i purchased them (he400i copper, mmcx copper, mmcx silver, all three with 2.5mm trrs balanced) at their retail price (discounted at 11.11). so i'm not affiliated to this seller in any way.
forgive the quality of the pics (my photo skills are near zero, and i'm red/green colors blinded), my english (not my mother nor my aunt language), and the lack of detailed info. this is my first review, fast one because i haven't got the time now to extend.
GUcraftsman is a new aliexpress seller. the name suggests he is an individual craftman, but there could be other craftmen in the team making their cables, i don't know. couldn't find any other site where he sells his cables.
link of his aliexpress shop:
links of the cables i've purchased and tested:
i've purchased some cables to various craftmen in the past (and i keep doing it now). got big satisfaction every time. examples; the guy of impact audio cables in the US, and Ghent in China.
they inspire me more confidence. artisans use to love their work, and they put effort and care on their creations. that's why i decided to try Gu's cables, and titled this review as "enthusiast craftsman".
he makes cables by demand, terminations for many types of headphones (the actual inventory of his shop doesn't reflect all the possibilities; you can ask for your custom needs), and jacks (4.4mm, 3.5mm, and 2.5mm balanced, 3.5mm single end, and lightning).
wire used is only of two types at this moment:
8 cores of 0.08mm*19strands (equivalent to 27awg per core), PVC sleeved, equivalent to 24awg (roughly) per signal (2 cores), of 6N OCC copper, or silver plated 6N OCC.
this wire provides quite good conductivity, while keeping good flexibility.
edit: more types of wires available now; cheaper 5N OFC, and others.
physical (look and construction)
the presentation is awesome.
black box. a bag, acrylic textile, has a good size, enough to carry your cable, earphones, and even an small dap. the best thing of the bag is its logo, Gu's logo, in white, which i guess it means Gu-Craftsman in chinese.
a very few cable sellers provide a rigid box instead of a bag. i prefer that rigid box to the bag, because your earphones are more protected, but the box needs to have enough size to not compress the earphones (risk of damaging them).
the cable comes into a zip plastic bag. a nice strap is attached to the cable.
the overall look is minimalist, maybe japanese style. black and white, and some not vivid colors, like grey or brown.
the color of the wire comes from the combination of the conductor, plus a colored translucent thin pvc sleeve.
copper variant color is light brown, slightly shiny. silver color is shiny grey. in the product description page, it's said that the sleeve is enough strong to avoid green de-coloration/oxidation. time will tell.
the pics doesn't reflect true color, because i had to use a warm artificial light when taking the photos.
(colors in this pic are near to real ones)
i'm in love with the splitter and chin slider (which is tight, it doesn't slide by its own). they are metallic, aluminum probably; the shape and text remind who and where they are made in, according with the minimalist design.
i think he has chosen the right size and shape (find too big other solutions); it's very elegant.
ear guides are optional (applies to iems cables). they are molded heat shrink plastic.
i chose cables with ear guides due to two reasons: plugs are more protected, the guides act as strong strain reliefs; there is no risk of being backwards molded with mmcx (you can find this issue with 2-pins plugs, because manufacturers use different orientations).
the plugs are black, alo audio branded or styled, according with the mentioned aesthetic. 2.5mm trs for hifiman are oyaide styled. strain reliefs are good in these hifiman plugs (short heat shrink plastic inside, longer and softer thermoplastic/silicone? outside). strain relief in jack is a bit short and rigid heat shrink plastic; this could be improved.
the wire is enough flexible. it doesn't get tangled, it's not springy, and didn't found noticeable microphonics.
i've found softer and more flexible wires, because the conductor is thinner and not so tight twisted and/or the sleeve material is TPU or kind of silicone. here, the sleeve is a stronger thin PVC; guess this protect the conductor better from scratches and cuts, and prevent de-coloration (as advertised), but it's a bit rougher and stiffer than softer plastics..
one thing that caught my attention, is the braid work. most 8 cores wires i've seen are differently braided; the result is like a prism, while this is like a cylinder.
i like the color of silver variant. shiny grey, original choice after seeing so many shiny white ones.
about the color of copper variant, i might prefer the orange tone of naked copper, but this moderately shiny light brown is ok. it's between the naked copper and the dark brown we are seeing lately.
silver variant (with detail of the gift, for purchasing three cables, an alo audio 2.5mm balanced female to 3.5mm male):
cables don't sound anyhow. they only conduct the signal. they can only degrade the signal.
the goal is trying to minimize that degradation. interference from outside can degrade the signal. twisting the strands into the cores, and also the cores, prevents some kind of interference. braided screens and other sleeves prevent other kind of interference, but this adds weight and stiffness, and it's not so important for earphones wearing. at least, this is what i've understood after some reading sessions.
other kind of "degradation" is internal: attenuation (and may be others) due to resistance of the conductor. all the materials advances look for better conductivity, less resistance: fewer impurities (purity grade), more linear structure (single crystal, occ).. but the impact grade of these advances on signal degradation compared to the difference of price is still questionable, imo.
i've compared frequency response and distortion using different types of wire (same conditions), and the difference, if any, is not noticeable. so no tonal variation. there is an exception of this, when using sensitive balanced armatures (hybrids included) earphones; resistance of the cable is added to output impedance of your source; above 1Ω (total) can alter tonal response noticeably (high frequencies specially). this is another reason to seek for minimal resistance cables. in my experience, i'd aim to cable resistance below 200mΩ (equivalent to 26awg conductor) per signal.
each time i listen to and compare cables, the more convinced i am about the difference consists mainly in something which affects to thickness and definition, to transients. this would explain why we perceive more detail (thinner), or fuller sound (warmer=thicker), which can be erroneously interpreted as tonal variations.
measured dc resistance of the three cables (L+, R+, L+, R-, in mΩ), and weight, plugs and strap included, of two of them:
he400i copper: 142 143 133 135
mmcx copper: 136 143 127 130 (26.85g)
mmcx silver: 135 133 124 128 (27.5g)
equivalent to 24awg (roughly) per signal (2 cores). quite good conductivity!.
i've tested them. xduoo x20 balanced with toneking t4, and zishan dsd ak4495 + ghostaudio miniA1 amp + he400i (single end).
when compared with 7n occ thicker cables, after trying hard, i barely notice any difference, which is great. minimal degradation.
when compared with stock he400i cable.. oh, man, the difference is quite noticeable immediately: this cable respects headphones resolution; you get less distortion, cleaner sound, so more detailed. amazing.
when saw Gu uses the same wires for all their hand-crafted cables, supposed that he chose that wire carefully. so the wire is true 6n occ, as claimed; i still don't know if the wire of silver color version is the same than copper version or it is silver plated copper.
i'd go silver for warm (thick) sounding phones, and copper for thin ones. maybe silver sounds a bit thinner.
edit: after listening comparison of both, i can't find differences between them, even you get darker sound with silver (or spc) one.
anyway, any of the two cables are a safe bet, so aesthetics criteria is also acceptable when choosing (the color of silver cable pairs great with stainless steel color).
once again, an artisan doesn't disappoint me. massively produced cables made by operators, equivalent to this, cost the same, and the work is not as fine as in this cable.
i really like the aesthetics, comfort, and performance of this cable.
there is another matter which i consider an special plus, specially after finding problems when dealing with some chinese vendors: Gu is a skilled worker with huge knowledge of audio, very communicative, enthusiast, love his work, provides every info you ask for, solves issues with ease, can make custom cables, and is very efficient, kind, and cordial. highly recommended.