September 2001

Male RCA Plug Shootout...
A DIY Deee-Lite!
Review by Steven R. Rochlin
Click here to e-mail reviewer

  Audio as a true hobby provides many options for the do it yourself (DIY) enthusiast. While it takes little effort to simply buy a pre-built product and place it in your system, the rabid DIY is never satisfied with such things. They will either build their own units or take a commercial product and tweak away. In either case, it seems that many of you out there are making your very own cables. My hopes are that this article will be the first in a series of reviews concerning the various bits and pieces that are available to the tweakers and home-brew DIY folks worldwide. As a professional musician who began soldering at the ripe old age of five, my first "day job" was with none other than the legendary Heathkit Electronics of Benton Harbor, Michigan. Yes, the same Heathkit from DIY kit fame who sold, in kit form, everything from triple trace oscilloscopes to robots... and of course tube amplifiers.

While this series of DIY Deee-lites will not venture into the tweaking of specific mainstream commercial products, we will be covering how to possibly improve many of the products currently residing in your music reproduction system. Please be mindful as not all tweaks will be easy, nor inexpensive. Worse still not all tweaks, no matter what the cost, are a guarantee to improve the sound quality of a components. There are synergistic factors one must realize. Sometimes the "sum is better than the individual parts".

In this first DIY Deee-Lite we will be taking a look at various RCA connectors. Since we audiophiles are generally stuck with the decades old RCA plugs whose design is inherently flawed and leaves much to be desired. No proper designer today would make a connector whose positive lead connects before the ground/negative lead. Still, short of directly soldering all our interconnects to components one is left using the RCA connector. Since many of you make your own cables, it seems natural to start this series with the male RCA plug.

And The Participators Are...

From Germany is the value-priced Clearaudio MPC (28DM, or about $15). As one expects with German precision, this connector is a no nonsense well-made plug with unique features of its own. This is Clearaudio's budget male RCA plug.

USA-based connector specialist Cardas manufactures a vast amount of connectors (RCA, BNC, and many for loudspeakers) has provided us with their SRCA ($14.95). This is possibly the most luxurious looking of the bunch. Ooooh la la!

Also coming to us all the way from Germany we have the mid-level WBT WBT-0147 ($17.50 each, $80 in a kit of four) and top line WBT WBT-0108 ($35 each, $150 in a kit of four). The kit of four comes in a nice display box; includes solder and Torx key. Think of precision German engineering gone to the Xtreme.

Another USA-based company, Canare Corporation of America, has provided their F-09 ($2.30) and F-10 ($2.68). Canare, while not technically an audiophile company, has long been specializing in making many different connectors for the professional marketplace. They concentrate on making items that work well and can withstand much use. A no-nonsense approach without going to extremes... or audiophillia as it were.

Lastly we have the most unusual RCA plug that is by our friends from the land down under (where women glow and men plunder). Eichmann Technology International designed the quite interesting Bullet Plug ($36 for a set of four). These blokes are no drongos and even a seppo like me could surely learn a thing or two from this innovative new design! One look at their Bullet Plug and sparkies like me become "happy as Larry".

Confused yet? Well then, let's get this two bit show on the road! It's time to fire up those soldering irons! And away we go...

Not many people realize that Clearaudio from Erlangen, Germany, manufactures more than just critically claimed turntables and cartridges. They also manufacture various chachkies and gadgets including their lower level MPC male RCA plug. While touring the Clearaudio facility and having many discussion with the genius behind the company, owner Peter Suchy is very adamant about the sound quality of the products they manufacture. This caused him to design and/or manufacture virtually everything within their products. This includes the critical tonearm cables and, of course, RCA plugs.

During my discussions with Peter he was very steadfast concerning the use of only nonmagnetic materials. In fact you will see that many of the male RCA plugs showcased here use nonmagnetic materials as well. This begs to question why. As i am trying to avoid long diatribes concerning electrical theory within our DIY Dee-Lite articles, basically magnetism is not a good thing when you are dealing with the electrical signal. It can alter the signal... especially where low-level signals are concerned such as those sent through an RCA connector. May we simply leave it at that?

Clearaudio's MPC male RCA plug are made out of Beryllium-Copper and feature direct 24-carat gold plating without the aid of a magnetic nickel layering. This design is said to prove extremely low contact resistance that remains the same after a high number of insertions. As a side note, the reason i love the Caig Audio products (as reviewed by me are here, here, and here) so much is that they aid in better signal transfer and reduce insertion loss (to name a few of the benefits). The point of this whole exercise is to get as much signal from point A to point B with the least amount of alteration/degrading as possible.

As seen above, Clearaudio employs a special center pin that is actually four spring-type "leafs" to insure the center pin positive signal is firmly against a female RCA jack's center pin receptacle. The reason for the spring-type center pin is obvious. Not all female RCA jacks are exactly the same size. Most of us who have used different components and cable know that some cables seem to fit loosely, or tightly, on various components. The spring center pin simply insures a tight fit and good connection. As a side note, Clearaudio's upper line male RCA jack uses approximately eight small spring-type wires for the center pin over the four larger leafs as employed within this review sample.

Removing the rear outer body reveals a precision-made main center section where DIY-types will directly solder the cable's center positive wire while the outside negative lead/shield can be soldered to one of four 3mm holes. Appearing at the rear of the main piece are four large sections that are draw together (clamped down) to firmly hold the outer section of the cable itself as a strain relief. This insures that accidental pulls on the cable itself will not cause the fragile soldering of the cable's parts to the RCA jack to be ripped out. Like virtually all male RCA plugs in this article, Teflon is used to insure proper isolation of the main body's center pin from the outer shield piece (for the uninitiated, this is the white stuff that separates the center pin from the outside shield when viewing inside the front of an RCA plug).

Clearaudio
Graefenberger Strasse 15
91054 Buckenhof
Germany


Voice: 011 49 9131-59595
Fax: 011 49 9131-51683
E-mail: clearaudio@t-online.de
Website: www.clearaudio.com

Cardas' SRCA male RCA plug is made from non-magnetic eutectic Brass with Rhodium over Silver plate. The brass outer body is gold plated (as seen above). This is about as close to "audio jewelry" as you can get. Virtually everything about the SRCA exudes class a refinement. The mechanical engineering is relatively simply and very functional.

While this is a two-piece design, technically, there are four pieces that make up the Cardas SRCA. The gold plated outer body, main inner body, center male pin, and a spring that insures the the five pieces that make up the outer circular ground will remain tight against the female RCA receptacle's outside piece. Soldering your cable's wires are straightforward for the center pin. While there are no holes for the outer negative/ground as with the Clearaudio MPC, there is a small bar that can be used to solder the cable's outer wire(s). The bumpy outer body section is easy to grip and allows for easy operation and access to the inner body while also aiding in the insertion and removal the assembled jack in to and out from your music reproduction gear.

The Cardas SRCA provides a very firm fit on to all the gear i have on hand. There is no doubt this connector provides a solid connection to insure the transfer of signal to the attached component. i can easily see why this is Cardas' ultimate male RCA jack. Easy to use, extremely functional, and constructed of metals and plated with high precision. Of course Teflon is used as a insulator between the center pin and outer shield as with the Clearaudio (and virtually all RCA connectors). Those looking for very high quality male RCA connectors that present prestige and provide top shelf engineering, the Cardas SRCA is hard to beat.



Cardas Audio, Ltd.
480 Eleventh Street, South East
Bandon, OR 97411

Website: www.cardas.com 
E-mail: cardas@cardas.com 

WBT WBT-0147

WBT WBT-0108

WBT began making their first precision RCA plug back in 1985 from a single piece of metal. Like the midline WBT-0147 and all out no-hold-barred WBT-0108 as seen above, an adjustable locking mechanism insures a vise-like grip of the outer negative/shield to the female RCA's outside sleeve. Today WBT has fully refined the original design and have taken many steps forward that other manufacture have yet to accommodate for.

There are a few things both WBT connectors share in, though also a few key differences. Oxygen free copper (OFC) alloy is the key metal used. The entire inner body is plated with 24-karat gold to fight against corrosion. Of course nonmagnetic metals are implemented in this design while Teflon is used as the insulation between the inner body's center pin and outer shield. In the white sheet/owner's manual included within the WBT-0147 it says "The contact quality of conventional RCA pin-plug connectors is undeniably poor. The reason for this is a lack of standardisation." This is why Clearaudio has a spring-type center pin, Cardas uses a spring around the outer shield section, and here we have WBT who has designed their male RCA jacks with a special locking outer shield. So how does this special outer shield work?

WBT's patented "collect chucking device" works in the same way we tighten drill bits/chucks. You turn the front outside body piece counter-clockwise to remove the male RCA from the female RCA. If you turn the front outside section of the male WBT RCA, it causes the inner body shield/negative pieces to clamp down against the female RCA's outside shield. Once tightened, the grip is so firm that it is virtually impossible to yank the cable's male RCA connector off the female RCA that is on your component. Do not try yanking off the connector at home as damage may occur to your equipment! The point here is that the WBT provides the strongest connection of any male RCA i have ever had the opportunity to use. Of course this one feature does not make for a complete solution...

WBT WBT-0147

The mid-line WBT-0147 seems to show no signs of design compromise... until you use the WBT-0108! The mid-line male RCA as seen above provides the usual inner receptacle to solder the center of your cable to the center pin. In fact with the "Kit" version you also receive a generous amount of WBT's Wonder Solder and a Torx key.

  
Critical inspection by WBT of their parts
to insure tight physical dimension tolerances
and guarantee high quality. 

As each manufacture seems to handle the connecting of the cable's outer shield/negative wire differently. Here WBT provides their own unique solution. Two small "U" pieces appear on an inner crossbar. These U pieces can hold the properly prepared outer shield/wire and you simply need to solder accordingly. As for strain relief to prevent accidental yanking off of the cable from the connector, the inner body piece (left piece in above photo) has a small sleeve inside its rear. The small Torx screw is tightened so that the inner sleeve crimps the cable's outside jacket securely.

As you recall in the beginning of this article i said no engineer would design a connector that makes a positive connection before the ground/negative connection. If the WBT male RCA is used in conjunction with the WBT female sockets, you will have achieved making a ground/negative connection first, before the male makes contact. While the WBT-0147 is extremely well made, feels extremely solid and provides ease of use for the DIY cable experimenter, the WBT-0108 is an all-out no-holds-barred design that provides many advantages.

WBT WBT-0108

WBT's WBT-0108 employs the same vise-like outer shield solution, nonmagnetic metals, 24 karat gold plating, and Teflon for insulation between the male center pin from the outer shield/ground. The main difference are in the way your connect the cable's wire to the inner main body (seen left in photo above). While soldering connectors is part and parcel of making cables, it is a known fact that NASA and other super high technology organizations dislike soldering. Why?

While solder is good, it also has operating temperature limits. If a wire that has been soldered to a connector get too hot, like re-entry to the earth atmosphere, the solder re-liquefies and the wire will probably fall off the connector. Not a good thing when you are trying to land a Space Shuttle with five astronauts and a billion dollar payload. Furthermore, while large and quite complete technical books have been written about how to properly solder, solder does age and there is also the possibly of making a bad soldering joint (usually a "cold solder" joint). In fact cold solder joints can be quite problematic and cause permanent failure of a circuit, if the circuit work at all! Worse still, a cold solder joint may cause intermittent problems that make troubleshooting by a technician a very frustrating experience! So what is the solution?

The simple answer is a cold welding technique, better known as crimping. Instead of using solder, there are set screws both at the inner tip and outer sleeve section of the WBT-0108's inner body. These screws are used to attach the bare wires to the RCA jack. The benefits for the DIY enthusiast is that there is no need for soldering, no added metals between the cable and the connector, and for the true creatively crazy cable chap you can change wires quickly and easily! Of course not all wire is the same diameter so what if you use super thin wires? No problem!

A set of crimping pliers and WBT's matching cable end sleeves will do the trick! These sleeves are thin tubes of various diamete which you would put the cable wire inside, then crimp the sleeve to the wire itself. To quote WBT "These sleeves are made of highly conductive electrolyte copper (E-Cu with purity exceeding 99.996% with 24-karat direct gold-plating which gives a flexible surface protection. Under the pressure of the pliers, the surface layers of the materials flow into one another and can no longer be distinguished. Intermediate air is also eliminated. This connection piece is them fitted to a plug connector using a grub screw, also known as a set screw." WBT provided me with various sleeves and they worked impressively well with every cable i tried.

WBT-USA 
2752 South 1900 West
Ogden, Utah 84401

Voice: (801) 621-1500
Fax: (801) 627-6980
E-mail: rich@wbtusa.com
Website: www.wbtusa.com

These are the least expensive male RCA jacks of the bunch, and comparing these to any of the above jacks was like the difference between driving a Bentley or dad's old Buick. The Canare jacks are very straight forward with no frills. The main inner body in which you would solder your wires to is gold-plated brass. The outer body is nickel-plated brass. Both the F-09 and F-10 (top and bottom image respectively) seem to use virtually the same inner piece and also spring wire strain relief. The main difference is that the F-09's outer body is more streamline for those who have little room between RCA jacks. While this may be a problem in the recording studio, high-end home audio components usually do not suffer from tightly spaced female RCA jacks.

Using either Canare is very straightforward. Simply solder the cable's center connector to the center pin. The outer shield/negative is soldered to the rather thin extension piece. Then simply crimp the cable's body to the cable clam at the opposite end of the male RCA pin. Before i forget, the Canare F-10 does include a small piece of black PVC that can go around the cable inside the jack for insulation. At best the F-09 and F-10 are functional. For those of you on a tight budget or do not require audio "jewelry", the Canare is about as basic yet usable as they come.

Canare Corporation of America
531 5th Street, Unit A
San Fernando, California 91340

Voice: (818) 365-2446
Fax: (818) 365-0479
E-mail: canare@canare.com
Website: www.canare.com

360 degree cable clamp. Nickel plated, bell brass main body with good grip-ability. Spring strain relief.

Last up eschews from all the designs above in virtually every way yet is among the most impressive from a functionality point of view (and fairly cheap to boot!). Just forget virtually everything you have read above and start fresh. Coming from our friends Down Under, the same people who bring us those great Fosters beer commercials in to America, here is a fresh and creative engineering approach to the long-in-the-tooth male RCA jack (pun intended). Eichmann Technology International designed their Bullet Plug to be of high functionality yet with minimal parts.

The blue main body section includes a single screw to secure the cable's outer body for strain relief. This blue parts then screws on to the red (or black) business end of the Bullet Plug's RCA connector. The front section as seen above consists of two small, yet unique connectors. No expense seems to be spared as the Tellurium copper contacts are said to provide 320% greater conductivity than that of Canare's brass parts. Like Clearaudio, the pieces are 24 karat gold plated using no nickel.

When i first saw the Bullet Plug i laughed due to the small negative/ground piece. Well after using these plugs i wish to be the owner of Eichmann Technology International. My best guess is that once word gets out how good these are, DIY guys from around the world will be swearing by them. So what's the secret? What makes these seemingly simply male RCA plugs so good? Less = more...

Less metal in the signal's path equals more signal going through. While you do need to solder the wire to the connector, only very small amounts need to be used. As for the use of a small pin for negative/ground, there are benefits! To quote Eichmann's website "Another problem is the return/ground collar - which can impair electron flow through:

> "Eddy current" distortion - as electrons proceed to and
   from the RCA socket into the collar through multiple
   contact points.

> "Capacitive" distortion - where gaps exist between
   the socket and collar.

> "Micro-arcing" distortion - an electrical short that can
   occur where gaps exist between the socket and collar.
 
> Additionally, RCA plugs are coaxial designs (metal
   return/ground surrounding signal pin) that have an impedance
   effect. This impedance can have a varied and adverse impact
   on performance."

The impedance effect does seem to make sense. In fact this connector did wonders on our highly acclaimed Max Rochlin Memorial Cable for digital/video DIY'ers. While i will not go into details to the sound improvement, rest assured that we will soon be changing the design from Canare's 75 Ohm RCA to the Eichmann Bullet Plug.

While there really isn't much here to comment on directly, as the Bullet Plug is about an minimalist as they come. the purity of metals, care to design and gold plating plus the benefit of installation ease make this male RCA plug a wonder of wonders! The only caveat is that once the connector is on your cable and you are ready to install it within your system, you will need to use a heat source (like a blow dryer) to subtly soften the polymer red (or black) colored collar. The reasoning is as I have mentioned before. Not all female RCA jacks are the same diameter. Since the Bullet Plug does not have a screw clamp like the WBT RCA jacks, all you have is the polymer's strength to insure a tight fit around the outer part of the female RCA jack. This is about the only thing making this male RCA "tweaky" as it were. But hey, you are a DIY guy, right? Every self-respecting DIY guys knows there is always something unique that must be done to achieve that DIY performance.

The one thing you must keep in mind is that the Bullet Plug is fragile. Too hot a soldering iron or gorilla handling on the unit can destroy it. Be careful!!! Before i forget, those of you who need better cable strain relief than the screw on the bluish body of the Bullet Plug, a few inches of heat shrink will do the trick. A three inch piece where one inch is around the blue body and the remaining two inches around the cable should suffice. Using the Bullet Plug is truly a unique experience not to be missed!

Eichmann Technologies International 
55 Lyndale Rd
Pullenvale Brisbane Qld
Australia 4069

Voice: +61 7 3374 3800
Fax: +61 7 3374 3855
E-mail: info@eichmannCables.com
Website: www.eti-research.com.au 

So there you have it. Seven models of male RCA jacks by five different companies. The Cardas and WBT connectors are used extensively by many cable companies. Their top-flight engineering and solid construction will insure many years of musical bliss. The WBT's clamp-like outer piece make it the most firmly connected jack of the bunch. Cardas' SRCA gives all the benefits of careful craftsmanship, nonmagnetic metals, and give it to you with a fine jewelry-like appearance.

On the other hand Clearaudio's MPC naturally employs precision German engineering with high-quality nonmagnetic metal and "proper" gold plating (read: not using Nickel). The center pin of the Clearaudio insures a tight fit to the positive lead unlike any other male RCA jack in this test. Canare's brass-based male RCA jacks are probably the lowest performer of the bunch, yet for a very low cost connector they are functional with the best strain relief system of the bunch.

And this brings us to the wildcard of the bunch. Eichmann Technology International's Bullet Plug does away with the usual RCA form, so to speak, and in a delicate package provides the most minimal yet high-quality signal transfer short of directly soldering your cables directly to components. Just remember to dust off your hair dryer from those debonair Disco days (ha!) and have at it. Of course in the end what really matters is that you... Enjoy the Music!