tried (with some of these being very popular and costing a great deal more). I have never had decent results, for instance, taking a single standard analog IC and using it in this application, so there is something more involved in making a good digital IC, but I do not feel that it being 75 ohm is necessarily a part of it. |
Welcome to the "wire DOES make a difference with digital" club. I found this out simply out of necessity and kind of by mistake. I had purchased a DAC & Transport and thought i had a spare digital cable or two laying around. Well, when the gear showed up, i didn't have any spares. As such, i temporarily had to resort to using standard "non-digital" interconnects. Those i did have tons of, so i began to experiment.
I quickly found out that cables that had a definite "sonic signature" in the analogue realm carried that over to the digital realm. Taking this a step further, i began experimenting with different digital cables to find the same thing. 75 ohms or not, each had a slightly different flavor with various high and low points. I think that this may have more to do with reflected energy / vswr than anything else though. Just a guess though.
While i normally don't play "devil's advocate", i will on this one. Are you sure that "personal pride" is not playing any part of your "increase in system performance ? Have any of your buddies been able to tell a difference ? It's always nice to have an outside source verify your observations, especially if they have not been tainted with what to listen for. Sean
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I have mentioned this before...but another overlooked item that can cause serious sonic problems..is DC voltage on the ground pin of your AC outlets..usually caused by the cable TV feed into your home being grounded to the same earth ground as your electrical feed. Get a VTVM and measure the ground pin of an AC outlet(better yet have someone do it that knows what ther're doing)... Way put so much effort into having "clean power",..meaning the AC into your system, if the ground of that same AC is poluted with a DC voltage.
You can prove this to yourself, by going outside your home and disconnecting the 75 ohm coax comming into you home,...and the green ground wire that the cable company has strapped to that pipe....Then re-listen to your system..about 50% of you will be very surprised.
Check out some of the prior posts that deal with "ground or
grounding".
Best, Jim |
Take a look at www.modwright.com for his mods on the 525 as a transport. If think the cable makes a difference wait to you here what the mods can do! |
So true, yes EVERYONE says digital is digital
the signal is
10101010 10101011
Sometimes you get a digital cable that is put together and you get the same signal but like :
101010?0 10?01011
The transfer..suffers .. I always say for digital, it more the quality of the cable then anything else, actually that applies to everything ...can't go wrong with quality! |
Congratulations, you are now a believer. You also show that you have an open mind. Wait till you try some of the better power cords. You will experience the same thing you discovered with your digital cable. All wires are not created equal. |
Just quick questions: was your previous digital cable a true 75 ohm cable (which is what needs to be used in digital, especially if runs are a meter or longer) or was it an standard RCA (a lower ohm rating, I believe)? Was the firmness of the connection any different between the two and were the two plugs of the same depth? For $10 though there's not much to complain. |
