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DAC End 24 PCM DAC - Hi-Resolution System      
December
2014

INTRODUCTION

After the great results achieved by the projects DAC End 2 created in collaboration with Quanghao for the realization of the modules, we had the idea of creating a new No Oversampling project based on the AD1865 chip.
The No Oversampling DAC give a more natural sound but if you ear the Phlips DAC chips like  the TDA1541 and the TDA1543 in this configuration seem to lose details.
The AD1865N-K with passive I/V give a perfect combination, natural sound and all all the details.
This DAC chip is used also by Audio Note in all the production range.
So if you want to continue to use the CD player because you have many CD and you are not interested to play the few DSD files available on the market, this project will give you the best sonic experience.
You can also connect the PC on USB input to play Hi-Resolution PCM tracks.
It is necessary a vacuum tube stage on output to have the standard 2Vrms but here you can find many solutions like SRPP or single ended.


The new DAC End 24 module have these features:

- separated fast shunt for the digital section
- separated fast shunt for the analog section
- Amanero module integrated to have USB input and to support 24bit 44,88,96 and192KHz PCM
- No oversampling
- No digital filter
- 3 spdif input: coax RCA, Toslink optical and AES/EBU
- passive I/V

Quanghao sell this complete DAC module assembled including the including the Amanero module at 300$ + shipping.
It is also available the single ended vacuum stage with the r-core transformer and the chassie, the cost of the assembled version is near to 850$.


 

USB - I2S  MODULE

I have tested these USB-I2S interfaces and I have found very big differences in the sound: After 3 tests in 2 different rooms, 3 different systems, with 2 my friends I can affirm that XMOS and Amanero modules are the best.
The Amanero module sounds more open and detailed but also less solid and less smooth of XMOS module.
The XMOS module sometimes seems more confused but it also have a larger image of the acoustic scene.
The Amanero can play also 32bit 384KHz and DSD files (SACD format) but this DAC is limited to 24bit 192KHz  PCM.
 

AD1865 DAC MODULE

The DAC module use a dedicated power supply with shunt separated for any section of the AD1865.

All the power supply use a controlled current source and a hi-speed shunt linear regulator.

This module can be configured to select 4 different inputs with a simple selector:

Follows the spectrum at 1KHz 0dB signal, the distortion is near to zero and we have 132mVrms on DAC outputs.

 

OUTPUT STAGE

This is a single ended vacuum stage output stage using 6922 tubes able to drive any amplifier with input impedance min 50Kohm.
The dedicated power supply of this output stage use a high voltage shunt regulator to have the best sonic performances.

 

PHOTOS

 

SOUND

There are many articles about no oversampling and digital filter-less DAC.
Also this project follow the philosophy of Ryohei Kusunoki.

These dac give very natural sound very close to the playback from analog sources.
If we compare this DAC with last generation of DAC like the ES9018 you will immediately feel a more natural sound but some little details may be missing.
I suggest to use this DAC with solid state amplifiers or single ended vacuum tubes.