Effect Audio Cadmus II 8 Wire Cable Review
An 8-wire earphone cable from Effect Audio's Signature Series II, listed at $299 with a choice of 2.5mm, 3.5mm or 4.4mm plug. The spec section gives silver-plated copper, 26 AWG and a ConX 2-pin connector, so it suits buyers who want to pick the plug size.
Our verdict
A fit for buyers who want an 8-wire cable that the page labels silver-plated copper, from Effect Audio's Signature Series II at $299, and who need a 2.5mm, 3.5mm or 4.4mm plug. Look elsewhere if you need a stated cable length, a pin spacing for the 2-pin connector, or figures from someone other than the store. The main caveat is that the sound claims are the page's own wording.
- Best for
- Buyers who want an 8-wire cable the page labels silver-plated copper, with a 2.5mm, 3.5mm or 4.4mm plug at $299.
- Skip if
- You need a stated cable length or a 2-pin connector with its spacing given in the page text.
Why 3.4/5: Held back by a spec section that is a short list of labels rather than a table of figures, by the store's own terms contradicting each other, and by figures that are the store's own with no independent test checked for this review.
Cadmus II is an 8-wire cable in Effect Audio's Signature Series II, priced at $299 on HiFiGO's page. The page describes a UP-OCC silver-plated copper litz solid core, and its spec section lists Single Material Litz, 6 multi-sized core bundles, EPO Pro 26 AWG 8 Wires and a ConX 2-pin connector. Three options name 2.5mm, 3.5mm and 4.4mm plugs.
Specifications
| Spec | Page says |
|---|---|
| Material | Single Material Litz |
| Conductor | Silver-Plated Copper with Central Solid Core Design |
| Core (description) | UP-OCC silver-plated copper litz solid core |
| Core bundles | Designed with 6 Multi-sized Core Bundles |
| Wire | EPO Pro 26 AWG 8 Wires |
| Insulation | EA Ultra Flexi Insulation |
| Connector | ConX 2-pin (Default) |
| Plug | EA Standard Rhodium Plated Brass Straight Type Plug |
| Plug options | 2.5mm, 3.5mm or 4.4mm (one per option name) |
Options and pricing
Three options are listed, Cadmus II 8W-2.5mm, Cadmus II 8W-3.5mm and Cadmus II 8W-4.4mm, each at $299 and orderable when the page was read. Only the plug size changes between the option names. The spec section describes one EA Standard Rhodium Plated Brass Straight Type Plug and labels the ConX 2-pin connector '(Default)'; the page text does not say whether another connector can be chosen.
How it compares
The Effect Audio Signature Series II Eros S II 8 Wire Earphone Cable is also $299 in the same series, so price does not separate the two. The Effect Audio Signature Series II DIONYSUS 8 Wires Earphone Cables start at $429 and their spec line reads 26 AWG 8 Wires, the same gauge and wire count listed here. The DUNU Hulk Pro Mini SA6 Ultra Original Earphone Cable starts at $199.99 with a spec line of 26AWG Wire Diameter. Cadmus II suits a buyer who wants a $299 cable with a 2.5mm, 3.5mm or 4.4mm plug choice; the DUNU suits a smaller budget.
Shipping, returns and warranty
HiFiGO sells from hifigo.com and says every order leaves its warehouse in China, usually 1-3 business days after it is placed, and says its delivery times are estimates, not promises. Its shipping policy gives the United States 1-2 weeks (about 10 days on average) by Priority and 6-10 days by Premium, both with duties and taxes prepaid by the store; Canada 2-3 weeks; the United Kingdom 1-2 weeks; and Australia 10-15 days. Express couriers (DHL, UPS, FedEx) take 3-7 days, but then the buyer pays any duties and taxes. No shipping page names New Zealand, PO boxes are not accepted, and the free-shipping thresholds differ between the store's own pages, so check the cart. One of its two shipping pages adds that a lost parcel on an order above $50 gets only a 50% refund. A US buyer reported a $40 tariff charge in August 2025, after which HiFiGO said it had added a customs notice at checkout.
Read the return terms before you order. The homepage advertises 7-day returns. Both of HiFiGO's policy pages offer a 7-day dead-on-arrival cover (a replacement or a full refund, with the return postage refunded) and also describe 30-day returns, but a request made 7 to 30 days after delivery loses 30% of the MSRP as a restocking fee (10% more if the packaging is incomplete), plus shipping both ways and duties, and the FAQ on the same pages says there is no refund or exchange once 7 days have passed. One version recommends reselling an opened product locally. Custom IEMs and custom cables cannot be returned, no return address is published, and buyers describe sending items back to China.
Cables and adapters get three months of warranty from the order date, against one year for DACs, amps and IEMs; a note on the same page also excludes cables from returns for hygiene reasons, while the FAQ says a cable can come back in its original condition. HiFiGO decides between repair and replacement and the buyer pays the shipping. Claims go to [email protected], the only contact the store lists: its pages name no company, street address or phone.
On Trustpilot, HiFiGO had 4.6 out of 5 from 378 reviews when we checked on 2026-10-28 (91% five-star, 5% one-star), and it had replied to about 75% of negative reviews; Trustpilot notes the store has not invited customers to review recently. The one-star reviews mostly concern the short return window and the deductions on returns, items listed in stock that turned out back-ordered, slow email support and a tariff charge on a US delivery in 2025. HiFiGO says its products are genuine and come in the brands' retail packaging; it does not claim to be an authorized dealer.
What we liked
- Three plug options (2.5mm, 3.5mm, 4.4mm) at the same $299
- The spec section gives 26 AWG, 8 wires and 6 multi-sized core bundles
- Conductor labels are given as the page words them: Single Material Litz and Silver-Plated Copper with Central Solid Core Design
- The spec section names the plug (EA Standard Rhodium Plated Brass Straight Type) and EA Ultra Flexi Insulation
Worth noting
- The page text gives no cable length
- The connector is given as ConX 2-pin (Default) with no pin spacing in the page text
- Sound claims (bass depth, a smoother and bolder sound, stronger sub-lows) are the page's wording, with no measurement in the page text
- Every spec figure is the store's own; no independent test of this cable was checked for this review
Questions before you buy
Which plugs does the Cadmus II come with?
The page lists three options, Cadmus II 8W-2.5mm, Cadmus II 8W-3.5mm and Cadmus II 8W-4.4mm, each at $299. The spec section describes the plug as an EA Standard Rhodium Plated Brass Straight Type Plug.
What conductor does the page list for it?
The spec section lists Single Material Litz, Silver-Plated Copper with Central Solid Core Design, 6 multi-sized core bundles and EPO Pro 26 AWG 8 Wires. The description names a UP-OCC silver-plated copper litz solid core. The page text gives no cable length.
Which connector does it use?
The spec section lists ConX 2-pin (Default). The page text gives no pin spacing and names no earphone model, so check your earphones' connector before ordering.
Where does HiFiGO ship from, and how long does it take?
From its warehouse in China, usually 1-3 business days after the order. The shipping policy gives 1-2 weeks to the US by Priority (6-10 days by Premium), both with duties and taxes prepaid, 2-3 weeks to Canada, 1-2 weeks to the UK and 10-15 days to Australia. Express couriers take 3-7 days, but the buyer pays any duties.
Can I send it back if I change my mind?
HiFiGO gives 7 days to report an item that arrives dead, damaged or wrong. Its policy also describes 30-day returns, but requests 7 to 30 days after delivery lose 30% of the MSRP plus shipping both ways and duties, and the FAQ on the same page says no refund or exchange after 7 days. Ask [email protected] before you open the box.
What warranty does HiFiGO give on cables?
Three months from the order date for cables and adapters, against one year for DACs, amps and IEMs. HiFiGO chooses repair or replacement and the buyer pays the shipping. Claims go to [email protected].
Sources & verification
What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.
From the store
- Effect Audio Signature Series II Cadmus II 8 Wire Earphone Cable product page: specs, options and priceSpecs, options and the listed priceRead October 28, 2026
- HiFiGO shipping policyShips from China in 1-3 business days; US 1-2 weeks by Priority or 6-10 days by Premium, duties prepaid; Express buyers pay dutiesRead October 28, 2026
- HiFiGO shipping and order tracking pageA second shipping text: Premium also for Canada and Australia, Canada free shipping from $99.99, lost-parcel rulesRead October 28, 2026
- HiFiGO refund policy7-day dead-on-arrival cover; 30-day returns minus a 30% restocking fee; its FAQ says no refund after 7 daysRead October 28, 2026
- HiFiGO warranty and refund policyWarranty by product class (1 year; cables and adapters 3 months); 30% fee for resealing an opened productRead October 28, 2026
- HiFiGO terms of serviceOperator named only as HiFiGo; governed by the laws of China; contact [email protected]Read October 28, 2026
Independent
- HiFiGO reviews on Trustpilot4.6 of 5 from 378 reviews (91% five-star, 5% one-star); the store has not invited reviews recentlyRead October 28, 2026
What we couldn’t verify
- The page's sound claims (enhanced bass depth, a smoother and bolder sound, stronger sub-lows) come with no measurement in the page text.
- The description calls the Y-split 30% sleeker without saying what it is compared with, and the page text gives no cable length.
- The spec section marks the ConX 2-pin connector '(Default)' while the three options name only plug sizes, so whether other connectors can be ordered is not stated in the page text.
- HiFiGO's policy pages contradict each other: 30-day returns with a 30% restocking fee in one place, no refund or exchange after 7 days in the FAQ.
- HiFiGO's pages name no company, street address or phone number; the only contact given is [email protected].
- HiFiGO's warranty page excludes cables from returns for hygiene reasons, while its FAQ says a cable can come back in its original condition.
Spotted an error or something out of date? Tell us and we’ll fix it and update the date.
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