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DAC-END R (ES9018) full assembled board - version 2

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Hi Quang Hao and Andrea,
I'm impatient for more information about the discrete output stage!
Earlier you indicated that the power supply is still being developed, but is the main circuit tested and working?
Are you happy with the sound?
What's the current draw?

Quanghao have tested the new shunt without op-amp on a single power supply of the first DAC module and the sound is good, no differences and less problems to keep it stable.

We have tested the new output stage with a prototype on one channel and the result is much better than op-amp.

In any case I think that Quanghao will produce a first little series of few pcb, 2 or 3 items, to test if all is ok.
 
Please write your name in the list below and choose you want to:

1. adeveza DAC module + output stage
2. papapew DAC module + output stage
3. smokingdog DAC module + output stage
4. gde3 DAC module + amanero
...
20 the end .

add or remove options, like output stage, chassie, transformers and Amanero usb module
 
Here the PCB layout of the new output stage (We say : DCS V/Istage ), 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
 

Attachments

  • DCS-VI.jpg
    DCS-VI.jpg
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I also want a DAC!

Please write your name in the list below and choose you want to:

1. adeveza DAC module + output stage
2. papapew DAC module + output stage
3. smokingdog DAC module + output stage
4. gde3 DAC module + amanero
5. villanueva DAC module +output stage
...

20 the end .

add or remove options, like output stage, chassie, transformers and Amanero usb module
 
Please write your name in the list below and choose you want to:

1. adeveza DAC module + output stage
2. papapew DAC module + output stage
3. smokingdog DAC module + output stage
4. gde3 DAC module + amanero
5. villanueva DAC module +output stage
...

20 the end .

add or remove options, like output stage, chassie, transformers and Amanero usb module, see relative cost on post #2
 
Here the PCB layout of the new output stage (We say : DCS V/Istage ), 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

Hi Quanhao and Andrea,

What would be needed to use new discrete feedback stage in the "old" version of the DAC? Can I just replace the op-amps?
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.