Reviewing the aeco Tellurium Copper Banana Plug ABP-0202R

【aeco ABP-1111 vs ABP-0202 Comparative Review】
ABP-0202｜ABP-1111 Construction｜Plating Comparison｜ABP-1111 Overall Verdict

I recently had the good fortune of becoming acquainted with aeco Japan Store, the Japanese distributor for Taiwan’s aeco, through cable loan reviews and — well — reviews where I say rather whatever I please, and thanks to their kindness I managed to get my hands on a banana plug that aeco had prepared for a Twitter retweet giveaway (now ended) — a flying early get, even before the entry deadline had closed. Having a blog really does pay off sometimes.

The one I chose was the aeco ABP-0202R (rhodium-plated, screw-lock type). There was a solder type as well, but since soldering is not my strong suit I deliberately went with the screw-lock. And so, this time around: an early flying review of the aeco banana plug. ※ This is a gifted item, but as always I have done my utmost to keep the review as fair and impartial as possible.

The aeco ABP-0202R given away by lottery on Twitter is structurally different from aeco’s current new-model banana plug, the ABP-1111 (grey in appearance) — it is an old-model (black in appearance) being cleared from stock. What surprised me on seeing the actual thing was just how small it is. aeco’s maximum hole diameter of 4.6 mm is an even more micro-sized affair than the audio-technica AT6301 or Nakamichi banana plugs. For the time being it seemed to manage reasonably well with speaker cables around 0.75 SQ to 2 SQ, but I suspect that once you get to thicker conductors of 2.5 SQ or above, you would probably need to thin out the strands a bit or they simply would not go in all the way. The SUPRA CLASSIC 2.5H at 2.5 sq goes in with room to spare on the AT6301, but on the ABP-0202R it looks like it would be a very tight fit. It is probably safest to regard these as compatible only with thinner speaker cables whose stripped conductor is under 2.5 SQ.

That said, being small is not necessarily a disadvantage — since there is less superfluous mass and electrical resistance intervening in the signal path by way of the banana plug, the benefit of keeping unwanted character addition to the system in check is not to be overlooked. If you want to minimise the sonic colouration and downsides introduced by banana plugs, a design that is as compact as possible is actually preferable.

Internal Construction and Manufacturing Precision of aeco Banana Plugs

What is striking about aeco’s banana plugs is not merely that they are small — the machining precision and thread-cutting accuracy are high, and they are made to micron-level tolerances that put the typical banana plugs of other manufacturers to shame. I have a large high-end banana plug, the CAB from American manufacturer Cardas, which costs over 10,000 yen for a set, and the aeco is far more precisely made than that. I was already rather impressed by the build quality of aeco’s RCA plug The STARS, but apparently they deliberately avoid the cheaper option of manufacturing in China and produce everything consistently within Taiwan — one can only wonder what extraordinarily precise machine tools they must be using.

The included screws for the aeco ABP-0202R come in three different lengths, eight of each, twenty-four in total. The screw material is brass (C3604 zinc alloy), but they are finished neatly with a direct silver plating. There are no spares, so losing one would be the end of the world… I dropped one onto the floor once or twice during fitting and searched frantically on hands and knees — but that’s just between us — though I imagine spare parts can be purchased from the distributor.

Each banana plug uses two screws to clamp the cable, but more screws means more spurious resonance, so if you are being strict about sound quality it may be better to use only the front screw. However, depending on the conductor — solid-core wire and the like — a single screw may not hold firmly enough, so it is best to try clamping it in practice and fix it with as few screws as possible without any risk of it coming loose. The lock head (contact pin) is made from costly tellurium copper finished with a direct rhodium plating, with no nickel undercoat.

As for the differences between the old model I received and the new model: the old type is a two-piece construction in which the tellurium copper lock head (banana) and body are integrated, with the cover being black-painted brass. The new type retains the tellurium copper material — known for its excellent conductivity — in the lock head (banana) section, while changing the shape from a straight hollow pin to a spiral pin. The construction has also become a five-piece design, with the sound quality having been more carefully considered in the redesign. The new model includes two polyacetal resin parts at the front and rear that provide resonance-damping, plus an added brass retaining ring. Removing the resin parts allows it to accommodate speaker cables from Φ4.5 mm up to Φ6.5 mm. In addition, the brass cover finish has changed from black paint to satin nickel plating — the same as on the RCA plug The STARS — so while there will be a degree of similarity, the sound is unlikely to be identical.

Initially the banana section — the straight hollow contact pin made from tellurium copper — was stiff and would not go into the speaker terminals of my integrated amplifier at all, so I enquired about what to do, and was told to screw it in clockwise. Following that instruction, it went in without any trouble. Once it has gone in once, the pin beds in and subsequent removal and insertion becomes easier. The new ABP-1111’s lock head uses a spiral construction, so it may be a little more forgiving from the start.

aeco ABP-0202R Sound Quality Review

The surface of the sound image is smooth, the outlines are crisp, the projection is extremely open and the imaging is sharp. There is a slightly hard tendency overall; the high frequencies in particular extend well, with a very bright tone reminiscent of a mercury lamp, and a beautifully ordered sound image. Compared to bare wire, the sense of space is trimmed back just a little, but the freshness and vitality of the performance comes through in a lively manner. Being brand-new rhodium plating, the highs will inevitably sting slightly until burn-in progresses, but given the fundamentally good character of the sound, that should resolve itself within a few weeks. In terms of tonal balance — and this depends entirely on the combination — it is broadly flat to perhaps slightly top-heavy. This impression is likely to shift depending on the type of plating as well.

Piano has clear outlines, high resolution, and a moderate density; there is a smoothness characteristic of rhodium plating, the right-hand range is crisp and articulate, while the left-hand range has a reasonable sense of weight though the attack feels ever so slightly gritty. Resolution is high, the sound opens up well in both directions, and vocals are smooth, fresh, and realistic, if a touch hard. The visual resolution of an orchestra is high, with the violin’s incisiveness being high-speed and refreshing. Rhythm instruments are spirited and the timing is good. The range is wide, but musically there is a tendency to trace the surface outlines in a linear fashion, and I would be glad of a little more dynamic expression on top of that.

Overall, the image I get is one of minimising the usual drawbacks of using banana plugs — the loss of information and freshness — by combining high-conductivity tellurium copper with precision-machined brass, while the high-quality rhodium plating adds brightness, crispness, and smoothness. Both the new and old models are available in gold and silver plating in addition to rhodium, making it possible to choose the plating to suit your system. Listening to the rhodium sound as I write this, I find myself thinking that I would personally prefer the highs to be a touch more mellow and the decay to linger a little more freely — so I am rather tempted to try the silver-plated type as well. As a general rule of thumb: gold plating tends to add more weight to the bass, while silver and rhodium plating tend to excel in high-frequency expression. With a bi-wiring connection, it might be interesting to deliberately mix platings — gold for the low-frequency side and rhodium or silver for the high-frequency side, for instance.

The ABP-0202R I received has now been adopted in sub-system M in my study, for connection to the speaker terminals on the amplifier side of the high-frequency speaker cable, Acoustic Harmony N1, in a bi-wiring setup between the valve digital amplifier Miuaudio MKTP-2 and the speakers QUAD L-ite2. I had long been dissatisfied with the sound of the audio-technica AT6301 it replaced, so having that bottleneck resolved by the swap was very welcome indeed.

Next time, I plan to do a sound quality comparison of four banana plugs including aeco, ranging from a few hundred yen to over 10,000 yen. There may be another article in between first!

＋For
　Fresh, vividly bright, and lively high-speed sound
　Sound quality degradation from using banana plugs is kept impressively small
　High-precision and exceptionally beautiful build quality
　High-conductivity tellurium copper (tellurium copper alloy)

－Against
　Those who find rhodium plating’s character unsuitable are advised to try a different plating type
　Slight contact resonance inherent to the screw-lock + straight hollow pin design
　The existence of the improved new model ABP-1111 series

【aeco ABP-1111 vs ABP-0202 Comparative Review】
ABP-0202｜ABP-1111 Construction｜Plating Comparison｜ABP-1111 Overall Verdict