MilleDAC ES9018 32bit DAC function:
MilleDAC is a digital-to-analog converter (dac) which based on a ESS Technology ES9018 32bit dac. He is used to convert a digital signal, whichever comes from a computer or a stereo system, in a analog signal. An analog signal may you hear with a headphone or feed it in an amplifier to hear it on loudspeakers.
The quality from an analog signal depends naturally from the dac itself and from the quality and sampling rate from the digital system, too. Here has the ESS Technology ES9018 32bit dac its strength.
From the data of the datasheet from the ESS Technology ES9018 32bit dac is the ES9018 momentary one of the best dac converter on the market.
Sure the electronic around the dac must be good too, else the best dac brings you nothing.
Below I show you my so baptized ES9018 MilleDAC.
Features of the ES9018 32bit DAC:
- based of the ESS Technology ES9018 DAC in 8ch stereo mode
- Amanero COMBO384 USB input. For up to DSD512 and PCM384 kHz
- optical and digital input
- full LME49990 I/V stage
- LME49600 audio buffer for 600 Ohm Headphone output
- additional analog line out
- Crystek cchd-575-50-100 ultra low noise Quarz Oszillator
- 8 power phases, based on TPS7A3301 and TPS7A4701
- Atmel AT32UC3L064 32bit Microcontroller
- 4 layer PCB with GND and Power plane + 2 signal layers
- 160×100 mm PCB
- fully seperate grounds for digital and analog
- in analog sector use of ±0.01% metall-film resistors
- use of very good Nichicon capacitors
- touchscreen lcd for notification and handling from inputs and volume
- galvanically seperation of analog and digital
- FTDI VM800 displaycontroller
Schematic of the ES9018 32bit DAC
Here is a small part of the schematic….I don´t wont to publish the full version 😉
The core of the ES9018 DAC is a microcontroller (AT32UC3L064) from the company Atmel. The microcontroller initialized the touch-display and the DAC ( ES9018 ). He processed all instructions which are inserted on the touch-display. Additionally stores the microcontroller all settings in a seriell EEPROM, so that when the ES9018 DAC turns on, all old settings will remain unaffected.
All digital external inputs and die communication between the microcontroller and the ES9018 DAC are galvanically separated.
Every individual section has a dedicated independent power supply:
- +15V analog
- -15V analog
- +3.3V oscillator
- +1.65V virtual ground
- +1.2V ES9018 Core
- +3.3V analog
- +3.3V digital
- +5V digital
Therefrom 6 TPS7A4701, 1 TPS7A3301, 1 LP5907.
The ES9018 DAC can operate either in voltagemode or in currentmode. This is controlled by the external circuit. The advantage of the currentmode is that the second and third harmonic are suppressed. This is the reason why I chose the currentmode in the ES9018 DAC project, which are operate in an active I/V (current- to voltage converter) with virtual ground (1.65V). The active I/V based of LME49990 op-amps from Texas Instruments.
Respectively 4 of the 8 channels of the DAC are parallel connected. This will optain a 8 channel stereomode, which again is more efficient. The analog part are only equipped with metal film resistors with a tolerance of 0,01% and a temperature efficiency of ±2ppm/°C. Condensators are equipped with NP0 with ±1%. the ultra low noise quarz oszillator is a Crystek CCHD-575-100 with 82fSec jitter and ±20ppm.
The Mille ES9018 DAC has 3 several inputs which can be controlled over the touch-display.
- optical toslink
- koax spdif
- USB over the OEM Combo384 modul from “amanero technologies”. With up to DSD512 and PCM384kHz.
The I/V converter is calculated in PSpice so, that he outputs a maximum level from ±5V on the output. It gives 2 outputs:
- line-out over chinch
- 3,5mm stereojack
The 3,5mm stereo jack are buffered over the LME49600 250mA high performance audio buffer. That means, that the output has enough power to drive a 600Ohm headphone.
PCB of the ES9018 DAC
4-Layer PCB with Top, Bot, Power, and GND Layer.
Display & Software & Projektinfo of the ES9018 DAC
3.5″ Touchdisplay VM800B35A with 320×240 Pixel.
The microcontroller of the ES9018 DAC initialized the System ( Memory, Display , ES9018, Inputs, ……). The microcontroller reads from the EEPROM the settings and configures the inputs, the ES9018, kalibration values of the touch-display.
The menu navigation of the ES9018 MilleDAC exist of 2 pages. The main menu and the display settings.
- selection of the input (USB, optical or chinch)
- volume setting 0-100% and muting
- information field (sampling rate, filter, ………)
- link to display setting page
- calibration of the touch-display
- brightness of the display
- link to mainmenu
project time: about 6 months
lines of code: circa 2000 rows own code
start of project: 2013