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-   -   DAC-END R (ES9018) full assembled board - version 2 (http://www.diyaudio.com/forums/quanghao-audio-design/242700-dac-end-r-es9018-full-assembled-board-version-2-a.html)

audiodesign 18th September 2013 07:01 AM

DAC-END R (ES9018) full assembled board - second group buy
 
After the great success the first version Quanghao opens this new group buy to produce a new series of DAC.

http://www.audiodesignguide.com/DAC32/index2.html

I can support you by email and chat until all will be happy for this project.

I do not take money from the production of these DAC.

Quanghao will produce these modules with little gain to promote this product, in the near future this DAC will be sold as a finished product at about 2500$ - 3000$.

This DAC ES9018 module have these features:

- top performance linear pre-regulator LT1963
- separated fast shunt for any digital section
- separated fast shunt for any analog channel
- remote volume control
- remote mute control
- remote input control
- digital filter control
- microcontroller to remap DAC to share I2S connection with DSD
- Amanero module integrated to have USB input
- Support 44,88,96,192,352,384KHz PCM and DSD to play SACD ISO
- ground isolation from USB module
- On board reference 100MHz Crystek oscillator with a jitter of 0.5psec
- 3 spdif input: coax RCA, Toslink optical and AES/EBU
- optional passive I/V
- 4 row x 20 characters LCD
- 5V LCD
- large dB volume display


This options are available and here the new cost:

1) DAC module assembled and tested with all components
- ES9018 chip,
- Crystek 100MHz top performances oscillator (CCHD-950-25-100),
- 5 shunt regulator
- All connectors
- 20x4 LCD
- Infrared remote command
- Amanero module not included
price 450$

2) Discrete differential no feedback output stage
- no feedback
- very low distortion because it work as current amplifier
- Vbe nonlinearity compensated using diamond buffer on output stage
- zero dc offset using dc servo loop
- variable voltage gain only changing a single resistor (I/V)
- 3 voltage amplification setting with jumps
- high output current to drive any low impedance headphone in pure class A
- high output voltage to drive any high impedance headphone
- very low output impedance to drive any cable
- both un-balanced and balanced output
- differential configuration to reduce common mode DAC errors
- output relay for the startup-up phase
- discrete high current shunt regulators
price 150$

3) Chassie
price 140$

4) Transformers, for the discrete output stage are used two r-core transformers, for the LL1684 output stage ony a toroidal trasformer is used.
price 40$ each

5) Amanero module
price 60$

6) LL1684 output stage (pcb, Clarity cap, LL1684)
price 420$

7) DAC controller 4x20 lcd to use with version 1
price 40$

8) Complete assembled DAC with the discrete differential output stage, this include the options 1,2,3,4,5
price 1000$

9) Complete assembled DAC with Lundahl LL1684 output stage, this include the options 1,3,4,5,6
price 1250$

quanghao 18th September 2013 07:25 AM

The prices for options:
1) DAC module assembled and tested with all components
ES9018 chip,
Crystek 100MHz top performances oscillator (CCHD-950-25-100),
five shunt regulator
all connectors
20x2 LCD
infrared remote command
(excluding Amanero module)
The price : 450 $

2) Discrete differential no feedback output stage
The price : 150 $

3) Chassie
The price : 100 $

4) R-Core transformer:
The price : 40 $

5) Amanero module:
The price : 60 $

6) Assembled DAC, this include option 1,2,3,4,5 (it is possible exclude option 2)
The price : 900 $


quanghao would like to thank you for your interest and invite you to register-list group purchased 32-bit DAC

linuxfan 18th September 2013 12:16 PM

Quote:

Originally Posted by quanghao (Post 3636260)
2) Discrete differential no feedback output stage
The price : 150 $

Ah, I'm very interested in this.
Can you give us any details, please Quanghao?
Especially the unbalanced outputs - are they just one phase of the balanced outputs?
If so, is noise and distortion OK?

audiodesign 18th September 2013 12:36 PM

Quote:

Originally Posted by linuxfan (Post 3636484)
Ah, I'm very interested in this.
Can you give us any details, please Quanghao?
Especially the unbalanced outputs - are they just one phase of the balanced outputs?
If so, is noise and distortion OK?

This circuit include a current differential amplifier so both the ES9018 outputs are considered to create the unbalanced output.

Noise zero and distortion less than 0.01% at the max output volume.

This output module could be used also for the first DAC-END R (ES9018) version.

tubo 18th September 2013 01:09 PM

Im very interested

NicMac 18th September 2013 01:55 PM

What is the difference between the version 1 that I have and the version 2 that you are now offering?

audiodesign 18th September 2013 04:13 PM

Quote:

Originally Posted by NicMac (Post 3636615)
What is the difference between the version 1 that I have and the version 2 that you are now offering?

Here we start a new group buy, there are few differences.

1) discrete shunt regulators to reduce feedback and cost but always fast
2) discrete no-feedback output stage instead of op-amp
3) 20x4 LCD instead of 16x2 LCD to have more informations and big dB info

Like the previous we will create a first test environment before start the production for teh group buy.

audiodesign 18th September 2013 05:00 PM

Direct coupled Differential No feedback module
 
1 Attachment(s)
Here the block diagram of the new output stage, the main specifications:

- no feedback
- very low distortion because it work as current amplifier
- Vbe nonlinearity compensated using diamond buffer on output stage
- zero dc offset using dc servo loop
- variable voltage gain only changing a single resistor (I/V)
- high output current to drive any low impedance headphone in pure class A
- high output voltage to drive any high impedance headphone
- very low output impedance to drive any cable
- both un-balanced and balanced output
- differential configuration to reduce common mode DAC errors

linuxfan 18th September 2013 05:50 PM

Thanks Andrea.
One more question; on the first version of I/V output boards, apparently the shunt regs ran a bit hot, and I'm guessing this is likely to be the same with version 2.
If I was to install the version 2 boards, should I consider some form of thermal coupling to the sides of the chassis?

audiodesign 18th September 2013 07:00 PM

Quote:

Originally Posted by linuxfan (Post 3636906)
Thanks Andrea.
One more question; on the first version of I/V output boards, apparently the shunt regs ran a bit hot, and I'm guessing this is likely to be the same with version 2.
If I was to install the version 2 boards, should I consider some form of thermal coupling to the sides of the chassis?

See new post of this evening on the old group buy.

This new output stage have a complete new regulator with high current.

Probably this will use hi-end linear regulator LTxx instead of shunt.


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