FiiO X7 | DXD | DSD | 384K/64B | ESS9018+ Android | WiFi | Bluetooth | 4 AMP modules | Balanced Out |
Apr 8, 2014 at 9:48 AM Thread Starter Post #1 of 18,016


Sponsor: FiiO
Mar 12, 2010
Call for third party X7 expansion module developers
--by James Chung, CEO of FiiO​

Any interested designers / companies may email us directly at!

As you may know, one big selling point of the X7 is its patented interchangeable expansion module. The expansion capability of this module is theoretically unlimited. For a start, headphone amps of different power / style may be made into modules for the X7. In the more advanced case, other DACs may also be built into the module, taking the place of the built-in ES9018S. One can even make a module to expand the X7’s storage and battery capacities.

Currently, the expansion modules officially planned for development / production by FiiO include:

Standard (IEM) module: suitable for driving most IEMs, earbuds, portable on-ear earphones and some efficient full-size headphones.
Medium power module: utilizing the renowned MUSE02 op-amp for higher output power and wider application.
High power module: Use of the LM49600 op-amp planned for power amplification of full size headphones.
Balanced output module: having 4-pin Kobiconn and 2.5mm balanced output ports, this will be the amp to have for various headphones / earphones on the market with balanced cables.

But I predict that, no matter how many different modules we make, the finite resources of our own company will be insufficient to meet everyone’s audio demands. For example, I predict that the following modules are just a few of the many that will find favor in the market:

Class A module: for those who are paranoid about crossover distortion and negative feedback
Tubey module: utilizing an op-amp with tubey sound sig, this module will add its own signature to the music, perhaps via even order distortions.
Basshead module: see title.
Vocals module: highlights the vocal bands, suiting the tastes of certain Hi-Fi enthusiasts, especially in China.
Female vocals module: aims to make female vocals as addictive as drugs.
ACG module: your solution to Fitear Monets not shipping overseas…

My thoughts are,

1. We will publicize the connector specifications for our expansion modules, both mechanically and electronically, including such details as PCB dimensions, connector dimensions, various signal voltages, currents, timings and protocols.

2. We will sell outer shells, inner chassis and fastening screws as development kits to third parties.

3. Third parties may design third party modules with the aid of the specifications and kits we provide.

4. After design is complete, they may provide us with samples of their completed modules for safety / reliability testing and certification. If they pass such tests, we will provide their modules with our certification logo and provide them with batch supplies of shells and chassis for their use in mass production of the modules. We won’t attempt to ban the production of uncertified modules, although we will not provide them with batches of shells and chassis.

5. The third parties may sell the modules themselves, or they may consign them to us for sale through our channels.

6. If the third party is willing, and we believe in the market value of the module, we can also purchase the exclusive rights to their module design for our own production and sale.

7. Limited edition modules may be available in the future, with e.g. special colours, design elements, etc. to increase customizability of the X7.

8. Third party expansion modules may be priced at the third party’s discretion, although we will of course offer our suggestions.

I hope this will create a win-win situation for all involved: consumers will have choices of more modules; aspiring designers will be able to have people throughout the world see and hear their designs through the FiiO X7; and we may increase the X7’s customizability and marketability. Any interested designers / companies may email us directly at
Updated on 10/9/2015
1, Dimension:                      128 * 16.5 * 64 mm
2, Screen:                            3.97 inch 800*480  full touch IPS
3, Battery life:                      up to 10 hours ( with IEM amp module, Display off ). 
4, Battery:                            3700mAh.
5, Hardware buttons:            power, play/pause, previous/next, volume+/- and one secret bottom. 
6, Input/Output interface:
                                             Micro SD slot  X 1

                                             Micro USB      X 1  ( As docking connector too, it is a 11 pins Micro USB socket )
                                             3.5mm Line Out/ Coaxial output X 1 ( Switched in the setting menu )
                                             Headphone out X 1, the output jack will changed from 3.5mm output jack, 4 pin balanced output ( same as ALO/RSA ), depended on the headphone amp module is installed.
7, Build in Memory:              32 GB .
8, Wifi/Bluetooth:                  802.11g/b/n, Not APT-X.
9, DAC chip:                          ESS9018 X 1,  ESS9018 already includes 8 channels DAC so it does not need 2 DAC chips. L/R both are quad DAC
10, OP and Buf for AMP:      Depended on headphone amp module. 
11, Output power :               100mW/32 ohms, 200mW/16 ohms ( IEM module ). 
12, Soc:                                RK3188
13, RAM:                               1GB
14, Weight:                           220g ( With IEM module )
15,S/N:                               117dB
16:  THD+N:                          0.002%
17,  Output impedance:       < 1 ohms
18,  Crosstalk:                      > 72dB ( PO ), > 110dB ( LO )
19,   Output level:                 1.5V ( LO )
20,   M.S.R.P:                        649.99  ( In U.S.A )
Below is our release plan, it is for Chinese customer but it is also value to you guys:
The X7 market release will come in four steps.
1,First 100 units are targeted for release at the end of September, to be sold at 20% off directly to FiiO’s VIP customers.  The firmware will be beta at this stage.
2,Second batch of 400 units are targeted for release on 15 October, to be sold at 12% off directly to existing FiiO customers.  The qualification of being an “existing FiiO customer” is to be established by product registration at, with the X7 to be shipped to early registrants first.  Register your FiiO products by clicking the link here:

The firmware will be FW1.0 at this stage.
3,Third batch of 1500 units are targeted for release on 30 October;  these will be sold through our agents in China.
4,X7 stock will be provided to our agents worldwide starting from the fourth batch at the end of November.
First 500 units are to be sold to VIP and existing FiiO customers for the following reasons:
1. We would like to provide some benefit to our longstanding loyal customers.
2. Owing to cash flow, risk management and utilization of new technology in new products, the initial production capacity of any company for any new product is limited, as is the initial available numbers of X7’s.  We hope to sell these limited units to those who really need and appreciate it, and not those who might resell it not two days after receiving the unit.
3. The X7 is comparatively expensive, heavy, large and generates relatively more heat.  So, for regular users, we hope for them to gather experience on the X7 from trying it out at a store or hearing from those first 500 users before deciding whether to buy.
4. Audio products are the product of art and technology; sound quality is especially subjective and personal.  Although the X7 comes with modular construction for sound tuning via exchanging amplifier modules, it’s still impossible for one audio device to satisfy everyone’s needs.  Therefore, we do not wish people to buy such an expensive product only to find it unsuitable for their tastes, and go from love to hate with FiiO.

I have been in contact with consumers a lot ever since we stepped into the music player industry. The most impressive thing is that everyone got a dream player in mind, from function to OPAMP, DAC and display, etc.  Meanwhile, we are also on the planning stage for some future high-end products, then why not we creating an ideal music player together, not only for FiiO, but for all the consumers.
No doubt this gonna be a very interesting thing, and we would try our best to seek all the possibilities to meet the demands from all of you. In case of any disagreements, we would start a vote to find out the best solution (PS. This activity would open to audiophiles all over the world, so we would coordinate the voting from users in China mainland as well).
Someone out there would doubt it to be unscientific or unserious, but HiFi is all about entertainment and to keep everyone happy, right? Rather than making profits, the main target of us in designing high-end players is to challenge ourselves to realize the dream of us and all the audiophiles.
Meanwhile, there would be some consumers claim that our X3 and X5 are not perfect enough, and will it be irresponsible to talking of dream device at this stage? Here I want to make a few explanations as follows:
1. Now we are only talk about this program in paper, our R&D staff will only get involved after the final design had been confirmed.
2. I’ve been in the process of recovering, so all the interaction would be in charge by me, which won’t affect the operation of the company. And actually, I am not responsible for any detailed daily work of our company, so please be rest assured.
------------------------------------------updated on 3st, May, 2014-----------------------------------------------------------------------------------------------------------------------------------------
Here we have some decision about our new flagship portable DAP as below.
Model NO. X7
ETA: 2015
M.S.R.P:   $699 in U.S
OS: Custom OS based on Android, can supports some third party APP from our website.
Weight: Less than 300g
Size: thickness will be almost the same as X5 , the other size is almost the same as 5 inch Android Phone.
Screen: 3.5 inch ~ 4.3 inch Full Touch Screen. To be decided.

Key layout: Full touch control+ Bottoms+ Volume Knobs
Output power: > 300mW/32 ohms, Power supply: +/- 6V ~ +/-11 V  . To be Decided.

Playtime: 10 hours
Battery: Build in Battery.

Data transfer: USB 2.0 ( Micro USB), WiFi

Blue Tooth: YES , supports APTX

DAC chip: ESS9018 , not ESS9018M2K, The ES9018 includes 8 channels DAC which means it is equal to 4 X ESS9018M2K
Enclosure: Metal
Build in memory: To be decided.
Extra Memory: Micro SD slot X 2

Accessory : Leather Case X 1,  Micro USB cable X 1, 
--------------------------------------------------------------One of the rending design picture of x7----------------------------------------------
Note this design had been denied  cause I am not satisfy with it .

-----------------------------here is the final photo of X7-----------------------------------------
FiiO Stay updated on FiiO at their sponsor profile on Head-Fi.
Apr 8, 2014 at 9:50 AM Post #3 of 18,016


Sponsor: FiiO
Mar 12, 2010
FiiO Stay updated on FiiO at their sponsor profile on Head-Fi.
Apr 8, 2014 at 10:00 AM Post #4 of 18,016


Headphoneus Supremus
Dec 28, 2009
Personally, I don't think weight or size should be required to make something better. I look to innovative thought and good compromise with a great UI and button placement as the way to do the near perfect player. Compromise is always relative to price and performance but it can't be that near perfect player if larger than an x5 for instance. Perhaps it would mean not giving options like dig/line out or usb dac functions to keep a reasonable size. I think a streamlined hot rod player with great sound would sell well if t could be made 1/3rd smaller. Another larger do everything model for a bit more could be sold along side for a bit more.
Apr 8, 2014 at 10:08 AM Post #5 of 18,016


Sponsor: FiiO
Mar 12, 2010
About the UE/UI, there are some basic feature:
1, Based on Android ,
2, 3.0inch or Above IPS high resolution  touch sreen
3, Individual volume control knob, play/forward/backward bottom.
4, Headphone out/Line out/Digital out ( maybe optical+ coaxial)
5, Extra TF slot ( Not support SD slot )
6, Battery life: not less than 6 hours ( it means it can be 8 or 10 hours ) because it should be decided by customers.
FiiO Stay updated on FiiO at their sponsor profile on Head-Fi.
Apr 8, 2014 at 10:53 AM Post #6 of 18,016

Joe Bloggs

Sponsor: HiBy
Member of the Trade: EFO Technologies Co
His Porta Corda walked the Green Mile
Oct 21, 2001
Hong Kong and Melbourne
Just a note that TF means microSD, ie Supporting microSD and not full size SD.
HiBy Stay updated on HiBy at their facebook, website or email (icons below). Stay updated on HiBy at their sponsor profile on Head-Fi.
Apr 8, 2014 at 10:58 AM Post #7 of 18,016


500+ Head-Fier
Dec 2, 2011
Why not modify an existing smart-phone to be an audiophile DAP? Take a Galaxy S3 or S4 and replace the DAC and amp sections plus add a larger battery. I have a 3650 mah battery in my old Galaxy S2. It came with an extended back-cover replacement. If you remove the camera and extend the back-cover straight, there's room for better audio chips.
The Galaxy line was just an example. There are many models made in China. Some are focused on audio (like the Vivo Xplay 3S with the Sabre DAC and good amp). FiiO could take it a step further with dual DACs, switchable amp power,  and an audio focused (processor focused) battery saving bloatware free custom rom.
Apr 8, 2014 at 12:46 PM Post #8 of 18,016


Headphoneus Supremus
Jun 4, 2005
Give me an AK120 that has much better battery life,a better UI and I am happy!
Apr 9, 2014 at 12:24 AM Post #11 of 18,016


Sponsor: FiiO
Mar 12, 2010
  That's what I mean by audio focused custom rom from a phone with a powerful processor. It can be designed to play various  formats and streaming.

it is very difficult to design a audio focused DAP based on a Android Phone, as I known, there are about 1,000 engineers in Vivo , and they only release couples phone per year. and maybe 10,000 engineers in Apple and they only release 2 phones per year.

but if you just need a normal android phone, you can buy a turn-key solution but nevery try to custom any thing , not to talk there are still very big difference between an DAP and an Android phone.
FiiO Stay updated on FiiO at their sponsor profile on Head-Fi.
Apr 9, 2014 at 12:27 AM Post #12 of 18,016


Sponsor: FiiO
Mar 12, 2010
The dimension and thickness of the player are also important to its sound quality.
With very small size and thickness, it’s hard to embed high capacity battery, and it has very strict requirements to the heat dispersion of its DAC and OPAMP chips.
On the contrary, if the player adopts better DAC and OPAMP chips and set higher output power, then it requires bigger space to embed larger capacity battery. No doubt it will affect its portability and might be regarded as “brick”.
How big a music player can you accept?

FiiO Stay updated on FiiO at their sponsor profile on Head-Fi.
Apr 9, 2014 at 12:53 AM Post #13 of 18,016


Exhaustively burning holes in his wallet
Jun 10, 2013
Under 2000usd, around the same size of HM901 with native DSD support, preferably with USB audio output and balance line/phone out. thanks,
Apr 9, 2014 at 1:30 AM Post #14 of 18,016


Headphoneus Supremus
Jun 26, 2009
Dear James,

My dream player is a X5 with an empty mSATA slot (so that I can add my own 1TB mSATA SSD for $530, 500GB for $300 or 250GB for $170). Or X5 with 4 (four) microSD (TF) slots.

I am sure you have seen the poll result (wish list) for X7's features. Ability to support large storage was the second most wanted feature from over 100 Headfi votes. Maybe you can set up another vote and ask how much storage people would "dream" of. In my humble opinion, if you have lots of (high resolution) music, 256 GB is a must, 512GB is nice, 1024GB is a "dream". One of the selling point of X5/X3/X1 is high resolution playback, correct?

MicroSD / TF cards are still too expensive for too little storage. With that said, if you equip X7 with 
4 microSD slots, I will happily fill them all with 128GB cards now. ~500GB of microSD will cost me over $480 now, while ~500GB of mSATA SSD costs only $300 currently. 

mSATA SSDs are getting even bigger and cheaper because they are commonly used in tablets/laptops. Currently a 480GB (Crucial/Micron) mSATA SSD can run for 8-13 hours in a Rockboxed iPod Video 5.5th generation with 850 mAh battery, so it does NOT need a huge battery or a super thick enclosure:
Apr 9, 2014 at 2:20 AM Post #15 of 18,016


100+ Head-Fier
Apr 3, 2012
Actually, when I saw this title, I was thinking Fiio is going to provide a service for customers to order and customize their own DAP (choose their own dac, op amp, battery, internal memory etc), something similar to what Dell does for their desktop PCs

Back to the topic. I would like to have followings for my ideal DAP
1. size no bigger than AK240
2. responsive GUI, not necessary touch sreen/android.
3. physical play/pause/forward/backward buttons
4. sabre chip
5. micro SD slot
6. HO, LO
8. costs less than USD1000

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