AD1865N-K nos DIY

[xiaolong]

Happy new year.
Year-end DIY work

[xiaolong]

Electric circuit is this,

http://www.ptsoundlab.com/secnumeriq...eroad1865n.htm

But this electric circuit contain mistake, just pass by to correct, the work is good

[xiaolong]

Its voice I had to contrasted the PCM63/ PCM1704/ PCM1798.
It is outstanding, in these DACs it express the most balanced

[digi01]

simple and neat happy new year!

Z

[ThorstenL]

Hi,

Originally posted by xiaolong
Electric circuit is this,

http://www.ptsoundlab.com/secnumeriq...eroad1865n.htm

But this electric circuit contain mistake, just pass by to correct, the work is good

I just had a look. The Analog stage shown IMHO is not particulary suited to the AD1865 and worse, it actually requires a modification to work well for non-oversampling DAC's.

I originally concieved this circuit for modifications on the Philips CD720/21/22/23 and related (Philips CD71X and Marantz CD3000/4000 & CD36/46 et al) which are equipped with a TDA1545 DAC chip which requires it's output to be held at around 3V DC offset.

The AD1865 is unlikely to be too fond of 3V DC offset on the output.

The rest appears to be basically the Audio Note DAC Kit, re-drawn.

Sayonara

[Elso Kwak]

Originally posted by Kuei Yang Wang


The rest appears to be basically the Audio Note DAC Kit, re-drawn.

Sayonara

The power supply is different.
Salut.

[philbyx]

Hello

On this schematic, I can't understand the purpose of the NOR gates.
Some one can explain ?
Obviously, inverter are needed for LL and LR, but for me it's all.


Kuei Yang Wang :
I don't understand when you speak about offset. The analog part is only a second order filter, just after the 270 Ohms I/V converter.
Please, can you explain ?

Philippe

[Elso Kwak]

Originally posted by philbyx
Hello

On this schematic, I can't understand the purpose of the NOR gates.
Some one can explain ?
Obviously, inverter are needed for LL and LR, but for me it's all.


Kuei Yang Wang :
I don't understand when you speak about offset. The analog part is only a second order filter, just after the 270 Ohms I/V converter.
Pease, can you explain ?

Philippe

Hi Philippe., I guess it is kind of zeros stuffing thing with the 74HC02.
I don't feel called for to figure it out.
It also works with a 74HC04 (only one inverter used ) for the latch of one of the stereo channels. Been there done that.

[philbyx]

Hi Elso

The 74hc02 figures also on the audio note shematic... But I agree with you, a 74HC04 is quite sufficient (only one inverter as you say, Elso).

Philippe (I wish everybody a nice new year's eve!!!)

[ThorstenL]

Konnichiwa,

Originally posted by philbyx
On this schematic, I can't understand the purpose of the NOR gates. Some one can explain ?

This is swiped straight from the AN Schematic. It does a bit more then merely inverting LE/Wordclock. One drawing error I noticed is that the line that should conncet to sdata connects to verf...

Originally posted by philbyx
I don't understand when you speak about offset. The analog part is only a second order filter, just after the 270 Ohms I/V converter.

I am refering to the Valve based IV/LPF schematic further down, which BTW is a bit cheeky, as it marked ptsoundlabs and no credit is given to the source....

Basically this one:



It is designed to have ~3V on the first ECC88 cathode to match the TDA1545. The LPF Capacitor/Resistor Values are only applicable to Oversampling circuits, for non-oversampling they need to be changed to offset the Sin(X)/(X) rolloff.

If one wanted to use a similar circuit for DAC's that expect 0V DC on the output one should replace the cathode resistor by a CCS and apply (probably servo based) offset nulling to the grid.

Sayonara