Doug Schroeder Method, Double ic

Very interesting experiment you have going on here Doug. Read through most but not all of this thread as well as the original article posted on Dagogo. Bob Smith's response also made much sense although to have a complete understanding of all he had to say would require another reading or two at least for me.

I'm sure some EE on this website will correct me if I'm wrong but wouldn't it be easier, much easier in fact to create your own interconnects using two twisted pairs of high quality wire using a cross connected method. By that I mean each pair would have a positive and negative and both positives and both negatives are soldered to respective terminals on the RCA plugs. Shielding if needed could be added as well. To my way of thinking this is a far simpler way of accomplishing what you're doing with a litany of accessories. The exact same method could also be used on XLR plugs as well but with the addition of a third wire be it shielding or otherwise. 

It is worth noting some cable companies prefer to use twisted pair wire vs coaxial for line level interconnects. Ray Kimber I believe is a big proponent of this implementation. 

In the past I have built cables like this myself, both RCA and XLR using nothing more than dissected CAT 5 cabling. Granted probably not the best copper available but it made for an inexpensive easy to assemble test and experiment. 

Now all that out of the way, what I don't understand and surely someone will school me on this is why you think doubling the capacitance on an already low capacitance set of interconnects will create harmful oscillation between pre-amp and amp. I know this is true for wide bandwidth amplifiers where high capacitance speaker cable is used to drive the speakers. Goertz flat wire as well as excessive multiple braided wires come to mind, but only on amps that have high bandwidth. There are numerous cable companies manufacturing interconnects both RCA and XLR with much higher capacitance than we are discussing using any of these experiments and to the best of my knowledge without any harm. I do understand your sense of caution but not entirely sure what translates to the amp/speaker combination also translates to pre-amp to amp or line source to pre-amp. Hopefully this make sense.

Hi Doug,

Well the DIY approach is certainly one option but you have obviously proven other ways too. Using the approach I previously described the only real difference (that I can think of) from an engineering and scientific stand point is the two sets of conductors share the same shield, assuming a shield is even implemented. If not, then less capacitance anyway. The two sets of conductors also are considerably closer to one another and that geometry "might" have some effect either for better or worse.

However one great advantage of twisted pair wires especially when using the cross connection scheme is the effect of common mode noise rejection which could eliminate the need for any other shielding to start with, not to mention that twisted pair wire to some degree provides some shielding as a side affect.

Allow me to digress for a moment. I am not an EE, but have just enough knowledge to get into trouble from time to time with this hobby. IOW's my hypothesis could be all wrong, but am inclined to think it is correct.

You mentioned the difficulty in acquiring XLR connectors to implement this but the DIY approach using twisted pair wiring cross connected would nip this in the bud quickly. I was able to find however what looked like some fairly high quality male to female as well as female to male XLR splitters made by Hosa. They seem to be available at a number of different online venues.

Hope this helps.

@ douglas_schroeder

Interesting regarding your use with the Hosa XLR's. It surprises me given they apparently use high purity copper and the actual connectors look like Neutrik brand. Oh well bad call on my part. The cost really starts ramping up with Audio Sensibility's system unfortunately. It appears Pangea has a modestly priced set of connectors (RCA) to implement parallel runs, as well as their own interconnects. I don't have any experience with their audio cables but do have one of their power chords which seems fine. Having owned and bought into hideously expensive cables in the past to the point of embarrasment its not likely I would ever repeat. At one point in my audio-foolish behavior I had more money sunk into cables than most people have in their entire two channel systems reading this thread. Never again. 

Since those days I have made dozens of interconnects (not scientifically based) of my own design, all of them outperforming expensive cables. At some point along the way it finally sunk in that the vast majority of cables are nothing more than tone controls, and people use them to make up for some other anomaly (sound defect) in their systems. How else can you explain the vast amount of used cables on the market for sale on places like Audiogon. 

Regarding the science of cables, if left up to me all cable manufacturers would be required to not only test and measure all of the necessary parameters but to also publish those specs in conjunction with their wild ads and claims. Perhaps many of you are aware of the extreme extent that Belden went into while developing their Iconoclast Cables. Its doubtful any other company has put so much science, technology and research into their cables. I don't have any experience with them directly, but have read all of the white papers and data that went into these cables. This is not to say they couldn't be improved by parallel runs however. While not cheap, they also are far from being anywhere near the most expensive cables on the market either. 

Bob Smiths comments in your original article kept to the science which is important while trying to explain why there is such a difference in parallel runs. I found this appealing and compelling.