IKKO CTU01 Review: A Friendly Companion

IKKO ARC-CTU01 Review: A friendly companion

Alongside the recently published OH2 Review, another IKKO item that flew into About Audio’s laboratory is the CTU01. The CTU01 is IKKO’s first standalone cable product with a retail price of $59. While those who aren’t into cables may find it costly, in the custom cable world this is considered quite affordable. Let’s go through the including, features, and matching impressions with a variety of IEMs.  


The included

ARC-CTU01 comes in a nicely designed packaging box with extra accessories. Along the cable itself, CTU01 comes with 3 pairs of Balanced tips, 3 pairs of Short tips, and a pair of double-flanged tips. Pretty interesting to see a cable product including eartips as an accessory. For the time being these eartips are not sold separately in the store and are only acquirable through the ARC01. The double-flanged eartips are similar to ordinary ones and are only offered in one size. As apparent from its name, the Short tips have a very short stem which is ideal for IEMs that have long nozzles.



The special eartips…

What I appreciate the most are the Balanced tips. These are similar to Acoustune AET07 eartips but longer in size. The lips are also slimmer with a moderately dense step that allows a comfy, secure fit. These are ideal for those who were having trouble fitting IEMs with short nozzles or had difficulty finding an eartip that doesn’t hurt the ears. I’m yet to find an identical eartip from the market, so the Balanced tips definitely hold its uniqueness as an accessory for CTU01. If there’s a chance perhaps a separate review will be done for these eartips.         



Design and specs

Cable materials are comprised of 127um OCC with silver-plated cores. The silver-plated layer offers stronger clarity and resolution for the mid-highs. CTU01 is available in MMCX or 0.78mm for the IEM connection and 2.5mm, 3.5mm, or 4.4mm for the player connection. All components are made of metal which ensures better durability. The outer tube shielding seems to have some thickness that causes a bit of stiffness but is no way near to getting springy or causing microphonics.



Paired with IKKO Musikv OH7 (Review Link)

Now is to try out some matchings with the IEMs. First is the Musikv OH7, IKKO’s flagship 1DD earphone. Paired with the CTU01, the OH7’s vocal texture sounds cleaner and smoother (yet not duller). The sound has also gained a clearer separation between lows and mids. Without feeling “disconnected”, mids are now creamier and sweeter in tone while making it colored. The upper-mid shine has also got more vivid and richer which suits well with OH7’s powerful bass. The purer high tones and clearer treble notes are noticeable.


As for the bass, the CTU01 makes the low-end slightly calmer in reverbs. it does get less bombastic, though unless you’re appreciating the exact boominess the original OH7 has, this change would likely feel appreciable. The original tuning does make the bass a tad overpowering, though matching the CTU01 makes OH7 keep a finer balance between grand bass and upper-range presence. the strong bass response and depth are the same but noticeably better in bass control.



Paired with NXEars Opera (Review Link)

Next is to pair CTU01 with the Opera, NXEar’s full-BA flagship earphone. The first difference I’ve noticed is the overall clarity of the sound. The Opera now sounds clearer in general, as if adjusting the focal point of a camera. Fuller mids and higher vocal density can also be spotted through the pairing. This change is just done appropriately so that it doesn’t break the original sound signature.


With improved clarity, lows also got a tad deeper and thicker in color. The bass tightness has also shown improvement but marginally. The upper ends are more open and a bit shinier in brightness. Lastly, trebles also get mildly better in separation and clarity.



Paired with Kinera Baldr

The final matching with the CTU01 is Kinera’s tribrid flagship earphone, the Baldr. After pairing the CTU01 the sound has got quite noticeably cleaner in the background and purer in tone. What I particularly appreciate from this matching is that the upper-mid energy is better tamed by sounding calmer without changing the original nuance. Lows stay almost the same in quantity but get slightly clearer and thicker in color. I can also sense that the three bands (lows/mids/highs) are now better organized. Each sound are being better distinguished from the others. The treble notes and splashes also feel creamier which makes them soothing while keeping the crisp.




There are numerous upgrade cables available out there especially from China, yet unlike many of them that have overstated or even fake spec info, the CTU01 is an easily accessible custom cable mady by a reliable brand, and made with reliable components. The CTU01 is very versatile as it shows flawless matching with different IEMs, sound characteristics, and driver setups. In all and in short, the CTU01 gently upboosting the upper-end shine and analyticity while retaining the IEM’s original characteristics. This one would be a nice choice for those who want a good taste of IKKO’s quality products but through an upgrade cable.



Thanks for reading. Have thoughts or questions? Leave a comment below!


IKKO OH2 Opal     IKKO OH1 Meteor     IKKO OH10 Obsidian

IKKO ITM03 Zerda   IKKO OH7 Flaghsip Musik

Well-balanced with cleaner mid-highs and denser lows
Includes a variety of unique eartips
Impeccable cost-efficiency
The cable tubing is slightly rigid
No carrying pouch or case included