Fully Balanced Resistor Networks

Discrete 1-Bit DAC for DSD Format

Purposively designed micro-miniaturized 1-bit DAC circuit from discrete components  
Convert digital signal to analogue signal through a fully differentiate 4-ch

DAC architecture

The 1-Bit DAC circuit is a resistor network composed of 128 pcs (4 x32) high

 precision Thin Film Resistors, this is closely resemble to the discrete DAC of

our N7 DAP

The output of the resistor network will go through a 3-level active LPF and

then converted to single-ended signal for volume adjustment. 

Dual amplifiers in parallel, 
providing 4-CH high power 
Balanced Driven output
 
The second phone amplifier 
is a parallel unity gain 
inverting phase amplifier

An impressive upgrade in 
phone output power :
3.5mm SE, 160mW @32Ω
4.4mm BAL, 400mW @32Ω

Shared Line Out Conveniently Connected

The shared line out function will 
configure the 3.5mm or 4.4mm 
phone output into fixed voltage 
output (bypassing volume control):
3.5mm Single-ended, 1.2Vrms
4.4mm Balanced, 2.4Vrms

The line out voltage are carefully 
selected to retain as much details 
and dynamic of the 1-Bit DAC with 
minimum noise and distortion. 

Enable you to connect the RU7 to 
portable/desktop amplifier or home 
audio system and used it as an 
miniature 1-Bit DAC 

Discrete Volume Control

Discrete Resistor Network DAC circuit is very demanding on incoming data integrity, 
we recommend users to keep the digital volume of mobile phone at full output to 
safeguard the quality of audio digital signal. 

When off-the-shelf analog 
volume options cannot meet high 
precision, low noise, low power 
consumption requirement of RU7, 
we developed our own discrete 
resistor network volume control 

100 steps volume control through 
3 segments of resistors and 
switching relays *, 
offer precise control over 
a wide volume range, 
satisfy even the need of 
most sensitive IEM users:
Segment 1: 1-49
Segment 2: 50-79
Segment 3: 80-100 
 

Outstanding Digital Audio Capability with
 

User Selectable All-to-DSD

RU7 supports PCM up to 384kHz and native  DSD from DSD64 to DSD256.
Its Audio Bridge will receive different audio format and  go through high precision signal enhancement.

All digital audio signal will convert to designated DSD format
(DSD64/DSD128/DSD256) before feeding to the discrete 1-bit DAC circuit.
 

Dual PCB to Minimise Interference 

To minimize interference, RU6 circuitry 
is splited into TWO 6-layers PCB, with 
digital and analog circuit 
installed in seperate  boards.

Safeguard signal integrity, make 
sure the noise from reference clock 
and DSP will not bleed into 
amplification circuit.

Functional Diagram for RU7 1-Bit Dongle DAC
 

Low Power Consumption

Compatible with Common Platforms

Discrete resisotr network is a low-power DAC circuit when compare to other highly integrated DAC chipset, minimise power drain from mobile source.

Redesigned amplification  circuit increase  output power dramatically  while maintains the overall power drain at 100-110mA

Low power consumption allows RU7 compatibles with the following digital audio sources: 
• Android  based mobile devices
• iOS and  iPad OS mobile devices
• macOS computers
• Window 7/8/8.1/10 computers
• Digital Audio Players with USB Audio output

An All-Rounder

Bundled Protective Case

Soft and tender handmade 
magnetic leather case 
Custom make for RU7, 
precise cutout 
offers tight-fit protection 
and elegant presentation 
Two circular metal plate with 
adhesive tape pad are included.

A Compact and Nimble Powerhouse

Weight: 
25g , small enough to slip 
into your smallest pocket

Dimension:
66*24*12 mm

Package List: 
① RU7 Dongle DAC  x1
② Type-C cable  x1
③ USB A to C adapter  x1
④ User Manual  x1
⑤ RU7 Protective Case x1