Model: X7
ETA: 2015
MSRP: $699 in US
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.
Since the X5 is 15.6 mm thick, 18 mm maximum thickness would be good.
Screen: 3.5 inch ~ 4.3 inch Full Touch Screen. To be decided.
The screen should have a luminance sensor to allow for auto brightness control in Android (but may be manually overridden, of course).
Key layout: Full touch control + Buttons + Volume Knobs
If the volume is a rotary knob, it should be oil-dampened and/or stepped, and protected from accidental bumps and alterations. For individual volume buttons, the volume control should be bevel-in for volume down, and bevel-out for volume up. Volume control should be a continuous sliding scale. Hold the volume down button for greater than two seconds, and it should quickly scale down to zero volume and soft-mute. Volume up should scale slower than volume down so that ears can be protected from volume increases that are too fast. The volume up button can also be weighted for heavier force pull than the volume down button. These are not a novel concepts; many higher-end consumer electronics employ these subtle design principles. High-end supercars often bias their paddle shifters differently such that upshifts are heavier than downshifts.
A screen-lock button is necessary for any Android-based device, to go with the typical slide to unlock screen.
Output power: > 300mW/32 ohms, Power supply: +/- 6V ~ +/-11 V . To be Decided.
As a reference, the DX100 is a 2/2.8/5 Vrms output design, the DX90 is 1.3/2.0/2.8 Vrms. My suggestions would be low gain at 1.0 Vrms (ideal for IEMs), medium gain at 2.0 Vrms (for Red Book equivalent line-out voltage), and high gain at 4.0 Vrms.
Playtime: 10 hours
Battery: Build in Battery.
Data transfer: USB 2.0 ( Micro USB), WiFi
The X7 as an USB DAC would be a welcome feature, since both the X3 and X5 already possess that feature. However, to take advantage of the ES9018, data support should be increased to 32/384 input (or at least 24/352.8) and support for DSD64/128 over DoP. Most people will use a maximum of 24/192 and PCM only, but higher support will present a selling point that may attract others.
Bluetooth: YES, supports APT-X
DAC chip: ES9018, not ES9018M2K, The ES9018 includes 8 channels DAC which means it is equal to 4 X ES9018K2M
The interface should allow for user selection of digital filters to take advantage of the pre-programmed filters and ASRC bypass, 8x OSF bypass options.
Volume control should be registered with the Sabre chip with 32-bit control for least loss in DNR. Additional interpolation with 64-bit floating point would be welcome, though probably not absolutely necessary. Stepping should be maintained at the minimum 0.5 dB increment. There are people who complain about volume control stepping being too small on the X5 (as well as the AK100/120/240) and that it takes forever to take the volume up to the desired level, but it is only ethically responsible for the volume stepping to be very small to allow for fine control of volume and to prevent users from blowing out their ears. If people want faster stepping control, then perhaps a toggle choice between 0.5/1.0/1.5 dB steppings inside the settings menu can be written into the interface.
Enclosure: Metal
Magnesium alloy would be nice for the main frame, aluminum for non-critical parts of the frame and casing.
Build in memory: To be decided.
If there are already two SDXC slots, then built-in memory should only be as much to support the ROM and to support those third-party apps, but others might disagree. If more memory is built-in, then it should come pre-loaded with sample tracks from high-resolution store partners like HDTracks and 2L Records to showcase the player's capabilities.
Extra Memory: Micro SD slot X 2
Accessory : Leather Case X 1, Micro USB cable X 1,
I don't believe it needs to be strictly a leather case. FiiO products have always strived to look contemporary and simple; a microfiber case would look fine. Leather only looks good if it's designed well. The key is good design, rather than expensive materials. Then again, quality microfiber is not cheap, either.