CrinEar Protocol Max DAC-Amp Review
A portable USB-powered DAC-amp from CrinEar, listed at $89.99 as a single option. The page lists up to 600mW from its balanced connection, a browser-based parametric EQ saved on the device and Eco and Boost power modes, and the listing text gives no DAC chip.

Our verdict
A fit for someone who wants a compact USB-powered DAC-amp at $89.99 with a power figure, two power modes and a browser-based EQ stored on the device. Look elsewhere if you need a named DAC chip, input list or sample rates, since the listing text gives none, or if you want the 600mW figure tied to a load. The main caveat is that the output, sound and distortion descriptions are the maker's own claims and were not checked here.
- Best for
- Someone who wants a compact USB-powered DAC-amp with an on-device parametric EQ.
- Skip if
- You need a named DAC chip, a sample-rate list or a power figure with a stated load.
The page presents the Protocol Max as CrinEar's debut in source gear and calls it a portable USB-powered DAC-amp with dual operational amplifiers and an aluminum body. It lists up to 600mW from its balanced connection, Eco and Boost power modes and a parametric EQ that is set in a browser and stored on the device. The listing text gives no DAC chip, input list or sample rates. The price is $89.99 for one option.
Options and pricing
The store lists a single option at $89.99, so there is no plug, color or bundle choice to compare, and the page shows no crossed-out price. The page describes two power modes, Eco Mode for efficiency and longer sessions and Boost Mode for demanding headphones, and says EQ settings stay stored on the device itself.
How it compares
The SIMGOT DEW4 Ultra costs $99 and its listing text mentions CS43198 and SGM8262 chips, which the Protocol Max page does not name. The Shanling Onix XI1 starts at $109 with the same two chips mentioned, and the SMSL AO10 is the same $89.99 with Bluetooth 5.3 mentioned in its listing text.
Shipping
- Methods and costs. The store's shipping page offers Standard Shipping (4PX, Yanwen or Yun Express), free for most countries, and Express Shipping (DHL Express, FedEx or SF Express) at 15-50 USD depending on the country, free for orders over 270 USD in most countries (checked 2026-11-11).
- Large items. The page says headphones and desktop DAC/AMPs count as large items, for which Express is free only for orders over $499.99.
- Delivery times. It says an in-stock order ships within 3 working days, Standard takes about 2 weeks after shipping out (up to 1-3 months for some countries, and the store makes no refund for that transit time) and Express takes about 3-7 days. Festive seasons and other circumstances can change the timing.
- Taxes and fees. The buyer pays any customs, import or processing fees. The page says Standard via YunExpress is tax-inclusive for some countries, that remote areas can carry extra Express charges, and that a parcel refused or left uncollected over taxes is deducted two-way freight and may be destroyed with no refund.
- Where it ships. The page says the store can generally ship to most countries by Express and many by Standard, and to confirm Standard with the team for your country. It cannot ship to PO boxes or APO/FPO addresses and can only use Express to Hawaii. It does not name the US, Canada, the UK, Australia or New Zealand, so confirm before you pay.
- Lost parcels. If a parcel has been in transit for at least 3 months, the page offers a one-time reshipment or a full refund for orders under $50 and a 50% refund for orders above $50.
Returns and warranty
- Returns. The return page allows returning any non-customized product that is still factory sealed within 30 days of receiving it, with the buyer paying the shipping. Email [email protected] within that period; the store asks for the return to be shipped within 5 working days of the RMA instructions and in most cases processes a refund within 5 business days of inspecting it (checked 2026-11-11).
- Opened items. A product opened within the first 7 days after delivery can be returned for the price minus a restocking fee of 35% of its retail value, including when it still works properly.
- Refund or credit. The buyer can choose a refund to the original payment method (PayPal or card) or store credit; with no answer within 48 hours of confirmation the default is store credit, which can also be prioritized during promotions, final-sale events and for items 40% or more off retail.
- Not returnable. Customized products, including faceplate designs, are non-refundable, and the page says the same applies to carry cases, cables, ear tips and other accessories, "due to hygiene purposes". If one item in a package is defective, incorrect or missing, the refund or replacement covers only that item.
- Warranty. The page gives a 1-year warranty on products, excluding carry cases, ear tips and other accessories, and 3 months on cables and adapters, from the date of purchase. It covers factory defects that affect proper function, not damage from human error, negligence, accidents, dismantling, water, abuse or modification (checked 2026-11-11).
- Not covered or limited. It does not apply to items bought elsewhere (AliExpress, Amazon, local dealers and the like), prize or giveaway items, normal wear or colour change, commercial use, or items that were stolen or went missing. Coverage is limited for products 40% or more off retail, for review units and for items repaired or modified by anyone Linsoul has not authorized.
- Claims. Email [email protected] with the order number, the issue and photos and videos of the fault. The store may ask for the unit back for a replacement. It covers shipping for some defects reported within 7 days of delivery if the fault can be shown on video or photo; after 7 days the buyer ships it back. For wrong or missing items an unboxing video of the whole sealed parcel is required.
Before you buy
Linsoul says it was founded in 2016 by the Crazy HiFi team to bring Chinese HiFi makers closer to listeners worldwide, and that it now sells other makers' products alongside four brands of its own, THIEAUDIO, Kiwi Ears, ZiiGaat and Tripowin (checked 2026-11-11).
We have not read any independent review of this product or of the store. Ratings and owner reviews shown on the store's own pages are the store's and were not verified.
What we liked
- The page gives an output figure of up to 600mW from its balanced connection
- EQ settings are saved on the device, per the page, so no app or software install is needed
- Eco Mode and Boost Mode are listed for different headphones, per the page
- The page names dual operational amplifiers
- One option at $89.99, so there are no price differences to weigh
Worth noting
- The 600mW figure comes with no load, so it cannot be compared with other amplifiers
- The listing text gives no DAC chip, input list, sample rates or output connector sizes
- Descriptions such as clean output and minimal distortion are the maker's wording and cannot be checked from the listing
Questions before you buy
How much power does the Protocol Max list?
The page says up to 600mW from its balanced connection. It gives no load for that figure, so it cannot be compared directly with ratings that state one.
How is the EQ set?
The page says the parametric EQ is adjusted in a browser, with no app or software install, and that the settings are saved on the device.
Does the page name a DAC chip?
No. The page mentions digital-to-analog conversion and amplification and names dual operational amplifiers, but the listing text gives no DAC chip.
Can I return it if I change my mind?
The return page allows returning a non-customized product that is still factory sealed within 30 days of receiving it, with the buyer paying shipping. An opened product returned within 7 days carries a 35% restocking fee. Refunds go to the original payment method or to store credit, which is the default if you do not choose.
How long does shipping take?
The shipping page says in-stock orders ship within 3 working days. Standard Shipping takes about 2 weeks after shipping out, up to 1-3 months for some countries, and Express takes about 3-7 days. Standard is free for most countries; Express costs 15-50 USD and is free over 270 USD (over $499.99 for large items such as headphones and desktop DAC/AMPs).
Does Linsoul ship to the US, Canada, the UK, Australia and New Zealand?
The page says Linsoul can generally ship to most countries by Express and many by Standard, and to ask the team about Standard for your country. It names no restriction for the US, Canada, the UK, Australia or New Zealand, but it does not list them either, and it can only use Express to Hawaii.
What warranty does it have?
The page gives a 1-year warranty on products from the purchase date for factory defects, not for human error, accidents or modification. Coverage is limited for items 40% or more off retail and for review units, and it does not apply to items bought from other sellers.
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
- CrinEar Protocol Max product page: specs, options and price (the buy buttons go there)Specs, options and the listed priceRead November 11, 2026
- Linsoul shipping pageStandard and Express shipping, costs and times, import taxes, lost parcels, couriers, trackingRead November 11, 2026
- Linsoul return policy and warranty page30-day returns of sealed items, 35% restocking fee on opened ones, 1-year and 3-month warranties, exclusions, how to claimRead November 11, 2026
- Linsoul support FAQThe same shipping, return and warranty rules in question form, plus order changes and cancellationsRead November 11, 2026
- About LinsoulFounded in 2016 by the Crazy HiFi team; names its own brands; the awards listed there are the store's own accountRead November 11, 2026
What we couldn’t verify
- The page's descriptions of pure sound, acoustic precision and clean output are the maker's claims and were not checked here.
- Per the page, the output is up to 600mW from its balanced connection with no load given, and the listing text gives no DAC chip, sample rates or inputs.
- Per the page, the minimal-distortion and stable-current statements for the dual operational amplifiers come with no measurements.
- We have not read an independent review of this product or the store, and the store's own ratings were not verified. We read the store's catalog description only: a specification table or image shown just on the live page was not read.
- The shipping page names no US, Canada, UK, Australia or New Zealand times or fees: its figures are general and we could not confirm them for these countries.
Spotted an error or something out of date? Tell us and we’ll fix it and update the date.


