Effect Audio Leonidas II Octa
Headfonics 2019

Effect Audio Leonidas II Octa Review

The Effect Audio Leonidas II Octa is the next step up from the original Leonidas II using a new mix of Silver and Palladium. The retail price is $1888.

Disclaimer: The Effect Audio Leonidas II Octa was sent to us in advance of retail release to allow us to complete this review. Many thanks to Effect Audio for giving us this opportunity.

To read more about Effect Audio products reviewed on Headfonics click here.

Note, this review follows our new scoring guidelines for 2022 which you can read up on here. 

Effect Audio Leonidas II Octa
Effect Audio Leonidas II Octa
If Leonidas II made me want to buy the Leonidas 1 to see what the original fuss was all about then the Leonidas II Octa creates a fuss that makes me want to sell the Leonidas II. This is the most technically brilliant cable I have heard from Effect Audio to date.
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Reader's Score

There were a couple of things I took away from my previous reviews of the palladium-infused Effect Audio Leonidas II and PLUSSOUND’s X8 Tri-Silver.

The first was just how holographic and yet natural-sounding the Leonidas II was for a 4-wire build. The second was just how much better an 8-wire version of the Leonidas II could be after hearing the X8 Tri-silver.

I remarked that the gap between the Leonidas II and the Tri-Silver was not as big as I expected it to be and that quite possibly an 8-wire version of the Leonidas might be the ‘king of kings’ all things considered.

Well, today we do have the chance to double-down on the Leonidas II and see if all my musings were accurate with the launch of their most ambitious and, yes, currently their most expensive cable in production, the $1888 Leonidas II ‘Octa’.


Yup, that price is no joke but neither is the ‘Octa’. For those that are thinking of upgrading, I can tell you this is simply not the Leonidas II with double the wire count. The Leonidas II Octa is a definite upgrade but it is also has a distinct and unique sound in its own right.

It still remains part of the Heritage Series though at the time of writing I believe it is on an upgrade and pre-order basis.

The Heritage Series of IEM cables are distinct for being the company’s bleeding-edge lineup. In short, they take a few risks, try something new and bring out something they think is genuinely unique as well as groundbreaking in the cable industry. Kind of their ‘blue sky’ thinking line-up.

Once everything settles down it will be interesting to see if it gets its own category or you can opt to upgrade to the Octa via the Leonidas II page on their website. The fact it has its own name may suggest it will be the flagship entry in its own right within this series.

Materials & Wire


Double the wire count so in theory double the amount of palladium used in the Octa. This is an element first used on the Janus Dynamic and Basso 8-wire Hall of Fame cable duo and it does not come cheap. The 4-wire Leonidas II is priced at $888 so the Octa was never going to be a bargain given the additional amount of palladium being used.

Palladium is not a budget metal to acquire or work with. The raw material combined with processing and application in wiring is significantly higher than gold, copper or silver.

It is also significantly less conductive as an element than either copper, silver and even gold. However, resistance in wiring can be used to achieve a certain type of signature so it is not necessarily a negative feature if the application of the metal is correctly done.

The Golden Ratio

Because the methodology of the build is unchanged the Octa retains the golden ratio aspect to its mix of palladium-plated silver & Litz silver hybrid wire.

The golden ratio is a unique mathematical formula used to create a unique layer of wiring strands that share no common resonant pattern. What this means is that a signal’s release timing is completely irregular on a wire per wire basis avoiding the potential for conflict with the other paired strands.

The less chance of different strands sharing common resonance signatures then the lower the level of resonance detected and the higher the purity of the signal will be in the wire. This is particularly important in the Octa which uses a hybrid of metal stranding that includes palladium, a known high resistance precious metal and silver, a highly conductive metal.

Effect Audio Leonidas II 8-wire

Wire Gauge & Stranding

The Leonidas II Octa uses the same 26AWG gauge Ultra Pure Onho Continuous Cast (UP-OCC) wire as the Leonidas II 4-wire. This is a fairly light strand composition in terms of threading size. It has an approx. 0.405mm diameter and 62.7 turns of wire not including the insulating depth of the palladium layering on top of the silver strands.

Because of the increased wire count, however, the final build of the Octa will look the thicker of the two cable builds. The Octa will also have a better low-resistance performance over the 4-wire build alternative.


Like the original Leonidas and the Leonidas II 4-wire, the LeonidasII Octa also uses individually enameled strands of wire in a woven 7-core bundled Litz type configuration. The only difference being is double the wire count from 4 to 8. The concept is this type of geometry of wiring will reduce the skin and proximity effect thereby reducing resistance, particularly on high-frequency performance.

Effect Audio Leonidas II 8-wire

Build Quality


For those coming to the Leonidas II style of build, you are in for a treat. This is a very attractive and unique looking cable with a healthy silver shimmer under that translucent PVC jacket.

The coloring is light and organic in tone compared to the likes of the Ares and Janus builds which are much darker. The tan and black Patina style leather y-cable finish is eye-catching and highly unusual. Jacks and connectors are terminated with chrome metals and carbon fiber finishes.


Of course, you will be familiar with this coming from the original 4-wire build so what is changing if you move to the Octa build?

For one it is a thicker cable than the 4-wire. There is no getting around the physics of a multi-core 8-wire build. However, I was surprised to find this Octa build to be somewhat smaller in volumetric dimension to the similar 26AWG 8-core build of PLUSSOUND’s Tri-Silver.  Effect Audio has done an excellent job minimizing its weight and dimensions for those that find 8-wire builds to be a bulky proposition.

Also, bigger cables sometimes simply look better. The picture above is a comparison of the 4-wire and Octa builds of the Leonidas II. The first thing that grabs your attention is the braiding and just how beautifully tight it is on the Octa. The braiding is excellent on the 4-wire but indeed smaller in dimension.

I actually find the braiding on the Octa to be even more striking with plenty of those attractive wiring grooves on display, more so than what the 4-wire Leonidas II can show. Certainly, the attractiveness of the build is on par with the slightly bigger Tri-Silver and that was one I raved about in its review so it makes sense to rave here also.

Effect Audio Leonidas II 8-wire


This is very light and flexible for an 8-wire and perhaps just a little easier than the Tri-Silver and 24AWG Janus Dynamic for general handling as a result. I would go out on a limb and say I have not seen such a compact 8-wire before and that is a good thing for those who hate 8-wire weight around their ear.

The Octa is also fabulously memory resistant and 100% tangle-free. It is one heck of a pliant build-quality with EA UltraFlex PVC jacket materials deadening the movement and removing any hint of stiffness in the build. This thing just drapes effortlessly around your ear or around your neck.

Microphonics do have slightly more presence on the Octa compared to the 4-wire build of the Leonidas II. You should not be surprised at that considering there is more surface area to contact and conduct physical noise. Overall, the Octa is a very quiet 8-wire build.



As with the 4-wire Leonidas, the Leonidas II Octa gets the PSquared jack treatment. The PSquared 2.5mm termination was developed in cooperation with Japanese specialty cable manufacturers, Oyaide Electric. Co., Ltd.

The PSquared jack is considered an upgrade on their rhodium plated plugs from their use of Palladium and Platinum. The contention is that this mix will sound better than the standard plug. In our previous testing with and without the plug on two Lionheart cables we found PSquared to be the more dynamic sounding of the two jacks.

Effect Audio Leonidas II 8-wire


All balanced PSquared plugs will have black rings and a carbon fiber/silver alloy finished barrel. The barrels are also a shade smaller and lighter than the Lionheart and Thor II barrels.

This particular Leonidas II Octa is finished with a 2.5mm balanced fitting which is my preferred termination. During your ordering process, you can also opt for different terminations depending on your preferences. Effect Audio supply both 3.5mm (green rings) and 4.4mm options.

For the connectors, you can choose from 2-pin, MMCX, JH Audio, Fitear, etc. The one connected to the Jomo Audio Salsa in the above picture is fitted with a standard 2-pin socket. This option will fit with flush or recessed sockets popularly used on custom monitors.

Comfort On-Ear

Just a few minor changes to an otherwise very comfortable fitting experience with the Octa. The first is the reintroduction of some memory wire finishing near the small EA chrome alloy connectors at the top. I suspect this is due to the nature of the 8-wire build being that bit more difficult to control than without them.

The memory hooks are not memory retentive, rather than bend and shape during use to fit better around your ear. You will not find too much additional strain around your ear but you will feel it a bit more than the 4-wire addition which did away with this type of memory wire finishing.

The second is the doing away with the chin cinch or chin adjuster form the Leonidas II 4-wire. That is a shame really as I would have liked to have seen that being retained. In fairness, the deadening effect of the PVC jacket and additional weight does offer a bit more stability and less movement to the Octa over the 4-wire. However, something like the Tri-Silver chin cinch ring would have been a nice touch.

Effect Audio Leonidas II

Accessories & Packaging

I will not comment at this point on the packaging as the sample sent to me was a pre-order build with no additional box and accessories. What I do know however is the Leonidas II Octa will have a new box and potentially some additional accessories over and above the Leonidas II package. When we get the info we will update the review to reflect that.

The Leonidas II Octa will come with the lovely patina inspired premium leather case that the Leonidas II comes with. This case is matched from the same Patina style leather bound as the Y-Split cable which is a really nice visually harmonious touch. The actual materials are a supple oil-pull leather and vegetable tan calf.

The case has a moderate level of flex and sturdiness and big enough to carry more than a single cable and set of IEMs. It is not as robust as a hard case but will give your cable and monitor reasonable protection against the elements and some knocks when out and about.

Click on Page 2 for Sound Impressions & Comparisons

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