I dont want those... i am sure they are directional via shield. I want the same ones talked about here by Max.
-Richard
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Inflator?
Eduardo de Lima of Audiopax indicated measured reduction of total distortion when a 0.8% distortion SE tube amp was used with a 2% distortion single driver at a certain polarity and addition of distortion when speaker polarity was inverted on his paper Whysingle-endedtubeamplifiers.pdf. Any comment?
Hi Nelson, I heard recently good things about your 25W power amp. A serious person, known to me, is using one or more with a horn loaded system with great results.
2'nd harmonic is something that I tend to remove, if I can. My latest JC-1 power amp design should remove a measurable amount compared to the original product now in production. I will have to make a comparison as to whether it sounds better or worse with this change.
These Bybee things take about 1sq in of space and don't do anything obvious, except they change the room 'dimensions' somehow after they sit around for awhile. Some sort of resonance I am told.
2'nd harmonic is something that I tend to remove, if I can. My latest JC-1 power amp design should remove a measurable amount compared to the original product now in production. I will have to make a comparison as to whether it sounds better or worse with this change.
These Bybee things take about 1sq in of space and don't do anything obvious, except they change the room 'dimensions' somehow after they sit around for awhile. Some sort of resonance I am told.
If the phase of the 2nd harmonic was opposite, then you see some cancellation.
Hi Richard, the cables currently in question are RG59 fitted with elcheapo RCA plugs.
This RG59 is solid centre core with braided outer and no platings, white polyethylene centre dielectric and black PVC sheath.
My first experience with cable directional properties was back in my early days.
I soldered both ends of a length of cheap shielded cable (thin hobby store type) to a turntable, cut the loop and soldered two RCA plugs.
The result was that stereo did not quite centre and the balance control did not cure this !.
I tore my hair out trying every diagnostic to trace the reason and came up cold (because I believed that cables cannot be directional).
At a friends Hi-Fi store I was shown the effect of reversing one interconnect and Bingo, there was the problem with my turntable.
As soon as I got home I reversed one length of the TT cable, refitted the RCA plug and problem solved, and a lesson I have never forgotten.
So that is three examples of directional effect causative cables.
Tonight I will try a few shoelace type OEM RCA cables and see if these are directional also.
I also have a high quality 2RCA marked OFC/OHNO and marked for direction cable that I will try but I don't listen to it because it sounds coloured and all wrong/awful.
The effect to listen out for is 'similarish' to flipping speaker cable polarity at the speaker end, 'same but different' and of course much less magnitude of effect and in the low level details not so much the large amplitude sounds.
Dan.
Pass the popcorn, please...
Directionality of shielded cables is an entirely diffferent issue than parallel twin conductor transmission lines like average speaker wire. Anyone in pro audio knows the performance difference between doubly terminated shielded balanced cable and singly terminated shielded balanced cable.
I was service manager of a large stereo chain in the 80's, and two of our vendors came to us with directional speaker cable. The tech rep for one very famous brand had bought the kool-aid but was consistently unable to hear a difference or tell the orientation in tests we did. The other wire-only vendor just came right out and said they were calling it directional because their competition had directional wire and it was another differentiating factor they could charge more for. Period. There was no difference of construction compared to their other comparable cable.
These are only two examples I have experienced, but I would be interested in seeing any other demonstrable facts surrounding the issue.
Howie
Eariler someone suggested that the cable needed to be tested without conneectors. This is obvious and critical. Connector contact resistance is very highly variable, especially with poor connectors like RCA plugs and represents a swamping variable in the test. In our many audio systems in the cassette and optical disc plants we had to constantly clean and maintain both BNC and XLR connectors which could variously show a level drop, rectification artifacts or intermittent noises.
Howie
Howie
Thank you Sir. This is exactly the practical information piece I need. Could you suggest a practical testing setup? It seems to elude simple DVM resistance measurement.
I'm speaking more to Nelson's tests where folks preferred 1% distortion of the right phase to no distortion. Accuracy schmacuracy.
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