Luminous Audio Accessories and Terminations
Tim Stinson of Luminous Audio contacts me from time to time and we chat about the audio industry and new products. On our last correspondence, Tim introduced me to his newer line of accessories. The list is not long – he is only offering spade and banana terminals, gold-plated RCA jacks, silver locking RCA plugs, and Sorbothane feet – but it’s a pretty stout line-up that should suit the needs of his customers. A week after our conversation, I received a box labeled Luminous Audio, which was filled with many of the before-mentioned items to play with. I did not have any DIY projects planned at that time, but I was sure I could scratch something together to test out these terminations and feet.
The first item in the box was the Sorbothane feet. Sorbothane, invented in 1982, is the brand-name of a pliable synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper. The feet are hemispherical in shape, 3/4″ wide and 3/8″ tall, and support two to four pounds of weight each. A set of four feet therefore supports eight to 16 pounds – enough for a headphone amp, a small speaker, or a lightweight CD player. Vibration isolation has long been a study of vinyl connoisseurs, as minimizing vibration is extremely important in physical medium playback. Since the feet themselves are tacky, they are easy to install and do not require any adhesive.
Luminous Audio Sorbothane Feet
To test them myself, I took my trusty, upgraded KingRex T20U Tripath amp out of the garage and gave it the Sorbothane feet treatment. The tiny integrated amp already has feet, but I was assured that the new feet could be stuck on the bottom of the old feet for improved isolation. After doing a little listening, and swapping the feet on and off a few times, I came to the conclusion that the feet made a small difference in overall noise of the unit and stability of the imaging. With even this simple test with inexpensive feet, I could hear the benefits of adding additional vibration dampening to a stereo component.
The next items for exploration were spade and locking banana terminations custom-made for Luminous. The high copper content brass banana are available in gold plating, and the all-copper spades are available in natural copper, gold, or silver plated finish. Both types of connectors are direct plated for better material purity, and can either be crimped or soldered onto speaker wire up to 10 AWG.
I decided to solder the terminations onto the wires as I prefer the electrical connection given by a high quality, silver content, eutectic solder. The spades soldered very easily with their copper body and low mass, and the larger bananas soldered solidly, but slowly with my 35 w iron. The solder flowed very well on the termination, and left a clean joint that was visually appealing, or easy to cover with heat-shrink depending on the desired look. I did not do any detailed A/B testing with the terminations against bare wire for sound quality. As speaker cable terminations are a physical change in the signal path of the speaker cable, it is possible that they have an effect on the sound. However, my biggest reason for using terminations was to ease connectivity with components, and to protect the copper conductors from physical damage and oxidation. Even though copper is more expensive and more difficult to use than brass, I am happy to see Tim choose it for the terminations as copper is more electrically conductive and a great match for copper wiring.
Luminous Audio Silver Spades
Last in the box were a few silver RCA plugs, also manufactured specifically for Luminous Audio. Silver, like copper, is also a great metal to use in audio propagation at it is the only metal electrically more conductive than copper. While reading the product info on the silver plugs, I noticed to my shock that they are constructed with a brass body! Obviously I was surprised as Tim’s other connectors and terminations are not made from brass, because it is a poorer conductor than copper. A pure silver RCA plug would have all the electrical and aural properties of silver, but would be far too soft as a metal and prohibitively expensive to construct an RCA plug out of. Switching to a copper plug with silver plating, the result is plug that would have all the electrical and aural properties of the combination of the two metals as they are similar. However, an RCA plug with a low conductivity, high impurity brass body, and extra-thick silver plating provides a conductor that mirrors pure silver. This is because there is a large conductivity differences between the two metals, and the silver plating conducts a majority of the signal leaving it with functionally the electrical and aural properties of silver.
Now as everyone knows, theory does not always translate into actuality, but the Luminous Audio Silver Locking RCA Plugs are as good in your stereo as they are in theory. These are the best sounding DIY RCA plugs I have used to date, and have been a great match with any cables I have mated them to. When compared to a copper bodied, gold-plated RCA plug of similar build, the Luminous Audio plugs have a little sweeter top end, with just a little more openness and clarity. I’ve tried many RCA plugs in my day, but never said wow at a plug until now.
Luminous Audio Silver RCAs
So what did I learn in a day of playing with accessories and terminations from Luminous Audio? Tim has only a small line of feet and terminations, so he is not offering everything for everyone. However, the few items that Luminous Audio is offering are very well designed and implemented; some of the best I’ve used. If you need to terminate any unbalanced interconnects or speaker cables, I highly recommend the Silver Locking RCA Plugs and Silver Spade lugs; so much so that I changed out the previous terminations on my cables once I heard the Luminous Audio offerings. And if you are considering using a set of the old rubber or cork/rubber isolators for your DAC or CD player, try something different and stick a set of polymer feet under your component. All accessories and terminations are not created equally, but these interesting designs are good enough to set themselves apart.
Manufacturers Comments
As always, I was delighted to read your evaluation of our terminals and accessories. We deeply appreciate the great detail conveyed in your review and are quite proud of all products described, and especially, given their inherent value vs. outlay of funds. Your descriptions were spot-on and we hope (and expect) all others who “pull the trigger” on these products to be equally impressed. We are monkeying around with a very simple and inexpensive beryllium copper banana plug as I write and very excited about it. Most importantly, however, is the announcement of the new AXIOM II passive pre. Chassis’ are complete and on order. We are expecting delivery in August at this point. Can’t wait for your impressions on the new chassis which you will receive early in the game! – Tim Stinson
